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Mechanical seed extraction of lodgepole pine 1975

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MECHANICAL SEED EXTRACTION OF LODGEPOLE PINE by JAMES DONALD MACAULAY, P.ENG. B.S.A. University of Guelph, 1965 M.Sc. University of Guelph, 1967 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n the FACULTY OF FORESTRY We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA May, 1975 In presenting th i s thes is in pa r t i a l fu l f i lment of the requirements for an advanced degree at the Univers i ty of B r i t i s h Columbia, I agree that the L ibrary shal l make it f ree l y ava i lab le for reference and study. I further agree that permission for extensive copying of th i s thes is for scho lar ly purposes may be granted by the Head of my Department or by his representat ives. It is understood that copying or pub l i ca t ion of th is thes is for f inanc ia l gain sha l l not be allowed without my writ ten permission. Department of A g r i c u l t u r a l E n g i n e e r i n g and F a c u l t y of F o r e s t r y The Univers i ty of B r i t i s h Columbia Vancouver 8, Canada Date May 22 . 1975 -6 ABSTRACT Seed e x t r a c t i o n from s e r o t i n o u s lodgepole p i n e cones (Pinus c o n t o r t a var. l a t i f o l i a Englem.) was i n v e s t i g a t e d t o i d e n t i f y the p h y s i c a l p r o p e r t i e s and c h a r a c t e r i s t i c s which a f f e c t seed e x t r a c t i o n by both c o n v e n t i o n a l k i l n d r y i n g -techniques and by mechanical means. T h i s i n f o r m a t i o n p r o v i d e d a b a s i s f o r s y s t e m a t i c d e s i g n of s p e c i f i c p r o c e s s i n g t o o l s f o r a p o r t a b l e continuous flow mechanical seed e x t r a c t i o n system. Cone s c a l e d e f l e c t i o n was c h a r a c t e r i z e d and i t s e f f e c t on seed r e l e a s e i s r e p o r t e d . The e f f e c t of moisture content upon s c a l e s t r e s s r e l a x a t i o n d u r i n g storage and sub- sequent r e d u c t i o n i n seed r e l e a s e i s d i s c u s s e d . F l a s h h e a t i n g of cones i n hot water and hot gas was found t o e f f e c t i v e l y r e l e a s e s e r o t i n o u s s e a l s without i n c u r r i n g thermal seed damage. Two continuous flow f l a s h h e a t i n g s e a l b reaking t o o l s were designed and t e s t e d . A flame s e a l breaker proved most s u i t a b l e f o r commercial o p e r a t i o n , and t h i s t o o l was c a l i b r a t e d f o r use on both young and weathered cones. Mechanical seed e x t r a c t i o n by cone core removal was e f f e c t i v e , but asymmetrical cones prevented accurate core b o r i n g , thus r e s u l t i n g i n c o n s i d e r a b l e seed d e s t r u c t i o n . Seed e x t r a c t i o n by t h r e s h i n g a l s o was e f f e c t i v e . T e s t i n g of f i r s t and second g e n e r a t i o n t h r e s h i n g t o o l s was c a r r i e d out on lodgepole p i n e , Douglas f i r , white spruce and western hemlock. F u r t h e r study i s recommended to i d e n t i f y the optimum value s of the many b i o l o g i c a l v a r i a b l e s , machine v a r i a b l e s and o p e r a t i n g c o n d i t i o n s which a f f e c t cone t h r e s h i n g . i i i . TABLE OF CONTENTS PAGE ABSTRACT TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES TERMINOLOGY ACKNOWLEDGEMENTS i n v i i x x i i i x v i i I INTRODUCTION I I CURRENT SEED EXTRACTION TECHNIQUES I I I OBJECTIVE IV SYSTEMATIC DESIGN PROCEDURE V COMPARISON OF KILN AND MECHANICAL EXTRACTION SYSTEMS 1 3 7 8 12 VI VII PART ONE {Pky^icai. Ph.opzKtA.z& o£ Zodgzpotz plnz conzA) PHYSICAL PROPERTIES AFFECTING MECHANIZATION OF SEED EXTRACTION 1. F r u i t i n g 2. S e r o t i n o u s Cone S c a l e S e a l s 3. S c a l e Opening Mechanism 4. Cone Opening a t M a t u r i t y 5. R e s i s t a n c e t o Thermal Damage 6. R e s i s t a n c e t o Mechanical Damage 7. S t r e s s R e l a x a t i o n o f Cone S c a l e s 8. Thermal P r o p e r t i e s 9. Dr y i n g Rate PRELIMINARY INVESTIGATIONS 1. I d e n t i f i c a t i o n and D e s c r i p t i o n o f Cones 2. P r e p a r a t i o n o f M a t e r i a l 3. Degree o f S e r o t i n y o f Cone Seed L o t 16 16 17 20 22 22 24 26 28 29 31 31 32 32 i v . TABLE OF CONTENTS (Continued) PAGE VII PRELIMINARY INVESTIGATIONS (Continued) 4. V i a b i l i t y o f Seeds by L o c a t i o n i n the Cone 34 5. V i a b i l i t y of Seeds and Ease of E x t r a c t i o n 37 6. V i a b i l i t y of K i l n T r e a t e d Seeds 38 7. M o i s t u r e Content 40 V I I I INVESTIGATION OF PHYSICAL PROPERTIES OF CONES 41 1. E q u i l i b r i u m M o i s t u r e Content 41 2. M e l t i n g P o i n t D e t e r m i n a t i o n f o r S e r o t i n o u s Bonds 43 3. S c a l e D e f l e c t i o n v s . M o i s t u r e Content 45 4. S c a l e D e f l e c t i o n o f S t r e s s Relaxed Cones 49 5. Degree of Seed Release With Respect t o S c a l e D e f l e c t i o n 52 6. Hot Water S e a l B r e a k i n g 54 7. Flame Treatment S e a l B r e a k i n g 58 8. M o i s t u r e Content on S e a l Breaking E f f e c t i v e n e s s 60 PART TWO [Veve£opmcnt o£ V*h.oce-6&Zng lool&) IX PROPOSED MECHANICAL EXTRACTION SYSTEM 65 X DEVELOPMENT OF SEROTINOUS SEAL BREAKING TOOL 67 1. P r e l i m i n a r y A n a l y s i s 67 2. Heat T r a n s f e r A n a l y s i s o f F l a s h Heated Cones 69 3. Hot Water Immersing T o o l 80 4. Flame T r e a t i n g T o o l 84 5. C a l i b r a t i o n of Flame T r e a t i n g S e a l Breaker 90 XI DEVELOPMENT OF MECHANICAL CONIFER SEED EXTRACTION TOOL 94 1. A l t e r n a t i v e Methods 94 2. E x t r a c t i o n by Cone A b r a s i o n 95 3. E x t r a c t i o n by Core B o r i n g 97 4. E x t r a c t i o n by T h r e s h i n g 103 V. TABLE OF CONTENTS (Continued) PAGE XI DEVELOPMENT OF MECHANICAL CONIFER SEED . EXTRACTION TOOL (Continued) (i ) A n a l y s i s 103 ( i i ) F i r s t P r o t otype T o o l , 107 ( i i i ) T e s t i n g 109 (iv) Second Ge n e r a t i o n P r o t o t y p e 115 (v) T e s t i n g 117 (vi) T h r e s h i n g Performance on Other Spe c i e s 122 PART THREE (Conc.JLn6A.OYi6 and Re.comrmndatA.on6) XII CONCLUSIONS 126 1. P h y s i c a l P r o p e r t i e s of Lodgepole P i n e Cones Which A f f e c t Seed E x t r a c t i o n 126 2. Development of S e a l Breaking T o o l 128 3. Development of Mech a n i c a l C o n i f e r Seed E x t r a c t i n g T o o l 128 XI I I RECOMMENDATIONS 131 LITERATURE CITED 134 APPENDIX A 139 v i . LIST OF TABLES TABLE I ' Seed v i a b i l i t y by l o c a t i o n i n cone PAGE 36 II Germination p e r c e n t f o r ease o f e x t r a c t i o n t e s t 38 I I I S c a l e d e f l e c t i o n angle a t v a r i o u s cone moisture contents 48 IV E f f e c t o f hot water immersion on cone opening and seed v i a b i l i t y 57 V E f f e c t o f flame treatment on cone opening and seed v i a b i l i t y 61 VI S e a l b r e a k i n g r e s u l t s a t t h r e e m o i s t u r e co n t e n t s 63 VII Simple c o r r e l a t i o n among v a r i a b l e s o f cone geometry 99 TABLES IN APPENDIX A A-1 Number o f seeds per cone, by l o c a t i o n • 140 A-2 V i a b i l i t y o f oven d r i e d cones 142 A-3 E q u i l i b r i u m moisture c o n t e n t (wet b a s i s ) o f cones over s a t u r a t e d s a l t s o l u t i o n f o r 30 days 143 A-4 Cone s c a l e r e l e a s e temperature 144 A-5 Maximum cone s c a l e angles of cones a t 21.2% MC 145 A-6 Maximum cone s c a l e angles of cones a t 17.4% MC 146 A-7 Maximum cone s c a l e angles of cones a t 13.5% MC 147 A-8 Maximum cone s c a l e angles of cones a t 9.5% MC 148 A-9 Maximum cone s c a l e angles of cones a t 7.5% MC 149 v i i . TABLE PAGE A-10 Maximum cone s c a l e angles o f cones a t 4.8% MC 150 A - l l Maximum cone s c a l e angles o f cones oven dry 151 A-12 Maximum s c a l e angle o f cones s t o r e d s i x months a t 11.2% MC (wb) unsealed and d r i e d t o 9.9% MC 152 A-13 Maximum s c a l e angle o f cones s t o r e d s i x months a t 11.2% MC (wb) unsealed, rewetted and d r i e d t o 11.1% MC (wb) 153 A-14 Maximum s c a l e angle o f cones s t o r e d s i x months a t 11.2% MC (wb), unsealed, rewetted and d r i e d t o oven dry 154 A-15 Maximum cone s c a l e angles f o r f i r s t seed r e l e a s e t e s t 155 A-16 Maximum cone s c a l e angles f o r second seed r e l e a s e t e s t 156 A-17 Maximum cone s c a l e angles f o r t h i r d seed r e l e a s e t e s t 157 A-18 Maximum cone s c a l e angles f o r f o u r t h seed r e l e a s e t e s t 158 A-19 Degree of s e r o t i n o u s s e a l b r e a k i n g i n C l a s s I (young) cones by flame treatment 159 A-20 Degree o f s e r o t i n o u s s e a l b r e a k i n g i n C l a s s I I weathered cones by flame treatment 161 A-21 Geometric v a r i a b l e s a f f e c t i n g core b o r i n g o f l o d g e p o l e p i n e cones 163 A-22 R e s u l t s o f t h r e s h i n g t e s t s on lodgepole p i n e 164 A-23 R e s u l t s o f improved t h r e s h e r t e s t s on lodgepole p i n e 167 A-24 Lodgepole p i n e seeds r e c o v e r e d through concaves from 100 cones ' 168 •a Lodgepole p i n e seeds r e c o v e r e d through s i e v e from 100 cones R e s u l t s o f t h r e s h i n g t e s t s on Douglas f i r R e s u l t s of t h r e s h i n g t e s t s on white spruce R e s u l t s o f t h r e s h i n g t e s t s on western hemlock i x . LIST OF FIGURES FIGURE PAGE 1. Steps i n the s y s t e m a t i c d e s i g n procedure 9 2. D e f i n i n g the a l t e r n a t i v e p r o c e s s e s 10 3. Flow c h a r t s comparing se p a r a t e k i l n d r y i n g andtumbling to mobile mechanical e x t r a c t i o n . 14 4. Cross s e c t i o n of t y p i c a l cones showing l o c a t i o n of s e r o t i n o u s s e a l 33 < 5. L o c a t i o n of s e r o t i n o u s s e a l s on a b a x i a l and a d a x i a l s u r f a c e s of t y p i c a l cone s c a l e s 33 6. T y p i c a l p a r t i a l l y opened cones from commercially c o l l e c t e d cone l o t s 35 7. Technique f o r manual opening o f s e a l e d cones 35 8. Curve of g e r m i n a t i o n p e r c e n t w i t h treatment time f o r cones i n 140 GF (60°C) oven 39 9. C o n t a i n e r s f o r e q u i l i b r i u m m o i s t u r e c o n t e n t d e t e r m i n a t i o n 42 10. E q u i l i b r i u m moisture c o n t e n t d u r i n g d r y i n g of lodgepole p i n e cones 42 11. Apparatus f o r d e t e r m i n a t i o n o f s e a l m e l t i n g temperatures 44 12. Cones prepared f o r s c a l e d e f l e c t i o n measurement b e f o r e and a f t e r opening 4̂,6 13. Alignment of c r o s s h a i r w i t h ground s c a l e s u r f a c e 46 14. Apparatus f o r measuring cone s c a l e d e f l e c t i o n angles 46 15. Maximum s c a l e angle v s . e q u i l i b r i u m m oisture content 48 Cones showing t y p i c a l degree o f opening when unsealed and brought t o 10% M.C. a f t e r one month of storage a t i n d i c a t e d m o isture contents Cross s e c t i o n o f open s t r e s s r e l a x e d and. n o n - s t r e s s r e l a x e d cones Seed e x t r a c t i o n v s . cone s c a l e angle Hot water immersion apparatus Cone d r y i n g r a c k s Flame t r e a t i n g apparatus S e a l b r e a k i n g by c r u s h i n g Dimensional data of cone f o r heat t r a n s f e r a n a l y s i s P r o t o t y p e h o t water s e a l b r e a k i n g t o o l View of s e a l breaker showing h e a t i n g and d r i v e mechanisms Pro t o t y p e flame t r e a t i n g s e a l breaker View of flame t r e a t e r showing d r i v e mechanism Curve of exhaust temperature vs. f u e l p r e s s u r e f o r flame t r e a t i n g s e a l b r e a k e r V i a b i l i t y v s . treatment time f o r flame t r e a t e r o p e r a t i n g a t 1000°F (538°C) Flame t r e a t e r c a l i b r a t i o n curves f o r complete s e a l b r e a k i n g of c l a s s I (young) lodgepole p i n e cones Flame t r e a t e r c a l i b r a t i o n curves f o r complete s e a l b r e a k i n g of c l a s s I I (weathered) lodgepole p i n e cones Cone a b r a s i o n t o o l Geometric v a r i a b l e s o f cones i n f l u e n c i n g seed e x t r a c t i o n by removal of cone core x i . FIGURE PAGE 34. Cross s e c t i o n o f t y p i c a l cones showing degree of asymmetry • 101 35. Cone b o r i n g t o o l 101 36. Cross s e c t i o n of bored cones 101 37. Bored and unsealed cones 101 38. Schematic diagram of t h r e s h i n g machine 104 39. C y l i n d e r and concaves of t h r e s h i n g t o o l 108 40. C y l i n d e r and concaves i n s t a l l e d i n frame 108 41. T h r e s h i n g t o o l w i t h plenum chamber 108- 42. Assembled p r o t o t y p e cone t h r e s h e r 110 43. S c a l p i n g s i e v e w i t h p a r t i a l l y t h r e s h e d cones 110 44. P a r t i a l l y t h r e s h e d cones a f t e r two passes w i t h c y l i n d e r speed of 2000 f t / m i n . 110 45. M a t e r i a l p a s s i n g through s c a l p i n g s i e v e 112 46. A i r - s c r e e n seed c l e a n e r 112 47. T y p i c a l damaged and a p p a r e n t l y undamaged seeds e x t r a c t e d by t h r e s h i n g 112 48. V i a b l e seed r e c o v e r y r a t e vs. c y l i n d e r speed f o r lodgepole p i n e cones 114 49. I n t e r n a l components showing l o c a t i o n of c u s h i o n i n g m a t e r i a l 116 50. D e t a i l of c u s h i o n m a t e r i a l on concaves 116 51. L o c a t i o n of d e c e l e r a t i o n c u r t a i n i n plenum chamber 116 52. Curves o f seed r e c o v e r y v s . c y l i n d e r speed f o r lodgepole p i n e e x t r a c t e d by the r u b b e r i z e d t h r e s h i n g t o o l .119 Accumulated v i a b l e seed r e c o v e r y from cones at 15% moisture content a t 2000 f t / m i n c y l i n d e r speed Seed r e c o v e r y by t h r e s h i n g o f f i r , spruce, and hemlock cones X i i i . TERMINOLOGY ABAXIAL - p e r t a i n i n g t o the r e g i o n o f an o b j e c t remote from i t s c e n t r a l a x i s . ADAXIAL - p e r t a i n i n g t o t h a t r e g i o n o f an o b j e c t a t or near i t s c e n t r a l a x i s . APOPHYSIS - the prominent p o r t i o n o r e x t e r n a l l y v i s i b l e t i p r e g i o n of a cone s c a l e . BIOT NUMBER - di m e n s i o n l e s s heat t r a n s f e r f u n c t i o n , r e l a t i n g the r a t i o o f i n t e r n a l t o e x t e r n a l t hermal r e s i s t a n c e . CASE HARDENING - the process of i m p a r t i n g hard, b r i t t l e c h a r a c t e r i s t i c s t o the outher s u r f a c e o f an item, as i n the c a r b u r i z i n g and quenching of s t e e l . Term a l s o used t o d e s c r i b e development of r e s i d u a l s t r e s s e s i n wood a f t e r k i l n d r y i n g . CELLULOSE MICROFIBRILS - f i b r i l s of c e l l u l o s e e x i s t i n g i n the c e l l w a l l s o f p l a n t m a t e r i a l , and b e i n g l a r g e l y r e s p o n s i b l e f o r the form and s t r u c t u r a l mechanics of the c e l l . CONE AXIS - the c e n t r a l a x i s of the c o n i c a l p r o f i l e d e s c r i b i n g the o u t e r s u r f a c e of the c o n i f e r cones under study. CONE CORE AXIS - the c e n t r a l a x i s of the c o n i c a l p r o f i l e d e s c r i b i n g the woody s t r u c t u r e o f a c o n i f e r cone to which the s c a l e s are a t t a c h e d . CONE SCALE DEFLECTION ANGLE - the angle through which a cone s c a l e d e f l e c t s from i t s c l o s e d p o s i t i o n d u r i n g d r y i n g . The angle i s measured a t the t i p o f the s c a l e . The average maximum s c a l e d e f l e c t i o n angle /'for a cone i s the average of the angles of a number o f s c a l e s which are l o c a t e d i n a band around the cone a t a p o i n t where s c a l e d e f l e c t i o n i s g r e a t e s t . CYLINDER AND CONCAVE ASSEMBLY - a seed e x t r a c t i n g t o o l used t o separate a g r i c u l t u r a l seeds from the seed s u p p o r t i n g p o r t i o n o f p l a n t s . The apparatus c o n s i s t s o f a r e v o l v i n g c y l i n d e r having a number o f t r a n s v e r s e rub-bars and a s t a t i o n a r y member, between which the seed c o n t a i n i n g m a t e r i a l i s passed d u r i n g t h r e s h i n g . x i v . EQUILIBRIUM MOISTURE CONTENT - t h a t moisture c o n t e n t o f a hy g r o s c o p i c m a t e r i a l a t which the m o i s t u r e w i t h i n t h a t m a t e r i a l i s i n e q u i l i b r i u m w i t h the mo i s t u r e i n the surrounding a i r . EXTRACTION (SEED) - the removal of seeds from t h e cones o f c o n i f e r t r e e s . FLASH HEATING - the b r i e f exposure o f s e r o t i n o u s cones t o very h i g h temperatures f o r the purpose o f m e l t i n g the r e s i n o u s bond h o l d i n g the cone s c a l e s i n a c l o s e d p o s i t i o n . FOURIER NUMBER - di m e n s i o n l e s s heat t r a n s f e r f u n c t i o n r e l a t i n g the thermal d i f f u s i v i t y and heat t r a n s f e r time t o body geometry. GERMINATION PERCENT - p e r c e n t of a g i v e n number o f seeds producing normal germinants w i t h i n a g i v e n p e r i o d o f time under optimum c o n d i t i o n s . May be expressed as a percentage o f t o t a l seed, o r as a percentage of f i l l e d seed. GERMINATIVE CAPACITY - the pe r c e n t o f seeds i n a g i v e n sample producing normal germinants, i r r e s p e c t i v e o f time. U s u a l l y c o n s i d e r e d t o be the t o t a l o f germinated seed p l u s a l l ungerminated seeds s t i l l sound a t the end o f th.e t e s t p e r i o d . HYGROSCOPIC - p e r t a i n i n g t o the a b i l i t y o f a m a t e r i a l t o imbibe water from the atmosphere. MECHANICAL SEED DAMAGE - damage caused by the o c c u r r e n c e o f s t r e s s e s i n a seed which exceed the y i e l d s t r e n g t h of the t i s s u e s i n v o l v e d . MOISTURE CONTENT - the amount of water r e t a i n e d by a hygro- s c o p i c m a t e r i a l , expressed as a perc e n t a g e , by weight of the t o t a l d ry matter o.f the m a t e r i a l (dry b a s i s ) o r of the t o t a l dry matter p l u s water (wet b a s i s ) . NORMAL GERMINANT - germinant whose s t r u c t u r e s appear normal once i t s development has produced a r a d i c l e e q u a l i n l e n g t h t o t h a t o f the seed. PEDUNCLE - the woody c o n n e c t i v e s t r u c t u r e which a t t a c h e s a cone t o the t r e e branch. XV. RELATIVE HUMIDITY - the r a t i o , expressed as a percentage, of the p a r t i a l p r e s s u r e of water vapor of an a i r - v a p o r mixture t o the p r e s s u r e o f s a t u r a t e d water v a p o r . a t the same dry bulb temperature. RHEOLOGY - the study o f the mechanical p r o p e r t i e s of m a t e r i a l s which r e s u l t i n deformation and flow o f a m a t e r i a l . SCLERENCHYMA - t h a t t i s s u e w i t h i n p l a n t s t r u c t u r e whose primary r o l e i s t o p r o v i d e s t r e n g t h and mechanical support f o r the p l a n t body. SEAL BREAKING - the b r e a k i n g o f the r e s i n o u s bonds which s e a l the s c a l e s o f s e r o t i n o u s c o n i f e r cones i n a c l o s e d p o s i t i o n . SEROTINY - a term used t o d e s c r i b e the c o n d i t i o n o f c o n i f e r cones i n which the s c a l e s are s e a l e d i n a c l o s e d p o s i t i o n by a r e s i n o u s bond between the o v e r l a p p i n g s u r f a c e s . Cones having t h i s c h a r a c t e r i s t i c are r e f e r r e d t o as " s e r o t i n o u s cones" or " c l o s e d cones". SHORE HARDNESS - an index i n d i c a t i n g the hardness, or r e s i s t a n c e t o p e n e t r a t i o n of a m a t e r i a l . Determined by measuring the rebound o f a diamond t i p p e d t o o l which i s dropped onto the s u r f a c e t o be e v a l u a t e d . STRESS RELAXATION - the decay of s t r e s s w i t h time when a m a t e r i a l i s s u b j e c t e d t o a cons t a n t s t r a i n . THERMAL CONDUCTIVITY - a c o e f f i c i e n t e x p r e s s i n g a p r o p o r t i o n - a l i t y between heat f l u x and temperature g r a d i e n t ., w i t h i n a media which, t r a n s m i t s thermal energy by con d u c t i o n . THERMAL DIFFUSIVITY - a heat t r a n s f e r parameter d e f i n i n g the r a t i o o f the thermal c o n d u c t i v i t y t o the thermal /capacitance o f a m a t e r i a l . THERMAL SEAL BREAKING - the opening, or b r e a k i n g o f the s e r o t i n o u s bond on s e a l e d cones by the a p p l i c a t i o n of heat. TOOL - the s p e c i f i c o p e r a t i o n a l d e v i c e which performs the b a s i c f u n c t i o n i n a pro c e s s o r machine. TRANSIENT HEAT FLOW - unsteady heat flow d u r i n g the t r a n s i - t i o n a l p e r i o d b e f o r e and a f t e r steady s t a t e heat flow. - x v i . UMBO - the c e n t r a l protuberance or s p i k e on the a b a x i a l s i d e o f the t i p of the cone s c a l e o f c e r t a i n c o n i f e r s p e c i e s . UNIT SURFACE CONDUCTANCE - the heat t r a n s f e r c o e f f i c i e n t combining the e f f e c t s o f heat flow by c o n v e c t i o n and r a d i a t i o n between a s u r f a c e and a f l u i d . VAPOR PRESSURE DIFFERENTIAL - the d i f f e r e n c e between the vapor p r e s s u r e of water c o n t a i n e d i n a m a t e r i a l a t a g i v e n temperature and the p a r t i a l vapor p r e s s u r e e x i s t i n g i n surrounding a i r . VIABILITY - the percentage o f a group of seeds expected t o be capable of produ c i n g normal germinants under optimum c o n d i t i o n s . VISCO ELASTIC MATERIAL - a m a t e r i a l d i s p l a y i n g l i q u i d - l i k e and s o l i d - l i k e c h a r a c t e r i s t i c s which r e s u l t i n the s t r e s s - s t r a i n r e l a t i o n s h i p w i t h i n the m a t e r i a l b e i n g dependent upon the r a t e o f deformation. WET BULB TEMPERATURE - f o r p r a c t i c a l purposes i s c o n s i d e r e d t o be the a d i a b a t i c s a t u r a t i o n temperature of water i n the a i r . I t i s the lowest temperature i n d i c a t e d by a moistened thermometer when evapora- t i o n takes p l a c e i n a c u r r e n t of a i r . x v i i . ACKNOWLEDGEMENTS The author wishes to express his sincere apprecia- t i o n to Dr. E.O. Nyborg for his i n s p i r a t i o n and continuing guidance throughout t h i s i n v e s t i g a t i o n , and to Dr. N.C. Franz for coordinating t h i s i n t e r d i s c i p l i n a r y program between the Department of A g r i c u l t u r a l Engineering and the Faculty of Forestry. The author also wishes to express h i s thanks to Dr. P.G. Haddock, Dr. 0. S z i k l a i , and Professor E.L. Watson for t h e i r i n t e r e s t in the investigation and to Mr. J . Konishi and Miss M. Henrich, B.C. Forest Service, for t h e i r technical assistance. Thanks i s extended to Mrs. E. Stewart f o r typing of the manuscripts. The author wishes to express his gratitude to the B r i t i s h Columbia Forest Service, whose f i n a n c i a l assistance made t h i s study possible. I. INTRODUCTION Pr e s e n t techniques f o r the c o l l e c t i o n and e x t r a c t i o n of c o n i f e r seeds f o r r e f o r e s t a t i o n are expensive and time consuming due t o the e x t e n s i v e use o f manual o p e r a t i o n s . The t r a n s p o r t i n g o f bulky seed b e a r i n g cones over long d i s t a n c e s t o c e n t r a l , e x t r a c t o r i e s f u r t h e r adds t o the h i g h c o s t o f the seed. C o n v e n t i o n a l c o n i f e r seed e x t r a c t o r i e s take the form of l a r g e permanent i n s t a l l a t i o n s i n which cones a r e k i l n d r i e d , and e x t r a c t e d by tumbling. The c a p a c i t y o f these e x t r a c t o r i e s i s l i m i t e d due to the time r e q u i r e d f o r k i l n treatment. Thus the l a r g e c a p i t a l and o p e r a t i n g c o s t s o f such i n s t a l l a t i o n s must be absorbed by a r e l a t i v e l y s m a l l q u a n t i t y o f e x t r a c t e d seed. I t i s apparent t h a t e x t r a c t i o n c o s t s can be reduced by the use of an e f f i c i e n t , continuous flow mechanical e x t r a c t i o n system, and t h a t s h i p p i n g c o s t s can be reduced by o p e r a t i n g the e x t r a c t o r a t r e g i o n a l cone c o l l e c t i o n s t a t i o n s . F u r t h e r , i t i s probable t h a t a p o r t a b l e mechanical e x t r a c t i o n system f o r c o n i f e r seed can be developed through the adap- t a t i o n o f the p r i n c i p l e o f t h r e s h i n g , as i s used f o r e x t r a c t i o n of a g r i c u l t u r a l seeds. The a d a p t a t i o n o f t h r e s h i n g t o c o n i f e r seed e x t r a c - t i o n appears simple f o r the s o f t - c o n e d s p e c i e s . T h r e s h i n g of the hard-coned s p e c i e s may be more d i f f i c u l t , w h i l e the 2. g r e a t e s t c h a l l e n g e would appear t o be the e x t r a c t i o n of the hard-coned s p e c i e s , having s e r o t i n o u s s c a l e s e a l s , which bond the cone s c a l e s t o g e t h e r i n a c l o s e d p o s i t i o n . To be s u i t a b l e f o r use i n B r i t i s h Columbia, a mechanical seed e x t r a c t i o n system must be capable of h a n d l i n g a l l t h r e e types of cones. I t i s a l s o apparent t h a t a t h r e s h i n g system which can operate s u c c e s s f u l l y on the hard-coned group, can be a d j u s t e d t o operate on the o t h e r types o f cones. For t h i s reason, the i n v e s t i g a t i o n of the mechanical e x t r a c t i o n of c o n i f e r seeds d e a l t w i t h i n t h i s r e p o r t has been l a r g e l y c o n f i n e d t o l o d g e p o l e p i n e (Pinus c o n t o r t a v a r . l a t i f o l i a Englem). T h i s s p e c i e s f a l l s i n the d i f f i c u l t t o e x t r a c t group, and c o n s t i t u t e s a s i g n i f i c a n t p o r t i o n of the cone crop h a r v e s t e d f o r r e f o r e s t a t i o n purposes i n the P a c i f i c Northwest. I I . CURRENT SEED EXTRACTION TECHNIQUES V i r t u a l l y a l l c o n i f e r seed e x t r a c t i o n systems c u r r e n t l y i n use operate on the p r i n c i p l e of k i l n d r y i n g and tumbling. D r y i n g of the cones causes the outward d e f l e c t i o n of the cone s c a l e s , w h i l e the tumbling treatment shakes the seeds f r e e a f t e r s c a l e d e f l e c t i o n has taken p l a c e . K i l n e x t r a c t o r i e s are g e n e r a l l y l a r g e , permanent i n s t a l l a t i o n s and may be c l a s s i f i e d i n t o the two f o l l o w i n g forms: (i) Separate d r y i n g and tumbling, where the cones are d r i e d i n t h i n l a y e r s on s t a t i o n a r y r a c k s i n the k i l n and tumbling i s performed a f t e r the d r y i n g treatment. ( i i ) Com- bin e d d r y i n g and tumbling, where the cones are tumbled d u r i n g k i l n treatment. P r o c e s s i n g of the cones i s s t r i c t l y on a batch b a s i s i n systems u s i n g separate o p e r a t i o n s , w h i l e systems u s i n g simultaneous treatment may operate e i t h e r on a b a t c h b a s i s , or on a continuous flow b a s i s where the cones pass through the system a t a steady r a t e . ' K i l n temperatures and treatment d u r a t i o n are con- t r o l l e d a c c o r d i n g t o the cone s p e c i e s . In some i n s t a l l a t i o n s , steam, o r water m i s t , i s i n j e c t e d i n t o the k i l n i n o r d e r t o reduce the r a p i d cone d r y i n g r a t e caused by the h i g h dry b u l b a i r temperatures. Without r e g a r d f o r economic c o n s i d e r a t i o n s , the k i l n - t u m b l i n g e x t r a c t i o n system i s e f f e c t i v e i n e x t r a c t i n g the seeds o f the s o f t - c o n e d s p e c i e s . The use of t h i s technique f o r the e x t r a c t i o n o f seeds o f the hard^-coned s p e c i e s has been l e s s s a t i s f a c t o r y . T h i s i s due c h i e f l y t o the reduced seed v i a b i l i t y b e l i e v e d t o be caused by the h i g h k i l n temperatures r e q u i r e d t o u n s e a l the cones, and the poor r e c o v e r y o f seeds caused by the incomplete cone s c a l e d e f l e c t i o n f r e q u e n t l y encountered. Although many r e p o r t s o u t l i n e i n d e t a i l the d e s i g n and o p e r a t i o n o f k i l n e x t r a c t i o n systems (7, 9, 41, 43)* l i t t l e c o n c l u s i v e i n f o r m a t i o n i s a v a i l a b l e on the techniques f o r and the f a c t o r s a f f e c t i n g seed e x t r a c t i o n o f s e r o t i n o u s cones. The use o f h i g h temperature k i l n s f o r c o n i f e r seed e x t r a c t i o n was o u t l i n e d i n 1941 by R i e t z (41). He recommended a d r y i n g schedule u s i n g the h i g h e s t temperature which the green cones can withstand', and the lowest r e l a t i v e h umidity t h a t w i l l dry the seeds t o the d e s i r e d s t o r a g e moisture content w i t h i n the d e s i r e d d r y i n g p e r i o d . He r e p o r t e d t h a t a k i l n temperature o f 170°F (76.7°C) and a r e l a t i v e humidity of 30% had been found s a f e f o r j a c k p i n e (Pinus banksiana) cones when t r e a t e d f o r 5 t o 6 hours. * Numbers i n parentheses r e f e r t o r e f e r e n c e s l i s t e d i n the L i t e r a t u r e C i t e d . Baldwin (7) i n 1942 i n d i c a t e d t h a t t h e r e i s an optimum moisture content o f seeds f o r both storage and r e s i s - tance t o e l e v a t e d temperatures, and recommended the lowest d r y i n g temperature and the s h o r t e s t treatment time which w i l l y i e l d s a t i s f a c t o r y seed r e l e a s e by the cones. He a l s o d e s c r i b e d s e v e r a l designs f o r k i l n d r y i n g and e x t r a c t i n g equipment, but noted t h a t t h e r e was c o n s i d e r a b l e l a t i t u d e i n the range o f d r y i n g c o n d i t i o n s recommended f o r optimum seed, e x t r a c t i o n . Edwards (18) i n 1955 recommended a k i l n treatment f o r e x t r a c t i o n of lod g e p o l e p i n e o f 6 t o 8 hours a t a tempera- t u r e o f 140°F (60°C). K i l n temperatures as h i g h as 160°F (71°C) f o r s e r o t i n o u s cones were r e p o r t e d i n 1971 by Schubert (43). He noted, however, t h a t temperatures 20° t o 30° lower would be used f o r i n i t i a l d r y i n g o f damp cones b e f o r e the h i g h e r temperatures are a p p l i e d t o complete cone opening. Wang (47) 1973, r e p o r t e d t h a t seeds are commercially e x t r a c t e d from lodgepole p i n e cones a f t e r a 16 hour treatment a t 60°C. He a l s o r e p o r t e d t h a t r e w e t t i n g and a d d i t i o n a l k i l n drying, of such cones r e s u l t e d i n f u r t h e r seeds b e i n g removed from the cones, but t h a t these had a reduced g e r m i n a b i l i t y as compared w i t h the seeds from the f i r s t k i l n treatment. P i t k i n (39) i n 1961 r e p o r t e d the development o f a combination k i l n and e x t r a c t o r i n which the cones were tumbled d u r i n g the k i l n d r y i n g p r o c e s s . The advantage o f t h i s combination i s t h a t the seeds are removed from the e l e v a t e d temperature of the k i l n as soon as they are r e l e a s e d by the cone, hence r e c e i v e a l e s s severe heat treatment without r e d u c i n g the q u a n t i t y of seed r e c o v e r e d . , Nyborg and B r i s b i n (37) i n 1973 i n v e s t i g a t e d the heat t r a n s f e r mechanism of the f l a s h h e a t i n g of l o d g e p o l e p i n e cones. T h e i r r e p o r t expressed concern f o r r e d u c t i o n i n v i a b i l i t y due t o thermal seed damage d u r i n g k i l n treatments. They proposed a technique of f l a s h h e a t i n g o f s e r o t i n o u s cones whereby the r e s i n o u s bond c o u l d be broken by m e l t i n g , without exposing the seeds to h i g h temperatures. E x p e r i m e n t a l r e s u l t s confirmed t h a t the cone s c a l e s of l o d g e p o l e p i n e cones can be r e l e a s e d by exposure of the cones t o a i r a t approximately 300°F (149°C) f o r a p e r i o d of approximately 15 seconds. Furthermore, they found t h a t the temperature of the seeds i n cones so t r e a t e d was r a i s e d by approximately 15°F (8°C) above the pre-treatment temperatures of the cones. I I I . OBJECTIVE The o b j e c t of t h i s p r o j e c t was t o i n v e s t i g a t e a l t e r n a t e methods of c o n i f e r seed e x t r a c t i o n and m o d i f i c a - t i o n s to e x i s t i n g seed e x t r a c t i o n t e c h n i q u e s . Because of the added d i f f i c u l t i e s of e x t r a c t i n g seed from s e r o t i n o u s cones, and the g o a l of a c h i e v i n g a mechanical e x t r a c t i o n system capable of h a n d l i n g a l l s p e c i e s , p a r t i c u l a r emphasis was p l a c e d on the e x t r a c t i o n o f lodgepole p i n e . The s p e c i f i c areas of i n v e s t i g a t i o n o f t h i s p r o j e c t are as f o l l o w s : A. To i n v e s t i g a t e the p h y s i c a l and mechanical p r o p e r t i e s of the cones o f PinUs c o n t o r t a v a r . l a t i f o l i a Englem, (lodgepole pine) f o r the purpose of i d e n t i f y i n g : (i) the f a c t o r s which i n f l u e n c e seed e x t r a c t i o n from s e r o t i n o u s cones; ( i i ) the f a c t o r s which a f f e c t s e a l r e l e a s e i n s e r o t i n o u s cones; ( i i i ) the e f f e c t of v a r i o u s cone treatment techniques on seed v i a b i l i t y . B. To d e s i g n , f a b r i c a t e and t e s t the p r i n c i p a l components of a p o r t a b l e continuous flow mechanical seed e x t r a c t i o n system. 8. IV. SYSTEMATIC DESIGN PROCEDURE The d e s i g n and development procedure used i n t h i s study f o l l o w s t h a t used by Persson (38) and Nyborg and Shikaze (36), and takes the form of a s y s t e m a t i c procedure o r i e n t e d toward the d e s i g n and t e s t i n g of a machine system to handle b i o l o g i c a l m a t e r i a l s . The s t e p s of t h i s procedure are out- l i n e d s c h e m a t i c a l l y i n F i g u r e 1. The s y s t e m a t i c procedure i s i n i t i a l l y c a r r i e d out a t two l e v e l s . In the f i r s t l e v e l o f a n a l y s i s , flow c h a r t s (Figure 2) o f p o s s i b l e sequences of o p e r a t i o n between the i n i t i a l and f i n a l c o n d i t i o n s of the p r o d u c t are c o n s t r u c t e d . The most a p p r o p r i a t e sequence i s then s e l e c t e d on the b a s i s o f economic c o n s i d e r a t i o n s , mechanical l i m i t a t i o n s of machine and product, and o t h e r p e r t i n e n t c r i t e r i a . In the second phase of the procedure, each i n d i v i d u a l treatment d e v i c e , or " t o o l " i s analyzed i n terms of i t s f u n c t i o n and o p e r a t i n g p r i n c i p l e . The i n p u t c o n d i t i o n s , output c o n d i t i o n s and opera- t i o n a l requirements of each t o o l i n the process are determined and p r e l i m i n a r y t o o l a n a l y s i s i s undertaken. In most d e s i g n p r o j e c t s i n v o l v i n g the p r o c e s s i n g of b i o l o g i c a l m a t e r i a l s , complete i n f o r m a t i o n on the p h y s i c a l - and mechanical p r o p e r t i e s o f the p r o d u c t i s not a v a i l a b l e . The t h i r d s t e p i n t h i s procedure i s t h e r e f o r e the determina- t i o n of the e n g i n e e r i n g p r o p e r t i e s n e c e s s a r y t o complete the t o o l a n a l y s i s . T h i s a l l o w s the mathematical models of the i n d i v i d u a l t o o l s of the p r o c e s s to be completed. ANALYSIS OF PROCESS ANALYSIS OF TOOLS r ANALYSIS OF PRODUCT f MATHEMATICAL MODELS OF TOOLS f DESIGN AND TESTING 0 F TOOLS t DESIGN OF CONTROL AND POWER 1 SYNTHESIS OF MACHINE EVALUATION OF MACHINE F i g u r e 1. Steps i n s y s t e m a t i c d e s i g n procedure. 10. INITIAL CONDITION MACHINE SYSTEM FINAL CONDITION TOOL 1 TOOL 2 TOOL 3 _j—i ALTERNATE MACHINE SYSTEM TOOL 8 —~- TOOL 9 TOOL 10 F i g u r e 2 D e f i n i n g the a l t e r n a t i v e p rocesses The f o u r t h s t e p i n the procedure i n v o l v e s the de s i g n , f a b r i c a t i o n , t e s t i n g and c a l i b r a t i o n of the i n d i v i d u a l t o o l s of the proposed machine system. T h i s step i n c l u d e s the p r o g r e s s i v e r e d e s i g n i n g o f i n d i v i d u a l t o o l s f o r o p t i m i z a t i o n of t o o l performance as i s found necessary by the t e s t i n g procedures. The f i n a l step i n v o l v e s the i n c o r p o r a t i o n of the i n d i v i d u a l t o o l s i n t o the machine, and p r o v i d i n g the c o n t r o l mechanisms and power systems a p p r o p r i a t e t o the o p e r a t i o n a l requirements and m a t e r i a l p r o p e r t i e s . The machine i s then f i e l d t e s t e d t o e v a l u a t e i t s f u n c t i o n a l performance and d u r a b i l i t y . 11. The r e s e a r c h p r o j e c t o u t l i n e d i n t h i s r e p o r t was undertaken f o l l o w i n g t h i s g e n e r a l d e s i g n procedure. A l t h o u g h the magnitude of the development of a complete c o n i f e r seed e x t r a c t i o n system capable of h a n d l i n g s e r o t i n o u s cones i s beyond the scope of t h i s r e s e a r c h p r o j e c t , the i n v e s t i g a t i o n s and development work r e p o r t e d here were o r g a n i z e d a c c o r d i n g to the o u t l i n e d procedure. The major p o r t i o n of the work d e a l t w i t h i n t h i s r e p o r t , t h e r e f o r e , d e a l s w i t h the i n v e s t i g a t i o n o f the p h y s i c a l and mechanical p r o p e r t i e s o f lod g e p o l e p i n e cones which a f f e c t mechanical seed e x t r a c t i o n . The machine d e s i g n work i s l i m i t e d t o the development of a continuous flow t o o l f o r b r e a k i n g the s e r o t i n o u s cone s c a l e s e a l s , and a cont i n u o u s flow t o o l f o r mechanical e x t r a c t i o n o f seeds from the u n s e a l e d cones. 12. • V. COMPARISON OF KILN AND MECHANICAL EXTRACTION SYSTEMS . As noted e a r l i e r , the procurement of t r e e seed f o r r e f o r e s t a t i o n purposes i s expensive, due i n p a r t , t o the l a r g e number of manual o p e r a t i o n s employed. A c o n s i d e r a b l e improve- ment i n the e f f i c i e n c y of h a n d l i n g and p r o c e s s i n g o f cones a f t e r they reach the r e g i o n a l cone c o l l e c t i o n s t a t i o n can be achieved through a modest l e v e l of mechanization. A comparison of the u n i t o p e r a t i o n s of a k i l n e x t r a c t i o n system u s i n g s e p a r a t e d r y i n g and tumbling treatments t o those of a continuous flow; mechanical seed e x t r a c t i o n system i s shown i n F i g u r e 3. The comparison i s based on steps i n v o l v e d i n c o n v e r t i n g seed f i l l e d cones a t the r e g i o n a l c o l l e c t i o n s t a t i o n i n t o semi c l e a n e d seeds a t the n u r s e r y . The most n o t a b l e c h a r a c t e r i s t i c of the k i l n e x t r a c - t i n g system shown, i s the l a r g e number of times which the. cones must be handled, most of which, are manually performed. K i l n e x t r a c t i o n v a r i e s g r e a t l y from mechanical e x t r a c t i o n because of the l e n g t h o f the w a i t i n g p e r i o d r e q u i r e d f o r d r y i n g , which commonly runs from 12 t o 24 hours per b a t c h . The c o s t of k i l n e x t r a c t e d seed i s f u r t h e r r a i s e d by the c o s t of t r a n s p o r t i n g l a r g e q u a n t i t i e s of bulky m a t e r i a l from the c o l l e c t i o n s t a t i o n s t o the e x t r a c t o r y , as w e l l as by the l a r g e c a p i t a l investment i n storage and p r o c e s s i n g f a c i l i - t i e s r e q u i r e d f o r t h i s type of o p e r a t i o n . I 13. A p o r t a b l e mechanical e x t r a c t i o n system such as the one e x e m p l i f i e d i n F i g u r e 3 d i f f e r s from k i l n e x t r a c t i o n systems i n both i t s o p e r a t i n g l o c a t i o n and i t s method of o p e r a t i o n . In t h i s case, seed e x t r a c t i o n i s c a r r i e d out a t the r e g i o n a l cone c o l l e c t i o n s t a t i o n s , and o n l y the semi- clea n e d seeds are t r a n s p o r t e d from t h a t p o i n t . The most n o t a b l e f e a t u r e of a continuous flow mechanical e x t r a c t i o n system i s i t s h i g h p r o d u c t i o n c a p a c i t y . The a b i l i t y t o process cones on a continuous flow b a s i s enables i t h i s r e l a t i v e l y s m a l l p o r t a b l e p i e c e of equipment t o have a p r o d u c t i o n c a p a c i t y e q u i v a l e n t to a l a r g e commercial e x t r a c t o r y . I t i s a n t i c i p a t e d t h a t a p o r t a b l e cone t h r e s h e r c o u l d have a c a p a c i t y i n the o r der o f one b u s h e l of cones per minute. The continuous flow p r o c e s s i n g performed by the system makes i t p a r t i c u l a r l y s u i t e d to automated m a t e r i a l s h a n d l i n g systems which g r e a t l y reduce the manual l a b o u r r e q u i r e - ment . The magnitude o f the savings i n t r a n s p o r t a t i o n c o s t s a c h i e v e d by e x t r a c t i o n o f seed a t r e g i o n a l depots i s e x e m p l i f i e d i n t h a t f a c t t h a t approximately 220 pounds of l o d g e p o l e p i n e cones y i e l d one pound of seeds. 14- KILN EXTRACTION MECHANICAL EXTRACTION LOAD TRUCK TRANSPORT CONES TO EXTRACTORY UNLOAD TRUCK STORE CONES CONVEY TO KILN SPREAD ON nRYTisrr; R A C K S DRY CONES CONVEY TO TUMBLER METER INTO TUMBLER EXTRACT CLEAN CONVEY CONES TO EXTRACTOR METER INTO EXTRACTOR EXTRACT CLEAN TRANSPORT SEEDS TO NURSERY i * I n i t i a l c o n d i t i o n s — c o n e s a t r e g i o n a l depot *•* F i n a l c o n d i t i o n s — c l e a n seeds a t n u r s e r y TRANSPORT SEEDS TO NURSERY F i g u r e 3. Flow c h a r t s comparing separate k i l n d r y i n g and tumbling e x t r a c t i o n t o mobile mechanical e x t r a c t i o n . P A R T O N E P H Y S I C A L P R O P E R T I E S O F L O D G E P O L E P I N E C O N E S 16. VI PHYSICAL PROPERTIES AND CHARACTERISTICS WHICH AFFECT MECHANIZATION OF SEED EXTRACTION Over the p a s t f i f t y y ears r e f o r e s t a t i o n i n North America has grown from a few i s o l a t e d p l a n t a t i o n s t o a p o i n t where many m i l l i o n s of d o l l a r s are spent on r e f o r e s t a t i o n each year i n B r i t i s h Columbia alone.. During t h i s time a wealth of knowledge has been gained i n the techniques f o r and f a c t o r s a f f e c t i n g the produc- t i o n of c o n i f e r s e e d l i n g s f o r r e f o r e s t a t i o n purposes. Only a s m a l l q u a n t i t y of i n f o r m a t i o n has, however, been r e p o r t e d on the f a c t o r s which i n f l u e n c e seed e x t r a c t i o n and the q u a l i t y of r e c o v e r e d seed (35). A review of the l i t e r a t u r e d e a l i n g w i t h the p r o p e r t i e s and c h a r a c t e r i s t i c s which a f f e c t the e x t r a c t i o n of l o d g e p o l e p i n e i s summarized. 1. F r u i t i n g The female seed b e a r i n g cones of l o d g e p o l e p i n e r e q u i r e two years to develop to m a t u r i t y . In the f i r s t y e a r the f l o w e r i s developed, and p o l l i n a t i o n takes p l a c e , w h i l e the development of the o v a r y begins i n the second y e a r . By the f a l l o f the second y e a r , maturation of the cones and t h e i r seeds has been completed (44). The opening of the cones a t t h i s time and the r e - s u l t i n g d i s p e r s a l of seed i s dependent upon the presence of 17. serotinous s e a l s on the cone s c a l e s (12). Unsealed or non- serotinous cones open according to t h e i r moisture content and dispense most of t h e i r seed immediately w h i l e s e a l e d cones remain on the t r e e , and can r e t a i n t h e i r seeds f o r many years w i t h l i t t l e r e d u c t i o n i n seed v i a b i l i t y (1, 14, 15). The magnitude of annual seed crops of lodgepole pine i s h i g h l y v a r i a b l e , but the a b i l i t y t o r e t a i n v i a b l e seeds i n serotinous cones on the t r e e ensures t h a t a source of seed i s a v a i l a b l e at a l l times f o r cone h a r v e s t i n g or f o r n a t u r a l regeneration. The number of cones on a mature t r e e varies from a few hundred to a few thousand (16), and the average number of seeds per cone i s f r e q u e n t l y i n excess of f o r t y seeds (12). 2. Serotinous Cone Scale Seals Lotan (29) reported t h a t the term " s e r o t i n o u s " i s used to d e f i n e the c o n d i t i o n of the cones of c e r t a i n c o n i f e r species on which the s c a l e s are bonded together by a resinous s e a l l o c a t e d near the t i p of the s c a l e s . The term i s d e r i v e d from the L a t i n serus, meaning l a t e , and r e f e r s t o the f a c t t h a t the bonding of the s c a l e occurs l a t e i n the development of the cones, j u s t p r i o r to the f u l l maturation. This c h a r a c t e r i s t i c i s reported (8,46) to-occur i n s e v e r a l species of Pinus, i n c l u d i n g : Pinus c o n t o r t a , P. banksiana, P. s e r o t i n a , P. r i g i d a , P. r a d i a t a , P. c l a u s a , and P. a t t e n i i a t a . 18. The s e r o t i n o u s c h a r a c t e r i s t i c v a r i e s w i t h i n l o d g e p o l e pine not o n l y w i t h geographic l o c a t i o n and v a r i e t y , but a l s o w i t h t r e e s w i t h i n a stand and from cone t o cone on a t r e e (29). C r o s s l e y (14) r e p o r t e d t h a t open o r non- s e r o t i n o u s cones r e l e a s e some o f t h e i r seeds i n almost every month of the y e a r , w h i l e the s e r o t i n o u s cones r e q u i r e exposure to h i g h temperatures i n o r d e r t o break the s e a l s and i n i t i a t e seed d i s p e r s a l . T h i s c h a r a c t e r i s t i c p l a y s a major r o l e i n the r a p i d r e g e n e r a t i o n of Lodgepole p i n e i n areas which have been ravaged by w i l d f i r e . In t h i s case, the heat o f the f i r e breaks the s e a l s of the cones and those which are not consumed, open and r e l e a s e a b o u n t i f u l supply o f seed a f t e r the f i r e has passed (29). Lotan (29), i n 1970, s t u d i e d the c h a r a c t e r i s t i c s of s e r o t i n o u s and non-serotinous: lodgepole p i n e cones i n o r d e r to i d e n t i f y the f a c t o r s which determine whether o r not the cones w i l l be s e a l e d . Both chem i c a l and anatomical a n a l y s e s f a i l e d t o i d e n t i f y the c o n t r o l l i n g f a c t o r . His work d i d , however, rule out the p o s s i b i l i t y of the s c a l e s e a l s b e i n g broken by t h e . f l e x u r a l f o r c e s o f the cone s c a l e s . He determined t h a t the f o r c e r e q u i r e d to break t y p i c a l s e r o t i n o u s bonds i s approximately t h i r t y times the f l e x u r a l s t r e n g t h o f the s c a l e s . The opening of s e a l e d cones by r a i s i n g the cone temperature was r e p o r t e d in•1910. by Clements (12) who i n d i c a t e d t h a t s e a l b r e a k i n g took p l a c e a t temperatures of 19. 45°C t o 50°C. Cameron (11) i n 1953 measured the temperature a t which s i x cones of lodgepole p i n e opened i n a water bath and found a range from 44.5°C t o 49°C, w i t h a mean va l u e of 45.3°C. He a l s o measured the m e l t i n g temperature of an et h e r e x t r a c t i o n of m a t e r i a l removed from the bond area o f cone s c a l e s and ob t a i n e d m e l t i n g temperatures o f 45°C and 46°C f o r the two t e s t s . Thompson (45) found, i n 1969, t h a t 140°F (60°C) was the lowest temperature a t which a l l cone s c a l e s o f lod g e p o l e p i n e would open. C r o s s l e y (13) i n 1956 s t u d i e d the opening of lodge- p o l e p i n e cones under the i n f l u e n c e o f s o l a r r a d i a t i o n . He found t h a t a i r temperatures up to. 3.5 f e e t above the ground o f 80°F (26.7°C) c o u l d r e s u l t i n s u f f i c i e n t h e a t i n g t o break s e r o t i n o u s s e a l s p r o v i d e d t h a t d i r e c t s u n l i g h t or r e f l e c t e d r a d i a t i o n from some nearby s u r f a c e c o u l d add a d d i t i o n a l heat. S p e c i a l treatment of s e r o t i n o u s cones t o break the r e s i n o u s bond o f the s c a l e s has been proposed i n a few i n s t a n c e s . Hebb (24) i n 1954, r e p o r t e d complete opening of the cones of pond p i n e a f t e r a s a c k f u l o f the cones were p l a c e d i h a tank of b o i l i n g water f o r "a moment". The e f f e c t on seed v i a b i l i t y was not r e p o r t e d . Meseman (32) i n 1973, r e p o r t e d improved seed r e c o v e r y from j a c k p i n e and c e r t a i n o t h e r s p e c i e s by submerging the cones i n a s o l u t i o n c o n s i s t i n g o f one p a r t Javex (hypo- c h l o r i t e b l e a c h i n g s o l u t i o n ) t o 20 p a r t s water. The s o l u t i o n was h e l d a t a temperature o f 150°F (65.5°C) and cones were 20. t r e a t e d f o r 1 to 2 minutes, a f t e r which they were d r i e d a t 145°F f o r 6 t o 12 hours. No r e f e r e n c e was made to the e f f e c t o f t h i s treatment on seed v i a b i l i t y . B e a u f a i t (10) i n 1960 s t u d i e d the e f f e c t s o f h i g h temperatures on the cones and seeds o f j a c k p i n e . He found t h a t cones opened i n a matter of seconds when p l a c e d i n an oven a t temperatures up t o 1300°F (704°C). Nyborg and B r i s b i n (37) i n 1974, e v a l u a t e d the thermal g r a d i e n t w i t h i n l o d g e p o l e p i n e cones b r i e f l y heated by a b l a s t of hot a i r . They found t h a t 15 seconds o f treatment was r e q u i r e d t o break the s e a l s o f cones s u b j e c t e d t o an a i r b l a s t o f 312°F (155°C), and t h a t the temperature r i s e of the seeds a t the time o f s e a l r e l e a s e was 14°F (7.8°C). A mathematical t r a n s i e n t heat flow a n a l y s i s i n d i c a t e d t h a t seed temperatures f o r such treatments c o u l d be f a i r l y a c c u r a t e l y e s t i m a t e d . 3. S c a l e Opening Mechanism The opening mechanism o f the s c a l e s o f c o n i f e r cones, and the r e l a t i o n s h i p between s c a l e d e f l e c t i o n and cone m o i s t u r e content has been d i s c u s s e d i n the l i t e r a t u r e o f s e v e r a l i n v e s t i g a t o r s (17, 19, 21, 26, 33). Although these r e p o r t s have d e a l t w i t h s e v e r a l species,, none have d e a l t s p e c i f i c a l l y w i t h lodgepole p i n e . Harlow, Cote and Day (21), i n 1964, s t u d i e d the c e l l s t r u c t u r e o f the cone s c a l e t i s s u e o f f i v e s p e c i e s o f p i n e , and r e p o r t e d t h a t cone s c a l e s are made up of two d i s t i n c t l a y e r s . The i n n e r o r a b a x i a l l a y e r i s made up of wood f i b r e s which 21. extend from the cone a x i s , w h i l e the outer or a d a x i a l l a y e r i s made up of short r e c t a n g u l a r t h i c k w a l l e d c e l l s . They found t h a t d u r i n g d r y i n g , the f i b r o u s t i s s u e d i s p l a y e d n e g l i g i b l e lengthwise shrinkage, w h i l e the outer t i s s u e shrank, upon d r y i n g , from 10 to 36 percent, depending upon the sp e c i e s . A comprehensive study of t h i s mechanism was conducted by A l l e n and Wardrop (3) i n 196 4, and d e a l t w i t h the opening and shedding of female cones of Pinus r a d i a t a . I n order t o e x p l a i n the hygroscopic mechanism of the a d a x i a l v a s c u l a r t i s s u e and the a b a x i a l sclerenchyma t i s s u e of the cone s c a l e , they s t u d i e d these t i s s u e s by means of e l e c t r o n microscopy. They found t h a t i n the v a s c u l a r t i s s u e s , the c e l l u l o s e m i c r o f i b r i l s , which make up the s t r u c t u r a l p o r t i o n o f the c e l l w a l l s , are o r i e n t e d l a r g e l y i n l i n e w i t h the l o n g i - t u d i n a l a x i s of the s c a l e . In the sclerenchyma t i s s u e s , however, the m a j o r i t y of the m i c r o f i b r i l s of the i n d i v i d u a l c e l l s are o r i e n t e d p a r a l l e l to the transverse a x i s of the s c a l e s . They reported t h a t s i n c e shrinkage of c e l l w a l l m a t e r i a l i s g r e a t e s t i n a d i r e c t i o n p e r p e n d i c u l a r to the d i r e c t i o n of m i c r o f i b r i l o r i e n t a t i o n , the d i f f e r e n t i a l shrinkage during d r y i n g of the two l a y e r s of cone s c a l e s can be explained i n terms of the predominant o r i e n t a t i o n of the m i c r o f i b r i l s w i t h i n these two t i s s u e s . The l o n g i t u d i n a l shrinkage d u r i n g d r y i n g of the va s c u l a r t i s s u e of the cone s c a l e s measured i n t h i s i n v e s t i g a - t i o n was reported t o be 1.5%, whil e t h a t of the sclerenchyma t i s s u e of the same s c a l e s was found to be 15%. 4. Cone Opening a t M a t u r i t y The opening o f the seed b e a r i n g cones of most c o n i f e r s p e c i e s i s • a t t r i b u t e d t o the d i f f e r e n t i a l s h r i n k a g e between the a d a x i a l v a s c u l a r t i s s u e and the a b a x i a l sclerenchyma of the cone s c a l e (3, 21, 30). A l l e n and Wardrop (3), i n 196 4, s t u d i e d the p h y s i o l o g y of cone maturation and opening, and the subsequent shedding o f the s c a l e s . They d e f i n e d f o u r stages i n the maturation o f the cones o f Pinus r a d i a t a , and examined the anatomy o f the cones i n each s t a g e . They found t h a t u n t i l the development of the cone was complete, the moisture content o f f r u i t i n g cones was e s t a b l i s h e d by the water economy of the o v e r a l l t r e e . Upon matur a t i o n , however, a b a r r i e r of r e s i n develops i n the t i s s u e at the base of the cone peduncle which i n h i b i t s the movement of moisture from the branch i n t o the cone. T h i s i s o l a t i o n of the cone from i t s source of moisture l e a v e s the cone t o be dependent upon atmospheric c o n d i t i o n s f o r the e s t a b l i s h m e n t of i t s moisture c o n t e n t . 5. R e s i s t a n c e to Thermal Damage Although many r e f e r e n c e s (2, 7, 10, 13, 41, 47) have been made throughout, the l i t e r a t u r e r e g a r d i n g the maximum temperature which c o n i f e r seeds can t o l e r a t e , l i t t l e d e t a i l has been p r o v i d e d with r e s p e c t to the type and d u r a t i o n of the treatment r e f e r r e d t o . A d d i t i o n a l l y , r e s e a r c h e r s have shown l i t t l e concurrence on the safe l i m i t f o r high temperature treatment of seeds. Most authors d e a l i n g w i t h t h i s aspect have c i t e d a s i n g l e - m o r t a l i t y - temperature f o r vari o u s species, w i t h no reference to seed moisture content or du r a t i o n of high temperature treatment. Research on a g r i c u l - t u r a l seeds has shown, however, t h a t the l e t h a l temperature f o r seeds i s dependent upon both moisture content and d u r a t i o n of h e a t i n g . A l l e n (2) i n 195 7 reported t h a t Douglas f i r seed which had been precured showed no i l l e f f e c t when k i l n d r i e d at 122°F (50°C) but at 140°F (60°C) l o s s e s i n v i a b i l i t y of 20% or more were observed. Immature cones showed heavy l o s s e s when d r i e d at 122°F a f t e r p r e c u r i n g , and at 104°F (40°C) when placed i n t o the k i l n i n a green s t a t e . Woodforde and Lawton (52) found i n 1965 t h a t t r e a t - ments of one hour d u r a t i o n at temperatures as low as 47°C i n i t i a t e d depression of the germination of c a r r o t seeds. This t h r e s h o l d temperature was reported t o be s l i g h t l y r a i s e d as seed moisture content was reduced to approximately 12%. B e a u f a i t (10) i n 1960 s t u d i e d high temperature treatment f o r the purpose of breaking the serotinous s e a l s of jack pine cones. He reported t h a t when cones were t r e a t e d at 1300°F (704°C) the seeds i n cones which i g n i t e d d i d not remain v i a b l e but t h a t the seeds i n cones which d i d not i g n i t e e x h i b i t e d very l i t t l e r e d u c t i o n i n germinative c a p a c i t y . Watson (48) i n 1965 s t u d i e d the h e a t i n g o f wheat i n s e a l e d c o n t a i n e r s . He found t h a t a temperature o f 140°F (60°C) f o r 6 hrs caused complete l o s s of v i a b i l i t y i f moisture content was above 15% w.b., but i f the moisture c o n t e n t was l e s s than 9%, a temperature o f 140°F f o r 10 hours caused no r e d u c t i o n i n g e r m i n a t i o n . C o n t i n u i n g t h i s work i n 1970, Watson (49) r e p o r t e d t h a t the r a t e of l o s s o f g e r m i n a t i o n c a p a c i t y was a l o g a r i t h m i c function of time, and t h a t the r e d u c t i o n was a t a slow r a t e i n the i n i t i a l phase of treatment, and took on a more r a p i d r a t e a f t e r a p e r i o d of treatment. The r a t e of l o s s o f g e r m i n a t i o n c a p a c i t y and the time to i n i t i a t e r a p i d r e d u c t i o n o f g e r m i n a t i o n c a p a c i t y was found to be dependent upon seed m o i s t u r e c o n t e n t and treatment temperature. He confirmed t h i s r e l a t i o n s h i p by r e p l o t t i n g data r e p o r t e d by o t h e r i n v e s t i g a t o r s u s i n g o t h e r seed s p e c i e s . He a l s o c l a r i f i e d the f a c t t h a t the concept o f a " k i l l i n g temperature" and " i n i t i a t i o n o f damage" are i l l d e f i n e d terms which d i d not r e f l e c t the time-temperature r e l a t i o n s h i p of the l o s s of v i a b i l i t y o f seeds. 6. R e s i s t a n c e t o Mechanical Damage Mechanical damage i n seeds i s r e p o r t e d by Mohsenin (34) to be due e i t h e r t o e x t e r n a l f o r c e s under s t a t i c or dynamic c o n d i t i o n s o r to i n t e r n a l f o r c e s caused by changes i n moisture or temperature. The f o r c e s of e x t e r n a l o r i g i n which cause damage t o seeds g e n e r a l l y a r i s e from the v a r i o u s 25. h a n d l i n g treatments employed i n the h a r v e s t i n g , s e p a r a t i n g and c l e a n i n g p r o c e s s e s . Damage from e x t e r n a l f o r c e s which r e s u l t s i n l o s s of v i a b i l i t y occurs e i t h e r i n the form o f a b r a s i o n o f the seed coat d u r i n g h a n d l i n g , o r as r u p t u r e of the seed c o a t and/or the i n t e r n a l seed s t r u c t u r e by e x c e s s i v e s t r e s s e s . These f o r c e s may be e i t h e r s t a t i c o r dynamic. The a b i l i t y o f seeds to r e s i s t m echanical damage has been shown (34) t o be v e r y dependent upon m o i s t u r e c o n t e n t . Each seed s p e c i e s has an optimum moisture c o n t e n t f o r h a n d l i n g . Above the optimum, the seeds are s o f t and e a s i l y i n c u r p l a s t i c d e formation, w h i l e below the optimum the seeds are hard and i n c u r b r i t t l e f a i l u r e . Gregg e t a l . (20) i n d i c a t e t h a t t h i s optimum moisture content l i e s between 10 and 16 p e r c e n t wet b a s i s f o r most seeds. Mohsenin a l s o r e p o r t e d t h a t the mechanical s t r e n g t h of b i o l o g i c a l m a t e r i a l s , and hence the r e s i s t a n c e t o mechanical damage, i s up t o f i v e times g r e a t e r under dynamic l o a d i n g than i t i s under s t a t i c l o a d i n g c o n d i t i o n s . The main source o f mechanical damage i n c u r r e d by f o r e s t t r e e seeds which are k i l n e x t r a c t e d i s from the a c t i o n of the dewinging treatment (17). T h i s i s most severe on those s p e c i e s whose seed wings are an i n t e g r a l p a r t o f the seed c o a t . M e c h a n i c a l damage may a l s o be i n c u r r e d d u r i n g o t h e r t r e a t m e n t s , i n c l u d i n g e x t r a c t i o n by tumbling and most o t h e r c l e a n i n g o p e r a t i o n s . The s u s c e p t i b i l i t y t o mechanical damage o f seeds s t i l l c o n t a i n e d i n t h e i r cones was i n v e s t i g a t e d i n 1958 by L y l e and Gilmore (31).who worked w i t h r i p e cones o f l o b l o l l y p i n e (Pinus t a e d a ) . They found t h a t as long as seeds remained i n t h e i r o r i g i n a l p o s i t i o n i n s i d e cones, any a c t i o n s h o r t o f c r u s h i n g the cones d i d not a f f e c t the germi n a t i o n p e r c e n t o f - t h e seeds. The s u s c e p t i b i l i t y t o mechanical damage o f seeds e x t r a c t e d by t h r e s h i n g i s r e p o r t e d by B a i n e r e t a l (6) t o be a f u n c t i o n of the seed moisture content, the p e r i p h e r a l t h r e s h i n g c y l i n d e r speed, and the c o n f i g u r a t i o n and adjustment of the c y l i n d e r and concaves.. Damage i s lowest at low c y l i n d e r speeds, but the t h r e s h i n g e f f e c t i v e n e s s i s a l s o reduced a t lower speeds. They a l s o s t a t e t h a t t h e r e appears t o be an optimum rub-bar and concave c o n f i g u r a t i o n f o r each s p e c i e s , a n d t h a t the use of rubber covered s u r f a c e s reduces the amount o f seed damage under a g i v e n s e t of c o n d i t i o n s . 7. S t r e s s R e l a x a t i o n o f Cone S c a l e s Baldwin (7) i n 19 42 d e s c r i b e d the poor r e l e a s e o f seeds of some cones which i s caused by inadequate cone s c a l e d e f l e c t i o n d u r i n g k i l n d r y i n g . He r e p o r t e d t h a t t h i s c o n d i t i o n i s most p r e v a l e n t i n s e r o t i n o u s cones which have d r i e d p r i o r t o k i l n e x t r a c t i o n , and termed the c o n d i t i o n "case h a r d e n i n g " . To improve seed y i e l d o f these cones he recommended t h a t they be soaked i n water, then d r i e d once more i n the k i l n . The term "case hardening" as used i n the above cont e x t i s not compatible w i t h the use o f t h i s term i n d e s c r i b - i n g the s u r f a c e hardening treatment o f metal components o r the development of r e s i d u a l s t r e s s e s w i t h i n wood d u r i n g d r y i n g (34). The c o n d i t i o n d e s c r i b e d by Baldwin and o t h e r s (29, 32, 47) i s more a c c u r a t e l y i d e n t i f i e d as a c o n d i t i o n caused by s t r e s s r e l a x a t i o n i n the cone s c a l e s . S t r e s s r e l a x a t i o n i s d e f i n e d (34) as the process whereby s t r e s s e s i n a m a t e r i a l s u b j e c t e d t o a co n s t a n t s t r a i n o r deformation undergo a decay w i t h time. The c l a s s i c a l study o f rh e o l o g y i n d i c a t e s t h a t . s t r e s s r e l a x a t i o n takes p l a c e o n l y i n v i s c o e l a s t i c m a t e r i a l s and t h a t v i r t u a l l y a l l b i o l o g i c a l m a t e r i a l s f a l l i n t o t h i s c l a s s i f i c a t i o n . The p r o c e s s of s t r e s s r e l a x a t i o n i n the s c a l e s o f s e r o t i n o u s cones takes p l a c e w h i l e the cones have a low moisture content which causes s t r e s s e s w i t h i n the s c a l e s . These s t r e s s e s a c t t o open the s c a l e s , but because o f the s e r o t i n o u s bond the s c a l e s are h e l d i n the c l o s e d p o s i t i o n and hence remain i n a s t r e s s e d c o n d i t i o n . While cones are h e l d i n t h i s s t r e s s e d c o n d i t i o n , the cone s c a l e m a t e r i a l deforms and 28. the s c a l e d e f l e c t i n g s t r e s s e s d i m i n i s h w i t h i n the s c a l e . The r e s u l t of t h i s process i s t h a t cones whose s c a l e t i s s u e has undergone a s t r e s s r e l a x a t i o n are unable t o d e f l e c t outward t o t h e i r f u l l extend a f t e r the s e a l s are broken. 8. Thermal P r o p e r t i e s The thermal p r o p e r t i e s o f the cones of Pinus banksiana were i n v e s t i g a t e d i n 1961 by Lee and B e a u f a i t (28). T h e i r work was c a r r i e d out on young cones one and two years o l d , and on o l d cones over t h r e e years o l d , which had a moisture content of 6% + 1% wet b a s i s . . Using a c y l i n d r i c a l s h e l l a n a l y s i s , they found the thermal c o n d u c t i v i t y o f young and o l d cones t o be r e s p e c t i v e l y , 0.123 and 0.114 BTU's per hour, f o o t , degree F. U s i n g a t h i n p l a t e a n a l y s i s , the thermal c o n d u c t i v i t y o f young cones was found t o be 0.113. The thermal d i f f u s i v i t y o f young and o l d cones was found t o be 0.0073 and 0.0090 square f e e t per hour r e s p e c t i v e l y . The heat t r a n s f e r a n a l y s i s c a r r i e d out i n 1973 by Nyborg and B r i s b i n (37) on the f l a s h h e a t i n g o f l o d g e p o l e p i n e cones was done u s i n g a thermal c o n d u c t i v i t y o f 0.07 BTU's per hour, f o o t , degree F, and a thermal d i f f u s i v i t y o f 0.005 square f e e t per hour. The temperature o f seeds d u r i n g f l a s h h e a t i n g determined by t h i s a n a l y s i s was found t o c o r r e l a t e w e l l w i t h measured seed temperatures. 29. 9. D r y i n g Rate The k i l n treatment of s e r o t i n o u s cones serves two f u n c t i o n s , namely t o break the r e s i n o u s bonds a n d to dry the cone s c a l e s t o cause t h e i r outward d e f l e c t i o n and the r e l e a s e of the seeds. As r e p o r t e d i n Chapter I I , k i l n temperatures i n excess or 140°F (60°C) are f r e q u e n t l y used f o r the e x t r a c t i o n of s e r o t i n o u s cones, w h i l e temperatures up to t h i s v a l u e are used f o r non-serotinous cones. In a d d i t i o n t o e l e v a t e d dry b u l b temperatures, the wet bulb temperature of k i l n a i r i s f r e q u e n t l y e l e v a t e d by the i n j e c t i o n o f steam or water m i s t (41, 47). The e l e v a t i o n of the dry bulb temperature to a p o i n t which e f f e c t s s e a l breakage i s a necessary s t e p i n seed e x t r a c t i o n by the c o n v e n t i o n a l k i l n ^ t u m b l e r method. Once s e a l breakage has been a c h i e v e d , however, temperatures i n the o r d e r o f 140°F are no l o n g e r r e q u i r e d because s a t i s - f a c t o r y cone d r y i n g can be achieved a t much lower temperatures. The p r a c t i c e of adding water vapor to the k i l n a i r i n o r d e r t o reduce the d r y i n g r a t e from t h a t e s t a b l i s h e d by the heated k i l n a i r i s i n c o n s i s t e n t w i t h e f f e c t i v e d r y i n g , seed q u a l i t y and energy economy. A study o f the mass t r a n s f e r process whereby water i s moved from a h y g r o s c o p i c m a t e r i a l i n t o the a i r (25, 40) r e v e a l s t h a t the d r y i n g r a t e i s s o l e l y dependent upon the magnitude of the vapor p r e s s u r e d i f f e r e n t i a l between the wet m a t e r i a l and the immediately a d j a c e n t a i r . In o t h e r words, 30. the d r y i n g o f cones i s dependent upon the d i f f e r e n t i a l i n vapor p r e s s u r e between the water w i t h i n the m a t e r i a l and the vapor p r e s s u r e of the a i r i n the boundary l a y e r surrounding the wet cone s u r f a c e . The e f f e c t o f i n j e c t i n g water vapor i n t o the k i l n a i r i s t o i n c r e a s e the vapor p r e s s u r e i n the boundary l a y e r a d j a c e n t t o the cones. The same e f f e c t can be achieved e i t h e r by r e d u c i n g the v e l o c i t y o f a i r over the cones which reduces the vapor p r e s s u r e g r a d i e n t a t the s u r f a c e o f the cones o r by r e d u c i n g the dry b u l b temperature of the a i r i n the k i l n . The l a t t e r i s c l e a r l y more d e s i r a b l e because i t reduces the danger o f thermal damage to the seed, and a l s o reduces the q u a n t i t y of heat r e q u i r e d . I t can be seen t h a t the most s u i t a b l e cone d r y i n g p r o c e s s i s achieved by keeping t h e wet b u l b temperature low, the a i r c i r c u l a t i o n r a t e h i g h , and by minimal r a i s i n g of the dry b u l b temperature of the k i l n a i r . These c o n d i t i o n s can be a c h i e v e d by e l i m i n a t i n g the i n j e c t i o n o f water, i n c r e a s i n g the r a t e o f a i r exchange, and by r a i s i n g the dry b u l b tempera- t u r e o n l y s u f f i c i e n t l y t o p r o v i d e an a c c e p t a b l e r a t e of d r y i n g In the case of s e r o t i n o u s cones, the b r e a k i n g of the s e a l s p r i o r t o k i l n treatment e l i m i n a t e s the need f o r h i g h temperatures w i t h i n the k i l n . A l t e r n a t i v e l y , the dry bulb temperature of the k i l n can be lowered as soon as s e a l b r e a k i n g i s achieved so t h a t e x c e s s i v e d r y i n g r a t e s and the r e s u l t i n g seed damage are avoided. 31. VII. PRELIMINARY INVESTIGATIONS A number of preliminary tests were c a r r i e d out on lodgepole pine cones i n order to determine c e r t a i n basic physical properties and c h a r a c t e r i s t i c s . These data were u t i l i z e d i n the development of subsequent t e s t i n g programs and procedures. These preliminary studies are discussed i n d i v i d u a l l y below. 1. I d e n t i f i c a t i o n and Description of Cones A l l tests were conducted on cones of i n t e r i o r lodgepole pine (Pinus contorta var. l a t i f o l i a Engleni) which were i d e n t i f i e d by the B r i t i s h Columbia Forest Service seed l o t c l a s s i f i c a t i o n as Nelson 3-3. The cones were obtained from a commercially harves ted seed l o t and thus were a representative sample of the typ of cones of t h i s species which would be processed by a commercial seed extractory. The cones varied i n length from approximately 0.75 i n (1.9 cm) to 2 i n (5.1 cm) and had an o v e r a l l c o n i c a l p r o f i l e varying between approximately 25 and 65 degrees. The appearance of the cones was consistent with the graphic description presented i n the B.C.F.S. lodgepole pine cone c o l l e c t i n g guide (4). A cross-sectional view of three t y p i c a l cones i s shown i n Figure 4, and the location of the serotinous cone scale seals i s i d e n t i f i e d . Figure 5 shows a view of the adaxial and abaxial surfaces of t y p i c a l cone sc a l e s . 2. Preparation of Material The cones used for a l l tests were c o l l e c t e d during the f a l l of 1973, and were dried on outdoor racks to a moisture content of approximately 25% wet basis. The cones were then mixed to ensure uniformity of samples for subsequent t e s t i n g . The mixing technique consisted of la y e r i n g approxi- mately 15 bushels of cones in t o a large p i l e and sho v e l l i n g them over into a new p i l e by l i f t i n g cones from the side of the o r i g i n a l p i l e and layering them across the top of the hew p i l e . This layering process was repeated seven times, a f t e r which, cones meeting the Class 1 s p e c i f i c a t i o n s of the B.C. Forest Service iodgepole Pine Cone C o l l e c t i n g Guide (4) were sorted out. Class 1 cones consist of those cones maturing i n the year of harvest, and having a l l scales sealed. The cones for subsequent te s t i n g were then placed i n sealed containers and stored at 34°F (1°C). 3. Degree of Serbtiny of Cone Seed Lot The degree of serotiny of the cones under study was determined at the time of cone sorting by selecting, a sample of the cones and c l a s s i f y i n g them according to t h e i r condition of serotiny. These cones were grouped i n t o : (i) cones having a l l of t h e i r scales open, ( i i ) cones having a po r t i o n of t h e i r 33. Figure 5. Location of serotinous seals on abaxial (above) and adaxial surfaces of t y p i c a l cone scales. 34. s c a l e s open, and ( i i i ) cones having a l l t h e i r s c a l e s s e a l e d i n the c l o s e d p o s i t i o n . A group of t y p i c a l p a r t i a l l y opened cones i s shown.in F i g u r e 6. Of the 425 cones i n the sample e v a l u a t e d , the p e r - centage of cones f a l l i n g i n t o each group was found t o be as f o l l o w s : (i) Cones f u l l y unsealed 2.2% ( i i ) Cones p a r t i a l l y u n s e a l e d 1.2% ( i i i ) Cones f u l l y s e a l e d 96.6% The cones used f o r a l l subsequent t e s t i n g i n t h i s p r o j e c t were p r e s o r t e d and o n l y completely s e a l e d cones were s t u d i e d . 4. V i a b i l i t y of Seeds by L o c a t i o n i n the Cone To i d e n t i f y the v i a b i l i t y of seeds from u n t r e a t e d cones, a c o n t r o l group of 100 cones was manually opened to e x t r a c t and count a l l seeds i n the cones. The e x t r a c t i o n was accomplished by removing i n d i v i d u a l s c a l e s from the cones u s i n g s i d e - c u t t i n g p l i e r s as shown i n F i g u r e 7. As each s c a l e was broken f r e e o f the s e r o t i n o u s s e a l and p e e l e d back, the seeds thus exposed were c o l l e c t e d f o r t e s t i n g . During the e x t r a c t i o n p rocess the seeds were sepa r a t e d i n t o three groups, a c c o r d i n g to t h e i r p o s i t i o n i n the cone. The three groups were (i) those seeds o r i g i n a t i n g toward the base or peduncle end of the cone, ( i i ) those o r i g i n a t i n g i n the c e n t r a l p o r t i o n of the seed b e a r i n g r e g i o n 35. F i g u r e 6. T y p i c a l p a r t i a l l y opened cones from c o m m e r c i a l l y c o l l e c t e d cone l o t s . F i g u r e 7. Technieque f o r manual opening of s e a l e d cones. 36. of the cone, and ( i i i ) those o r i g i n a t i n g near the t i p o f the cone. The d i v i s i o n p o i n t between groups was a r b i t r a r i l y chosen to p r o v i d e p r o p o r t i o n s o f the t o t a l seed q u a n t i t i e s of a p p r o x i - mately 25%, 50% and 25% r e s p e c t i v e l y . The number of seeds from each cone going i n t o the t h r e e groups was r e c o r d e d and i s * r e p o r t e d i n Table A-1 i n the Appendix. The v i a b i l i t y o f seeds from each of these groups was subsequently determined, and the g e r m i n a t i o n p e r c e n t f o r each group was o b t a i n e d . These data are shown i n T a b l e 1. The r e s u l t s of t h i s t e s t i n d i c a t e t h a t a s l i g h t l y h i g h e r percentage of seeds a t the e x t r e m i t i e s o f the seed b e a r i n g r e g i o n o f these cones are empty, but f i l l e d seed show e s s e n t i a l l y the same ge r m i n a t i o n p e r c e n t i n the t h r e e r e g i o n s of the cones. TABLE 1. SEED VIABILITY BY LOCATION IN CONE Lower Mid T i p T o t a l T o t a l Seeds 592 1076 724 2392 % of Seeds F i l l e d 83.0% 88.0% 79.3% 84.1% Number o f F i l l e d Seeds 491 . 947 574 2012 % F i l l e d Seed Producing Normal Germinants 91.2% 90. 9% 91.6% 91.1% Number of V i a b l e Seeds 448 861 526 1835 % T o t a l Seed Producing Normal Germinants 75.5% 80.0% 72.6% 76.7% Number of V i a b l e Seeds/Cone 4.5 8.6 5.3 18.4 Weighted Average Germination Percent f o r ' T o t a l Sample — 91 — 76 . 6 % f o r f i l l e d Seed f o r "rotal Seed Tables whose numbers are p r e f i x e d by the l e t t e r A appear i n Appendix A. 37. 5. V i a b i l i t y o f Seeds w i t h Respect to Ease of E x t r a c t i o n The r e l a t i o n s h i p between the v i a b i l i t y o f Lodgepole p i n e seeds and the ease of t h e i r e x t r a c t i o n a f t e r s e a l b r e a k i n g was i n v e s t i g a t e d . The purpose of t h i s was to determine whether or not the more d i f f i c u l t t o remove seeds had a lower v i a b i l i t y than the e a s i l y e x t r a c t e d seeds. In t h i s t e s t , approximately two hundred c l a s s 1 cones were removed from s t o r a g e a t 34°F (T°C) and were immersed f o r t h i r t y seconds i n water having a temperature o f 205°F (96°C). The cones were then d r i e d a t room temperature f o r f o u r days and manually e x t r a c t e d . Each cone was i n d i v i d u a l l y t r e a t e d to e x t r a c t f i r s t the e a s i l y removed seeds,then the d i f f i c u l t t o e x t r a c t seeds. Those seeds which were removed from t h e i r cone by f i v e l i g h t taps on the t i p end of the open cone, w h i l e i t was h e l d w i t h the s c a l e s opening downwards, were c o n s i d e r e d t o be e a s i l y e x t r a c t e d seeds. Those seeds remaining i n the cones a f t e r t h i s treatment were c o n s i d e r e d t o be d i f f i c u l t - t o - e x t r a c t seeds, and were recovered by manually d i s s e c t i n g the cones by i n d i v i d u a l l y t e a r i n g the s c a l e s from the cone to f r e e the seeds. The l i g h t t a p p i n g treatment used i n t h i s t e s t e x t r a c t e d approximately t h r e e - q u a r t e r s of the t o t a l seed con- t a i n e d by the cones. The seeds remaining i n the cones a f t e r the t a p p i n g treatment were found to be mainly c o n c e n t r a t e d i n 38. the lower o r b a s a l end of the seed b e a r i n g r e g i o n of the cones. The r e s u l t s of t h i s t e s t , as shown i n Table I I i n d i c a t e t h a t the e a s y - t o - e x t r a c t seeds o f Lodgepole p i n e have a h i g h e r percentage of f i l l e d seed, and a s l i g h t l y h i g h e r germination percent of t h e f i l l e d seeds. The f a c t t h a t the l e s s e a s i l y e x t r a c t e d seeds have a lower p o r t i o n of f i l l e d seeds concurs w i t h the o b s e r v a t i o n t h a t these seeds tend to be con- c e n t r a t e d i n the lower r e g i o n of the cones where the p r e v i o u s t e s t found a h i g h e r p o r t i o n of empty seeds. TABLE I I GERMINATION PERCENT FOR EASE OF EXTRACTION TEST % of F i l l e d % Germination % Ctermination Seeds i n of f i l l e d of Sample Seeds Total Seeds E a s i l y E x t r a c t e d Seed 83.8 98.7 82.7 D i f f i c u l t t o E x t r a c t Seed 70.1 93.2 65.3 6. V i a b i l i t y o f K i l n T r e a t e d Seeds In order to assess the s e n s i t i v i t y of Lodgepole p i n e seed t o thermal damage d u r i n g c o n v e n t i o n a l k i l n e x t r a c t i o n , v i a b i l i t y t e s t s were c a r r i e d out on seeds recovered from cones t r e a t e d f o r v a r i o u s p e r i o d s i n a c o n s t a n t temperature oven. A temperature of 140°F _ 3° (60°C + 1.5°) c o r r e s - , ponding to temperatures commonly used f o r the k i l n e x t r a c t i o n of s e r o t i n o u s cones, was used f o r t h i s p r e l i m i n a r y i n v e s t i g a t i o n . Groups of cones having an i n i t i a l moisture content o f 23% w.b. were oven treated f o r p e r i o d s r a n g i n g from 4 to 72 h r s . 39. The g e r m i n a t i o n p e r c e n t o f these groups are t a b u l a t e d i n Table A-2 i n Appendix A, and the p l o t o f v i a b i l i t y a g a i n s t treatment time i s shown i n F i g u r e 8. The r e s u l t s of t h i s t e s t i n d i c a t e t h a t seed germina- t i o n p e r c d n t i s not a p p r e c i a b l y reduced by d r y i n g cones from a moisture c o n t e n t o f 25% wet b a s i s i n a n o n - c i r c u l a t i n g oven f o r p e r i o d s up t o 72 hours. <D o u CD ft CJ O -rH 4-> rd a •rl e u 0) 0 100 _ 80 60 40 20 20 40 60 Treatment Time Hrs. 80 100 F i g u r e 8. Curve of g e r m i n a t i o n p e r c e n t w i t h treatment time f o r cones d r i e d i n a 140°F (6QOC) oven. 40. 7. Moisture Content A l l cone moisture content d e t e r m i n a t i o n s made throughout t h i s i n v e s t i g a t i o n were c a r r i e d out a c c o r d i n g to, the method o f a n a l y s i s f o r p l a n t m a t e r i a l s recommended by the A s s o c i a t i o n o f A g r i c u l t u r a l Chemists (5), where the samples were d r i e d f o r two hours a t a temperature of 135°C. Moisture contents are r e p o r t e d on a wet b a s i s , which i s determined by weight a c c o r d i n g t o the f o l l o w i n g e q u a t i o n : M o i s t u r e Content (wet b a s i s ) = Moxsture • . X 100%. Dry Matter + M o i s t u r e The average o v e r a l l moisture c o n t e n t o f cones r e c e i v e d f o r t e s t i n g was approximately 25% wet b a s i s . These cones were immediately s t o r e d i n s e a l e d c o n t a i n e r s , hence a l l subsequent t e s t s were conducted on cones whose i n i t i a l moisture content was very c l o s e t o t h i s v a l u e . 41. V I I I . INVESTIGATIONS CONDUCTED ON PHYSICAL PROPERTIES OF CONES E i g h t i n v e s t i g a t i o n s were conducted t o determine the p h y s i c a l p r o p e r t i e s and c h a r a c t e r i s t i c s c o n s i d e r e d t o be i n f l u e n t i a l i n the e x t r a c t i o n of lodgepole p i n e cones. These are d e t a i l e d i n d i v i d u a l l y below. 1. E q u i l i b r i u m M oisture Content of Cones The e q u i l i b r i u m moisture content d u r i n g d r y i n g was determined a t s e v e r a l p o i n t s over a range o f r e l a t i v e humidi- t i e s from 11.3% to 100%. Determinations were made by p l a c i n g a number o f cones over s a t u r a t e d s a l t s o l u t i o n s i n s e a l e d c o n t a i n e r s (Figure 9) and a l l o w i n g them t o stand a t room temperature f o r t h i r t y days t o achieve e q u i l i b r i u m . The s p e c i f i c s a l t s used and the r e p o r t e d e q u i l i b r i u m r e l a t i v e humidity f o r each (50) are as f o l l o w s : Barium c h l o r i d e 90.2% Ammonium c h l o r i d e 78% Ammonium n i t r a t e 61% Sodium i o d i d e 39% Potassium a c e t a t e 23% L i t h i u m c h l o r i d e 11.3%. D i s t i l l e d water was used t o e s t a b l i s h a r e l a t i v e humidity of 100%. P r i o r t o be i n g p l a c e d i n the s e a l e d chambers, the s e r o t i n o u s s e a l s were broken by immersing the cones i n b o i l i n g water f o r approximately 20 seconds. T h i s a llowed the cones t o open, thus exposing a g r e a t e r s u r f a c e a r e a , and p e r m i t t i n g a more r a p i d exchange of m o i s t u r e . Figure 9. Containers for equilibrium moisture content determination. The equilibrium moisture content of cones during drying i s shown i n Table A-3 i n the Appendix and i s plotted i n Figure 10 below. The range of values determined, and the shape of the drying curve for these cones i s t y p i c a l of most b i o l o g i c a l materials. • 5-i •H +J cn W (C •H J Q O S -P | •H U Xi - P - H C rH (1) •H 4-> 0 t r 0 w U 20 40 60 80 % Relative Humidity 100 Figure 10. Equilibrium moisture content during drying of lodgepole pine cones. 43. 2. M e l t i n g P o i n t D e t e r m i n a t i o n f o r S e r o t i n o u s Bonds The b r e a k i n g of the r e s i n o u s bond h o l d i n g s e r o t i n o u s cones c l o s e d i s e s s e n t i a l f o r seed e x t r a c t i o n . C o n v e n t i o n a l e x t r a c t i o n r e q u i r e s k i l n temperatures s u f f i c i e n t l y h i g h t o cause m e l t i n g o f the bond m a t e r i a l , but not so h i g h as t o cause damage t o the seeds. The m e l t i n g p o i n t temperature of the s e r o t i n o u s s e a l s of lodgepole p i n e cones, assumed t o be the temperature at which s c a l e s e p a r a t i o n takes p l a c e , was determined. Young cones, h a r v e s t e d i n the year i n which they matured, and weathered cones s e v e r a l y e a r s o l d we're s t u d i e d . Cones to be t e s t e d were c u t i n two by sawing the cones a x i a l l y . One p a r t o f each cone was p l a c e d i n a c l o s e d g l a s s j a r which was immersed i n a c o n s t a n t temperature water ba t h , as shown i n F i g u r e 11. S i x t y cones from each age c l a s s were t e s t e d . The cone h a l v e s were allowed t o reach e q u i l i b r i u m temperature w i t h the bath water, and were i n d i v i d u a l l y examined t o d e t e c t s c a l e s e p a r a t i o n . Cone h a l v e s which had undergone s e a l s e p a r a t i o n on the m a j o r i t y of the s c a l e s i n the seed b e a r i n g r e g i o n were considered, t o have reached the s e a l m e l t i n g temperature and were removed and counted. The j a r s c o n t a i n i n g the cones were then r e t u r n e d t o the bath and the temperature was i n c r e a s e d by approximately 0.5°C. T h i s p r o c e s s was c a r r i e d out on t h r e e to f o u r hour i n t e r v a l s f o r the d u r a t i o n o f the t e s t s . 44. Figure 11. Apparatus for determina- t i o n of seal melting temperatures. The number of cones whose scales were released at each test temperature i s shown i n Table A-4. The res u l t s of these tests indicate a r e l a t i v e l y wide range of tempera- tures over which the seals are broken. The mean temperature at which new cones opened was found to be 52.5°C with a standard deviation of + 5.7°C. The mean temperature at which old cones opened was found to be 54.5°C with a standard deviation of + 5.8°C. 45. 3. S c a l e D e f l e c t i o n Angle v s . Moi s t u r e Content The r e l a t i o n s h i p between moisture c o n t e n t and the angle o f cone s c a l e d e f l e c t i o n a f t e r cone opening was s t u d i e d by e v a l u a t i n g the maximum s c a l e d e f l e c t i o n angles on i n d i v i d u a l cones. The cone s c a l e angles were measured, by o p t i c a l l y o b s e r v i n g the angular o r i e n t a t i o n o f a r e f e r e n c e p l a ne c u t i n t o the t i p o f the cone s c a l e s p r i o r t o s e a l breakage. The r e f e r - ence plane was made by g r i n d i n g a f l a t s u r f a c e on the umbo of each s c a l e t o be measured. Cones t o be s t u d i e d were f i t t e d w i t h an alignment p i n which was i n s e r t e d i n t o a s m a l l h o l e d r i l l e d i n t o the cone c o r e . T h i s p i n served as the angular r e f e r e n c e f o r bot h the c u t t i n g o f the f l a t s u r f a c e on the s e a l e d cones, and the measuring o f the s c a l e d e f l e c t i o n angle o f the opened cones. F i g u r e 12 shows t y p i c a l cones prepared i n t h i s way, both b e f o r e and a f t e r s c a l e d e f l e c t i o n . The f l a t s u r f a c e on the s c a l e umbos used f o r d e t e c t i n g s c a l e d e f l e c t i o n was c u t by means of a t a b l e saw f i t t e d w i t h a s i d e c u t t i n g g r i n d i n g wheel. During c u t t i n g , the alignment p i n was h e l d p a r a l l e l t o the c u t t i n g f a c e by a machine t o o l h o l d e r . The umbo of a l l s u i t a b l e s c a l e s l o c a t e d around the mid p o i n t o f the cones under study were s u r f a c e d i n t h i s manner. The apparatus used t o measure s c a l e angles i s shown i n F i g u r e 14 and c o n s i s t s o f a m o d i f i e d d r a f t i n g machine F i g u r e 12. Cones p r e p a r e d f o r s c a l e d e f l e c t i o n m easurement b e f o r e and a f t e r o p e n i n g . F i g u r e 1 3 . A l i g n m e n t o f c r o s s h a i r w i t h g r o u n d s c a l e s u r f a c e . F i g u r e 14. A p p a r a t u s f o r m e a s u r i n g c o n e s c a l e d e f l e c t i o n a n g l e s . and a b i n o c u l a r microscope. The s c a l e of the d r a f t i n g machine i s r e p l a c e d w i t h a "vee-block" clamp which g r i p s the alignment p i n and o r i e n t s the a x i s of the cone p a r a l l e l t o the c r o s s h a i r of the microscope when the d r a f t i n g machine head was i n the zero p o s i t i o n . S c a l e angles are read from the d r a f t i n g machine v e r n i e r a f t e r the head and the a t t a c h e d cone are r o t a t e d t o o r i e n t the edge view of the ground s u r f a c e o f each s c a l e , p a r a l l e l t o the microscope c r o s s h a i r , as shown i n F i g u r e 13. S c a l e d e f l e c t i o n angles can, i n t h i s way, be measured t o the n e a r e s t degree. The datum r e p o r t e d t o r e p r e s e n t each cone i n t h i s study was the average d e f l e c t i o n angle of the f i v e t o n i n e s c a l e s having the g r e a t e s t d e f l e c t i o n on t h a t cone. The s c a l e s measured f o r t h i s purpose were chosen a f t e r the cones opened, and were l o c a t e d i n a band around the cone near i t s midpoint. Groups of s i x t e e n cones were used f o r each t e s t . Cones f o r s c a l e angle measurement were removed from s t o r a g e and t h e i r s e a l s broken by hot water treatment. By the method d e s c r i b e d i n S e c t i o n 1, above, they were then brought to the wet b a s i s e q u i l i b r i u m moisture c o n t e n t s shown i n T a b l e I I I . The maximum s c a l e d e f l e c t i o n data f o r cones a t each moisture c o n t e n t are shown i n T a b l e s A-5 t o A - l l . These are summarized i n Table I I I , and p l o t t e d i n F i g u r e 15. 48. From F i g u r e 15 i t i s apparent t h a t the onset o f s c a l e d e f l e c t i o n o f open l o d g e p o l e p i n e cones o c c u r s as the wet b a s i s moisture content i s reduced below approximately 25%. Seale d cones i n t h i s m oisture range a c q u i r e s t r e s s e s which tend t o open the s c a l e s . TABLE I I I . SCALE DEFLECTION ANGLE AT VARIOUS CONE MOISTURE CONTENTS E q u i l i b r i u m M o i s t u r e Average Maximum Cone S c a l e Content.,. Wet B a s i s . D e f l e c t i o n Angle 28.3% 0° 21.2% 8.5° + 3.8° 17.4% 31.7° + 7.8° 13.5% 50.0° + 9.4° 9.5% 62.6° + 11.5° 7.5% 71.8° + 12.8° 4.8% 86.6° + 13.1° Oven Dry 97.0° + 15.7° E q u i l i b r i u m M o i s t u r e Content (%) F i g u r e 15. Maximum s c a l e angle v s . e q u i l i b r i u m m o i s t u r e content f o r n o n - s t r e s s r e l a x e d cones. 4. S c a l e D e f l e c t i o n Angles o f S t r e s s Relaxed Cones S t r e s s r e l a x a t i o n occurs i n the s c a l e s o f s e a l e d s e r o t i n o u s cones while the cones are a t a moisture content which would cause outward s c a l e d e f l e c t i o n i f the s e r o t i n o u s s e a l s d i d not r e s t r a i n such movement. T h i s occurs i n lodge- p o l e p i n e cones a t moisture contents below approximately 25% wet b a s i s . The degree t o which cone s c a l e d e f l e c t i o n i s impaired by s t r e s s r e l a x a t i o n i s i l l u s t r a t e d i n F i g u r e 16. The cones shown were s t o r e d f o r one month a t the moisture contents noted, and a f t e r t h e i r s e a l s were r e l e a s e d by hot a i r , they were brought t o a moisture content o f approximately 10% wet b a s i s . The c r o s s s e c t i o n a l view of s t r e s s r e l a x e d and n o n - s t r e s s r e l a x e d cones shown i n F i g u r e 17 i n d i c a t e s the form o f s c a l e f l e x u r e and the width of the seed e x i t i n g path f o r cones i n both c o n d i t i o n s . The e f f e c t o f s t r e s s r e l a x a t i o n on s c a l e d e f l e c - t i o n was i n v e s t i g a t e d by s t u d y i n g cones whose s c a l e s were kept i n a s t r e s s e d c o n d i t i o n f o r a p e r i o d o f one month. . For t h i s study, cones were prepared f o r s c a l e angle measurement as d e s c r i b e d above, but the s e r o t i n o u s s e a l s were not broken u n t i l the end of the s t r e s s r e l a x a t i o n p e r i o d . A t e s t group of twenty cones was allowed t o dry t o approximately 50. §#*§##$ &Z 11% (7Z ZIZ 2,5 £ Z8% S/Z Figure 16. Cones showing t y p i c a l degree of opening when unsealed and brought to 10% M.C. after one month of storage at indicated moisture contents. »i|inpp|Hii|iiii|iiii|iiii|iiii|iiii|iiii|ini|ini|iiii »i/pipiiinrfiii|fH Stress Relaxed Not Stress Relaxed Figure 17. Cross section of t y p i c a l open stress relaxed and non-stress relaxed cones. 51. 10% moisture content, wet b a s i s , and was s t o r e d f o r one month a t t h i s moisture content. The cones were then t r e a t e d w i t h hot a i r t o break the s c a l e s , and were allowed t o stand f o r f o u r days d u r i n g which s c a l e d e f l e c t i o n took p l a c e . The maximum s c a l e d e f l e c t i o n angles were measured, and the moisture content determined. In o r d e r t o determine the permanence o f the r e d u c t i o n i n s c a l e d e f l e c t i o n caused by s t r e s s r e l a x a t i o n , an attempt was made t o r e v i v e the s c a l e f l e x i n g a b i l i t y o f the cones d e s c r i b e d above. The cones were soaked i n water f o r s i x hours and were allowed t o dry t o a moisture content c l o s e t o t h a t o f the e a r l i e r t e s t . The maximum s c a l e d e f l e c t i o n angles were again measured, and the moisture c o n t e n t determined. F i n a l l y , the e f f e c t o f s t r e s s r e l a x a t i o n on s c a l e d e f l e c t i o n and i t s e l i m i n a t i o n by r e w e t t i n g , was e v a l u a t e d a t the oven dry c o n d i t i o n . The cones from the above two treatments were subsequently oven d r i e d a t 105°C, and the s c a l e angles once more measured. The s c a l e d e f l e c t i o n data f o r the above t h r e e treatments are r e p o r t e d i n Tables A-12, A-13, and A-14 r e s p e c t i v e l y . The mean value o f maximum s c a l e d e f l e c t i o n of the s t r e s s r e l a x e d cones was found t o be 20.3° a t a moisture con- t e n t o f 9.9% wet b a s i s . T h i s compares t o d e f l e c t i o n o f approximately 60° f o r cones a t the same moisture c o n t e n t but which d i d not undergo s t r e s s r e l a x a t i o n . The e f f e c t o f r e w e t t i n g these s t r e s s r e l a x e d cones was t o permit them t o d e f l e c t t o an average angle o f 62.6° when they were r e d r i e d t o a moisture content o f 11.1% wet b a s i s . When these cones were d r i e d t o an oven dry c o n d i t i o n , the average d e f l e c t i o n angle was found t o be 93.6°. These r e s u l t s are p l o t t e d i n F i g u r e 15 as p o i n t s R l , R2, and R3 r e s p e c t i v e l y . From t h i s , i t i s apparent t h a t s t r e s s r e l a x a - t i o n reduces the opening a b i l i t y o f s e a l e d l o d g e p o l e p i n e cones, and t h a t the opening a b i l i t y can be almost c o m p l e t e l y r e s t o r e d by r e w e t t i n g o f the a f f e c t e d cones. 5. Degree o f Seed Release w i t h Respect t o S c a l e D e f l e c t i o n As d i s c u s s e d e a r l i e r , the degree o f cone s c a l e d e f l e c t i o n i n f l u e n c e s the percentage o f seeds which can be e x t r a c t e d from cones by tumbling. T h i s r e l a t i o n s h i p was e v a l u a t e d by e x t r a c t i n g the f r e e seeds from a group o f cones a t s e v e r a l moisture l e v e l s d u r i n g t h e i r d r y i n g , and i d e n i f y - i n g the mean s c a l e d e f l e c t i o n angle a t each p o i n t . A group o f twenty cones was removed from s t o r a g e and prepared f o r s c a l e angle measurement as d e s c r i b e d above. They were then t r e a t e d w i t h hot a i r to r e l e a s e the r e s i n o u s s e a l s , and were allowed t o p a r t i a l l y dry under room c o n d i t i o n s . The seeds were then e x t r a c t e d by tapping the i n v e r t e d cones f i v e times i n t o a t r a y , and the cone s c a l e d e f l e c t i o n angles were immediately measured. This process was repeated at four moisture contents. The f i n a l measurements were made on oven dry cones, and the remaining seeds were removed from the cones. The maximum cone s c a l e d e f l e c t i o n data, and the number of seeds recovered a t each p o i n t are r e p o r t e d i n Tables A-15, to A-18. The r e s u l t s of t h i s t e s t are p l o t t e d i n F i g u r e 18 which shows the cumulative percentage of t o t a l seed e a s i l y e x t r a c t e d a g a i n s t the maximum s c a l e angle. From t h i s p l o t , i t can be seen t h a t maximum s c a l e angles of approximately 100° are r e q u i r e d i n order to achieve complete seed e x t r a c t i o n by a m i l d tumbling treatment. I H CO I 100 80 60 40 - 20 - _L JL F i g u r e 18, 20 40 60 80 100 Cone Scale Angle (Degrees) Seed e x t r a c t i o n vs. cone s c a l e angle. 54. 6. Hot Water S e a l Breaking The b r e a k i n g o f s e r o t i n o u s s c a l e s e a l s of l o d g e p o l e p i n e cones by means of momentarily immersing the cones i n hot water was i n v e s t i g a t e d from two p o i n t s o f view. These were (i) the e f f e c t i v e n e s s i n a c h i e v i n g s e a l breakage, and ( i i ) the e x t e n t o f thermal damage t o the seeds as r e v e a l e d by reduced seed v i a b i l i t y . Hot water immersion was c a r r i e d out by submerging groups of one hundred cones, c o n t a i n e d i n a mesh basket, i n water heated i n a steam k e t t l e . The basket, shown i n F i g u r e 19 was covered so t h a t the cones were f o r c e d down i n t o the water f o r complete immersion. Continuous movement of the submerged basket ensured t h a t the cones were surrounded by water a t tank temperature. At the end of the s p e c i f i e d treatment time, the cones were l i f t e d from the water and immediately s p i l l e d onto a d r a i n i n g r a c k . The cones were d r i e d i n i n d i v i d u a l mesh bottom d r y i n g racks (Figure 20) i n an a i r c o n d i t i o n e d room which was h e l d a t 72°F (22.2°C) and having a r e l a t i v e h umidity ra n g i n g between 44% and 56%. D r y i n g was a i d e d by the use of a c i r c u l a t i n g fan which moved the a i r over the d r y i n g r a c k s . A l l t e s t s were c a r r i e d out u s i n g water a t a o o o o temperature of 205 F + 2 (96.1 C+ 1 ), and immersion time was v a r i e d from 10 t o 120 seconds. The i n i t i a l temperature of the cones was 34°F (1°C) and the i n i t i a l cone m o i s t u r e 55. Figure 20. Cone drying racks. content f o r these t e s t s was 25% ± 3%, wet b a s i s . A f t e r d r y i n g u n t i l the degree of s e a l breaking.on each cone was c l e a r l y e v i d e n t by the open or c l o s e d p o s i t i o n of the cone s c a l e s , the cones were s o r t e d i n t o the f o l l o w i n g c l a s s i f i c a t i o n s : (i) F u l l y opened — c o n e s i n which a l l s c a l e s e a l s i n the seed b e a r i n g r e g i o n of the cone were broken. ( i i ) P a r t i a l l y opened — cones on which o n l y a p o r t i o n of the s c a l e s i n the seed b e a r i n g r e g i o n were broken. ( i i i ) F u l l y c l o s e d — cones on which no s c a l e s e a l s i n the seed b e a r i n g r e g i o n of the cone were broken. A l l seeds from opened cones were subsequently e x t r a c - te d f i r s t by t a p p i n g , then by manually removing the s c a l e s i n the manner d e s c r i b e d e a r l i e r i n t h i s r e p o r t . Germination t e s t s were conducted on seeds from each group, and the v i a b i l i t y was r e p o r t e d as the percentage of f i l l e d seeds p r o d u c i n g normal germinants. The data used f o r the c o n t r o l i n t h i s t e s t were those r e p o r t e d i n S e c t i o n V I I (4) of t h i s r e p o r t which i n d i c a t e d a v i a b i l i t y o f 91.2% of the f i l l e d seeds p r o d u c i n g normal germinants. The r e s u l t s o f the cone opening t e s t s and the v i a b i l i t y o f the seeds so t r e a t e d are shown i n Table IV. From Table IV i t can be seen t h a t immersion times of 20 seconds, or more r e s u l t e d i n over 90% of the cones b e i n g completely unsealed. Longer treatment o f cones d i d not TABLE IV. EFFECT OF HOT AND WATER IMMERSION SEED VIABILITY ON CONE OPENING Inmersion Time Seconds Cones Fully Closed Cones Partia l l y Opened Cones Fully Opened Seed * V i a b i l i t y 10 35 33 32 95.2% 15 15 28 57 96. 8% 20 2 8 90 9 8.2% 25 2 5 93 97.0% 27.5 2 9 89 97.5% 30 2 4 94 98.0% 40 2 3 95 97.5% 60 1 2 97 90.0% 120 0 0 100 0% * Expressed as % of f i l l e d seed p r o d u c i n g normal germinants IMMERSION CONDITIONS: Water Temperature : 205°F ± 2°F (96.1°C ± 1°C) I n i t i a l Cone Temperature : 34°F (1 PC) I n i t i a l Cone Moisture Content: 25% ± 2% (w.b.) 58. s i g n i f i c a n t l y improve s e a l breakage without i n c u r r i n g a r e d u c t i o n i n v i a b i l i t y . From Table IV, i t can a l s o be seen t h a t the seed v i a b i l i t y showed no a p p r e c i a b l e d e v i a t i o n from t h a t o f the c o n t r o l group f o r a l l treatments up to 40 seconds i n dura- t i o n . The v i a b i l i t y was s l i g h t l y lower f o r those cones which r e c e i v e d a 60 second treatment, but immersion o f s e a l e d cones i n 205°F water f o r 120 seconds r e s u l t e d i n complete seed m o r t a l i t y . 7. Flame Treatment S e a l B r e a k i n g The b r e a k i n g o f the s e r o t i n o u s s e a l s by p a s s i n g cones through an open flame was i n v e s t i g a t e d . As i n t h e case o f hot water immersion treatment, flame t r e a t i n g was s t u d i e d from the p o i n t of view of s e a l b r e a k i n g e f f e c t i v e n e s s and thermal seed damage. The apparatus shown i n F i g u r e 21 was c o n s t r u c t e d t o flame t r e a t cones by c a u s i n g them to tumble down an i n c l i n e d tube i n t o which a flame was i n t r o d u c e d . The apparatus c o n s i s t e d of a f o u r i n c h diameter i n s u l a t e d tube which was i n c l i n e d a t angles between t h i r t y and f o r t y degrees. A f e e d chute d i r e c t e d manually metered cones i n t o the upper end o f the tube and a c o l l e c t i n g s c r e e n gathered the cones as they emerged from the lower end. Heat was s u p p l i e d by a propane t o r c h which was o r i e n t e d t o d i r e c t i t s flame i n t o the lower end of the tube. 59. Temperatures w i t h i n the tube were c o n t r o l l e d by m a i n t a i n i n g a c o n s t a n t gas p r e s s u r e of the f u e l b e i n g d e l i v e r e d t o the t o r c h . The temperature o f the tube a t a p o i n t s i x f e e t from the lower end was monitored w i t h an i r o n - c o n s t a n t a n thermocouple to ensure u n i f o r m i t y of t r e a t - ment c o n d i t i o n s . The range of temperatures a t t h i s p o i n t d u r i n g the v a r i o u s treatments was from 900°F (482°C) to 1350°F (732°C). Treatment d u r a t i o n was c o n t r o l l e d by v a r y i n g the tube l e n g t h between f i f t e e n and t h i r t y f e e t by the a d d i t i o n or removal o f pipe s e c t i o n s , and a l s o by v a r y i n g the angle of i n c l i n a t i o n o f the tube. Treatment times from f o u r t o twelve seconds were used. A f t e r the flame treatment, the cones were allowed to c o o l and p l a c e d on mesh bottomed racks to a i r dry. A f t e r r e a c h i n g approximately 10% moisture content, the cones were e v a l u a t e d i n the same manner as were the hot water immersed cones as d e s c r i b e d i n the p r e v i o u s s e c t i o n o f t h i s r e p o r t . T e s t i n g was c a r r i e d out on groups of 100 cones which had an i n i t i a l moisture content o f 25% ± 2% wet b a s i s , and had an i n i t i a l temperature of 34°F (1°C). The r e s u l t s of the cone opening 1 t e s t s and the v i a b i l i t y o f the seeds t r e a t e d i n the flame tube are p r e s e n - ted i n Table V. From t h e t a b l e , i t can be seen t h a t the degree o f cone opening achieved i n c r e a s e d w i t h i n c r e a s i n g 60. Figure 21. Flame treating apparatus. flame treatment i n t e n s i t y , and that complete seal breaking was accomplished by a treatment at 6.5 seconds at a reference temperature of 1280°F (693°C). From the table, i t can also be seen that the seed v i a b i l i t y did not suff e r an appreciable reduction by flame treatment severe enough to e f f e c t complete seal breakage. 8. E f f e c t of Moisture Content on Seal Breaking Effectiveness Experience from the above f l a s h heating tests suggests that cone moisture content influences the effectiveness 61. TABLE V. EFFECT OF FLAME TREATMENT ON CONE OPENING AND SEED VIABILITY Average Treatment Time Seconds Flame Tube Reference Temp. °F Cones Fully Closed Cones Part i a l l y Opened Cones Fully Opened Seed * V i a b i l i t y 4.5 1155 75 12 13 ** 5.0 1280 66 16 18 93.9% 5.5 1195 28 24 48 97.3% 7.5 1160 35 10 55 98.0% 5.1 1345 8 15 77 95.6% 6.5 1252 0 6 94 94.9% 6.5 1280 0 o 100 93.4% * Expressed as % of f i l l e d seeds producing normal germinants ** I n s u f f i c i e n t seeds r e l e a s e d f o r v i a b i l i t y d e termination TREATMENT CONDITIONS: I n i t i a l Cone Temperature : 34°F (1°C) I n i t i a l Cone Moisture Content: 25% ± 2% (w.b.) of heat treatment f o r the purpose o f b r e a k i n g s e r o t i n o u s cone s c a l e s e a l s . The mechanism b e l i e v e d t o cause t h i s e f f e c t was the degree o f s t r e s s w i t h i n the cone s c a l e s t e n d i n g to d e f l e c t the s c a l e s outward which i s p r e s e n t i n the s c a l e s a t the time the r e s i n o u s s e a l i n g m a t e r i a l i s melted. The e f f e c t o f such s t r e s s e s a t t h i s time would be t o s p r i n g the s c a l e s s l i g h t l y a p a r t w h i l e the r e s i n o u s s e a l i s melted. The r e s u l t o f t h i s would be t h a t upon r e s o l i d i f i c a t i o n of the r e s i n , the bond s u r f a c e s would no l o n g e r be i n c o n t a c t w i t h each o t h e r , and hence the r e s i n c o u l d not re-bond them. T h i s phenomenon was i n v e s t i g a t e d by e v a l u a t i n g the e f f e c t i v e n e s s o f a s p e c i f i c s e a l b r e a k i n g treatment on cones a t d i f f e r e n t m o i s t u r e c o n t e n t s , thus having d i f f e r e n t l e v e l s of s c a l e d e f l e c t i n g s t r e s s . Three groups of 100 cones were pr e p a r e d f o r s e a l b r e a k i n g as f o l l o w s : one group was soaked i n water f o r 24 , hours to r a i s e the moisture content above 30% wet b a s i s , the second group was d r i e d a t room temperature t o a m o i s t u r e con- t e n t of approximately 10% wet b a s i s , and the t h i r d group was t r e a t e d as they came from s t o r a g e a t approximately 25% M.C. wet b a s i s . Each group o f cones was brought t o a temperature of 34°F (1°C) and was immersed f o r 27.5 seconds i n water a t 205°F (96.1°C). A f t e r d r y i n g a t room temperature, the cones were c l a s s i f i e d i n t o the t h r e e c a t e g o r i e s of cone opening d e s c r i b e d i n e a r l i e r t e s t s . 6 3 . The results of t h i s t e s t aire shown i n Table VI and indicate that seal breakage effectiveness for a given heat treatment increases with a decrease i n cone moisture content. TABLE VI. SEAL BREAKING RESULTS AT THREE MOISTURE CONTENTS 1 . Cones heat treated at moisture content i n excess of 3 0 % wet basis: F u l l y opened 3 2 % P a r t i a l l y opened 5 4 % Closed 1 4 % 2 . Cones heat treated at moisture content of approxi- mately 2 5 % wet basis: F u l l y opened 89% • P a r t i a l l y opened 9% Closed 2% 3 . Cones heat treated at moisture content of approxi- mately 1 0 % wet basis: F u l l y opened 9 8% . P a r t i a l l y opened 2% Closed 0 % 64. P A R T T W O D E V E L O P M E N T O F P R O C E S S I N G T O O L S IX. PROPOSED MECHANICAL EXTRACTION SYSTEM The second phase of t h i s p r o j e c t i n v o l v e s the s y s t e m a t i c d e s i g n , f a b r i c a t i o n , and t e s t i n g of a mechanical c o n i f e r seed e x t r a c t i o n system. The proposed system c o n s i s t s of a p o r t a b l e machine which operates a t the r e g i o n a l seed c o l l e c t i o n s t a t i o n s t o m e c h a n i c a l l y separate seeds from cones on a continuous flow b a s i s . The purpose o f t h i s system i s t o p r o v i d e a more e f f i c i e n t and economical means of c o n i f e r seed e x t r a c t i o n which r e q u i r e s a lower l a b o u r i n p u t and which e l i m i n a t e s the t r a n s p o r t a t i o n of l a r g e q u a n t i t i e s o f waste cone m a t e r i a l t o c e n t r a l e x t r a c t o r i e s . The o p e r a t i n g p r i n c i p l e of t h i s system was d e s c r i b e d i n Chapter V and flow c h a r t s comparing i t w i t h a c o n v e n t i o n a l k i l n e x t r a c t i o n system were p r e s e n t e d . The s u c c e s s f u l development of the proposed e x t r a c - t i o n equipment i s dependent upon the achievement o f a number of s p e c i f i c o p e r a t i o n a l requirements, as l i s t e d below: (a) Must p r o v i d e a h i g h seed r e c o v e r y r a t e w i t h minimum seed damage. (b) Must be capable of e x t r a c t i n g seed from both s e r o t i n o u s and n o n - s e r o t i n o u s cones. (c) Must be capable of o p e r a t i n g s a t i s f a c t o r i l y on cones over a reasonable range of moisture c o n t e n t . (d) Must p r o v i d e a p r o d u c t i o n r a t e commensurate w i t h the economic o p e r a t i o n of the system. (e) Must operate w i t h a minimum manpower i n p u t . (f) Must be e a s i l y t r a n s p o r t e d on a l i g h t duty t r u c k . (g) Must be e a s i l y s e t up and taken down a t each o p e r a t i n g s i t e . (h) Must have a simple, d u r a b l e d e s i g n so t h a t breakdowns are minimized and the machine i s easy t o s e r v i c e i n the f i e l d . The f i n d i n g s o f the p r e l i m i n a r y i n v e s t i g a t i o n s o f the p h y s i c a l p r o p e r t i e s o f lodgepole p i n e cones, as p r e v i o u s l y d i s c u s s e d , i n d i c a t e t h a t the s e r o t i n o u s s c a l e s e a l s of t h i s s p e c i e s can be e a s i l y broken by f l a s h h e a t i n g , w i t h l i t t l e damage to the seeds. The b r e a k i n g of s e r o t i n o u s s e a l s p r i o r t o mechanical e x t r a c t i o n w i l l undoubtedly reduce the s e v e r i t y o f the mechanical treatment r e q u i r e d t o a c h i e v e f u l l e x t r a c t i o n , and hence w i l l reduce the l i k e l i h o o d of mechanical seed damage. For t h i s reason a thermal s e a l b r e a k i n g process was i n c l u d e d i n the d e s i g n of the proposed mechanical e x t r a c t i o n system. The development o f each of the two primary t o o l s o f t he proposed e x t r a c t i o n system i s d e t a i l e d i n the f o l l o w i n g s e c t i o n s o f t h i s r e p o r t . 67. X. DEVELOPMENT OF SEROTINOUS SEAL BREAKING TOOL 1. P r e l i m i n a r y A n a l y s i s Experience from the study of the p h y s i c a l p r o p e r t i e s of l o d g e p o l e p i n e cones i n d i c a t e d t h a t b r e a k i n g the s e r o t i n o u s s e a l s would s i g n i f i c a n t l y reduce the degree of s e v e r i t y of treatment necessary t o m e c h a n i c a l l y e x t r a c t the seeds of such cones. A d d i t i o n a l l y , the use of an e f f e c t i v e s e a l b r e a k i n g d e v i c e can r e s u l t i n more e f f i c i e n t e x t r a c t i o n of s e r o t i n o u s cones u s i n g the c o n v e n t i o n a l k i l n e x t r a c t i o n p r o c e s s . Study of the p h y s i c a l p r o p e r t i e s of s e r o t i n o u s cones a l s o i n d i c a t e d t h a t the bonds h o l d i n g the cone s c a l e s i n a c l o s e d p o s i t i o n can be broken by both mechanical f r a c t u r e of the s e a l and by m e l t i n g o f the r e s i n o u s bonding m a t e r i a l . A p r e l i m i n a r y a n a l y s i s of mechanical s e a l b r e a k i n g by c r u s h i n g and thermal s e a l b r e a k i n g by f l a s h h e a t i n g i s o u t l i n e d below. (i) C r u s h i n g — Mechanical f r a c t u r i n g of s c a l e s e a l s can be achieved by s l i g h t l y c r u s h i n g the cones thereby c a u s i n g the bonds to f a i l as a r e s u l t of s t r e s s e s which exceed the y i e l d s t r e s s of the bond m a t e r i a l . The d e f l e c t i o n o f t h i s c r u s h i n g a c t i o n must be a p p l i e d evenly over the l e n g t h of the t a p e r e d cone. Furthermore, c r u s h i n g must be a p p l i e d a t s e v e r a l p o i n t s around the p e r i p h e r y of the cone and must be c a r r i e d out a f t e r the cone has been d r i e d t o a f a i r l y low m o isture c o n t e n t , i n o r d e r t o ensure the r e l e a s e o f a l l cone s c a l e s . 68. The e f f e c t i v e n e s s of s e a l b r e a k i n g by t h i s method was q u a n t i t a t i v e l y e v a l u a t e d by c r u s h i n g a number of cones wi t h a h y d r a u l i c p r e s s as shown i n F i g u r e 22. Cones having a range of moisture contents were t e s t e d . S e a l breakage was achieved i n a l l cones t e s t e d , but as cone moisture i n c r e a s e d , the degree of d e f l e c t i o n r e q u i r e d t o achieve s e a l breakage i n c r e a s e d s h a r p l y . Cones below approximately 10% M.C. wet b a s i s were almost completely opened by a s m a l l d e f l e c t i o n a p p l i e d a t two or t h r e e p o i n t s around the cones. Cones above 20% M.C. wet b a s i s , however, r e q u i r e d severe c r u s h i n g , which probably damaged the seeds, i n o r d e r t o open most of the s c a l e s . The complexity of automated equipment necessary to o r i e n t i n d i v i d u a l cones and p r o v i d e t h i s treatment a t s e v e r a l angular p o s i t i o n s , t o the wide range cone s i z e and p r o f i l e which e x i s t s i n commercially h a r v e s t e d cones renders t h i s o p e r a t i n g p r i n c i p l e u n s u i t a b l e . Furthermore, the low p r o d u c t i o n r a t e i n h e r e n t i n a system which t r e a t s cones i n d i v i d u a l l y , and the p o s s i b i l i t y of seed damage, f u r t h e r reduce the s u i t a b i l i t y o f t h i s , method. ( i i ) F l a s h h e a t i n g — Breaking of s e r o t i n o u s s e a l s by the a p p l i c a t i o n of heat has t r a d i t i o n a l l y been the method used f o r the purpose of e x t r a c t i n g seed from such cones. In the p a s t , t h i s treatment has been employed d u r i n g normal k i l n d r y i n g by the use of h i g h e r k i l n temperatures. Figure 22. Seal breaking by crushing. Flash heating of cones for the purpose of breaking the seals of lodgepole pine cones was investigated i n part one of t h i s report. Based on the information and experience gained from that study, two prototype seal breaking tools were fabricated for te s t i n g . The prototype tools designed were a hot water immersing device, and a flame treating device. Both of these tools were designed for continuous flow operation and were used to evaluate the s u i t a b i l i t y of t h e i r respective performance for use i n a portable mechanical conifer seed extraction system and for use with present k i l n extraction f a c i l i t i e s . The analysis, design and testing of these two prototype f l a s h heating tools i s described below. 2. Heat Transfer Analysis of Flash Heated Cones In order to evaluate the fl a s h heating process of cones, a heat transfer analysis was carr i e d out to i d e n t i f y the thermal g r a d i e n t s w i t h i n f l a s h heated cones and the r e s u l t i n g i n t e r n a l temperatures d u r i n g the p r o c e s s . The concept o f f l a s h h e a t i n g w i t h v e r y h i g h tempera- t u r e s f o r the purpose o f s e a l b r e a k i n g i s based on the p r i n c i p l e t h a t r a p i d h e a t i n g o f the out e r r e g i o n o f the cone w i l l a chieve m e l t i n g o f the r e s i n o u s s e a l b e f o r e the c e n t r a l r e g i o n s which c o n t a i n the seeds are heated much above t h e i r i n i t i a l tempera- t u r e . T h i s s i t u a t i o n i s p o s s i b l e because o f the r e l a t i v e p o s i t i o n o f the s e a l s and the seeds w i t h i n the cone, and the r e l a t i v e l y low thermal c o n d u c t i v i t y of the cone s c a l e t i s s u e s . The maximum temperature t o which the seeds are exposed i s , however, a t t a i n e d a f t e r the cones have been removed from the heat source. T h i s occurs because the h i g h l e v e l of thermal energy p r e s e n t i n the o u t e r r e g i o n s o f the cone a t the end o f the h e a t i n g p e r i o d moves through the cone t o e s t a b l i s h e q u i l i b r i u m c o n d i t i o n s . I f the cones are s u b j e c t e d t o c o o l i n g immediately upon emerging from heat treatment, much of t h i s energy w i l l be d i s s i p a t e d t o the sur r o u n d i n g s , so t h a t the e f f e c t o f the inward moving wave of heat w i l l not cause a p p r e c i a b l e f u r t h e r i n c r e a s e i n the seed temperature. A q u a n t i t a t i v e a n a l y s i s o f t h i s heat t r a n s f e r p r o - cess was c a r r i e d out by employing the techniques used f o r t r a n s i e n t heat flow i n s t a t i o n a r y systems which are heated by c o n v e c t i o n , and which have h i g h i n t e r n a l temperature g r a d i e n t s . These techniques are o u t l i n e d by K r e i t h (27) , Rohsenow and Choi (42). The a n a l y s i s c o n s i s t s of d e f i n i n g the f u n c t i o n a l r e l a t i o n s h i p among a d i m e n s i o n l e s s r a t i o d e f i n i n g the temperature g r a d i e n t , a f u n c t i o n a l r e l a t i o n s h i p d e s c r i b i n g the r a t i o o f i n t e r n a l and e x t e r n a l thermal r e s i s t a n c e s , and a r a t i o r e l a t i n g time of h e a t i n g t o thermal energy v e l o c i t y i n the m a t e r i a l . Due t o the complex nature o f these r e l a t i o n - s h i p s , a n a l y s i s i s c a r r i e d out u s i n g g r a p h i c a l s o l u t i o n s which have been formulated f o r c e r t a i n geometric shapes under i d e a l c o n d i t i o n s o f homogenity, u n i f o r m i t y and a c c u r a t e l y known m a t e r i a l p r o p e r t i e s . The r e l a t i o n s h i p of these c h a r a c t e r i s t i c s i s g i v e n by the f o l l o w i n g e q u a t i o n : T - T x Y CO T - T. = f (Bi, FO, L ). (1) o C O More s p e c i f i c a l l y t h i s i s hL •• a t Y = f (k ' 2 L x L) (2) where: Y = d i m e n s i o n l e s s r a t i o o f the change o f i n t e r n a l energy due to h e a t i n g , w i t h r e l a t i o n t o the s t o r e d i n t e r n a l energy. = temperature of any p o i n t a t time t . 72. = temperature of surrounding f l u i d . T Q = i n i t i a l temperature o f body h = u n i t s u r f a c e conductance of body L = c h a r a c t e r i s t i c dimension of body ( r a d i u s ) k = thermal c o n d u c t i v i t y o f m a t e r i a l of body a = thermal d i f f u s i v i t y o f m a t e r i a l o f body t = time measured from b e g i n n i n g o f pr o c e s s x = dimension of l e n g t h , l o c a t i n g the p o i n t under study B i = B i o t number, d i m e n s i o n l e s s heat t r a n s f e r r a t i o . Fo = F o u r i e r number, di m e n s i o n l e s s time r a t i o . G r a p h i c a l s o l u t i o n s t o these r e l a t i o n s h i p s have been prepared f o r i d e a l shapes, i n c l u d i n g sphere, i n f i n i t e s l a b s , i n f i n i t e c y l i n d e r s , semi i n f i n i t e s l a b s , e t c . (27, 42). In order to apply t h i s technique t o the f l a s h h e a t i n g of cones the f o l l o w i n g assumptions are made: - Sealed cones can be an a l y z e d as an i n f i n i t e c y l i n d e r h a v i n g a diameter equal t o t h a t o f the cone a t the p o i n t under study. - Sealed cones are homogeneous having u n i f o r m p h y s i c a l p r o p e r t i e s w i t h i n the r e g i o n of the cone under study. - The heat of f u s i o n o f the r e s i n o u s s e a l i s n e g l i g i b l e . - The f i l m c o e f f i c i e n t ( u n i t surface conductances) remains constant. - The f l u i d , i n t o which the cones are immersed maintains a constant temperature. - Heat i s t r a n s m i t t e d to the cones by convection only. The heat t r a n s f e r a n a l y s i s c a r r i e d out was based on the average dimensional data taken from a number of cones con- s i d e r e d to represent the t y p i c a l s i z e and shape of cones from the cone l o t under study. The data used are l i s t e d below and shown i n Figure 23. Cone leng t h 1.65 i n . (4.2 cm) Maximum diameter .70 i n . (1.8 cm) Diameter at top of seed b e a r i n g region .42 i n . (1.1 cm) Diameter at base of seed b e a r i n g r e g i o n .70 i n . (1.8 cm) Seal depth .060 i n . (0.15 cm) Depth of seed .140 i n . (0.36 cm) Figure 23. Dimensional data of cone for heat transfer analysis. The thermal p r o p e r t i e s f o r cones used f o r t h i s a n a l y s i s was t h a t r e p o r t e d by Lee and B e a u f a i t (28) f o r young cones of Pinus banksiana, and are as f o l l o w s : Thermal c o n d u c t i v i t y k = 0.123 BTU/hr f t F° 2 Thermal d x f f u s i v i t y = 0.0073 f t / h r . The u n i t s u r f a c e conductance f o r cones i n hot water and hot gas, based on t y p i c a l v a l u e s f o r comparable c o n d i t i o n s (42), was assumed t o be, r e s p e c t i v e l y , 100 BTU/hr f t 2 F ° , and 2 n 20 BTU/hr f t F . C a l c u l a t i o n s were c a r r i e d out t o determine the time r e q u i r e d t o r a i s e the temperature of the m a t e r i a l a t the r e s i n o u s s e a l t o i t s m e l t i n g p o i n t , which was e a r l i e r determined t o be 52.5°C (126°F). The f i r s t s e r i e s of c a l c u l a t i o n s was made t o i d e n t i f y the c o n d i t i o n s when newly matured cones are f l a s h heated from an i n i t i a l temperature of 34°F (1°C) by immersion i n water a t 205°F (96.1°C). Using d i m e n s i o n a l data f o r c o n d i t i o n s a t the t i p of the seed b e a r i n g r e g i o n o f the cone, the c a l c u l a t i o n s are as f o l l o w s : 1 = k _ .123 X 12 B i h r " 100 X .21 " - 0 / 0 r ° f b _ .150 P o s i t i o n r a t i o , r ~ .210 "~ -714 o T - T (.15") . ioo _ 126 - 205 A c n T - T - 34 - 205 " - 4 6 2 From the g r a p h i c a l s o l u t i o n s (27, 42) f o r heat t r a n s f e r 75. i n an i n f i n i t e c y l i n d e r , a F o u r i e r Number of .14 i s i d e n t i f i e d . T h i s , i n t u r n , enables the c a l c u l a t i o n o f the immersion time t r e q u i r e d t o b r i n g the s e a l s t o the m e l t i n g temperature. 2 r F 2 4 - O O .21 X .14 r.r.r-o-7 t = o — = .0073 X 144 = - 0 0 5 8 7 h r S = 21.1 seconds The temperature t o which seeds l o c a t e d a t the t i p of the seed b e a r i n g r e g i o n would be heated a f t e r 21.1 seconds treatment i s determined as f o l l o w s : r P o s i t i o n r a t i o f o r seeds, = * = .333 o Using the curves of the g r a p h i c a l s o l u t i o n o f heat t r a n s f e r in' an i n f i n i t e c y l i n d e r a g a i n , and these d a t a i n d i c a t e : a temperature r a t i o of .78. From t h i s , the seed temperature i s found t o be: T, = .78 (T - T ) + T (seed) v o OO 'T co = .78 (34 - 205) + 205 = 71.6°F (22.0°C). Using the same a n a l y s i s , c a l c u l a t i o n s were c a r r i e d out t o determine the time r e q u i r e d t o melt the s e a l s a t the lower or peduncle end of the seed b e a r i n g r e g i o n o f the cone. These are shown below: 1_ _ k_ .123 X 12 . B i h r 100 X .35 -U4^ o r o _ .29 _ ~ - 735 _ ' 8 3 o 76. The g r a p h i c a l heat t r a n s f e r data i n d i c a t e a F o u r i e r Number of .09. The time t o b r i n g the s e a l s i n t h i s r e g i o n t o the m e l t i n g temperature i s : r 2 F 2 t = O O .35 X .09 m n c v ~>n -i j — = nm? v 1 / 1 / 1 =" .0105 hrs = 37.7 seconds a .0073 X 144 The temperature of seeds a t t h i s l o c a t i o n a t the end of 37.7 seconds i s found as f o l l o w s : r (seed) _ .21 _ c — — — — . D r .35 o T h i s i n d i c a t e s a temperature r a t i o o f .70 which gives a seed temperature T_ o f : T , = .70 (T - T ) + T seed o °° °° = .70 (34 - 205) + 205 = 85.3°F = (29.6°C). As a r e s u l t o f the lon g e r time r e q u i r e d t o melt the s e a l s i n the lower r e g i o n of the cone, the temperature o f seeds i n the t i p r e g i o n o f the cone w i l l be heated above the temperature p r e v i o u s l y c a l c u l a t e d . The temperature of seeds i n the t i p r e g i o n a f t e r treatment f o r 37.7 seconds i s found as f o l l o w s : I i = - 0 7 0 r s .070 r .21 o .333 F = a t = .0073 X 37.7 X 144 _ 2 4 g ° r 2 .21 2 X 3600 o T h i s i n d i c a t e s a temperature r a t i o o f .42 which, i n t u r n , g i v e s a seed temperature o f : T ( s e e d ) = .42 (34 - 205) + 205 = 133.2°F (56.2°C) A second s e r i e s o f c a l c u l a t i o n s was c a r r i e d out t o determine the same seed temperatures under the c o n d i t i o n s o f f l a s h h e a t i n g i n a i r a t 1000°F (538°C). These c a l c u l a t i o n s are shown below: 1 _ k .123 X 12 B i h r Q 20 X .21 P o s i t i o n r a t i o r n r.„ s _ .150 .210 T(.15") " T°° = 126 - 1000 T - T 34 - 1000 o °° .351 = .714 = .907 Data from the r e f e r e n c e s i n d i c a t e a F o u r i e r Number of .070. T h i s , i n t u r n , g i v e s a treatment time o f : 2 t = r ° F ° = -21 2 X .070 = r a .0073 X 144 , U U ^ 4 n r s = 10.6 seconds Seed temperature a t t h i s p o i n t i s c a l c u l a t e d as f o l l o w s : P o s i t i o n r a t i o r n n n s _ . 070 r .210 * o The g r a p h i c a l data i n d i c a t e a temperature r a t i o o f .97 which, i n t u r n , g i v e s a seed temperature o f : 78. T s e e d = * 9 7 ( 3 4 ~ 1 0 0 0 ) + 1000 = 63.0°F (17.2°C) The time t o b r i n g the s e a l s i n the lower r e g i o n of the cone t o the m e l t i n g temperature i s c a l c u l a t e d i n a s i m i l a r f a s h i o n : 1__ _ _k _ .123 X 12 B i h r 20 X .35 o ^ = m = .83 r .35 o T ( . 3 5 " ) " T°° = 126 - 1000 _ q n 7 T - T 34 - 1000 o 0 0 T h i s i n d i c a t e s a F o u r i e r Number of .04, which g i v e s a s e a l b r e a k i n g time t o f : - r 2 F 2 o o .25 X .04 .' ~a = .0073 X 144" . ° ° 4 6 h r s - . = 16.7 seconds. The temperature of seeds a t t h i s p o i n t a f t e r 16.7 seconds of treatment i s found by the f o l l o w i n g : 1 r s = .21, — - = .6, F = .04 B i ' r ' o o and from t h i s the temperature r a t i o , i s .96, thus: T , = .96 (34 - 1000) + 1000 = 72.6°F (22.6°C) seed . , 1 — The temperature of seeds i n the t i p r e g i o n o f the cone a f t e r the 16.7 seconds of treatment r e q u i r e d t o melt the s e a l s i n the lower r e g i o n o f the cone i s s i m i l a r l y determined as f o l l o w s : From t h i s the temperature r a t i o i s .92 which g i v e s a seed temperature o f : T s e e d = " 9 2 ( 3 4 ~ 1 0 0 0 ) + 1 0 0 0 = 1 H - 3 ° F (44.1°C Treatment times c a l c u l a t e d by the above analyses, correspond w e l l w i t h the treatment times which were determined e x p e r i m e n t a l l y and r e p o r t e d i n P a r t One of t h i s r e p o r t . C a l c u l a t e d seed temperatures are i n the g e n e r a l range of temperatures measured by Nyborg and B r i s b i n (37). The above c a l c u l a t i o n s i n d i c a t e the s u i t a b i l i t y o f f l a s h h e a t i n g f o r s e a l b r e a k i n g o f s e r o t i n o u s cones. In a l l p r o b a b i l i t y , the a c t u a l h e a t i n g of seeds i n the cones would be l e s s severe than t h a t p r e d i c t e d by these c a l c u l a t i o n s f o r the reasons o u t l i n e d below. I t was assumed t h a t cones are homogeneous through- out, when i n f a c t they are not. Most seeds of l o d g e p o l e p i n e are covered w i t h i n the cone by t h r e e or f o u r s c a l e s , l y i n g one over the o t h e r . Thus the seeds are not s h e l t e r e d from e x t e r n a l heat by a uniform l a y e r of woody t i s s u e , but by t h r e e or f o u r l a y e r s , each separated by an a i r gap. The o v e r a l l thermal 80. conductance between the seed and the cone s u r f a c e would t h e r e - f o r e be lower than t h a t used i n the c a l c u l a t i o n s , hence the a c t u a l seed temperatures would be lower than the c a l c u l a t e d v a l u e s . I t was a l s o assumed i n the case of flame h e a t i n g t h a t heat was imparted t o the s u r f a c e of the cones by convec- t i o n o n l y , w h i l e i n f a c t , heat i s t r a n s m i t t e d by r a d i a t i o n as w e l l . The r e s u l t of t h i s a d d i t i o n a l heat t r a n s f e r would be t o cause a more r a p i d t r a n s f e r of thermal energy t o the s u r f a c e of the cone, which, i n t u r n , would cause a s t e e p e r temperature g r a d i e n t w i t h i n the cone. The a c t u a l seed temperature would t h e r e f o r e be f u r t h e r reduced from the c a l c u l a t e d v a l u e s a t the time o f s e a l m e l t i n g . The temperatures and heat treatment times determined above are c o n s i d e r e d t o be w e l l w i t h i n the a c c e p t a b l e l i m i t s f o r a continuous flow system and f o r freedom from thermal damage t o the seeds. The process of f l a s h h e a t i n g can t h e r e f o r e be c o n s i d e r e d t o be an a c c e p t a b l e and e f f i c i e n t method o f b r e a k i n g the s e r o t i n o u s s e a l s of Lodgepole p i n e cones. 3. Hot Water Immersion T o o l A p r o t o t y p e hot water immersion t o o l was designed and f a b r i c a t e d i n o r d e r t o e v a l u a t e t h i s p r o c e s s f o r t h e r m a l s e a l b r e a k i n g of s e r o t i n o u s cones. The o p e r a t i o n a l requirements of a s e a l b r e a k i n g t o o l s u i t a b l e f o r o p e r a t i o n i n c o n j u n c t i o n w i t h a mechanical seed 81. e x t r a c t i o n system or f o r use w i t h c o n v e n t i o n a l k i l n e x t r a c t i o n are l i s t e d below. - Operate on a continuous b a s i s . - Possess adequate p r o d u c t i o n c a p a c i t y . - Be p o r t a b l e . - Operate w i t h a minimum o f l a b o u r i n p u t . - E x h i b i t e f f i c i e n t f u e l u t i l i z a t i o n . - Be a d j u s t a b l e i n treatment d u r a t i o n . The hot water immersion t o o l was designed t o accommo- date the v a r i o u s c h a r a c t e r i s t i c s and p r o p e r t i e s o f the cones which were determined i n p a r t one of t h i s r e p o r t . In t h i s r e s p e c t , the range of water temperature and treatment times at which t h i s t o o l c o u l d operate was designed t o c o i n c i d e w i t h the optimum c o n d i t i o n s determined by the immersion t e s t s . The d e s i g n i n c l u d e d the a b i l i t y t o handle both s e a l e d and u n s e a l e d cones, and thermal damage from e x c e s s i v e treatment was a v e r t e d by the i n c l u s i o n of a p o s i t i v e t r a n s p o r t c a p a b i l i t y o f the immersing t o o l . The d e s i g n of the immersion t o o l chosen f o r f a b r i c a - t i o n c o n s i s t s of a r e v o l v i n g drum having s e v e r a l compartments around i t s p e r i p h e r y and which i s p a r t i a l l y immersed i n a tank of heated water. The cones are f e d i n t o these compartments j u s t above the water l i n e , and as the drum r e v o l v e s , the cones are c a r r i e d down i n t o the water. The buoyancy of the cones h o l d s them up a g a i n s t the w a l l o f the compartments, d u r i n g submergence. As each compartment emerges 82. from the water an e l e v a t i n g chute supports the cones u n t i l they are l i f t e d t o a p o i n t where they are dumped i n t o the d e l i v e r y chute. A f e e d hopper and a metering d e v i c e was a l s o i n c o r - p o r a t e d i n t o the d e s i g n of the e x p e r i m e n t a l apparatus i n order to i d e n t i f y the performance c h a r a c t e r i s t i c s of the t o o l under continuous flow o p e r a t i o n . The immersing drum i s e l e c t r i c a l l y powered and i s d r i v e n by a v a r i a b l e speed d r i v e mechanism. Immersion time i s c o n t r o l l e d by a d j u s t i n g the speed a t which the immersion wheel i s d r i v e n . The f e e d auger i s c h a i n d r i v e n by a s e p a r a t e motor. Water i n the tank i s maintained a t a u n i f o r m temperature by e l e c t r i c a l h e a t i n g elements, w h i l e the temperature i s monitored by a thermocouple l o c a t e d near the c e n t r e o f the tank. The exposed s u r f a c e s of the tank are i n s u l a t e d and an e n c l o s i n g chamber covers the upper r e g i o n of the r e v o l v i n g drum i n o r d e r t o reduce e v a p o r a t i v e c o o l i n g . The p r o t o t y p e h o t water immersion t o o l i s shown w i t h i t s i n s u l a t i n g drum cover removed i n F i g u r e s 24 and 25. E x t e n s i v e t e s t i n g was c a r r i e d out on the immersion s e a l b r e a k i n g d e v i c e , both i n the l a b o r a t o r y and under c o n d i - t i o n s e x i s t i n g a t a t y p i c a l commercial seed e x t r a c t i o n p l a n t . A q u a l i t a t i v e e v a l u a t i o n of t h i s p r o t o t y p e s e a l b r e a k i n g t o o l i d e n t i f i e d the f o l l o w i n g p o i n t s : - A hot water immersing t o o l i s an e f f e c t i v e d e v i c e f o r the b r e a k i n g o f s c a l e s e a l o f s e r o t i n o u s F i g u r e 24. Prototype hot water s e a l breaking t o o l . F i g u r e 25. View of s e a l breaker showing h e a t i n g and d r i v e mechanisms. 84. cones. - Cones whose s e a l s are broken w i t h hot water r e q u i r e a moderate d r y i n g process b e f o r e o t h e r phases of e i t h e r mechanical or k i l n e x t r a c t i o n can e f f e c t i v e l y be c a r r i e d out. - The energy requirement o f t h i s type o f s e a l b r e a k i n g t o o l i s h i g h due t o e v a p o r a t i v e c o o l i n g of the machine components and the l o s s o f hot l i q u i d . - Cones having a moisture content i n excess o f 25% w.b. pose o p e r a t i o n a l problems due t o t h e i r tendency t o s i n k i n the h e a t i n g water. - A hot water s e a l b r e a k i n g t o o l has a long s t a r t up time due t o the l a r g e mass of water and components which operate a t e l e v a t e d tempera- t u r e s . Problems of f r e e z i n g e x i s t d u r i n g shutdown when a hot water s e a l b r e a k i n g t o o l i s used i n an unheated l o c a t i o n d u r i n g w i n t e r o p e r a t i o n . The r e s u l t s o f the above e v a l u a t i o n i n d i c a t e t h a t a hot water immersing d e v i c e performs e f f e c t i v e l y as a continuous flow s e r o t i n o u s s e a l b r e a k i n g t o o l , but t h a t t h i s type o f t o o l has a number of disadvantages which reduce i t s s u i t a b i l i t y f o r commercial o p e r a t i o n . 4. Flame T r e a t i n g T o o l The d e s i g n i n g and f a b r i c a t i o n o f an a l t e r n a t e s e a l 85. b r e a k i n g t o o l , which f l a s h heats cones i n a flame, was under- taken as an a l t e r n a t i v e t o the hot water immersion t o o l . The o p e r a t i o n a l requirements s t a t e d f o r the hot water s e a l breaker, above, apply t o the d e s i g n of the flame t r e a t i n g t o o l as w e l l . The i n f o r m a t i o n on the p h y s i c a l p r o p e r t i e s and c h a r a c t e r i s t i c s of s e r o t i n o u s cones, which was determined i n p a r t one of t h i s r e p o r t , was s i m i l a r l y u t i l i z e d i n the d e s i g n of t h i s t o o l . The o p e r a t i n g p r i n c i p l e of the flame t r e a t i n g s e a l b reaker i s . t h a t of tumbling the cones w i t h i n a h o r i z o n t a l tube i n t o which a flame i s i n t r o d u c e d . The d e s i g n of t h i s p r o t o t y p e f l a s h h e a t e r i s based on a 10 i n c h diameter tube, 30 inches i n l e n g t h , i n s i d e of which i s a f o u r t u r n s i n g l e p i t c h auger f l i g h t . The t h r e e i n c h f l i g h t i s a t t a c h e d to the w a l l of the tube, and flame d e f l e c t i n g b a f f l e s are l o c a t e d a t s e v e r a l p o i n t s along the f l i g h t and extended i n t o the r e g i o n of the tube a x i s . The purpose o f the a u g e r . f l i g h t i s to t r a n s p o r t the cones through the tube as i t r o t a t e s . The ends of the tube are capped w i t h 14 i n c h diameter end p l a t e s which support the tube by r e s t i n g on the d r i v e p u l l e y s . At the c e n t r e of the p l a t e on the i n l e t end of the tube i s 3 i n c h diameter h o l e through which the cones are f e d i n t o the tube, and exhaust gases escape. The p l a t e on the e x i t end of the tube has a s i m i l a r h o l e through which the flame i s i n t r o d u c e d , but which i s extended a t one p o i n t t o the 86. c i r c u m f e r e n c e of the tube t o p r o v i d e a d i s c h a r g e p o r t f o r t r e a t e d cones as shown i n F i g u r e 26. The flame tube i s supported by f o u r d r i v i n g p u l l e y s which are a t t a c h e d t o two powered s h a f t s h e l d i n b e a r i n g s a t t a c h e d t o the frame a t e i t h e r s i d e of the tube. These s h a f t s are d i v e n by a v a r i a b l e speed e l e c t r i c motor thus p e r m i t t i n g the drum t o be r o t a t e d a t a l l speeds over a range from t e n seconds per r e v o l u t i o n t o one second per r e v o l u t i o n . In t h i s way treatment time can be c o n t r o l l e d over a range from f o u r to f o r t y seconds. Cones t o be t r e a t e d are metered out of the f e e d hopper by an auger and are d i r e c t e d i n t o the f l a s h h e a t i n g t o o l by a chute. The cones are p r o p e l l e d through the flame tube as they tumble a g a i n s t the s p i r a l f l i g h t i n s i d e the r e v o l v i n g tube. The tumbling a c t i o n a l s o serves t o ensure t h a t a l l s u r f a c e s o f the cones r e c e i v e u n iform exposure t o the hot s u r f a c e o f the tube and the hot gases from the flame. T r e a t e d cones are d i s c h a r g e d from the tube i n t o a d i s c h a r g e chute which c a r r i e s them t o a conveyor o r s u i t a b l e c o n t a i n e r . Heat i s s u p p l i e d t o the t o o l by a 190,000 BTU per hour propane t o r c h which d e l i v e r s i t s flame d i r e c t l y i n t o the t r e a t i n g tube. Temperatures w i t h i n the f l a s h h e a t e r are monitored by the use of a thermocouple l o c a t e d j u s t i n s i d e the cone i n l e t p o r t where the exhaust gases are d i s c h a r g e d . T h i s i s shown i n the d e t a i l o f F i g u r e 27. The drum temperature i s c o n t r o l l e d by 87. D e t a i l of t o r c h and discharge chute. Figure 26. Prototype flame treating seal breaker. 88. r e g u l a t i n g the p r e s s u r e of f u e l d e l i v e r e d t o the n o z z l e . Heat l o s s i s reduced by a l a y e r of asbestos i n s u l a t i o n on the o u t e r s u r f a c e of the t r e a t i n g tube. P r e l i m i n a r y t e s t i n g was c a r r i e d out u n d e r : l a b o r a t o r y c o n d i t i o n s t o i d e n t i f y the o p e r a t i n g c h a r a c t e r i s t i c s of the flame t r e a t i n g s e a l b r e aker. The e f f e c t of f u e l p r e s s u r e on temperature o f gas i n the tube, as measured a t the exhaust p o r t , was s t u d i e d . The curve of gas temperature i n terms of f u e l p r e s s u r e f o r the p r o t o t y p e t o o l i s p l o t t e d i n F i g u r e 28. The e f f e c t of treatment time on seed v i a b i l i t y o f cones having a moisture content of 12.5% wet b a s i s , and an i n i t i a l temperature o f 34°F (1°C) was determined, f o r an opera- t i n g temperature of 1000°F (538°C). The v i a b i l i t y , expressed as the percentage of f i l l e d seeds p r o d u c i n g normal germinants, of seeds from cones t r e a t e d f o r p e r i o d s up t o 100 seconds i s p l o t t e d i n F i g u r e 29. The r e s u l t s of the q u a l i t a t i v e e v a l u a t i o n o f the performance of t h i s p r o t o t y p e f l a s h h e a t i n g t o o l i n d i c a t e the f o l l o w i n g c o n c l u s i o n s : - A flame t r e a t i n g t o o l p r o v i d e s an e f f e c t i v e and v e r s a t i l e method of f l a s h h e a t i n g s e r o t i n o u s cones f o r the purpose of s e a l b r e a k i n g . - A flame t r e a t i n g t o o l f o r s e a l b r e a k i n g has a number of advantages over the hot water t o o l . 89. i , I I 1 5 10 15 20 Fuel Pressure (psi) FIGURE 28. Exhaust temperature vs. f u e l p r e s s u r e f o r flame t r e a t i n g s e a l b r e aker. CD o u CD PA C O • H -P fd C • H e u CD O 100 80 60 FIGURE 29. 40 L 20 20 40 60 80 100 Treatment Time, (seconds) V i a b i l i t y v s . treatment time f o r flame t r e a t e r o p e r a t i n g w i t h an exhaust temperature of 1000°F (538°C) 9G. These a r e : lower weight, q u i c k e r s t a r t u p , no cone d r y i n g r e q u i r e d , no cones l o s t d u r i n g treatment, more e f f i c i e n t heat u t i l i z a t i o n . — The f i r e hazard posed by a flame t r e a t i n g t o o l i s low, p a r t i c u l a r l y i f needles and o t h e r m a t e r i a l are s c a l p e d from the cones p r i o r t o treatment. Under normal o p e r a t i n g c o n d i t i o n s cones are not i g n i t e d by the treatment, and on l y when treatment time i s more than 25 t o 30 seconds does the p i t c h on h e a v i l y c oated cones become i g n i t e d . Such flames q u i c k l y e x t i n g u i s h themselves upon emerging from the treatment tube. 5. C a l i b r a t i o n of Flame T r e a t i n g S e a l Breaker In view of the s a t i s f a c t o r y performance o f flame t r e a t i n g s e a l b r e a k i n g t o o l , d e t a i l e d c a l i b r a t i o n of t h i s t o o l was undertaken f o r the purpose of p r e d i c t i n g the optimum t r e a t - ment f o r s p e c i f i c cone c o n d i t i o n s . The t o o l was c a l i b r a t e d , over a range of moisture content f o r f r e s h c l a s s I cones and f o r o l d weathered c l a s s • I I I cones. A l l c a l i b r a t i o n was c a r r i e d out w i t h the flame t r e a t e r o p e r a t i n g under ambient temperature c o n d i t i o n s between 65°F and 70°F (18°C and 21°C). The gas temperature, as measured at the exhaust p o r t was maintained a t 1000°F ± 20°F (538°C ± 11°C). The i n i t i a l temperature of a l l cones t r e a t e d was 34°F (1°C), and the c a l i b r a t i o n t e s t s were conducted on cones which had been c o n d i t i o n e d t o a number of moisture contents r a n g i n g from 9% t o 32% wet b a s i s . Groups of 100 cones from each c l a s s i f i c a t i o n and moisture c o n t e n t were pr o c e s s e d by the t o o l f o r treatment times of 5, 10, 15, 20, 25 and 30 seconds. A f t e r treatment, cones were d r i e d a t room tempera- t u r e so t h a t the degree o f s e a l b r e a k i n g on each was c l e a r l y e v i d e n t b y the open or c l o s e d p o s i t i o n of the cone s c a l e s . The cones were then s o r t e d i n t o the c l a s s i f i c a t i o n s o f (i) F u l l y unsealed, ( i i ) P a r t i a l l y unsealed, and ( i i i ) Not uns e a l e d , which have been r e p o r t e d e a r l i e r i n t h i s r e p o r t . The c a l i b r a t i o n data from these t e s t s are r e p o r t e d f o r young and weathered cones i n Tables A-19 and A-20, r e s p e c t i v e l y . Curves showing the p e r c e n t of cones a c h i e v i n g f u l l s e a l breakage i n each o f the two cone c l a s s i f i c a t i o n s , are shown i n F i g u r e s 30 and 31. FULLY OPENED Flame Treatment Duration (seconds) FIGURE 30. Flame treater calibration curves for complete seal breaking of Class I (young) Lodgepole Pine cones. FULLY OPENED vo Flame Treatment Duration (seconds) FIGURE.31. Flame treater calibration curves for complete seal breaking of Class III (weathered) Lodgepole pine cones. XI. DEVELOPMENT OF MECHANICAL CONIFER SEED EXTRACTING TOOL. 1. A l t e r n a t i v e Methods The development of a mechanical c o n i f e r seed e x t r a c - t i o n system i s dependent upon the s u c c e s s f u l development of an e f f e c t i v e mechanical e x t r a c t i o n t o o l . The f u n c t i o n and importance of t h i s type of t o o l i n the d e s i g n and o p e r a t i o n o f a p o r t a b l e c o n i f e r seed e x t r a c t i o n system was d i s c u s s e d i n Chapters I and V o f t h i s r e p o r t . Three a l t e r n a t i v e o p e r a t i n g p r i n c i p l e s were proposed f o r the d e s i g n of the e x t r a c t i o n t o o l under c o n s i d e r a t i o n . These a r e : ( i ) the removal by a b r a s i o n o f the o u t e r r e g i o n s of the cone s c a l e s and a reduced k i l n treatment f o r seed e x t r a c t i o n , ( i i ) the removal by b o r i n g or d r i l l i n g o f the c e n t r a l woody core of the cones which would reduce the cones t o a mass o f f r e e s c a l e s mixed w i t h the seed, ( i i i ) the t h r e s h i n g o f e n t i r e cones i n a manner s i m i l a r t o t h a t used f o r a g r i c u l t u r a l c r o p s . In each of the above p r o c e s s e s , the f u n c t i o n of the e x t r a c t i o n t o o l i s t o r e l e a s e the seeds from t h e i r p o s i t i o n w i t h i n the cone. A subsequent t o o l i s r e q u i r e d t o perform the task of s e p a r a t i n g the seed from the cone d e b r i s . Each of these p r o c e s s e s must a l s o be supplemented w i t h heat treatment. Process (i) r e q u i r e s a k i l n d r y i n g treatment and subsequent tumbling e x t r a c t i o n , and p r o c e s s ( i i ) r e q u i r e s a heat t r e a t i n g process t o break, the s e r o t i n o u s s e a l s a f t e r b o r i n g , and proc e s s ( i i i ) appears t o r e q u i r e a heat treatment t o break the s e r o t i n o u s bonds p r i o r t o t h r e s h i n g . Each o f the above e x t r a c t i o n methods was e v a l u a t e d by p r e l i m i n a r y t e s t i n g . The most promising e x t r a c t i o n t o o l was developed i n t o a f i r s t and a second g e n e r a t i o n p r o t o t y p e , each o f which was s u b j e c t e d t o e x t e n s i v e t e s t i n g . 2. E x t r a c t i o n by Cone A b r a s i o n The treatment o f c o n i f e r cones by abrading the cone s c a l e s t o remove the o u t e r p o r t i o n and the s e r o t i n o u s bond r e g i o n i s not intended t o achieve seed e x t r a c t i o n i n i t s e l f , but i s proposed as a means t o reduce k i l n treatment and t o speed the c o n v e n t i o n a l k i l n e x t r a c t i o n p r o c e s s . The a b r a s i o n t o o l used t o e v a l u a t e t h i s concept i s shown i n F i g u r e 32, and c o n s i s t s o f a s t a t i o n a r y and a r o t a t i n g concave d i s k mounted one above the o t h e r on a common a x i s . Cones are i n t r o d u c e d between the d i s k s through a h o l e a t the c e n t r e o f the s t a t i o n a r y d i s k . As the out e r p o r t i o n of the cone s c a l e s are abraded away, the cones move r a d i a l l y outward from the c e n t r e o f the two concave s u r f a c e s . When the cones are reduced t o a s i z e determined by the d i s t a n c e between the d i s k s a t t h e i r p e r i p h e r y , the cones are d i s c h a r g e d r a d i a l l y from between the d i s k s . A f t e r treatment by t h i s t o o l , the seeds are e x t r a c t e d from the remaining cone m a t e r i a l by the c o n v e n t i o n a l k i l n Figure 32. Cone abrasion t o o l . extraction process. Abraded cones do not, however, require as long a drying time, and the high temperatures used for seal breaking are also unnecessary. Preliminary i n v e s t i g a t i o n of t h i s technique indicated that t h i s t o o l did not meet the operational requirements of the proposed mechanical conifer seed extracting t o o l . This f a i l u r e was due to the fact that a f t e r treatment, cones s t i l l required a c e r t a i n period of drying, followed by a tumbling or v i b r a t i o n process i n order to extract the seeds. Also, the reduction i n k i l n treatment achieved did not appear to outweigh the extra handling required to abrade the cones p r i o r to drying. Additionally,the successful development of the flame t r e a t i n g f l a s h heater for breaking the seals of serotinous cones further reduced the u t i l i t y of t h i s t o o l . 97. 3. E x t r a c t i o n by Core B o r i n g The f u n c t i o n of a core b o r i n g e x t r a c t i n g t o o l i s t o remove the woody core from s e a l e d s e r o t i n o u s cones. The purpose of the removal of the core i s to remove the s t r u c t u r e t o which a l l cone s c a l e s are a t t a c h e d , thereby c a u s i n g the cone scales - to have no means of remaining a t t a c h e d t o one another once the s e r o t i n o u s s e a l s are r e l e a s e d . When the s e a l s are broken by c r u s h i n g or f l a s h h eating,boredcones are reduced t o an accumulation o f i n d i v i d u a l cone s c a l e s , amongst which the seeds are mixed. S e p a r a t i o n o f the seeds from the cone s c a l e d e b r i s would be e f f e c t e d by con^ v e n t i o n a l s c a l p i n g and seed c l e a n i n g t e c h n i q u e s . The f e a s i b i l i t y of t h i s technique was f i r s t i n v e s t i - gated by a n a l y z i n g the geometry o f a sample of l o d g e p o l e p i n e cones. A group of cones was s t u d i e d t o determine the range of v a r i a b i l i t y of a number of geometric v a r i a b l e s which would c h a r a c t e r i z e the shape and s i z e o f cones. These v a r i a b l e s were determined by measuring a group of cones which had been c u t through the l o n g i t u d i n a l a x i s t o p r o v i d e a c r o s s s e c t i o n a l view as i s shown i n F i g u r e 3.4. These data were r e q u i r e d i n o r d e r t o i d e n t i f y the shape and s i z e of both the c u t t i n g t o o l and the h o l d i n g t o o l , as w e l l as the r e l a t i v e p o s i t i o n of each a t the deepest p o i n t of the core removing o p e r a t i o n The cone v a r i a b l e s which were s t u d i e d are i d e n t i f i e d s c h e m a t i c a l l y i n F i g u r e 3 3 -, and are r e p o r t e d i n T a b l e A-21. The data of Table A-21 are summarized i n T a b l e V I I which a l s o shows the simple c o r r e l a t i o n c o e f f i c i e n t s among the 98. geometric v a r i a b l e s under study. From the data, i t i s evident t h a t there i s a l a r g e range i n cone p r o f i l e angles (0) and core p r o f i l e angles (0) w i t h i n a given seed l o t . T h i s , along w i t h the wide range of cone dimensions i n d i c a t e s t h a t a l a r g e number of b o r i n g t o o l s and c u t t i n g depths are r e q u i r e d t o remove the core of a l l cones without damaging the nearby seeds. The low degree of symmetry i n the cones f u r t h e r hinders the mechanization of t h i s o p e r a t i o n . The c o r r e l a t i o n c o e f f i c i e n t s of Table V I I a l s o i n d i c a t e t h a t there i s no simple combination of these v a r i a b l e s which would reduce the complexity of the mechanizing of t h i s o p e r a t i o n . Figure 33. Geometric v a r i a b l e s of cones i n f l u e n c i n g seed e x t r a c t i o n by removal of cone core. TABLE V I I . SIMPLE CORRELATION AMONG VARIABLES OF CONE GEOMETRY (Sample S i z e - 60 Cones) Cone Cone Core Core Tip Core Axis Core Core Length Angle Angle to to Axis Edge L 9 0^ Core Apex Cone Axis Misalign- to in . B a ment Seed i n . <£° C i n . Mean Value 1.396 37.9 25.5 .966 6.9 4.0 .034 Std. Dev. ±.245 ±11.4 ±8.4 ±.301 ±4.1 ±9.4 ±.011 Cone Length 1.00 Cone Angle -.32 1.00 Core Angle -.25 .57 1.00 Tip to Apex .57 -.71 -.36 1.00 Core to Cone Axis .24 .20 .35 -.02 1.00 , Core Axis Misalign. .22 .08 -.02 -.02 .15 1.00 Core Edge to Seed .07 -.05 .05 .8 -.20 -.07 1.00 Preliininary i n v e s t i g a t i o n o f the o p e r a t i n g c h a r a c t e r i s - t i c s o f a core removing t o o l was c a r r i e d out by d r i l l i n g the core r e g i o n of s e v e r a l groups o f cones u s i n g a number of t a p e r e d c u t t i n g t o o l s . T h i s was done by o p e r a t i n g the c u t t e r s i n a l a t h e , and h o l d i n g i n d i v i d u a l cones i n the lathe, chuck as shown i n F i g u r e 35. In the c u t t i n g p r o c e s s , a t o o l was chosen h a v i n g a p r o f i l e angle c o n s i d e r e d t o be near t o t h a t o f the apex of the cone core and i t was guided t o c u t as c l o s e as p o s s i b l e t o the 100. c e n t r e of the cone core a x i s . The t o o l was stopped when i t reached the p o i n t estimated t o be the t i p of the core t i s s u e . The cones, which a t t h i s p o i n t were s t i l l h e l d t o g e t h e r by the s e r o t i n o u s s e a l s , were then removed from the chuck jaws f o r e v a l u a t i o n . The e f f e c t i v e n e s s of t h i s core b o r i n g p r o c e s s was e v a l a u t e d by i n s p e c t i n g s e a l e d cones which were cu t through the c e n t r a l a x i s , as shown i n F i g u r e 36, and by i n s p e c t i n g these - cone h a l v e s a f t e r they r e c e i v e d thermal s e a l b r e a k i n g as shown i n F i g u r e 37. The attempts t o remove cone cores by b o r i n g r e s u l t e d i n v i r t u a l l y no cones b e i n g completely reduced t o f r e e s c a l e s without a s i g n i f i c a n t p o r t i o n of the seeds b e i n g d e s t r o y e d i n the p r o c e s s . The c u t t e r a c hieved complete c o r e removal o n l y i n the symmetrical cones, and i n cones which were bored w i t h a wide angled c u t t i n g t o o l . In the symmetrical cones the t o o l angle and depth of cut were the f a c t o r s c o n t r o l l i n g seed damage, w h i l e the use o f the wide angle t o o l removed the c o r e and p a r t of the s c a l e t i s s u e t a k i n g w i t h i t a l a r g e p o r t i o n o f the seeds. The b i g g e s t problem i n core removal was, however, the alignment of the c u t t e r w i t h the core a x i s of the l a r g e number of asymmetrical cones which occur i n t h i s s p e c i e s . In t h i s case, even the proper t o o l angle and c u t t i n g depth d i d not achieve complete core removal, and f r e q u e n t l y d e s t r o y e d a p o r t i o n of the seeds. The incomplete removal of the core r e s u l t e d :' Figure 34. Cross section of t y p i c a l cones showing degree of asymmetry. Figure 36. Cross section Figure37. Bored and un- of bored cones. sealed cones. 102. i n o n l y p a r t i a l f ragmentation of the cone and hence p a r t i a l seed r e l e a s e a f t e r s e a l b r e a k i n g . T h i s c o n d i t i o n i s shown i n F i g u r e 37. The q u a l i t a t i v e e v a l u a t i o n of seed e x t r a c t i o n o f s e a l e d Lodgepole p i n e cones by removing the cone cores i n d i c a t e s the f o l l o w i n g c o n c l u s i o n s : - Seed e x t r a c t i o n can be achieved by removal, o f .... - the core t i s s u e o f cones, but t h i s t e c h n i q u e does not l e n d i t s e l f t o the d e s i g n o f a simple p o r t a b l e seed e x t r a c t i o n system. - The wide range of cone shape and s i z e found i n commercially c o l l e c t e d cones n e c e s s i t a t e s p r e - s o r t i n g of the cones t o ensure t h a t a l l cones are bored by a s u i t a b l e c u t t e r and t o the a p p r o p r i a t e depth. T h i s i s n e c e s s a r y i n order t o achieve complete s c a l e s e p a r a t i o n and t o minimize seed d e s t r u c t i o n . - Thermal b r e a k i n g of the s e r o t i n o u s s e a l s o f cones cannot be performed p r i o r t o b o r i n g as the cone would d i s i n t e g r a t e d u r i n g b o r i n g , c a u s i n g damage t o the seeds. During s e a l b r e a k i n g j a f t e r b o r i n g the b a s a l end o f cones must be p r o t e c t e d from the heat so t h a t the seeds are not exposed to h i g h temperatures through the bore h o l e s . Thus cones cannot be f l a s h heated w h i l e tumbling, but must be 103. t r e a t e d w h i l e o r i e n t e d t o p r o t e c t the b a s a l r e g i o n of the cone. - The complexity of an automated machine system capable of meeting the above c r i t e r i a would r e s u l t i n p r o h i b i t i v e i n i t i a l and o p e r a t i n g c o s t s . - The p r o d u c t i o n r a t e of an e x t r a c t i o n system employing t h i s type o f e x t r a c t i o n t o o l would be low, due t o the n e c e s s i t y o f t r e a t i n g cones i n d i v i d u a l l y . I t i s e s t i m a t e d t h a t a h i g h l y automated system of t h i s t y p e c o u l d handle from 20 to 30 cones per t o o l , per minute. 4. E x t r a c t i o n by T h r e s h i n g (i) A n a l y s i s The e x t r a c t i o n of c o n i f e r seeds by t h r e s h i n g i s p r o - posed as an a d a p t i o n of the technique which has l o n g been used . t o e x t r a c t seeds from a g r i c u l t u r a l c r o p s . The e x t r a c t i o n o f seed by t h r e s h i n g i n v o l v e s the m a n i p u l a t i o n of seed b e a r i n g m a t e r i a l between a r e v o l v i n g t h r e s h i n g c y l i n d e r and.: a s e t of s t a t i o n a r y s e p a r a t i n g concaves or g r a t e s . The f r e e seeds are then separated from the o t h e r m a t e r i a l by a subsequent mechanism which, i n most cases, i s an a i r - s c r e e n seed c l e a n e r . The l a y o u t of a t y p i c a l a g r i c u l t u r a l t h r e s h i n g •• : • system i s shown s c h e m a t i c a l l y i n F i g u r e 38. The diagram shows. 104. both the e x t r a c t i n g t o o l and the seed s e p a r a t i n g t o o l which are combined i n t o what i s t r a d i t i o n a l l y termed a t h r e s h i n g machine. The f u n c t i o n of the c y l i n d e r and concaves e x t r a c t i n g t o o l i n a t h r e s h i n g machine i s t o f r e e the seeds from t h e i r attachment t o and/or l o c a t i o n i n the p r o t e c t i v e p l a n t t i s s u e . The f u n c t i o n of the s e p a r a t i n g t o o l i s t o separate the output of the e x t r a c t i n g t o o l i n t o : ( i ) coarse m a t e r i a l which i s d i s c h a r g e d d i r e c t l y ; ( i i ) p a r t i a l l y t h r e s h e d m a t e r i a l which i s r e t u r n e d t o the entrance of the e x t r a c t i n g t o o l f o r r e - t h r e s h i n g ; ( i i i ) f i n e m a t e r i a l s m a l l e r i n s i z e than the seeds, and (iv) seeds combined w i t h a q u a n t i t y of d e b r i s s i m i l a r t o the seeds. The o p e r a t i o n of a c o n i f e r seed t h r e s h e r would be very s i m i l a r to t h a t d e s c r i b e d above. E x t r a c t i o n o f s e r o t i n o u s Debris Tailings F i g u r e 38. Schematic diagram of t h r e s h i n g machine. 10 5. cones, u s i n g t h i s system, would i n c l u d e a s e a l b r e a k i n g o pera- t i o n p r i o r t o t h r e s h i n g , w h i l e the s o f t - c o n e s p e c i e s would be fed d i r e c t l y i n t o the t h r e s h i n g t o o l . The v a r i a b l e s i n v o l v e d i n the a n a l y s i s o f c y l i n d e r - concave seed e x t r a c t i n g t o o l s i n c l u d e : c y l i n d e r v e l o c i t y , c y l i n d e r t o concave c l e a r a n c e , type o f m a t e r i a l t o be e x t r a c t e d , moisture content of m a t e r i a l , a r c l e n g t h o f concave, con- f i g u r a t i o n , number, and m a t e r i a l o f c y l i n d e r rub b a r s , type and s i z e o f concave s u r f a c e s , f e e d r a t e and v e l o c i t y , t y p e and l o c a t i o n of d e c e l e r a t i o n s u r f a c e s . The a n a l y s i s o f many of these v a r i a b l e s i s empirical,- and a l l of them i n v o l v e a degree of s u b j e c t i v e e v a l u a t i o n . Although l i t t l e i s known of the use o f t h i s method of e x t r a c t i o n f o r c o n i f e r seeds, a v a s t q u a n t i t y o f i n f o r m a t i o n has been p u b l i s h e d on the e x t r a c t i o n o f a g r i c u l t u r a l seeds by t h r e s h i n g . O b v i o u s l y much of t h i s has d e a l t w i t h t h e c l a s s i c a l t h r e s h i n g o f g r a i n c r o p s , but e q u a l l y s i g n i f i c a n t i s the l i t e r a t u r e d e a l i n g w i t h the t h r e s h i n g of o t h e r c r o p s . The seeds f o r both consumption and r e p l a n t i n g o f v i r t u a l l y every a g r i c u l t u r a l crop w i t h the e x c e p t i o n of f r u i t c rops i s p r e s e n t l y e x t r a c t e d by means of a c o n v e n t i o n a l c y l i n d e r and concaves t h r e s h i n g mechanism. A p a r t i a l l i s t of the crops whose seeds are e x t r a c t e d by t h r e s h i n g (51) i s : c e r e a l g r a i n s , c o r n , peas, beans, r i c e , c l o v e r , timothy, a l f a l f a , rape, f l a x , c a r r o t s , l e t t u c e , t u r n i p s . 106. B a i n e r e t a l . (6) d e s c r i b e d the e x t r a c t i o n p r o c e s s of a t h r e s h i n g c y l i n d e r as one depending upon impact o f the c y l i n d e r bar upon the seed c o n t a i n i n g capsule which r e s u l t s i n the s h a t t e r i n g of the cap s u l e and the f r e e i n g o f the seed from the p r o t e c t i v e c o v e r i n g m a t e r i a l . F u r t h e r t h r e s h i n g i s ob t a i n e d by the rubbing a c t i o n as the m a t e r i a l i s a c c e l e r a t e d and passed through the c l e a r a n c e between the c y l i n d e r and the concave. The e f f e c t i v e n e s s o f t h r e s h i n g i s s t a t e d (6) t o be a f u n c t i o n o f the f o l l o w i n g : c y l i n d e r speed, concave c l e a r a n c e , c y l i n d e r - c o n c a v e d e s i g n , type o f cr o p , moisture c o n t e n t o f crop, and r a t e o f feed o f m a t e r i a l . For each c r o p , t h e r e i s an optimum p o i n t f o r each of these v a r i a b l e s which w i l l r e s u l t o i n a maximum seed r e c o v e r y and minimum seed damage. Hawthorne and P o l l a r d (23) i n 1954 d e s c r i b e d the c o n s t r u c t i o n o f an a l l purpose c y l i n d e r and concave t h r e s h i n g t o o l which was capable of e x t r a c t i n g the seeds o f a wide range of v e g e t a b l e , f l o w e r and g r a i n c r o p s . The t h r e s h e r i s designed w i t h rubber covered raspbars and concaves, and the speed and concaves p o s i t i o n are e a s i l y a d j u s t a b l e t o operate over a wide range of s e t t i n g s . The removal of the seeds from the cone d e b r i s d i s - charged from the t h r e s h e r i n v o l v e s the use of a c l e a n i n g t o o l i n the flow path o f the e x t r a c t i o n systems. A wide range of t o o l s f o r t h i s f u n c t i o n are commercially a v a i l a b l e (22) and 107. are r e a d i l y adaptable t o the proposed c o n i f e r seed e x t r a c t i o n system. ( i i ) F i r s t p r o t o t y p e t o o l A p r o t o t y p e cone t h r e s h i n g t o o l was designed f o r l a b o r a t o r y i n v e s t i g a t i o n of the e x t r a c t i o n of c o n i f e r seeds by t h r e s h i n g . The key components of the p r o t o t y p e e x t r a c t i n g t o o l are the t h r e s h i n g c y l i n d e r and concaves which are shown i n F i g u r e 39. The c y l i n d e r i s s i x inches i n width, and has s i x o n e - i n c h h i g h rub-bars mounted on i t s p e r i p h e r y . The diameter of the c y l i n d e r measured a t the top of the rub-bars i s t en i n c h e s . The concave s e t i s c o n s t r u c t e d of V x 1" s t e e l b a r s mounted a t 7/8" s p a c i n g over an a r c of approximately 150° of the c y l i n d e r . The 3/16" r e t a i n i n g rods running through the l e n g t h of the concaves are spaced a t 3/8" i n t e r v a l s . During f a b r i c a t i o n , a l l concave p a r t s were welded i n t o a s i n g l e assembled u n i t . These components are mounted i n a frame as shown i n F i g u r e 40, and the plenum chamber i n F i g u r e 41 was added t o p r o v i d e a means t o c o l l e c t the m a t e r i a l coming o f f the c y l i n d e r . T h i s chamber h o l d s a manually operated s c a l p i n g s i e v e which separates p a r t i a l l y t h r e s h e d cones f o r t h e i r r e t u r n t o the i n p u t and f u r t h e r treatment. Threshed m a t e r i a l p a s s i n g through the c y l i n d e r was c o l l e c t e d below the s c a l p i n g s i e v e , w h i l e t h a t p a s s i n g through the concaves was c o l l e c t e d i n a separate pan. The assembled p r o t o t y p e cone t h r e s h e r i s shown i n F i g u r e 42. 108. F i g u r e 41. Threshing t o o l with plenum chamber. 109. The t h r e s h i n g c y l i n d e r i s b e l t d r i v e n and i s powered by a v a r i a b l e speed e l e c t r i c motor which i s capable of d r i v i n g the c y l i n d e r a t p e r i p h e r a l speeds up t o 8000 f e e t per minute (2438 meters per minute). A uniform feed r a t e f o r t e s t batches i s p r o v i d e d by an i n c l i n e d feed chute and hopper. U n i f o r m i t y o f flow i s achieved by a feed gate and a pneumatic b a l l v i b r a t o r mounted below the d e l i v e r y trough as shown i n F i g u r e 42. ( i i i ) T e s t i n g For reasons d i s c u s s e d e a r l i e r , t e s t i n g o f the f i r s t g e n e r a t i o n p r o t o t y p e cone t h r e s h i n g t o o l was c o n f i n e d t o lodgepole p i n e cones whose cone s c a l e s had been p r e v i o u s l y r e l e a s e d by f l a s h heat t r e a t i n g . Groups of approximately 100 cones having moisture contents of 8.5, 12.8, 15.8, 19.9 p e r c e n t were threshed u s i n g c y l i n d e r speeds o f 1800, 2300, 2800, 3300, 3800, and 4300 f e e t per minute (548, 701, 854, 1006, 1158, and 1310 meters per minute) r e s p e c t i v e l y . Because on l y p a r t i a l t h r e s h i n g i s u s u a l l y achieved i n each pass through the e x t r a c t i n g t o o l , the cone fragments r e t a i n e d on the s c a l p i n g s i e v e were r e t u r n e d t o be r e t h r e s h e d i n the same manner as the t a i l i n g s from an a g r i c u l t u r a l t h r e s h e r . For t h i s s e r i e s of t e s t s , the m a t e r i a l was r e t u r n e d as necessary, up t o a t o t a l of f i v e passes through the c y l i n d e r . At h i g h speeds t h i s treatment was s u f f i c i e n t t o completely reduce the cones i n two or t h r e e passes, but a t low speeds, some seeds s t i l l remained u n e x t r a c t e d w i t h i n cone p a r t i c l e s . 110, Figure 42. Assembled prototype cone thresher. gure 43. Scalping sieve with p a r t i a l l y threshed cones. i Figure 44. P a r t i a l l y threshed cones after two passes with cylinder speed of 2000 ft./min. 111. The condition of p a r t i a l l y threshed cones i s exemplified i n Figure 44 which shows cone fragments from 20 cones retained by the scalping sieve af t e r two passes at a cylinder speed of 2000 ft/min. Figure 45 shows t y p i c a l material passing through the sieve under the same conditions. After extraction, the mixture of cone debris and. seeds was separated using the air-screen cleaner shown i n Figure 46. In the f i r s t cleaning treatment, the large p a r t i c l e s were scalped using a number 11 round hole sieve with no a i r flow. The remaining seed mixture was processed again using a number 8 round hole sieve and a number 6 X 27 screen. The f i n a l material was then hand sorted using a spatula and smooth table surface to separate those seeds which showed no v i s i b l e mechanical damage from the damaged seed as shown i n Figure 47. The sound seeds from each t e s t were weighed a f t e r drying, and sample counts taken to determine the number of seeds recovered from each group of cones. A l l cone material from each t e s t was also retained, dried and weighed for c a l c u l a t i o n purposes. Germination tests were then conducted on represen- t a t i v e samples of u n s t r a t i f i e d seeds from each t e s t . The germination percent was reported as tha percentage of t o t a l seeds producing normal germinants having r a d i c l e s at l e a s t twice the length of the seed. Cones i n the control group were extracted by f l a s h heating to break the seals, drying for several days at room 112. F i g u r e 4 5. M a t e r i a l p a s s i n g t h r o u g h s c a l p i n g s i e v e . F i g u r e 46. A i r - s c r e e n s e e d c l e a n e r . F i g u r e 47. T y p i c a l damaged and a p p a r e n t l y undamaged s e e d s e x t r a c t e d b y t h r e s h i n g . 113. temperature and shaking i n a mesh bottomed c o n t a i n e r . Seeds i n the c o n t r o l group were t r e a t e d by p a s s i n g them through the a i r - s c r e e n seed c l e a n e r i n o r d e r t o e l i m i n a t e v a r i a b i l i t y caused by c l e a n i n g . The data o b t a i n e d from the above t e s t i n g are r e p o r t e d i n Table A-22. A n a l y s i s was c a r r i e d out t o determine the averagec.number of v i a b l e seeds c o n t a i n e d i n each cone, and the expected number of v i a b l e seeds r e c o v e r e d by each t h r e s h i n g treatment a t each moisture c o n t e n t . The d i f f e r e n c e i n these two numbers r e p r e s e n t s the sum of the number of seeds r e m a i n i n g i n the cone fragments a f t e r f i v e passes and the number o f seeds damaged i n the e x t r a c t i o n p r o c e s s . From t h i s , the percentage of v i a b l e seeds r e c o v e r e d by the p r o t o t y p e t h r e s h e r a t the one s e t t i n g of t h r e s h e r v a r i a b l e s was determined and i s r e p o r t e d as the r e c o v e r y r a t e . The r e c o v e r y r a t e determined f o r the v a r i o u s moisture contents and o p e r a t i n g speeds are shown i n T a b l e A-22 and are p l o t t e d i n F i g u r e 48. The r e s u l t s o f t h i s f i r s t s e r i e s of t e s t s i n d i c a t e t h a t the unbroken seed e x t r a c t i o n r a t e was reasonably h i g h , but t h a t i n t e r n a l mechanical damage g r e a t l y reduced the v i a b l e seed r e c o v e r y r a t e . The f a c t t h a t some seeds remained i n cone fragements a t the end o f f i v e passes, a l s o reduced the o v e r a l l r e c o v e r y r a t e . T h i s f a c t o r i s p a r t i c u l a r l y important a t low speeds where both t h e degree of e x t r a c t i o n per pass and the degree of seed damage i s low. 114. >i M <D > O U CD tf CD CD W CD Xi rci •H > 30 h 20 10 -h: MOISTURE CONTENT (w.b.) 19.9% Xl5.8% 12.8% 8.5% 1000 2000 3000 4000 Cylinder Speed (ft/min) 5000 F i g u r e 48. V i a b l e seed r e c o v e r y r a t e i n , l o d g e p o l e p i n e f o r f i r s t p r o t o t y p e t h r e s h e r . F i g u r e 48 a l s o shows that v i a b l e seed r e c o v e r y i s h i g h e s t a t the lower c y l i n d e r speeds, where the impact f o r c e s are low. The b e s t moisture content f o r e x t r a c t i o n appears t o be i n the range of 12 t o 20 p e r c e n t wet b a s i s . Although the recover y r a t e s of these t e s t s on the f i r s t p r o t o t y p e cone t h r e s h i n g t o o l are low, much i n f o r m a t i o n was gained c o n c e r n i n g the d e s i g n and performance of t h i s type of t o o l . ' The r e s u l t s of these t e s t s and the ex p e r i e n c e gained from them i n d i c a t e t h a t f u r t h e r developmental work on t h i s e x t r a c t i o n t o o l can r e s u l t i n h i g h e r seed r e c o v e r y r a t e s and much lower seed damage. The f a c t t h a t the f u n c t i o n a l o p e r a t i o n of t h i s p r o t o t y p e meets a l l the other o p e r a t i o n a l 115. requirements necessary f o r a p o r t a b l e mechanical c o n i f e r seed e x t r a c t i o n t o o l holds s i m i l a r promise of the s u c c e s s f u l development of the proposed e x t r a c t i o n system, (iv) Second g e n e r a t i o n p r o t o t y p e Based on the i n f o r m a t i o n gained from the above t e s t s , a number of m o d i f i c a t i o n s were c a r r i e d out on the d e s i g n o f the o r i g i n a l p r o t o t y p e t h r e s h i n g t o o l . The c h i e f g o a l o f these m o d i f i c a t i o n s was the r e d u c t i o n of damage t o e x t r a c t e d seeds by t h e i r impact w i t h the i n t e r n a l c o n t a c t areas of the t h r e s h e r . T h i s seed p r o t e c t i o n was p r o v i d e d by the i n s t a l l a t - i o n of c u s h i o n i n g m a t e r i a l on a l l i n t e r n a l s u r f a c e s coming i n c o n t a c t w i t h the t h r e s h e d seeds. For t h i s purpose, the i n n e r s u r f a c e s o f the top p l a t e and feed-end p l a t e , as shown i n F i g u r e 49, were covered w i t h a one-eighth i n c h t h i c k l a y e r of n a t u r a l rubber having a Shore hardness o f 40 t o 45. The l e a d i n g s u r f a c e s of the c y l i n d e r rub bars were covered w i t h n a t u r a l rubber having a Shore hardness of 70. A v u l c a n i z i n g p rocess was used to bond a l l rubber to the s u r f a c e s they covered. The c u s h i o n i n g , shown i n F i g u r e 50, was a p p l i e d t o the concaves assembly by d i p p i n g the component i n a v i n y l p l a s t i s o l m a t e r i a l , and c u r i n g t o a Shore hardness of 70 t o 75. A c y l i n d e r s t r i p p e r bar, which was rubber coated, was a l s o added t o reduce the r e c i r c u l a t i o n of m a t e r i a l around 116. Figure 49. Internal components showing location of cushioning material. Figure 51. Location of decelera- tion curtain i n plenum chamber. 117. the c y l i n d e r . T h i s i s a l s o shown i n F i g u r e 49. A rubber d e c l e r a t i o n c u r t a i n was added t o the housing so as to i n t e r c e p t the path of m a t e r i a l e x i t i n g from between the c y l i n d e r and concaves. T h i s c u r t a i n , shown i n F i g u r e 51, i s hung j u s t t o the r e a r of the s t r i p p i n g bar, and a c t s t o slow the h i g h v e l o c i t y m a t e r i a l , and drop i t onto the s c a l p i n g s i e v e , (v) T e s t i n g Upon completion of the m o d i f i c a t i o n s o u t l i n e d above, the performance of t h i s second g e n e r a t i o n t h r e s h i n g t o o l was t e s t e d . A m o d i f i e d t e s t i n g procedure was used to take advantage of experience gained i n the e a r l i e r t e s t s . T e s t s were conducted on cones a t 15% and 20% moisture c o n t e n t , c o r r e s p o n d i n g t o the moisture range which produced the h i g h e s t r e c o v e r y r a t e s i n the e a r l i e r t e s t s . Based on the f i n d i n g t h a t the peak r e c o v e r y i s a t the low end of the o p e r a t i n g speed range, o p e r a t i n g speeds of 1600, 2000, 2400 and 2800 f e e t per minute (487, 609, 732, and 853 meters per minute ) r e s p e c t i v e l y , were chosen f o r the second s e r i e s o f t e s t s . Groups o f 100 cones were used f o r each t e s t . In o r d e r t o ensure complete e x t r a c t i o n a l l cone fragments were r e c y c l e d through the t h r e s h e r u n t i l complete t h r e s h i n g was a c h i e v e d . In the case of the low speed t r e a t - ment, upwards of f i f t e e n passes were r e q u i r e d i n o r d e r t o reduce the l a s t few cone fragments. 118.° S e p a r a t i o n of the seeds from the cone d e b r i s was c a r r i e d out under the same c o n d i t i o n s as the e a r l i e r t e s t s . In the f i n a l c l e a n i n g , the hand s o r t i n g was r e p l a c e d by p a s s i n g the m a t e r i a l over a manually o s c i l l a t e d c l o t h covered s u r f a c e which was s l i g h t l y i n c l i n e d . In t h i s p r ocess the smooth round seeds t r a v e l l e d down the i n c l i n e sooner than the cone fragments, and the l a t t e r were removed from the c l o t h by vacuum. A f t e r a l l d e b r i s and o b v i o u s l y damaged seeds were removed from the samples, the seeds were counted on an e l e c t r o n i c seed c o u n t e r . In order t o account f o r seeds which may have been l o s t d u r i n g the c l e a n i n g p r o c e s s , seeds from the c o n t r o l group were mixed w i t h the d e b r i s from one group of t h r e s h e d cones, and were r e - s e p a r a t e d u s i n g the same treatment g i v e n t h e threshed seeds. Germination t e s t s were c a r r i e d out on seeds and the g e r m i n a t i o n p e r c e n t s were c o r r e l a t e d t o g i v e the number of v i a b l e seeds per cone ; recovered by the e x t r a c t i n g t o o l . The r e s u l t s of these t e s t s are t a b u l a t e d i n T a b l e A-23 and the r e c o v e r y r a t e s are p l o t t e d a g a i n s t p e r i p h e r a l t o o l speed i n F i g u r e 52. From the f i g u r e i t can be seen t h a t maximum r e c o v e r y r a t e f o r Lodgepole pine i s much h i g h e r f o r the second g e n e r a t i o n t h r e s h e r than i t was f o r the f i r s t p r o t o t y p e . The b e t t e r o f the two moisture contents t e s t e d i n the r u b b e r i z e d t h r e s h e r i s c l e a r l y shown t o be the 15.5% v a l u e . The optimum c y l i n d e r speed 119. f o r the c o n d i t i o n s t e s t e d i s i n the range of 2000 f t per minute. These f i g u r e s f o r optimum moisture content and c y l i n - der speed correspond w e l l w i t h those determined i n the e a r l i e r s e r i e s o f t e s t s . 100 90 80 * 7 0 u CD > O o CD PJ CD CD U3 CD i H fd • H > 60 50 40 30 20 10 20% M.C. J L 500 100 1500 2000 2500 Cylinder Speed (feet per minute) 3000 F i g u r e 52. Curves of seed r e c o v e r y v s . c y l i n d e r speed f o r Lodgepole p i n e e x t r a c t e d by the r u b b e r i z e d t h r e s h i n g t o o l . 120. The r e s u l t s of these t e s t s show a; marked improvement i n the seed r e c o v e r y r a t e of the t h r e s h e r by the m o d i f i c a t i o n of o n l y one of the many v a r i a b l e s which a f f e c t the performance of such a machine. I t i s t h e r e f o r e apparent t h a t a d d i t i o n a l developmental work w i t h t h i s and o t h e r v a r i a b l e s which a f f e c t t h r e s h i n g e f f e c t i v e n e s s can be expected t o r e s u l t i n f u r t h e r improvements i n the r a t e o f v i a b l e seed r e c o v e r y from c o n i f e r seed t h r e s h i n g t o o l s . A f u r t h e r t e s t was c a r r i e d out on the second p r o t o - type i n o r d e r t o assess the degree of seed e x t r a c t i o n a c h i e v e d w i t h s u c c e s s i v e passes through the t h r e s h i n g t o o l . F or t h i s t e s t , a group of 100 cones was s t u d i e d under the optimum t h r e s h i n g c o n d i t i o n s of 15.0% moisture con- t e n t , and a c y l i n d e r speed of 2 000 f t / m i n as determined e a r l i e r . The cones were passed through the t h r e s h e r , and the seeds p a s s i n g through the concaves and through the s c a l p i n g s i e v e were c o l l e c t e d . The unthreshed cones and cone fragments were then r e t h r e s h e d n i n e times and the seeds were c o l l e c t e d from each r e g i o n of the t h r e s h e r a f t e r each pass. The number of seeds from each r e g i o n a f t e r each pass was r e c o r d e d , and g e r m i n a t i o n p e r c e n t s determined f o r each group. From the d a t a , the number of v i a b l e seeds r e c o v e r e d from the concaves and from the s c a l p e r s i e v e a f t e r each pass was determined, and i s r e p o r t e d i n Tables A-24 and A-25. Cumulative curves showing the p o r t i o n of t o t a l v i a b l e seeds re c o v e r e d through the concaves and through the s i e v e , f o r each s u c c e s s i v e pass, are p l o t t e d i n F i g u r e 53. These curves show t h a t l e s s than h a l f o f the seeds are r e c o v e r e d through the concaves, and t h a t approximately 95% pf the v i a b l e seeds recovered are e x t r a c t e d i n the f i r s t f o u r . passes through the t h r e s h e r . The data of Tables A-24 and A25 a l s o show t h a t the v i a b i l i t y r a t e o f seeds e x t r a c t e d i n a c e r t a i n pass i s not s i g n i f i c a n t l y reduced by s u c c e s s i v e passes through the t h r e s h e r . I ' , I I i i t i I I 1 2 3 4 5 6 7 8 9 10 Number of Successive Passes F i g u r e 53. Accumulated v i a b l e seed r e c o v e r y from cones a t 15% moisture content threshed a t a c y l i n d e r speed of 2000 f t / m i n u t e . 122. (vi) T h r e s h i n g Performance on Other Species The performance of the second g e n e r a t i o n t h r e s h i n g t o o l was a l s o e v a l u a t e d by e x t r a c t i n g cones of the f o l l o w i n g s p e c i e s : Douglas f i r (Pseudotsuga men.ziesii (Mirb.) F r a n c o ) ) , white spruce (Picea g l a u c a (Moench) V o s s ) ) , and western hemlock (Tsuga heterophy11a (Raf.) S a r g . ) ) . These cones were i d e n t i - f i e d by the B.C. F o r e s t S e r v i c e seed l o t numbers as 0.1-2, N7-3, and N2 2-5 r e s p e c t i v e l y . T e s t s were conducted on each s p e c i e s a t two m o i s t u r e c o n t e n t s . One moisture l e v e l was where the cones were j u s t dry enough t o shed seeds, the o t h e r , where the cones were wet enough to remain c l o s e d . The concaves of the t h r e s h i n g t o o l was s e t a t one a r b i t r a r y p o s i t i o n f o r t h e t e s t s which were c a r r i e d out at. f i v e c y l i n d e r speeds. P a r t i a l l y e x t r a c t e d cones were r e p r o c e s s e d u n t i l t h r e s h i n g was complete. S e p a r a t i o n of the seeds from the cone d e b r i s was c a r r i e d out u s i n g the same techniques as used f o r l o d g e p o l e . p i n e above, except t h a t s i e v e s i z e s a p p r o p r i a t e t o each seed s i z e were used. Seeds i n the c o n t r o l group were e x t r a c t e d by d r y i n g and shaking i n a mesh bottom c o n t a i n e r . These c o n t r o l seeds were mixed w i t h the d e b r i s from a group o f cones and then r e - separated u s i n g the same techniques as the t h r e s h e d seeds. Germination t e s t s were c a r r i e d out on each group of seeds, and the number of v i a b l e seeds r e c o v e r e d i n each t e s t was determined. T h i s was compared t o the number of v i a b l e seeds 123. re c o v e r e d from the c o n t r o l group i n order t o determine the p e r c e n t r e c o v e r y . The data from the t e s t s on f i r , spruce and hemlock cones are shown i n Tables A-26, A-27 and A-28 r e s p e c t i v e l y . The r a t e s of r e c o v e r y of v i a b l e seed f o r each group o f t e s t s i s p l o t t e d a g a i n s t c y l i n d e r speed i n F i g u r e 54. 100 >1 U CD > O O CD « CD CD CO CD Xi rd • H > 80 60 40 20 ~ •— -— — Douglas F i r ........... Spruce Hemlock V V MOISTURE CONTENT V \ l l . 5 % \ \ \ \ V «*£1.6% \ " \ \ \ \ .^24.3% ~ V*». V .*28.4% !4.4% •o 1000 2000 3000 4000 Cylinder Speed (feet per minute) 5000 F i g u r e 54. Seed recov e r y by t h r e s h i n g of f i r , spruce and hemlock cones. 124. The curves of F i g u r e 54 i n d i c a t e t h a t the b e s t seed r e c o v e r y r a t e f o r the p a r t i c u l a r c o n d i t i o n o f t h r e s h e r v a r i a b l e s used i n these t e s t s was achieved w i t h Douglas f i r cones, a t 11.5% moisture c o n t e n t . U n f o r t u n a t e l y the r e s u l t s o f the t e s t a t t h i s moisture content a t a c y l i n d e r speed o f 150 0 f t / m i n u t e were d e s t r o y e d d u r i n g c l e a n i n g . The curve d i d , however, i n d i c a t e a maximum seed re c o v e r y r a t e i n excess o f 80%. The maximum r e c o v e r y r a t e a c h i e v e d i n spruce was s l i g h t l y above 40%, wh i l e t h a t o f hemlock was below 20%. I t i s a l s o e v i d e n t from the curves t h a t the maximum r e c o v e r y r a t e f o r the p a r t i c u l a r t h r e s h e r c o n f i g u r a t i o n and adjustment used i n these t e s t s was achieved a t c y l i n d e r speeds between 2000 and 3000 f e e t per minute. The r e s u l t s o f these t e s t s i n d i c a t e t h a t s a t i s f a c t o r y seed e x t r a c t i o n can be achieved by t h r e s h i n g once t h e optimum c o n d i t i o n o f each o f the many v a r i a b l e s o f machine parameters and b i o l o g i c a l m a t e r i a l c o n d i t i o n s are i d e n t i f i e d . P A R T T H R E E C O N C L U S I O N S A N D R E C O M M E N D A T I O N S 126. XII CONCLUSIONS The c o n c l u s i o n s a r i s i n g from the i n v e s t i g a t i o n s o u t l i n e d i n t h i s r e p o r t are l i s t e d i n p o i n t form below. 1. P h y s i c a l P r o p e r t i e s o f Lodgepole Pine Cones which A f f e c t Seed E x t r a c t i o n - Seeds l o c a t e d i n the e x t r e m i t i e s o f the seed b e a r i n g r e g i o n o f lod g e p o l e p i n e cones have a s l i g h t l y h i g h e r percentage o f empty seeds, but f i l l e d seeds from a l l r e g i o n s o f the cones have e s s e n t i a l l y the same germi n a t i o n p e r c e n t . Seeds which are e a s i l y e x t r a c t e d by tumbling tend t o have a h i g h e r p o r t i o n of f i l l e d seeds than those which are more d i f f i c u l t t o e x t r a c t . - A d e c l i n e i n ge r m i n a t i o n p e r c e n t i s i n i t i a t e d w i t h i n hours i n seeds of wet cones which are s l o w l y d r i e d i n a n o n - c i r c u l a t i n g k i l n a t 140°F (60°C). The e q u i l i b r i u m moisture content, d u r i n g d r y i n g , o f lod g e p o l e p i n e cones has been determined and the c h a r a c t e r i s t i c i s c o n s i s t e n t w i t h t h a t o f o t h e r h y g r o s c o p i c b i o l o g i c a l m a t e r i a l s . The mean temperature a t which the s e r o t i n o u s s e a l s o f young cones of l o d g e p o l e pine are broken i s 52.51°C + 5.7°C. Old weathered cones are opened at a mean temperature of 54.50°C ± 5.8°C. The angle t o which the s c a l e s of lodgepole p i n e cones open upon d r y i n g , a f t e r s e a l b r e a k i n g , has been 127. determined, and i s approximately a l i n e a r r e l a t i o n - s h i p w i t h cone moisture content i n the range of moisture content below 25% wet b a s i s . The s c a l e s of lodgepole p i n e cones undergo a process of s t r e s s r e l a x a t i o n when they are h e l d a t mo i s t u r e contents below 25% wet b a s i s w h i l e t h e i r s c a l e s are s e a l e d i n the c l o s e d p o s i t i o n . Cones which experi e n c e t h i s p r o c e s s s u f f e r a r e d u c t i o n i n the angle t o which t h e i r s c a l e s w i l l open f o r any gi v e n moisture content a f t e r t h e i r s e a l s are broken. Cones which have undergone a s t r e s s r e l a x a t i o n p r o c e s s can r e c o v e r most of t h e i r s c a l e d e f l e c t i n g a b i l i t y i f t h e i r moisture content i s r a i s e d t o a h i g h l e v e l b e f o r e r e d r y i n g . The p o r t i o n of t o t a l seeds c o n t a i n e d by cones which can be e a s i l y e x t r a c t e d by tumbling i n c r e a s e s a t a d i m i n i s h i n g r a t e as the angle o f s c a l e d e f l e c t i o n i s i n c r e a s e d beyond 60° by d r y i n g . The s e r o t i n o u s s e a l of l o d g e p o l e p i n e cones can be broken by f l a s h h e a t i n g i n e i t h e r hot water, o r i n a flame, without c a u s i n g a r e d u c t i o n i n seed v i a b i l i t y . Complete s e a l breakage can be achieved w i t h a m i l d heat treatment i f the cones are at a moisture content below 25% wet b a s i s , so t h a t s c a l e f l e x i n g s t r e s s e s separate the s c a l e s when the s e a l i n g m a t e r i a l i s melted. 128. Development of S e a l Breaking T o o l Mechanical s e a l b r e a k i n g can be a c h i e v e d by a c r u s h i n g p r o c e s s , but t h i s technique does not l e n d i t s e l f t o continuous flow commercial o p e r a t i o n . - Thermal s e a l b r e a k i n g by f l a s h h e a t i n g cones i s an e f f e c t i v e method of opening cones which lends i t s e l f t o continuous flow commercial o p e r a t i o n . Seed temperatures w i t h i n cones so t r e a t e d can be . p r e d i c t e d w i t h reasonable accuracy. A continuous flow hot water f l a s h h e a t i n g t o o l f o r s e a l b r e a k i n g was developed and found t o operate e f f e c t i v e l y , but had c e r t a i n disadvantages which reduce i t s s u i t a b i l i t y f o r commercial o p e r a t i o n . - A continuous flow flame t r e a t i n g f l a s h h e a t i n g t o o l f o r s e a l b r e a k i n g was developed and found t o operate e f f e c t i v e l y . T h i s d e v i c e was the most s u i t a b l e t o o l found f o r opening s e r o t i n o u s cones under commercial o p e r a t i n g c o n d i t i o n s and was c a l i b r a t e d over a range o f moisture contents f o r two c l a s s e s o f lodgepole p i n e cones. Development of Mechanical C o n i f e r Seed E x t r a c t i n g T o o l - M e c h a n i c a l a b r a s i o n of the o u t e r p o r t i o n o f s e r o t i n o u s cones w i l l reduce k i l n treatment f o r seed e x t r a c t i o n 129. purposes, but does not appear s u i t a b l e as a t o o l f o r commercial o p e r a t i o n . Seed e x t r a c t i o n by the removal of the core o f s e r o t i n o u s cones i s an e f f e c t i v e a l t e r n a t i v e , but t h e h i g h degree of asymmetry o f the cones o f l o d g e p o l e p i n e causes e x t e n s i v e seed damage when the c o r e b o r i n g t o o l c u t s beyond the woody c o r e . T h i s o c c u r s when the b o r i n g t o o l , which can a u t o m a t i c a l l y a l i g n i t s e l f o n l y w i t h the a x i s o f the e x t e r n a l cone p r o f i l e , i s operated on cones whose woody core i s not c o n c e n t r i c w i t h the e x t e r n a l cone p r o f i l e . - The e x t r a c t i o n o f c o n i f e r seed by t h r e s h i n g i s an ac c e p t a b l e a l t e r n a t i v e i n terms of the d e s i g n o f a mechanized seed h a n d l i n g system. A f i r s t and second g e n e r a t i o n c o n i f e r t h r e s h i n g t o o l was developed and t e s t e d . With a l i m i t e d degree of o p t i m i z a t i o n o f machine v a r i a b l e s , v i a b l e seed r e c o v e r y r a t e s as h i g h as 44% were a c h i e v e d w i t h t h i s t o o l on unsealed l o d g e p o l e p i n e cones. F u r t h e r developmental work on t h i s t o o l can be expected t o r a i s e t h i s f i g u r e s i g n i f i c a n t l y . P r e l i m i n a r y t e s t s performed w i t h t h i s p r o t o t y p e t h r e s h i n g t o o l on cones o f Douglas f i r , white spruce and western hemlock, i n d i c a t e t h a t the 130. optimum c o n d i t i o n o f the many machine and m a t e r i a l v a r i a b l e s which a f f e c t t h r e s h i n g must be determined f o r each i n d i v i d u a l s p e c i e s . 131. X I I I RECOMMENDATIONS Recommendations f o r the a p p l i c a t i o n o f the f i n d i n g s of t h i s i n v e s t i g a t i o n t o the commercial seed e x t r a c t i o n o f the s e r o t i n o u s c o n i f e r s p e c i e s , as w e l l as g e n e r a l comments on the development of a mechanized c o n i f e r seed e x t r a c t i o n system are l i s t e d below: Se r o t i n o u s cones which are t o be e x t r a c t e d by k i l n d r y i n g and tumbling should be s t o r e d a t low temperatures, a t a moisture content, o f app r o x i m a t e l y 25% wet b a s i s i n o r d e r t o minimize the o c c u r r e n c e of s t r e s s r e l a x a t i o n i n the cone s c a l e s . Non-serotinous cones which are to be k i l n e x t r a c t e d should not be allowed t o dry below approximately 25% u n l e s s they are i n c o n t a i n e r s which p e r m i t f r e e d e f l e c t i o n of the s c a l e s . T h i s i s because s t r e s s r e l a x a t i o n occurs i n non-serotinous cones which are d r i e d , but whose cone s c a l e s a re prevented ; from d e f l e c t i n g f u l l y . I t i s recommended t h a t f u r t h e r work be c a r r i e d out to complete the development o f the d e s i g n o f a flame t r e a t i n g f l a s h h e a t e r f o r the s e a l b r e a k i n g of s e r o t i n o u s cones. T h i s machine w i l l be a v a l u a b l e t o o l f o r s e a l b r e a k i n g p r i o r t o conven- t i o n a l k i l n treatment, as w e l l as f o r f u t u r e -. development of a mechanized c o n i f e r seed e x t r a c t i o n system. The f o l l o w i n g d e s i g n f e a t u r e s are recommended f o r i n c l u s i o n i n the d e s i g n of subsequent machines: © Longer flame tube having l a r g e r diameter and at l e a s t double run conveying f l i g h t s . ® Hopper f e e d i n g and metering system based on v i b r a t i o n . ® Double e n c l o s u r e over flame tube t o reduce heat l o s s e s . I t i s recommended t h a t f u r t h e r study be c a r r i e d o ut to determine the optimum c o n d i t i o n s of t h e machine and m a t e r i a l v a r i a b l e s which a f f e c t the t h r e s h i n g of cones. The f o l l o w i n g parameters are suggested as p o s s i b l e avenues t o improved t h r e s h i n g performance. a A study of cone and seed morphology and p h y s i o l o g y to i d e n t i f y the c h a r a c t e r i s t i c s o f , and means to reduce mechanical seed damage. ® The u t i l i z a t i o n o f a l a r g e r t h r e s h i n g c y l i n d e r diameter, and the r e s u l t i n g g r e a t e r concave l e n g t h . © E x p e r i m e n t a t i o n w i t h s h o r t e r , c l o s e r spaced c y l i n d e r rub-bars, i n c l u d i n g s p i k e t o o t h c y l i n d e r and concaves. 133. © E x p e r i m e n t a t i o n with a l t e r n a t e concave d e s i g n s , and s e t t i n g s . ® I n v e s t i g a t i o n of a i r a s s i s t e d t r a n s p o r t of seeds out of the area of the c y l i n d e r . 134. LITERATURE CITED 1. 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"How t o Open Pond Pine Cones". J o u r n a l of F o r e s t r y , V o l . 52, No. 10, pp 770. 25. Henderson, S.M. and P e r r y , R.L. 1966. A g r i c u l t u r a l Process E n g i n e e r i n g , 2nd ed., Edwards P u b l i s h i n g Co., Michigan, U.S.A. 136. Kozlowski, T.T. 1962. Growth and Development of T r e e s . Academic P r e s s , New York. K r e i t h , F. 1973. P r i n c i p l e s of Heat T r a n s f e r , 3rd ed. I n t e r t e x t E d u c a t i o n a l P u b l i s h e r s , New York. Lee, L. and B e a u f a i t , W.R. 1961. Thermal C o n d u c t i v i t y and D i f f u s i v i t y o f Cones of Pinus Banksiana. Tech. B u l l . 8, Michigan C o l l e g e o f Mining and Technology, Houghton, Mi c h i g a n . Lotan, J.E. 1970. "Cone S e r o t i n y i n Pinus C o n t o r t a " . Ph.D. t h e s i s , U n i v e r s i t y of Michigan, Ann Arbor, Michigan. L u c k w i l l , L.C. and C u t t i n g , C,V. 1970. " P h y s i o l o g y of Tree Crops". 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Proceedings of Symposium oh Seed P r o c e s s i n g , V o l . 1, Paper No.17, Bergen, Norway. Watson, E.L. 1965. " E f f e c t o f Heat on the Germination of Wheat", Paper presented a t the 1965 Annual Meeting P a c i f i c Northwest Region, American S o c i e t y of A g r i c u l t u r a l E n g i n e e r s , Moscow, Idaho. Watson, E.L. 1970. " E f f e c t o f Heat Treatment Upon the Germination of Wheat". Can. J . of P l a n t S c i e n c e , V o l . 50, 107. Wexler, A. and Wildhack, W.A. ( E d i t o r s ) . 1965. Humidity and Moisture Measurement and C o n t r o l , V o l . 3, Re i n h o l d P u b l i s h i n g Corp., New York. 138 51. Wheeler, W.A. and H i l l , D.D. 1959. Grassland Seeds. Van Nostrand Co. Ine., P r i n c e t o n , New J e r s e y . 52. Woodforde, J . and Lawton, P.J. 1965. "The Drying of Seeds". J . of A g r i c . Eng. Research, V o l . 10, 283 139. A P P E N D I X A 140. TABLE A-1. NUMBER OF SEEDS PER CONE, BY LOCATION Basal Central Upper Total Basal Central Upper Total Region Region Region Seeds/Cone Region Region Region Seeds/Cone 4 8 7 19 17 15 21 53 0 5 2 7 10 14 6 30 4 5 5 14 3 14 . 18 35 8 14 6 28 7 10 7 24 11 16 6 33 3 4 2 9 9 17 12 38 8 14 4 26 16 8 7 31 5 12 1 18 6 10 5 21 4 11 5 20 9 9 6 24 8 14 12 34 5 10 5 20 6 8 4 18 4 12 6 22 1 12 4 17 11 12 3 26 9 13 3 25 4 io 2 16 1 12 2 15 13 16 10 39 3 13 6 22 2 5 7 14 13 11 4 28 13 13 9 35 9 13 10 32 6 15 4 25 5 13 8 26 5 8 4 17 0 8 6 14 4 6 6 16 4 10 11 25 7 7 15 29 5 15 6 26 10 16 22 48 7 18 15 40 9 10 5 24 6 12 4 22 4 4 0 8 6 11 10 27 3 17 10 30 6 13 5 24 8 4 2 14 5 10 3 18 4 7 6 17 7 11 9 27 5 6 2 13 7 14 10 31 7 15 11 33 5 15 11 31 8 11 6 25 5 6 3 14 6 11 13 30 5 11 13 29 3 10 6 19 16 23 25 64 141. TABLE A-1 (Continued) Basal Central Upper Total Basal Central Upper Total Region Region Region Seeds/Cone Region Region Region Seeds/Cone 0 6 3 19 7 9 15 31 2 13 5 20 5 4 1 10 6 5 4 15 7 17 10 34 2 10 13 25 6 14 4 24 4 9 10 23 10 22 11 43 2 8 3 13 4 5 8 17 10 12 10 32 . 2 6 5 13 6 14 7 27 5 12 7 24 2 . 7 3 12 7 9 2 18 0 5 2 7 5 17 4 26 2 11 17 30 5 6 6 17 7 8 13 28 5 15 6 26 4 6 4 14 6 10 8 24 7 11 6 24 3 8 10 21 5 10 6 21 7 13 3 23 6 10 8 24 9 11 3 23 6 5 1 12 5 21 11 38 5 7 11 23 5 14 15 34 6 5 8 19 3 5 2 10 TOTAL 592 1076 724 2392 AVERAGE SEEDS PER CONE 5.9 10.8 7.2 23.9 PERCENT. OF TOTAL SEEDS 25% 45% 30% GERMINATION % OF GROUP .91.2% 90.9% 91.6% AVERAGE GERMINATION % OF ALL SEEDS 91.21% 142. TABLE A-2 VIABILITY OF OVEN DRIED CONES I n i t i a l cone c o n d i t i o n s 34°F (2°C), 23% MC (w.b.). Oven temperature 140°F ± 3°F (60°C ± 1.5°C). Open a i r movement by c o n v e c t i o n o n l y . Sample Treatment Germination Number Time i n % o f F i l l e d Hours Seed 1 4 87% 2 8 93% 3 12 91% 4 16 92% 5 20 92% 6 24 94% 7 36 95% 8 48 97% 9 72 93% 0 143. TABLE A-3 EQUILIBRIUM MOISTURE CONTENT (WET BASIS) OF CONES OVER SATURATED SALT SOLUTIONS AFTER 30 DAYS Salt D i s t i l l e d Barium Ammonium Ammonium Sodium Potassium Lithium Solution Water Chloride Chloride Nitrate Iodide Acetate Chloride E q u i l i - brium R H @ 72°F 100% 90.2% 78.0% 61.0% 39.0% 23.0% 11.3% 27.88 22.14 17.89 13.21 9,51 7.70 4.67 27.81 21.95 16, 93 13.55 9,59 7.28 4.96 27.97 20.58 17.66 13.61 9,91 7.56 4.81 26.35 21.29 17.87 13,13 9.80 7.56 4.85 INDIVIDUAL 29.79 20.51 17,46 13.50 9,64 7.39 4.84 29.89 20.12 17.18 13,34 9.64 7.43 4.60 CONE 21.82 16.89 13,94 9.65 7.45 4.76 22.85 17.64 13,35 9.47 7.21 4.71 MOISTURE 20.95 16.82 13.55 9.50 7.33 4.92 20.92 16.80 13,45 9.54 7.59 4.86 CONTENTS 20.98 17.37 13,08 8.03 7.32 4.87 20.73 17.53 13.62 9.74 7.38 5.01 21.35 17,59 13.09 9.21 7.36 4.60 21.44 17.44 13,64 10.18 7,27 4.78 21.68 17.96 13,43 9.52 7.78 4.72 20.72 13.78 9.48 7.56 4.98 Mean Equb'm 28.28% Moisture +1.35 Content 21.23% +0.73 17.40% +0.39 13.45% +0.25 9.52% +0.45 7.45% +0.16 4.81% -0.13 144. TABLE A-4 CONE SCALE RELEASE TEMPERATURES Bath Number of Number of Bath Number of Number of Temp New Cones Old Cones Temp New Cones Old Cones °C Opened Opened cc Opened Opened 42.3 1 1 52.6 1 0 43.1 2 2 52.8 2 1 43.2 1 1 53.3 1 0 43.8 2 0 53.4 3 1 44.5 3 2 54.1 4 1 44.8 0 1 54.3 2 2 45.1 1 1 54.7 1 1 45.4 0 1 54.8 0 3 45.7 2 1 55.0 0 0 46.0 0 1 55.5 0 1 . 46. 4 1 0 55.6 1 1 46.5 2 0 56.3 1 3 47.0 1 0 56.8 0 3 47.1 0 0 57.0 1 0 Al .1 0 2 57.5 0 4 48.3 0 0 57.6 0 1 48.4 0 0 58.0 1 2 48.9 0 0 58.1 3 1 49.2 o o 58 .7 1 2 49.7 1 0 59.2 4 3 49.9 2 0 59.3 1 2 50.5 2 1 59.7 1 2 50.6 0 0 60.1 0 2 51.0 0 1 60.4 1 2 51.1 1 1 61.2 2 3 51.8 0 0 61.6 1 1 51.9 5 1 62.5 1 1 Mean Temperature 52.51°C 54.50°C Std. D e v i a t i o n ±5.7 °C ±5.8 °C Number of Cones 6 0 60 TABLE A-5 MAXIMUM CONE SCALE ANGLES OF CONES 21.2% M.C. (w.b.) (In Degrees) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 12 15.5 6.5 10 9 8.5 12 11 9 4 4 6 15 8 11 12 14 4.5 7 6 4.5. 15.5 11 9 8.5 10 5 20.5 5.5 14.5 10 12 4 4.5 5.5 3 17 11.5 6 7 8 20 8 13 8 8 6 3.5 2 2.5 10.5 11 2 4 8.5 TJ 18.5 7 11 8.5 9.5 5 2 5 5.5 9.0 9 4.5 4 7 1 19.5 8 13.5 9 9 4 7.5 4 2 8 9 10 3 9.5 a if 18 7 11.5 9.5 14.5 7 5.5 4.5 10.5 11.5 10.5 9 6 16.5 8.5 Mean Value 9.86 11.78 5.00 5.93 5.28 4.50 11.78 10.57 7.29 5.64 7.57 Or 5.5 18.28 7.25 11.86 Std. Deviation 1.60 2.98 1.05 2.73 2.12 2.10 3.33 1.09 3.18 2.46 2.09 0.71 1.98 0.99 1.99 OVERALL AVERAGE SCALE DEFLECTION 8.54° + 3.79° TABLE A-6 MAXIMUM CONE SCALE ANGLES OF CONES AT 17.4% M.C. (w.b.) (In Degrees) Cone No. 1 2 .3 4 . .5 . . . .6 . .7 .: . . 8 . . 9 10 11 12 13 14 15 16 44.5 38 51.5 25 32 22 33.5 23 30 31 24 21 34 31 47 30 51 31. .5 34.5 25 29 31 26.5 24.5 30 28.5 34 31 43.5 39. 5 48.5 35 33 35 29.5 39 25.5 22 25 26 29 27 To c at 45 30 47 35 42 32 23.5 31 24.5 22 17 26 TS cu. 22 26. 5 & 45 39 54 33 34.5 24 34 34 24.5 30 28 21 d 24 22 33 50.5 33 36 32 31 31 28 30.5 27.5 19.5 25. 5 29. 5 rH 28 53 32 34 26 30 26 27 21 32. 5 24 Mean o a. Value 45.00 33. 93 50.78 33. 50 35.14 28,00 30.08 31.29 26,50 26.57 24,07 23,28 28. 71 27. 36 Std. Deviation 1.27 ' 4. 83 2.43 1. 50 3.27 4.93 3.81 4.78 2.17 3.94 4.14 3.46 4. 96 3. 55 OVERALL AVERAGE SCALE DEFLECTION 31 .73° + 7,78° (71 TABLE A-7 MAXIMUM CONE SCALE ANGLES OF CONES AT 13.5% M.C. (w.b.) (In degrees) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 : 13 14 15 16 67 55 42 38 45 78 41 49. .5 43 59.5 59 54 54 43.5 65 54 46.5 36.5 52 68 61 45. .5 44 60.5 64 48.5 42 49.5 59 57 51 35 51 45.5 53 51. .5 47 54 64 42 43 55 60 58.5 43 30 50 60 53 46 41 50.5 51.5 35.5 44 44.5 OJ 77 54 32 26 56. 5 69 57 40 40 61.5 54 47 38 i 71 54 42 33 47 71 50.5 39 35 52 51.5 32 i 36 64. 5 58 50 41 45 50 42 44 59 51 38 33. 5 rH A1 71. 5 oo r •8 Mean Value 66. 85 55.78 43.78 34.21 49. 42 65.25 52.21 44. ,78 42.0 56.71 56.5 42.42 41. 5 48.12 Std. Deviation 2. 00 6.38 5.05 4.56 11. 26 6.26 4.72 3. .83 4.44 5,42 7.84 7.84 6. 73 1 5.28 OVERALL AVERAGE SCALE DEFLECTION 49.97° + 9.42° TABLE A-8 MAXIMUM CONE SCALE ANGLES OF CONES AT 9.5% M.C. (w.b.) (In degrees) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 74.5 70 58.5 6.85 49 58.5 89.5 75.5 65 52 45 75 49 65.5 62 48 57 62 88 57 59 72.5 65.5 70 58 35.5 64.5 50 68.5 61.5 43 58 60 76 52 68.5 63 61 72 60.5 34 71 49 67.5 62.5 67 71 48 72.5 54 66 50.5 70 69.5 52 34 71.5 52 68 58 74.5 71.5 64 59.5 61 60 84 67 61.5 33 66 54 56 64 73 68 52.5 58.5 72.5 76 75 58 41 63 53 64 70 65 58.5 74 69 81.5 70 Mean Value 64.36 65.78 58.59 76.25 54.64 60.25 68.86 72.99 69.54 57.00 37.08 72.31 51.17 65.59 61.60 Std. Deviation 13.2 6.1 6.2 8.4 3.8 3.0 12.4 8.2 3.13 4.1 4.8 8.2 2.1 4.7 2.2 OVERALL AVERAGE SCALE DEFLECTION 62.57° + 11.5° TABLE A-9 MAXIMUM CONE SCALE ANGLES '. OF CONES AT 7.5% M.C. (w.b.) (In degrees) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 99.5 57.5 64.5 67 83 82 58 81 104.5 74 72.5 51.5 63 65 57 56.5 102.5 66 64 79 61 85 60 70 87 79.5 76 62 61 69 57.5 70.5 94.5 59.5 72 88 48 88 62 71 103 74 66.5 54 69 66 71.5 68 91 69 67 87.5 55 98 69 85.5 95 70 72 49 56 72 71 60.5 93.5 61 69.5 74 58 88.5 69 77.5 102 59 75.5 49 64 71 63 75.5 89 59 69.5 69 59 99.5 78 76.5 73 79 66 67 57 92 58 56 69.5 89.5 68 79 79 78 63 55 Mean Value 94.57 61.43 66.07 76.28 60.67 90.07 66. 28 77.21 98.30 72.64 74.21 53.10 62.60 67. 42 63.14 64.1 Std. Deviation 4.81 4.38 5.29 8.76 11.84 6.45 6. 85 5.44 7.29 6.88 4.27 5.39 4.72 3. 31 6.86 7.: OVERALL AVERAGE SCALE DEFLECTION 71.79° + 12.82° vo TABLE A-10 MAXIMUM CONE SCALE ANGLES OF CONES AT 4.8% M.C. (w.b.) (In degrees) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 91 106 72.5 79 79 94.5 88.5 68 74 97.5 94 114 81.5 87 85 80 83 122 77 105.5 76 74.5 99 73 107.5 86.5 86 109.5 79.5 91 80 77 82.5 116.5 84 87 82 80 87 73 91 90.5 80.5 131 78.5 90.5 77 81 93 117 84 84 80 95.5 87.5 70 94 85 91.5 95 71 79 74 88.5 92 121.5 81.5 89 76 . 121 84.5 69 79 79.5 79.5 106.5 70 74.5 76 75 89.5 118 90 83 82.5 92.5 74.5 69 88 74 87.5 103.5 84.5 75.5 76 92 79.5 88 75.5 91 78 69 95.5 94 75 83.5 87 81.5 Mean Value 88.50 116.83 81.21 87.93 78.7192.71 85.57 70.14 88.92 86.93 87.57 109.92 77.14 83.00 79.28 82.14 Std. ... Deviation 4.60 5.78 5.62 8.47 2\94 14.76 7.91 21.03 11.81 8.41 6.00 12.14 5.38 6.84 4.96 6.07 OVERALL AVERAGE SCALE DEFLECTION 86.59° + 13.09° TABLE A - l l MAXIMUM CONE SCALE ANGLE OF CONES OVEN DRY Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 IS 16 17 18 19 20 88.0 106.0 7S.0 82.0 108.0 89.0 111.0 82.5 127.0 96.5 76.5 91.0 84.0 108.5 88.5 74.0 132.0 90.0 103.0 87.5 103.5 128.0 87.0 126.0 105.0 90.5 110.0 77.5 122.0 106.0 70.0 76.0 90.0 97.5 83.5 88.0 128.5 96.0 94.5 9S.5 89.5 125.0 87.0 112.0 108.0 97.0 112.0 95.5 117.0 104.0 62.5 76.0 89.0 102.0 81.0 88.0 121.0 98.0 90.0 86.0 89.0 125.0 86.5 117.0 115.5 83.0 107.0 97.0 109.5 102,0 66.5 77.5 88.5 99.5 81.5 84.0 117.0 101.0 107.0 93.0 84.5 107.0 87.0 113.0 107.0 81.0 122.5 109.0 101.5 94.S 79.5 66.5 87.0 99.0 79.0 85.5 110.5 106.0 101.5 93.5 87.5 101.0 76.5 112.0 107.0 85.0 123.0 ' 104.0 107.0 98.5 71.0 71.S 94.5 105.0 79.0 90.5 123.0 97.0 113.0 92.0 95.0 125.0 81.0 116.0 107.0 93.0 117.0 102.0 115.0 103.5 68.0 76.5 102.0 93.0 72.5 83.0 127.0 93.5 109.0 88.0 Mean Value 91.00 116.71 82.85 111.14 108.21 88.36 114.64 95.36 114.14 100.71 70.57 76.43 90.71 100.64 80.71 84.71 122.71 97.36 102.57 90.3 Std. Deviation 6.35 11.47 5.32 13.74 3.36 5.71 6.29 11.49 8.82 4.27 5.83 7.49 5.90 5.08 4.99 5.38 7.34 5.15 8.11 3.33 MEAN SCALE ANGLE 97.02° + 15.68° TABLE A-12 MAXIMUM SCALE ANGLES OF CONES STORED SIX MONTHS AT 11.2% M.C. (w.b.), UNSEALED AND DRIED TO 9.9* M.C. (Stress Relaxed Cones) Cone No. 1 2 3 4 S 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22.0 13.0 14.0 20.0 17.5 18.5 19.5 '20.0 23.0 14.5 20.0 22.5 24.5 24.5 29.0 25.0 18.0 18.0 17.0 29.5 21.0 13.0 13.0 19.5 15.0 18.5 23.0 17.5 20.0 14.0 20.0 20.0 22.5 25.0 24.0 27.0 19.5 19.0 27.0 32.0 21.0 12.0 12.5 11.5 17.0 17.0 19.5 20.0 23.0 10.5 22.5 19.0 19.5 21.S 24.5 20.5 18.0 20.0 24.0 37.0 20.0 8.0 16.0 19.5 17.0 17.0 23.0 20.0 23.5 14.0 23.0 16.5 19.0 30.0 18.0 26.0 12.5 27.0 21.5 37.0 19.5 11.0 15.5 16.0 19.0 18.0 23.0 19.0 23.5 14l,0 25,0 17.0 18,0 26.0 18.0 26.0 13.0 25.0 21.5 36.5 20.0 12.0 16.0 15.0 19.0 18.0 20.5 23.0 25.0 14.0 24.0 18.0 17.5 27.0 18.0 24.0 14.0 22.5 20.5 33.0 20.0 11.5 19.5 16.0 19.0 18.0 18.0 24.0 21.0 15,0 24.5 17.5 23.0 28.0 21.0 21.0 14.0 30.5 19.5 32.5 MEAN SCALE ANGLE 20.28° + 5.35° 153. TABLE A-13 MAXIMUM SCALE ANGLES OF CONES STORED SIX MONTHS AT 11.2% M.C. (w.b.) UNSEALED, REWETTED AND DRIED TO 11.1% M.C. (w.b.) (Stress Relaxed Cones) Cone No. 1 2 3 4 5 6 7 8 9 10 52.0 61.0 57.0 53,0 62.5 66.0 64.0 63.0 78.0 58.0 51.5 65.0 58.0 54.5 63.0 66.0 61.0 70.0 89.0 59.5 50.5 61.0 54.0 60,0 61,5 72,0 60.5 79.5 88.5 53.5 53.0 61.0 57.0 60,0 65.5 61.5 62,5 78.0 83,0 55.0 51.5 64.5 56.5 64.0 65,0 64,0 70,5 64.0 70.5 53.5 50.0 59.0 55.0 62.0 71,0 64,5 62,5 65,0 72.0 56.5 46.0 61.0 49,0 62.0 66.0 70.0 62.0 62.5 71.5 64.0 MEAN SCALE ANGLE 62.63° + 8.66° TABLE A-14 MAXIMUM SCALE ANGLES OF CONES STORED SIX MONTHS AT 11.2* M.C. (w.b.) UNSEALED, REWETTED AND DRIED TO OVEN DRY (Stress Relaxed Cones) Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 57.5 90.0 80.5 87.0 107.5 113.0 99,5 84.5 119.5 85.0 96.0 97.5 100.5 99.0 102.0 90.5 89.5 95.5 102.5 99.0 72.0 89.0 84.0 87.0 97.0 96.5 101.0 83.0 102.0 84,5 86.0 96.5 101.0 101.5 104.0 91.0 91.0 94.5 114.0 105.0 65.0 95.5 87.0 85.5 102.0 98.5 97.S 92,5 102.0 87,0 90.0 100,5 97.5 96.5 94.5 87.0 87.5 92.0 113.0 102.0 66.0 86.5 86.0 83.5 92.0 91.5 85.0 92.0 95.5 89.0 88.0 99,5 98.5 105,5 96.5 85.5 88.5 87.0 122.0 106.0 68.0 86.0 86.0 91.0 102.0 104.0 79.5 106.0 96,0 88.0 84.0 102.0 100.5 100.5 100.0 92.0 85.5 86.5 114.0 103.0 64.0 86.0 79.5 89.5 96.0 98.5 85.0 99,5 96,5 89.0 81.0 102.0 100.S 100.0 108.0 90.0 100.5 92.S 110.0 99.0 70.5 88.5 80.0 -85.5 96.0 108.0 99.0 94.5 96,5 87.0 80,0 99.0 100.0 99,5 96,5 93.0 93.5 90.0 117.0 101.0 MEAN SCALE ANGLE 93.64° + 10.65° TABLE A-15 MAXIMUM CONE SCALE ANGLES FOR FIRST SEED RELEASE TEST Cone No. 50.0 50.0 49.5 43.5 40.5 45.0 45.0 36.0 33.5 41.0 46.0 46.0 46.0 45.0 47.0 43.0 41.0 44.0 45.0 42.0 42.0 35.0 29.0 30.0 39.0 35.0 33.0 29.0 33.0 36.0 30,0 45.0 34.0 37.0 33.0 42.0 38.0 37.5 32.0 38.0 36,0 39.5 42.5 55.0 50.0 57.5 45.0 50.5 47.5 46.5 48,0 41,5 44.5 46.0 43.5 52.0 37.0 39.0 37.S 41.5 36.0 31,0 39.5 10 27,0 37.0 43,0 42.0 40.0 37,0 37.0 11 34.5 34.0 . 34,0 31.0 31.0 34.0 32.0 12 31.0 32.0 32,0 34.0 36,0 '31.0 33.0 13 69.0 76.0 75,0 69.0 67,0 67,0 47.5 14 51.5 55.0 57,5 53.5 50,0 41.0 41.5 IS 42.5 40.5 37,5 34,0 36.5 35.5 38.0 16 31.5 37.5 17 39.0 44.5 37,5 45,5 34.0 50.0 32.0 47.0 35,0 49.0 34.0 46.5 18 50.0 47.0 47.0 45,0 45.0 40.0 39.0 19 36.0 33.5 36.5 35,0 37.0 29.0 42.5 20 48.0 49.5 54.0 51.5 •51.5 53.5 46.0 MEAN SCALE ANGLE 42.00° + 9.20° Number of Seeds Released this Test 226 Cumulative number of Seeds Released 226 Cumulative percentage of total Seeds Released SOS TABLE A-16 MAXIMUM CONE SCALE ANGLES FOR SECOND SEED RELEASE TEST Cone No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 IS 16 17 18 19 20 62.5 60.5 54.0 42.0 44.5 48.0 66.0 57.0 46.5 48.0 41.0 45.0 88.5 66.5 39.0 50.0 66.S 60.0 52.0 73.5 69.5 58.5 56.0 38.5 41.5 49.5 80.0 70.0 46.5 47.0 38.0 48.0 77.5 65.5 56.0 52,0 80.5 46.0 65.0 58.5 63.0 53.0 62.0 47.0 44.0 52.0 79,0 60,0 45.0 45.0 41,0 44.5 74.5 54.5 52.0 53.0 74.5 57.0 50.0 72.5 71.5 45.0 65.0 39.5 45.0 53.0 67.0 47.0 35,0 44.5 40.0 49.0 74.5 64.0 54.0 48.0 65.0 63.0 45.0 70.0 72.0 63.0 62.0 39. S 33.5 59.0 60.0 64.0 45.0 45.0 44.0 55.0 90.0 75.5 51.0 45.5 72.0 57.5 33.0 67.0 70.0 61.S 62.0 48.0 57.5 59.5 70.0 65.0 42.0 40.0 46.0 44.0 90.0 76.5 46.0 45.0 74.0 65.5 .48.0 71.0 70.0 64.S 58.S 44.5 50.0 65.0 64.0 67,0 43.0 41.0 47.0 47,5 87.5 75.0 48.0 50.0 78.5 60.0 58.5 73.0 MEAN SCALE ANGLE 56.97° + 12.85° Number of Seeds Released this Test 93 Cumulative number of Seeds Released 319 Cumulative percentage of total Seeds Released 70.3% Ln TABLE A-17 MAXIMUM CONE SCALE ANGLES FOR' THIRD SEED RELEASE TEST Cone No. 1 2 3 4 5 fi 7 8 9 10 11 12 13 14 IS 16 17 18 19 20 89.0 76.0 84.5 58.0 54.0 59.5 94.0 71.0 60,0 59.5 57.0 66,5 98.0 88.0 61.5 56.5 89.5 74.0 68.0 81.0 83.5 71.5 85.5 66.0 64.5 67.0 96.0 71.0 60,5 64.5 55,0 72,5 103,5 86.5 59.0 66.5 79.0 73.0 64.0 81.0 84.0 70.0 80.0 51,0 63,0 72.0 93,0 67.5 58.0 62,5 54.0 74,0 89.0 90.0 60.0 65.5 85.5 80.0 74.0 81.5 88.0 74.5 86.0 62.0 60.0 77.0 84.5 76.5 61,0 59,0 50,0 74,0 87.6 82.5 65,0 67.0 86.0 75.0 62.5 84.0 88.5 77.0 72.0 60.0 61.0 82.0 84.5 73,0 57,0 54,5 52.5 77,0 93,5 93,5 55.0 64.0 84.5 75.0 63.0 79.5 78.0 75.0 80.0 S8.0 68.0 73.5 91.0 74,0 54,0 56.0 55,0 72,0 105.0 91.0 56.5 60.0 90.0 76.0 73.0 85.0 86,0 76.0 76.5 56.0 67,5 83.5 98.0 71.0 59.S 55,0 62.0 67.5 105.0 81,0 60.0 63,0 89.5 72.0 81.0 84.0 MEAN SCALE ANCLE 73,10° + 12,92° Number of Seeds Released this Test 65 Cumulative number of Seeds Released 384 Cumulative percentage of total Seeds Released 84.84 TABLE A-18 MAXIMUM CONE SCALE ANGLES FOR FOURTH SEED RELEASE TEST Cone No. 1 2 3 4 5 6 7 • 8. 9 10 11 12 13 14 .15 16 17 18 19 20 • 120.S 112.0 97.0 73.0 83.0 97.5 117.5 95.0 87,0 95,0 91.0 99,0 124.0 119,0 88.0 84.0 117.0 108.5 105.0 111.0 122.0 110.5 109.0 87.5 81.0 95.5 125.0 94.5 83,5 94,0 95,0 97,5 131,0 124,0 99.0 101.0 134.0 107.0 115.5 113.0 122.0 109.5 109.0 85.0 89.0 106.0 126.0 87.0 83,0 91.0 91,0 99,0 126,0 113.5 96.5 98.5 138.0 107.0 105.0 112.0 11S.0 101.5 100.0 85.5 92.0 118,0 126.0 109,0 88,0 84,0 86,5 103,0 117.0 114.0 89.0 92.5 138.0 104.0 101.0 113.0 122.5 99.5 112.0 83.0 91.0 124.5 124.0 96,0 85,0 ' 90,5 81,0 116,0 121,0 117.0 93.5 85.0 126.0 104.5 102.0 108.0 122.0 102.5 110.0 87.5 98.5 123.0 124.0 93,0 88,0 92,0 91,0 116,0 126,0 112.0 97.0 92.0 115.0 101.5 91.5 102.0 122.0 97.0 108.0 89.0 93.0 103,0 124,0 89.0 84,0 100.0 85,0 104,0 125.0 124,0 89.5 84.0 115.0 107.0 107.0 110.0 MEAN SCALE-ANGLE 103.86° + 13.60° Number of Seeds Released this Test 69 Cumulative number of Seeds Released 453 Cumulative percentage of total Seeds Released 1004 H 159. TABLE A-19 DEGREE OF SEROTINOUS SEAL BREAKING IN CLASS I (YOUNG) CONES BY FLAME TREATMENT Sample Number Treatment Time Number of Cones Reiraining Sealed Number of Cones Par t i a l l y Unsealed Number of Cones Fu l l y Unsealed IA IB IC ID IE IF 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 8.26% MOISTURE CONTENT 62 0 0 0 0 22 2 0 0 0 16 98 100 100 100 10.7% MOISTURE CONTENT 2A 2B 2C 2D 2E 2F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 71 3 0 0 0 18 12 1 2 0 11 85 99 98 100 16.71% MOISTURE CONTENT 3A 3B 3C 3D 3E 3F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 98 9 1 0 0 1 26 5 2 0 1 65 94 98 100 20'. 7 3% MOISTURE CONTENT 4A 4B 4C 4D 4E 4F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 100 63 5 0 0 0 0 12 16 1 1 0 0 25 79 99 99 100 TABLE A-19 (Continued) 160. Sample Number Treatment Time Number of Cones Rernaining Sealed Number of Cones Par t i a l l y Unsealed Number of Cones Fully Unsealed 5A 5B 5C 5D 5E 5F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 21.78% MOISTURE CONTENT 74 14 1 0 0 16 20 8 0 0 10 66 91 100 100 25.13% MOISTURE CONTENT 6A 6B 6C 6D 6E 6F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 95 63 12 0 0 1 10 8 1 0 4 27 80 99 100 27.82% MOISTURE CONTENT: 7A 7B 7C 7D 7E 7F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 100 92 34 3 0 0 6 12 5 4 0 2 54 92 96 31.2 0% MOISTURE CONTENT 8A 5 sec - - ; 8B 10 sec 99 1 0 8C 15 sec 97 3 0 8D 20 sec 61 10 29 8E 25 sec 5 11 84 8F 30 sec 7 4 89 161. TABLE A-20 DEGREE OF SEROTINOUS SEAL BREAKING I N CLASS I I I WEATHERED CONES BY FLAME TREATMENT Sample Number Treatment Time Number o f Cones Remaining Sealed Number• of Cones Partial l y Unsealed Number of Cones Fully Unsealed 10A 10B IOC 10D 10E 10F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 8% MOISTURE CONTENT 24 23 0 8 0 1 0 0 0 0 53 92 99 100 100 11% MOISTURE CONTENT 11A 5 sec 63 25 12 11B 10 sec 18 26 56 11C 15 sec 0 8 92 11D 20 sec 0 1 99 H E 25 sec 0 0 100 11F 30 sec r- • - 13% MOISTURE CONTENT 12A 5 sec 86 11 3 12B 10 sec 22 34 44 12C 15 sec 0 9 91 12D 20 sec 0 2 98 12E 25 sec 0 0 100 12F 30 sec 0 0 100 16% MOISTURE CONTENT 13A 5 sec 95 5 0 13B 10 sec 40 36 24 13C 15 sec 6 19 75 13D 20 sec 1 11 88 13E 25 sec 0 6 94 13F 30 sec 0 1 99 162. TABLE A-20 (Continued) Sample Number Treatment Time Number of Cones Remaining Sealed Number of Cones Par t i a l l y unsealed Number of Cones Ful l y Unsealed 14A 14B 14C 14D 14E 14F 19% MOISTURE CONTENT 5 sec 96 4 10 sec 68 25 15 sec 8 20 20 sec 0 6 25 sec 0 4 30 sec 0 1 0 7 72 94 96 99 22% MOISTURE CONTENT 15A 15B 15C 15D 15E 15F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 92 49 1 3 0 8 28 16 11 6 0 23 83 86 94 16A 16B 16C 16D 16E 16F . 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 24% MOISTURE CONTENT 90 7 53 32 2 18 2 14 0 5 3 15 80 84 95 17A 17B 17C 17D 17E 17F 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec 28% MOISTURE CONTENT 97 3 90 8 16 28 12 24 3 15 0 2 56 64 82 163. TABLE A-21 GEOMETRIC VARIABLES AFFECTING CORE BORING OF LODGEPOLE PINE CONES.* . Cone Overall Core Core Tip to Core Axis to Core Axis Core Edge Length Cone Angle Cone Apex Cone Axis Misalign- to Seed A Angle B Angle ment C Inches 0° 0° Inches o a Inches 1.75 49 28 .73 11 .035 1. 57 28 19 .99 4 .030 1.67 39 21 .77 8 28 .035 1.42 33 22 .90 6 .020 1.27 35 18 .84 10 .035 1. 51 32 28 .98 7 .025 1.70 43 26 .73 10 .035 1. 52 36 17 .98 4 .040 1.42 40 15 .80 8 10 .030 1.37 25 14 1,21 0 .045 1.42 36 22 ,98 7 . . .025 1.35 34 25 •1.00 1 .035 1.38 35 21 .88 8 .035 1.26 39 30 .80 3 8 .030 1.06 51 30 . 59 7 .030 1.08 57 39 .77 2 .035 1. 63 49 32 .78 7 26 .030 1.71 50 22 .80 5 .035 1.17 61 37 .60 11 .030 1.45 52 27 1.00 9 .050 1. 01 37 20 1, 05 0 .030 1. 63 57 44 . 72 14 20 .045 1.43 26 13 1. 28 3 .7 .040 1.31 43 31 .86 0 .040 1.51 2 7 19 1.22 5 10 . .025 1. 52 31 23 1.29 4 .040 1. 58 24 23 1,26 6 .030 * Geometric variables are defined i n Figure 33. TABLE A-21 (Continued) Cone Overall Core Core Tip to Length Cone Angle Cone Apex A Inches Angle . e° 0° B Inches 2.03 27 24 1.77 2.06 26 19 1.84 1.58 31 23 1.26 1.30 52 27 .67 1.31 30 38 1.12 1.38 36 24 .88 1.48 25 37 1,23 1.37 27 32 .96 .96 47 32 .48 1.18 50 42 .64 1.15 64 32 ,63 .98 44 46 .75 1.39 31 15 ,91 1.46 24 27 1,37 1.51 19 17 1.83 1.19 26 20 .96 1.13 32 12 .86 .92 57 28 .62 1.64 38 16 1.01 1.33 ' 29 24 1.16 1.21 34 24 .94 1.35 52 35 .84 .1.21 24 13 .69 Core Axis to Core Axis Core Edge Cone Axis Misalign- to Seed Angle ment C o a 3° Inches - 12 .055 12 25 .050 13 .045 11 38 .045 18 ,035 9 .035 9 .035 15 .025 7 ,025 3 .035 8 ,030 5 .040 7 • .020 7 •." .030 1 ,035 .4 30 ,025 4 .030 13 .030 3 ,050 10 .040. 6 .050 10 .035 0 .040 1.396 37.9 25.5 .966 ±.24 ±11.4 ±8.4 ±.30 6.9 ±4.2 4.0 ±9.4 .034 ±.011 TABLE A-22 RESULTS OF THRESHING TESTS ON LODGEPOLE PINE CONES (F i r s t Prototype) Sample Cone Cyl. Dry Wt. No. of Wt. of Wt. of No. of Germ'n No. Viable No. M.C. Speed of Cone Cones Whole Seeds/ Whole % Seeds Recovery % wb ft/min g. Seed 100 Seeds (of Per Cone % * Cones g. Total) 4 8.5 1800 600.5 125.5 1.3613 1.0847 489 36.5 1.43 8.3% 5 8.5 2300 535.5 111.9 1.7431 1.5577 439 38.9 1.53 9.1% 6 8.5 2800 515.6 107.8 1.3513 1.2535 327 35.7 1.08 6.4% 7 8.5 3300 560.3 117.1 1.0600 .9488 256 36.1 .80 4.8% 7A 8.5 3800 536.1 112.0 1.2217 1.0908 321 17.0 .49 2.9% 7B 8.5 4300 555.4 116.0 .7670 .6872 200 20.5 .35 2.1% 8 12.8 1800 507.8 106.1 1.8859 1.7774 576 46.3 2.51 15.0% 9 12.8 2300 535.5 111.9 1.8842 1.6838 636 42.7 2.43 14.5% 10 12.8 2800 559.5 116.9 1.7392 1.4877 608 27.1 1.41 8.4% 11 12.8 3300 480.2 100.4 1.9040 1.8964 624 22.7 1.41 8.4% 11A 12.8 3800 515.3 107.7 .9420 .8746 340 25.3 .80 8.4% LIB 12.8 4300 573.5 119.8 .8600 .7178 303 21.6 .55 3*3% * Viable seeds recovered, expressed as percentage of viable seeds in control. TABLE A-22 (Continued) Sample Cone Cyl. Dry Wt. No. of Wt. of Wt. of No. of Germ'n No.Viable No. M.C. Speed of Cone Cones Whole Seeds/ Whole % Seeds Recovery % wb ft/min Seed 100 Seeds (of Per Cone % * g- Cones q Total) 12 15.8 1800 462.8 96.7 1.8370 1.8996 587 38.7 2.34 14.0% 13 15.8 2300 521.9 109.0 2.4400 2.2385 831 26.7 2.04 12.2% 14 15.8 2800 593.5 124.0 2.2008 1.7748 729 40.0 2.35 14.0% 15 15.8 3300 633.6 132.4 1.7022 1.2850 591 27.8 1.24 7.4% 15A 15.8 3800 579.8 121.2 1.1171 .9217 380 28.3 .89 5.3% 15B 15.8 4300 588.7 123.0 1.5347 1.2477 575 23.3 1.09 6.5% 16 19.9 1800 590.4 123.4 2.0560 1.6661 696 44.3 2.50 14.9% 17 19.9 2300 389.5 81.4 1.5541 1.9092 540 33.9 2.25 13.4% 18 19.9 2800 649.0 135.7 1.9288 1.4217 657 43.8 2.13 12.7% 19 19.9 3300 622.1- 130.0 .9580 .7369 442 50.5 1.33 7.9% 19A 19.9 3800 562.1 117.5 1.7557 1.4942 618 41.7 2.19 13.0% CONTROL 100 2129 89.3%; 19.01 Viable seeds recovered, expressed as a percentage of viable seeds i n co n t r o l . 167. TABLE A-23 LODGEPOLE PINE SEED RECOVERY FROM RUBBERIZED THRESHER (Second Prototype) Test Cyl. Moisture No. % No. of Germ. % No. No. Speed Content Seeds F i l l e d F i l l e d (of Good Recove ft/min % w.b. Recov- Seeds F i l l e d Seeds o, * ered Seeds) Recov- ered 1 1600 15.5 1230 89 1094 61 668 39.8% 2 2000 15.5 1403 90 1263 59 745 44.4% 3 2400 15.5 1171 91 1066 49.5 527 31.4% 4 2800 15.5 1271 87 1106 55 608 36.2% 5 1600 20.0 970 95 922 40.5 373 22.2% 6 2000 20.0 978 94 919 41 377 22.4% 7 2400 20.0 796 93 740 43 318 18.9% 8 2800 20.0 758 89 675 30 202 12.0% CONTROL 2074 91 1887 89 1679 V i a b l e seeds r e c o v e r e d expressed as a percentage o f v i a b l e seeds c o n t a i n e d by c o n t r o l . 168. TABLE A-24 LODGEPOLE PINE SEEDS RECOVERED THROUGH CONCAVES FROM 10 0 CONES No. Recovered F i l l e d F i l l e d ( 0 f Viable Viable Viable Seeds F i l l e d Seeds Recovered Recovered Seed) Recovered - by (Concaves concaves - & Sieve) 1 297 91 270 46 124 26.8 13.2 2 569 93 529 41 217 46.8 23.1 3 221 92 203 33 67 14.4 7.1 4 99 89 88 27 24 5.2 2.6 5 44 90 40 38 15 3.2 1.6 6 18 90 16 13 2 .4 .2 7 8 88 7 38 3 .6 .3 8 8 88 7 60 4 .8 .4 9 5 100 5 0 0 0 0 10 0 - TOTAL 1165 39.1% 456 100.0% 48.5% 169. TABLE A-25 LODGEPOLE PINE SEEDS RECOVERED THROUGH SIEVE FROM 10 0 CONES Pass No.of Seeds % No. of Germ. % No. of % of % Total No. Recovered F i l l e d F i l l e d (of Viable Viable Viable Seeds F i l l e d Seeds Recovered Recovered Seeds) Recovered by Sieve (Concaves & Sieve) 1 484 88 426 36 153 31.5 16.3 2 513 95 487 37 180 37.1 19.1 3 292 89 260 32 82 16.9 8.7 4 131 82 107 35 38 7.8 4.0 5 54 90 49 24 12 2.5 1.2 6 24 92 22 20 4 •8 .4 7 18 88 16 36 6 1.2 .6 8 15 93 14 40 6 1.2 •6 9 9 100 9 33 3 .6 .3 10 4 100 4 25 1 .2 .1 TOTAL 1 3 9 4 34.8 485 100.0% 51.5% TABLE A-26 DATA FROM THRESHING OF DOUGLAS FIR CONES Cyl Cone Wb. of Wt. of No.Seeds Wt. of Wt. of No. of % Germ.% No. of Speed M.C. Uncleaned Seed in Debris Clean Seeds Filled of Viable Recover ft/min % wb Seed Sample Sample in Seed Seed Filled Seeds % * • g. g. Sample g. Seed Recov-g. ered F-l 1500 11.5 S A M P L E D E S T R 0 Y E D F-2 2500 11.5 7.1954 .3784 60 .0745 6.0118 953 66 35 220 82.7% F-3 3500 11.5 7.8325 .4200 60 .1368 5.9081 844 55.5 22 103 38.7% F-4 4500 11.5 6.0582 .4854 63 .2430 4.0312 524 40 22.5 47 17.7% F-5 5500 11.5 3.7438 .3600 61 .1158 2.8326 480 63.5 13 39 14.7% F-6 1500 24.3 7.9290 .4432 58 .2581 5.0109 655 80 16 84 31.6% F-7 2500 24.3 7.9176 .4476 58 .1562 5.8694 761 74 13 73 27.4% F-8 3500 24.3 6.1868 .4466 55 .3186 3.6109 445 73 13 42 15.8% F-9 4500 24.3 4.5265 .4346 54 .2500 2.8735 357 79 14 39 14.7% F-10 5500 24.3 5.8110 .4328 58 .3353 3.2907 436 73 7.5 23 8.6% CONTROL 1618 . 37.5% 44% 266 Sample Size - 100 cones. * Viable seeds recovered expressed as percentage of viable seeds contained by control TABLE A-27 DATA FROM THRESHING OF WHITE SPRUCE CONES Cyl. Speed ft/rain Cone MC %(wb) Wt.of Unclean Seed g- Wt.of Seed Sample g. No. of Seeds in Sample Wt. of Debris in Sample g. Wt. of Clean Seed No. of Seeds % Filled Seed Germ. % . of Filled Seed No.Viable Seeds Recovered Recovery % * S-l 1500 21.6 5.4552 .1259 67 .6394 4.1550 2211 79.5 29 510 24.6% S-2 2500 21.6 6.2669 .1068 69 .0439 4.4316 2884 89.5 35 903 43.6% S-3 3500 21.6 6.1492 .1412 87 .1290 3.2134 1979 91.5 30 543 26.2% S-4 4500 21.6 4.7788 .1353 83 .0716 3.1250 1917 88.5 34 577 27.9% S-5 5500 21.6 4.3230 .1182 81 .1052 2.2873 1567 87.0 30 409 19.8% S-6 1500 28.4 4.7324 .1672 90 .1010 2.9503 1588 89.0 23 325 15.7% S-7 2500 28.4 4.9200 .0977 60 .0846 2.6368 1619 88.5 16 229 11.1% S-8 3500 28.4 6.5427 .1428 83 .1300 3.4248 1990 85.0 10 169 8.2% S-9 4500 28.4 6.9434 .0993 61 .1078 3.3292 2045 86.0 20 352 17.0% S-10 5500 28.4 4.6170 .1040 57 .1049 2.2985 1259 82.0 18 186 9.0% CONTROL 5.1928 .0350 50 7418 36.0% 77. 5% 2069 Sample Size = 100 cones. * Viable seeds recovered expressed as percentage of viable seeds contained by control TABLE A-28 DATA FROM THRESHING OF WESTERN HEMLOCK Cyl, Speed ft/min Cone MC %(wb) Wt. of Unclean Seed g. • Wt. of Seed Sample g. No.of Seeds in Sample Wt. of Debris in Sample g. Wt. of Clean Seed g. No. of Seeds % GermV %".r No.Viable Filled of Filled Seeds Seed Seed % Recovered Recovery 9- * o H-1 1500 24.4 1.2567 .0955 50 .0430 .8665 1173 87 19.5 198.1 9.8% H-2 2500 24.4 1.4717 .1017 51 .0379 1.1119 1279 80 15 153 7.6% H-3 3500 24.4 1.5130 .1171 59 .0242 1.2538 1052 88 7.5 69 3.4% H-4 4500 24.4 1.5472 .1007 52 .0524 1.0176 946 78. 2.6 19 .9% H-5 5500 24.4 1.7846 .1050 52 .0543 1.1763 768 85 6.0 39 1.9% H-6 1500 30.4 2.2484 .1065 55 .0500 1.5300 970 80 5.6 43 2.1% H-7 2500 30.4 3.0877 .1120 56 .0696 1.9043 146 80 6.9 61 3.0% H-8 3500 30.4 2.1250 .1318 65 .0611 1.4519 915 78 6.4 46 2.3% H-9 4500 30.4 2.3137 .1000 55 .0610 1.4371 989 72.5 .7 5 .3% H-10 5500 30.4 2.0070 .1191 63 .1072 1.0562 664 82 3.7 20 1.0% CONTROL 6.4946 .1142 54 .0080 6.069 3029 79.5% 83.5% 2011 Sample Size = 200 cones. Viable seeds recovered expressed as percentage of viable seeds contained by control ro PUBLICATIONS MacAulay, J.D. and W.K. B i l a n s k i . "Mechanical P r o p e r t i e s A f f e c t i n g Leaf Loss i n B i r d s f o o t T r e f o i l " . Trans. of ASAE, V o l . 11, No. 4, 1968. MacAulay, J.D. "The A g r i c u l t u r a l Engineer i n the F o r e s t I n d u s t r y " , Canadian A g r i c u l t u r a l E n g i n e e r i n g J o u r n a l V o l . 12, No. 1, 197 0. MacAulay, J.D. "Low D e n s i t y , R i g i d P o l y r e r e t h a n Foam as an I n t e g r a t e d Insulation-Weather P r o t e c t i v e Covering f o r A g r i c u l t u r a l B u i l d i n g s " , Paper presented t o F a l l Meeting, A c a d i a Section,.American S o c i e t y of A g r i c u l t u r a l E n g i n e e r s , October, 1971. MacAulay, J.D. " P h y s i c a l P r o p e r t i e s of Low D e n s i t y R i g i d Polyurethane Foam".Information B u l l e t i n No. 1, Dept. of Bio-Resources E n g i n e e r i n g , Nova S c o t i a T e c h n i c a l C o l l e g e , H a l i f a x , N.S.'^October, 1972. MacAulay, J.D; " F a c t o r s A f f e c t i n g T r a c t i o n and F l o t a t i o n of Farm Equipment, Information B u l l e t i n g No. 2, Dept. of Bio-Resources E n g i n e e r i n g , Nova S c o t i a T e c h n i c a l C o l l e g e , H a l i f a x , N.S., May, 197 3. MacAulay, J.D. "Development of a Seed Covering Technique f o r E a r l y P l a n t i n g of C e r e a l s " . Paper No. 73-316, presented to Annual Meeting of. Canadian S o c i e t y of A g r i c u l t u r a l E n g i n e e r s , V i c t o r i a , B.C., August, 197 3 MacAulay, E.O. Nyborg and J . Metzger. "Development of Thermal S e a l Breaking Techniques f o r Seed Release of S e r o t i n o u s C o n i f e r Cones". Paper No. 74-506, presented to Annual Meeting of Canadian S o c i e t y of A g r i c u l t u r a l E n g i n e e r s , Quebec, P.Q., August, 1974.

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