不同时期灌水对冬小麦干热风的防御效应

灾前灌水是防御灾害发生的有效措施,为掌握灌水的关键发育期及适宜灌水量，在防雨棚和自然大田进行冬小麦抽穗期、开花期、灌浆初期灌水试验。结果表明：在开花期，灌水100、150 mm自然大田干热风穗的发生率比遮雨棚降低31.77%、32.85%，而穗粒重自然大田比防雨棚提高12.25%、5.45%；无论开花期还是抽穗~灌浆初期，灌水处理的千粒重均比对照大，防雨棚中随灌水时间推后千粒重逐渐增大，而自然大田以开花期灌水千粒重最大，为47.664 g。灌水100、150 mm处理，灌水效率自然大田均比防雨棚高，且均以开花期灌水效率最高，为4.110 g·m^-2·mm^-1,防雨棚灌水150 mm比灌水100 mm高约0.2 g·m^-2·mm^-1，而自然大田受自然降水补给调节土壤水分，灌水150 mm比灌水100 mm低0.565~1.301 g·m^-2·mm^-1。灌水对干热风防御效应效果自然大田较防雨棚更为显著，且以开花期灌水效应最为显著。

Defensive effect of irrigation at different stage on hot dry wind stress on winter wheat

Hot dry wind is one of the meteorological factors causing the annual fluctuation of wheat yield. Pre-disaster defense can effectively mitigate the damage caused by disasters. When the hot dry wind occurs, it will cause irreversible physiological harm to the wheat plant and the grain filling in the kernel, and the pre-disaster irrigation is an effective measure to prevent the occurrence of the disaster. In order to master the key development period of irrigation water and appropriate irrigation water, during the heading stage of winter wheat, flowering and milking, the irrigation of 100 mm and 150 mm were respectively tested in the waterproof canopy and natural field. The results showed thatat the flowering stage, the incidence of hot dry air spikes and the grain weight per panicle of 100 mm and 150 mm irrigation fields were about 30% and 3% higher than that of the covered, which was 18.03% and 15.14% lower than that of the control.Regardless of the flowering stage or the heading-filling stage, the 1000-grain weight from the irrigation treatment was significantly greater than that of the control.In the rainproof shed, the 1000-grain weight gradually increased with increasing irrigation time, while the natural field had the largest 1000-grain weight in the flowering stage, which was 47.664 g.The irrigation efficiency was naturally higher than that of the rainproof shed, and the irrigation efficiency was the highest at the flowering stage, which was 4.110 g·m^-2·mm^-1. The irrigation efficiency of the rain shed irrigation of 150mm was about 0.2 g·m^-2·mm^-1 higher than that with 100mm, while the natural field was regulated by natural precipitation to regulate soil moisture. The irrigation efficiency of irrigation of 150mm was 0.565~1.301 g·m^-2·mm^-1 lower than that of 100mm.The effect of irrigation on the dry and hot air defense effect was obvious, and the natural field was more prominent than the canopy, and the effect was most significant in the flowering period. Therefore, the accurate climate prediction and agricultural meteorological service of hot dry wind should be paid attention to, and it can effectively defend and mitigate the loss of hot dry wind on the winter wheat before the disaster.