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落叶松落叶病在不同危害程度下,每公顷立木材积生长损失量方程为Y=9.8/(1+e~(7.345 9-0.1x))。采用经济阈值法确定防治指标,其方程为:9.8C[1/(1+e~(7.345 9-0.1x))-1/(1+e~(7.345 9-0.1(1-Q)x))]-E=0。按现实防治技术和经济水平求得的防治指标为病情指数46。根据感病损失量方程,病情很轻时损失甚微,经相对误差限法分析,将病情指数26定为该病的发生指标。
Larch deciduous disease under different degrees of harm, the growth of timber volume per hectare volume loss equation is Y = 9.8 / (1 + e ~ (7.345 9-0.1x)). The economic threshold method is used to determine the control index. The equation is 9.8C [1 / (1 + e ~ (7.345 9-0.1x) -1 / (1 + e ~ (7.345 9-0.1 (1-Q) x) )] - E = 0. According to the actual prevention and control technology and economic level of the prevention and control index for the disease index 46. According to the sensory loss equation, when the condition is very light, the loss is negligible. After the relative error limit analysis, the index of disease 26 is taken as the indicator of the disease.