辣椒疫病产量损失与防治指标研究

Study on the yield loss induced by Phytophthora capsici Leonian and its controlling index

疫病对辣椒产量的影响主要表现为对有效株的影响,病情严重时单株结果数量与平均果重也受到一定影响。辣椒受疫病危害后的反应类型属于超补偿型。在较低的危害水平内(病株率≤4.16%),辣椒受害后,由于病株旁的健康植株增加了结果枝数,产生边际优势,从而单位面积的产量反而有所增加。只有当超过经济危害水平时,单位面积的产量随着株发病率的增加而迅速下降,超补偿作用难以发挥而造成减产。经相关分析,辣椒疫病的株发病率(X)与产量损失率(Y)之间存在显著的相关性,其回归方程为Y=-5.6321+1.3531X(r=0.9913**),并以此为基础,建立了辣椒疫病的防治指标动态模型。

The yield loss induced by Phytophthora capsici Leonian and its controlling index in capsicum field were studied by field investigation and statistics. The results showed that the percentage of infected plants （X） was positively correlated with the percentage of yield loss （Y）. The regression equation was Y = -5.6321 ＋ 1.3531 X （r=0.9913^＊＊）.When the percentage of infected plants exceeded 4.16%, the yield loss increased with increasing the percentage of infected plants. On the contrary, if the percentage of infected plants was less 4.16%, the yield of capsicum increased. Base on the study, the model of controlling index for Phytophthora capsici Leorfian in capsicum field was established.