UBC Theses and Dissertations
Some effects of water table, pH, and ammonium and nitrate nitrogen upon the growth and composition of highbush blueberry Herath, Herath Mudiyanselage Edward
Frequent drainage and aeration problems occur in blueberry plantings on acid peats (pH 3.0 to pH 4.2) of British Columbia during a part of the growing season. The effect of waterlogging, pH, and form of N were studied under greenhouse conditions. Using one year old plants of Bluecrop blueberry, a split plot design was employed with two water tables for main plots and a factorial combination of 4 pH levels and 3 levels each of ammonium and nitrate N (20, 40, and 60 lbs. N/acre). An unfertilized check treatment was also included as a treatment. Growth records and leaf analysis showed that poor aeration under waterlogged conditions exhibited characters symptomatic of poor nutrition. Sparse leaf growth, smaller leaves with severe yellowing and premature leaf abscission were observed in the high water table treatments. Leaf analysis revealed highly significant differences in foliar N, P, K, Ca, Mg, and Fe levels. There was also a greater growth response to ammonium N and nitrate N. Higher levels of nitrate N (40, and 60 lbs. N/acre) caused severe leaf scorch. Although higher levels of ammonium N (40, and 60 lbs. N/acre) gave better growth response, growth was prolonged and fall leaf drop and wood maturation were delayed. Plants receiving 60 lbs. N/acre as ammonium N showed symptoms of dieback in the following spring. Although pH had very little effect on leaf nutrient composition, growth appeared to be better at a pH level of around 4.2.
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