滴施生物药剂对棉花生长、黄萎病防治及土壤微生物数量的影响
Effects of Different Biological Agents Application through Drip Irrigation Systems on Cotton Vertillium Wilt Prevention,Cotton Growth and Soil Microbial Quantity

设置田间小区试验，开展枯草芽孢杆菌粉剂(15.0、30.0 和45.0 kg/hm2)、“施倍健”哈茨木霉菌剂(15.0、18.0 和24.0 kg/hm2)和渝峰“99植保”(15.0、22.5 和30.0 kg/hm2)不同的滴施用量对棉花黄萎病、生长发育及棉田土壤微生物数量的影响研究。结果显示：(1) 3种施药处理均不同程度降低棉花黄萎病发病率和病指，防病效果随着枯草芽孢杆菌剂施药量的增加而显著提高；木霉菌剂施药量18.0 kg/hm2防效显著高于15.0和24.0 kg/hm2，全生育期达到61.86%；“99植保”不同的用量处理平均防效达到72.46%，但22.5和30.0 kg/hm2防效增幅差异不大。(2) 3种施药处理对棉花生长表现一定的促进作用，棉花的株高、果枝数和蕾铃数随枯草芽孢杆菌剂施药量增加显著增加；木霉菌剂、“99植保”施药量的增加对株高影响不大，但果枝数和蕾铃数基本上随施药量增加而增加，中、高施药量之间的结蕾数差异较小。(3) 3种药剂滴施后对棉田根际土壤微生物菌群结构具有显著影响，细菌数量均随施药量的增加而增加；枯草芽孢杆菌剂和“99植保”处理后放线菌数量表现为随施药量的增加而增加，而真菌数量随施药量增加依次降低，木霉菌剂施药量18.0 kg/hm2的放线菌数量高出15.0和24.0 kg/hm2近2倍。综合棉花防病效果及生长表现，“99植保”滴施用量建议22.5 kg/hm2 、木霉菌剂18.0 kg/hm2、枯草芽孢杆菌45.0 kg/hm2。
Field plot experiment was designed to study the effects of Bacillus subtilis agent(15.0, 30.0 and 45.0 kg/hm2), Trichoderma humatum agent (15.0, 18.0 and 24.0 kg/hm2) and “Yufeng 99” (15.0,22.5 and 30.0 kg/hm2) through drip irrigation systems on the change of cotton Vertillium wilt prevention, cotton growth and soil microbial quantity.The results showed that three biological agents application could reduce incidence and disease index of the cotton Vertillium wilt.The control effects of Vertillium wilt increased significantly with the increase of dosage of Bacillus subtilis agent.When the dosage of Trichoderma humatum was 18.0 kg/hm2, the control effect reached 61.86% at whole growth period, which was significantly higher than 15.0 kg/hm2 and 24.0 kg/hm2.The control effect of “Yufeng 99” agent for Vertillium wilt reached 72.46%, but the increasing proportion was not significant between 22.5 kg/hm2 and 30.0 kg/hm2 application levels.Meanwhile, there were obvious promotion effects on cotton growth and yield when three agents were applied.The cotton height, branch number and boll number were significantly increased with the increase of dosage of Bacillus subtilis agent.Application of Trichoderma humatum and “Yufeng 99” agents, the cotton height had no obvious change, but the number of branch and boll increased with the increase of dosage level.The microbial community structure was significantly affected by three kinds of biological agents through drip irrigating in rhizosphere soil of cotton field.When Bacillus subtilis and “Yufeng 99” were used, the number of actinomycetes significantly increased with the increase of application level, but the number of fungi decreased.The number of actinomycetes were about two times higher at 18.0 kg/hm2 application level than other application levels under Trichoderma humatum agent treatment.Therefore, according to effects of cotton disease control and growth performance,