15%三唑酮喷施次数对小麦条锈病的防治效果

小麦条锈病是小麦生产上的最主要病害之一，三唑酮在小麦条锈病防治上具有极好的控病增产作用，但随着其长期施用，在天水地区小麦生产上已出现抗药菌株，导致防效偏低。为了给小麦条锈病的科学防治和三唑酮的合理高效使用提供技术支撑，在甘肃省农业科学院植物保护研究所甘谷试验站以感病品种冬小麦新冬43号为指示品种，开展了15%三唑酮可湿性粉剂不同喷施次数对小麦条锈病的田间防效试验。试验结果表明，喷药次数对小麦条锈病的田间防效及指示品种的产量、千粒重、穗粒重有极显著的影响。与不喷药对照相比较，15%三唑酮可湿性粉剂药剂量1 200 g/hm2兑水675 kg喷施1次、喷施2次、喷施3次对小麦条锈病的田间终期防效分别为58.4%、83.6%、98.6%，折合产量分别为5 000.0、5 580.0、6 080.0 kg/hm2，较不喷药对照分别增产58.23%、76.58%、92.40%，千粒重分别提高15.5%、32.4%、38.5%，平均穗粒重分别提高7.6%、10.7%、12.2%。认为选用15%三唑酮可湿性粉剂在小麦条锈病防治达标期(病叶率达到10%)时对小麦进行喷雾防治，间隔7 d喷1次，连喷3次，可达到极好的控病增产效果，值得在小麦生产上推广应用。

The Control Efficiency of 15% Triadimefon Spray with Different Frequencies against Wheat Stripe Rust

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most important foliar diseases in wheat production. Triadimefon shows an excellent effect in controlling of wheat stripe rust, but with its long-term application, resistant strains have emerged in wheat production in Tianshui area, resulting in low control efficiency. To provide technical support for the scientific control of wheat stripe rust and the rational and efficient use of Triadimefon, the susceptible variety winter wheat Xindong 43 was taken as the indicator variety and the control effects of different spraying frequencies using fungicide Triadimefon 15% WP against stripe rust was conducted at Gangu Expeimental Station, Institute of Plant Protection, Gansu Academy of Agricultural Sciences. The results showed that spraying efficiency had significant effcts on control efficiency, yield, 1 000-grain weight and kernel weight in field. Compared with no fungicide spraying, the final control efficiencies of 1 time, 2 times, 3 times fungicide spraying (Triadimefon 15% WP at 1 200 g/ha diluted with 675 kg water) were 58.4%, 83.6% and 98.6%, respectively in the field, the average yields were 5 000.0, 5 580.0 and 6 080.0 kg/ha, respectively, which were 58.23%, 76.58% and 92.40% higher that that of the control with no fungicide spraying, respectively, 1000-grain weights were increased by 15.5%, 32.4% and 38.5%, respectively, and the average kernel weights were increased by 7.6%, 10.7% and 12.2%, respectively. The results showed that the fungicide Triadimefon 15% WP spraying conducted at 1 time every 7 days for 3 circles during the standard period for prevention and control of wheat stripe rust(diseased leaf rate above 10%) could achieve excellent disease control efficiency and yield increase effect, which could be promoted in wheat production.