在郁闭林分中失叶量25％达到经济阈值。
On the contrary, the amount of defoliation of 25% reach the ElL.
与棉虫动态模型偶联，可研究棉虫动态经济阈值。
Besides, coupling with pest dynamic models, this model could be used to study dynamic economic thresholds.
并将它们耦联在一起，形成了动态经济阈值模型。
并提出用害虫种群潜在密度确定卷叶螟经济阈值的方法。
Economic threshold for this pest insect was estimated by measuring the increasement rate of population density.
在森林害虫科学管理决策专家系统中，害虫危害的经济阈值是最重要的判别依据。
The economic thresholds of insect pests are the most important distinguish basis in the scientific management system of forest pests.
本文还给出了各云南松林区可以用来根据自己的具体情况计算出适合自己的经济阈值的公式。
The paper also gives formulae for different Yunnan pine forest areas to calculate their own economic threshold according to their special situations.
建立了病害发生的短期测报模型和材积损失率估测模型，确定了病害的防治指标和经济阈值。
Short term forecast model of disease development and wood loss rate are built. Control guideline and economic threshold value are decided.
对不同输入条件模型可以得到相应的模拟结果，据此可以研究稻纵卷叶螟的动态经济阈值和确定最优管理措施。
Simulation results can be obtained under different input conditions. Besides, this model can be used to study dynamic economic thresholds and determine the optimal control strategies.
根据防治的直接收益与直接代价，算出了第三代棉铃虫的经济阈值为百株累计卵量35粒，这一阈值可适用于不同肥力水平的地块。
Based on the direct benefit and cost, the economic threshold of the third generation bollworm was calculated to be 35 eggs per 100 plants for all the levels of soil fertility.
根据防治的直接收益与直接代价，算出了第三代棉铃虫的经济阈值为百株累计卵量35粒，这一阈值可适用于不同肥力水平的地块。
Based on the direct benefit and cost, the economic threshold of the third generation bollworm was calculated to be 35 eggs per 100 plants for all the levels of soil fertility.
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