钙素对叶用莴苣营养吸收和生长发育的影响

 采用NFT 栽培, 研究了叶用莴苣钙素与主要无机成分间的相互关系, 以及对叶用莴苣生长发育的影响。结果表明, 缺钙胁迫引起叶绿素含量降低, 缘腐病发病率上升, 叶片干、鲜样质量降低。生长中后期, 特别是新生内叶易发生钙素营养失调症。营养液中钙浓度过高会降低钾、镁的吸收, 而对氮、磷吸收影响不大。提高营养液中NH₄⁺ -N 比例会抑制钙吸收, 降低其有效性。

Effects of Calcium on Nutrient Absorption and Growth and Development of Lactuca sativa var.longifolia Lam.in Nutrient Film Technique Culture

Mutual relations between calcium(Ca) and other main elements and the effects of Ca on the growth and development of lettuce in NFT culture were studied. Results showed that Ca deficiency resulted in a reduction of Chlorophyll, an increase in the incidence of tipbum and a decrease of both fresh and dry weigh, all these changes are the major reasons of low yield and bad quality. During the mid- and later growing period,Ca disturbance was easily appeared in inner leaves of plant. Assimilation of potassium(K) and magnesium(Mg)was retarded by excessive Ca, while that of nitrogen(N) and phosphor(P) was little affected. Ca was less effective if the proportion of NH +_4-N in nutrient solution was increased.