用通径系数法分析苹果腐烂病的越冬场所和造成的产量损失

A Study on Hibernacula and Yield Loss of the Apple Canker's Pathogens by Using Path Coefficient Method

用通径系数法对苹果腐烂病的越冬场所及产量损失进行分析 ,结果表明 :苹果腐烂病越冬场所主要是上年未经刮治的病斑 ,其次为上年发病经刮治处理再度扩展的病斑 ,地表病残枝上的病原对越冬后的侵染也起间接作用 .产量损失由两部分造成 ,果枝发病直接损失占 71 .96 % 。

The Path Coefficient method is used to study the hibernacula of apple-tree canker and the yield loss caused by it. The result shows that the pathogens of apple-tree canker hibernate in the last year's lesions which were not treated, its secondary hibernacula is those lesions that were treated last year but expanded again, the pathogens in twigs on the earth surface acted indirectly on re-infect after hibernation. The yield loss is caused by two factors: one is that the disease which occurs in the fruit and in the lateral branches, causes 71.96% loss, the disease occurring in the trunk aggravates the seriousness and affects the yield indirectly.