UBC Theses and Dissertations
A nutritional study of grand fir and amabilis fir in the greenhouse Davidson, John Gerard Noel
Grand fir (Abies grandis (Dougl.) Lindl.) and amabilis fir (A. amabilis (Dougl.) Forbes) were grown in sand cultures from seed for two growing seasons in a greenhouse. The effects of deficiencies of nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur on the growth and development of the seedlings were studied. Four soil treatments were included to provide a comparison with natural media. These deficiencies caused a significant reduction of growth of both species, except in the low sulphur treatment; this was attributed to contamination. The treatments also affected the root/shoot and foliage/stem ratios, and produced a reduction in the total moisture content. The foliage was analysed for the total concentration of each of the six elements studied. In each case that of the deficient element was much reduced. The grand fir foliage concentrations were consistently higher than for amabilis fir and were influenced more greatly by the treatments. Each deficiency produced a different visual effect. These were documented photographically, chiefly in colour. The actual colours of symptoms were not specific, but the patterns generally were. Diagnostic keys to the deficiency symptoms were prepared. Magnesium and phosphorus symptoms were very distinctive, potassium and calcium were usually so, and nitrogen the least. An unreported type of calcium deficiency symptom, interpretable as a dieback phenomenon, was observed and described. Neither dry weight nor any other single criterion was able to express the net result of any treatment. A method to do this is proposed. It was found that the expression of the deficiency symptoms changed with time. In general it was observed that grand fir is more sensitive to deficiencies than amabilis fir.
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