生物杀虫剂组合在有机水稻种植中的作用效果

针对上海市崇明区有机水稻生产过程中病虫害防治效果不佳的问题，在水稻无化肥、无化学农药种植条件下开展了生物杀虫剂对水稻主要害虫稻纵卷叶螟和稻飞虱的田间防控效果评价。在崇明区的2个试验基地，于水稻不同生长时期，以绿僵菌、白僵菌产品分别与病毒杀虫剂MbNPV、植物源杀虫剂苦参碱和细菌杀虫剂Bt组合进行施药处理。结果表明，应用绿僵菌/白僵菌与MbNPV组合，能够有效防治稻纵卷叶螟，在稻纵卷叶螟发生较早的基地，施药后7 d和14 d的防效可达58.2%～81.2%,而在稻纵卷叶螟发生较晚的另一基地，施药后7 d防效可达61.3%和65.6%;绿僵菌/白僵菌与苦参碱组合，可用于防治稻飞虱，7 d和14 d的防效达64.7%～76.1%;绿僵菌/白僵菌与苏云金杆菌组合防治稻纵卷叶螟的14 d防效分别达64.0%和75.4%,优于对稻飞虱的防效；各组合试验结果显示，白僵菌有相对较长的持效作用，且在害虫迁入早期阶段(水稻发育分蘖盛期至拔节期)施用生物农药比在中后期(抽穗期及之后)施用的防效高。可见，生物杀虫剂组合可作为农作物绿色防控的有效手段。

Efficacy of combined biological insecticides under rice farming without chemical fertilizers and chemical pesticides

Aiming at the poor effect of disease and insect pest control in rice production in Chongming district, the field control effect of biological insecticides on the main pests of rice without chemical fertilizer and chemical pesticide was evaluated. In two experimental bases in Chongming district of Shanghai, Metarhizium anisopliae and Beauveria bassiana products were combined with viral insecticide MbNPV, botanical insecticide matrine and bacterial insecticide Bt at different stages of rice growth. The results showed the combination of M. anisopliae/B. bassiana and MbNPV could effectively control Cnaphalocrocis medinalis. In the base where the C. medinalis occurred earlier, the control efficacy could reach to 58.2%-81.2% 7 and 14 days after application, while in the base where the C. medinalis occurred later, the control efficacy reached 61. 3% and 65.6% 7 days after application. The combination of M. anisopliae/B. bassiana and matrine can be used to control rice planthoppers, and the control efficacy can reach 64.7%-76.1% 7 and 14 days after application. The 14th-day-control efficacy of M. anisopliae/ B. bassiana combined Bacillus thuringiensis (Bt) against C. medinalis was 64.0% and 75.4%, respectively, which was better than that against rice planthoppers. Among these combinations, B. bassiana demonstrated a relatively long lasting effect. Besides, the control efficacy of applying biological pesticides in the early stage of pest migration (from the peak tillering stage to jointing stage of rice) was higher than that in the middle and late stage (heading stage and after). It suggested that the combinations of biological insecticides can be an effective means for green crop pest management.