摘要
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。
The volume loss caused by larch leaf cast can be expressed by the equation: r = 9.8/(1+ e7.3459-0.1x). The control threshold can be determined by the equation:9.8 C[1/(l + e7.3459-0.1x) - 1/(1+ e7.3459-0.1(1-Q)x)] - E = 0Therefore, the control threshold was settled at 46 of disease index in terms of current control technique and economic standard. The volume loss can be neglected when the disease index was below 26, according to the volume loss equation. The developmental threshold was fixed at 26 of disease index based on the relative error margin analysis.
出处
《林业科学研究》
CSCD
北大核心
1991年第2期128-132,共5页
Forest Research
关键词
落叶
落叶病
发生
指标
防治
larch leaf cast
developmental threshold
control threshold
