玉米螟为害玉米的产量损失估计及单株允许残留虫量

ON THE YIELD LOSS ESTIMATION OF CORN CAUSED BY ASIAN CORN BORER AND TOLERANT LARVA NUMBER PER PLANT

为探明亚洲玉米螟为害春、秋玉米的产量损失,于1990年始在浙江东阳玉米研究所采用田间自然种群为害与在玉米不同生育期采取药剂控制使害虫造成一定梯度相结合的方法,研究螟害对产量损失的影响。结果获得螟害对产量损失的两个曲线方程: 春玉米:Y_1=1-[0.67+(1-0.67)×0.7558^(P+0.7)] 秋玉米:Y_2=1-[0.70+(1-0.70)×0.7767^(P+1)] P为单株玉米上平均虫量,0.7和1为最后单株玉米上允许的残留虫量(包含蛀孔),损失率分别为5.9％、6.7％。

In 1990 - 1992, the effects of damage of Asian corn borer (ACB) Ostrinia fur-nacalis (Guenee) on the yield loss of spring and autumn corn were studied in Dongyang Institute of Corn Researches, by adopting insecticide spraying on natural population of ACB at different developmental stages of corn. Two larva density-yield loss equations derived from the results were as follows: where Y1 and Y2 are the yield loss rates of spring and autumn corn, respectively; P is the mean larva number/plant; and 0. 7 and 1 are the tolerant thresholds of larva number/plant; the corresponding yield loss rate of corn are 5. 9% and 6. 7%, on spring and autumn corn, respectively.