48%毒死蜱乳油对水稻稻纵卷叶螟的防治效果

Efficacy of Chlorpyrifos 48% EC Against Cnaphalocrocis medinalis(Guenee)

为了明确48%毒死蜱乳油(EC)的使用剂量及持效期,设3种浓度处理进行了田间试验。结果表明:48%毒死蜱乳油对稻纵卷叶螟有良好的防治效果,在幼虫高峰期用药450、6007、50 g/hm2,药后10 d和25 d杀虫效果分别为87.95%、92.78%、97.19%和89.69%、94.35%、98.45%,药后25 d保叶效果为88.48%、93.85%、96.44%,均显著优于30%敌百虫562.5 g/hm2。水稻每株穗数、每穗实粒数、每穗总粒数、结实率、单株重和实际产量随着48%毒死蜱乳油用药量的增加而增加,与30%敌百虫562.5 g/hm2的差异均达到极显著水平;而株高和千粒重在各处理间的差异不显著。稻叶受稻纵卷叶螟虫危害后,蒸腾速率下降,光合作用效率亦显著下降,从而影响水稻的多个产量相关性状,最终导致减产。药剂处理可以显著降低由此导致的产量损失,从而相对提高水稻产量。

Chlorpyrifos 48% EC provided excellent control of Cnaphalocrocis medinalis（Guenee） medinalis in field demonstration trials.Chlorpyrifos 48% EC application improved the light conditions in field,and photosynthesis and transpiration rate increased with the dosage of herbicide.The application of chlorpyrifos had no effect on 1 000-seed weight and plant height,whereas panicles per plant,grains per panicle,spikelets per panicle,seed set rate and yield per plant were markedly influenced,resulting in a significant yield increase of rice.It is indicated that the efficiency of chlorpyrifos 48% EC was much better trichlorfon 30% EC applied at 562.5 g/hm^2.