不同生防药剂对燕麦白粉病的防治效果

Effectiveness of bio-medicaments against oat powdery mildew

中文为筛选安全高效的生防药剂,本研究选取3种类型的7个生防药剂在甘肃省定西市通渭县华家岭乡对田间自然诱发的燕麦白粉病(Blumeria graminisf.sp.avenae)进行了田间防效试验。结果表明:第1次施药后7d,生防药剂防效普遍不及化学药剂三唑酮和腈菌唑,仅有苦参碱和大黄素甲醚防效较好,分别为85.01%和83.93%;第2次施药后7d,各生防药剂的防效与第1次施药后7d相比有所提高,其中大黄素甲醚和枯草芽孢杆菌防效较高,分别为91.82%和91.46%;第2次施药后20d表现为大黄素甲醚的防效最高,达85.12%,高于化学药剂三唑酮(80.60%)和腈菌唑(84.12%),其他生防药剂如蛇床子素、枯草芽孢杆菌、苦参碱与化学药剂间防效差异不显著。与对照相比,生防药剂处理显著提高了燕麦旗叶SPAD值、千粒重和种子产量,其中0.5%大黄素甲醚效果较好,种子产量较对照增加16.77%。研究表明,参试的7个生防药剂对燕麦白粉病均有一定防治效果,虽与化学药剂相比速效性稍差,但其持效性较好。结合防效、持效性及燕麦种子产量来看,植物源杀菌剂中的0.5%大黄素甲醚是防治燕麦白粉病的有效药剂,在发病初期开始喷施,间隔7d喷第二次,可有效控制白粉病的发生危害,确保燕麦种子产量,有效降低经济损失。

In order to compare the effectiveness of seven bio-control fungicides against natural oat powdery mildew (Blumeria graminis f. sp. avenae) infections, a field experiment was conducted in Huajialing Township, Tongwei County, Gansu Province, China. At 7 d after the 1st application, the biocontrol agents were generally less effective than either of the chemical fungicides (triazolone and myclobutanil), and only matrine and physcion provided sufficient control (85.01% and 83.93%, respectively). At 7 d after the 2nd application, the effectiveness of each biocontrol agent was better than at 7 d after the 1st application, and physcion and Bacillus subtilis provided the greatest level of control (91.82 and 91.46%, respectively). At 20 d after the 2nd application, physcion provided the greatest level of control (85.12%), which was greater than provided by either of the chemical fungicides, triazolone (80.60%) and myclobutanil (84.12%), and there was no significant difference in the control provided by the chemical fungicides and that provided by osthole, B. subtilis, or matrine. Furthermore, plants treated with the biocontrol agents yielded significantly greater flag leaf chlorophyll content, 1 000-grain weight, and seed yield, with 0.5% physcion treatment yielding the best results, also with 0.5% physcion treatment the seed yield increased by 16.77% compared with the control. These results indicated that biological fungicides were slightly less effective against oat powdery mildew at 7 d after the 1st application but were more persistent. Furthermore, 0.5% physcion was an effective control agent against B. graminis f. sp. avenae with regard to control efficacy, persistence, and seed yield. In the early onset spraying pesticides on plants and spraying the 2nd time interval 7 d, could effectively control occurrence of powdery mildew, achieve to ensure the production and reduce economic losses.