水稻穗期灰飞虱防治适期的探讨

摘要

为了明确防治水稻穗期灰飞虱的适宜时间，以水稻品种甬优12号为试材，分别在水稻破口前5 d （8月26日）、破口期（8月31日）、齐穗期（9月7日）、齐穗后5 d （9月12日）和齐穗后10 d （9月17日）喷施25％吡蚜酮可湿性粉剂225 g/hm2＋40％毒死蜱乳油1125 mL/hm2，研究不同施药时期对水稻穗期灰飞虱的田间药效。结果表明：在破口前5d或破口期施药，对降低水稻灌浆盛期的灰飞虱虫口密度无显著影响；而在齐穗期～齐穗后10 d 施药，能有效控制灌浆期灰飞虱的发生。因此我们认为，采用25％吡蚜酮225 g/hm2＋40％毒死蜱1125 mL/hm2防治水稻穗期灰飞虱时，防治适期为水稻齐穗后10 d内，即9月7～17日。%To identify the proper time of protecting rice from Laodelphax striatellus in panicle stage, using rice variety Yongyou No.12 as the test material, 1 125 mL/hm2 of 25% pymetrozine wettable powder and 225 g/hm2 of 40% chlorpyrifos EC were sprayed in 5 different periods of rice including 5 days before break ( August 26 ) , break stage (August 31), full heading stage (September 7), 5 days after heading (September 12) and 10 days after heading ( September 17 ) . The field efficacy of different spraying stages to control Laodelphax striatellus in rice panicle stage was studied.The results indicated that there was no significant effects on reducing the insect density applied pesticides in 5 days before break and break stage, and the Laodelphax striatellus was effectively controlled applied from full heading stage to 5 days after heading.Therefore, the optimum sprayed period of pesticide against Laodelphax striatellus in rice panicle stage was within 10 days after heading when using the pesticides of 25%pymetrozine wettable powder 225 g/hm2 and 40% chlorpyrifos EC.