“一喷三防”施药时间对小麦病虫害的防治效果
Effects of Spraying Time of Several Control Measures on Control of Wheat Diseases and Pests

为准确掌握“一喷三防”施药时间对小麦主要病虫害的防治效果，选择小麦抽穗前（4月22日）、小麦抽穗约20%（4月27日）、小麦抽穗约70%（4月30日）和小麦扬花末期（5月9日） 4个时期，以w=4.5%高效氯氰菊酯乳油300 mL/hm、w=15%三唑酮可湿性粉剂1 200 g/hm、KH2PO4 1 500 g/hm 3种溶液的混合液为供试药剂，以穗期不施药为对照进行田间试验，研究“一喷三防”不同施药时间对当地4种小麦穗期主要病虫害（小麦条锈病、小麦赤霉病、小麦蚜虫和小麦吸浆虫）的防治效果。结果表明，不同施药时间，小麦主要病虫害的防治效果和保产效果不同。在以蚜虫为小麦穗期主要害虫，且喷药1次的情况下，从保产效果来看，“一喷三防”的最佳喷药时间为小麦抽穗约70%时，其次为小麦抽穗约20%时。喷药时间过早或过晚，保产效果均明显下降。
In order to know the control effects of praying time of several control measures on diseases and pests ,wheat stripe and rust,wheat scab,wheat midge and wheat aphid. At four different stages of before wheat heading (April 22th),20% of wheat heading (April 27th) ,70% of wheat heading (April 30th) and end of wheat flowering (May 9th),mixture of w=4.5% beta cypermethrin emulsifiable concentrate (300 mL/hm),w=15% Triadimefon wettable powder (1 200 g/hm) and KH2PO4 (1 500 g/hm) were sprayed respectively,no pesticide at the four stages was used as CK. The results indicated that there are significantly different effects both on controlling wheat disease and pests by applying pesticide. The most optimal time was 70% of wheat heading when wheat aphid was a main kind of pests and pesticide was sprayed only once,followed by the 20% of wheat heading. Furthermore,a bad effect on the yield of wheat occurred when the pesticides were used too early or too late.