烟草赤星病发生与钾肥水平及品种间钾吸收能力的关系

本文调查了两个地点5个不同的钾肥用量水平的赤星病病情指数，分析了7个抗病性不同品种的含钾量，结果表明：（1）随钾肥用量水平增加，赤星病发病程度渐轻；高钾肥用量水平的烟株赤星病的发病程度显著低于低钾肥用量水平，但高钾肥用量水平间赤星病发生程度差异不明显；在根部施肥基础上于团探期、旺长期、平顶期喷施3次1％磷酸二氢钾，对于赤星病的减轻作用相当于高钾肥用量水平。（2）初步分析了7个对赤星病抗性不同的品种净叶黄、许金四号、Beinhart1000－1、G28、金星6007、G140、NC82烟叶含钾量，发现3个对赤星病抗性较强的品种烟叶中钾含量显著高于感病的3个品种，品种的抗性与钾含量间的相关系数R=0.8236，说明品种的抗赤星病能力与其对钾的吸收能力间可能有较强的相关性。

The Relation Between Tobacco Brown Spot Incidence and Potassium

Various amounts of potassium were applied at 2 different locations to investigatediscase index, and 7 tobacco varities with the range of brown spot susccptibility wereadopted to analyse K content in leaf. The results suggested that:(1) Brown spot severity decreased with the increasing of potassium amount.Significant difference of disease severity was observed between treatments of high potassium amount and low potassium amount. Disease indexes btween the high potassium amount treatments were not significantly different. ixsease reductive effect of the treatments with a KH2PO4 spraying besides rhizophere fertilizer at rosette, vigorous growthand toppng,was not distinguishable from that of the high potassium amount treatments.(2) Resistant varieties Xu jin the Fourth, Beinhart 1000-1 and Jingyehuang had.higher K content in leaf compared with the susceptible Jinxing 6007, G140 and NC82.The correlation between brown spot index and K content had a coefficient of 0. 8236,suggested the significant correlation between disease resistance and capacity of Kabsorbing.