3种农药对莲藕叶斑病防治效果和残留试验研究

The Efficacy and Residual of Three Fungicides Against Alternaria Nelumbii in Nelumbo Nucifera Gaertn

为筛选防治莲藕叶斑病的适合药剂,本文研究了嘧菌酯、多菌灵、丙环唑3种杀菌剂对莲藕叶斑病的室内杀菌活性、田间药效、安全性和残留。结果表明,嘧菌酯、多菌灵、丙环唑对莲藕叶斑病的EC50分别为0.53μg/m L、0.38μg/m L和0.12μg/m L,丙环唑对叶斑病杀菌活性显著高于嘧菌酯和多菌灵(P<0.05)。田间药效试验结果表明,嘧菌酯、多菌灵、丙环唑对莲藕叶斑病防效较好,其防治效果随用药量增加而递增,且对莲藕产量无明显影响。作物安全性试验表明,试验剂量下供试药剂对莲藕的发芽率和幼苗生长有一定影响,但生产上防莲藕叶斑病要在浮叶期之后。嘧菌酯、多菌灵和丙环唑在莲叶上的半衰期分别为2.6~8.5d、7.6~12.8d和4.5~8.4d。莲藕收获后,3种药剂在莲藕、莲子残留均低于0.01mg/kg,对其品质无明显影响。

To control the Alternaria nelumbii in Nelumbo nucifera Gaertn, three fungicides including azoxystrobin, carbendazim and propiconazole were selected to determine their biological activity, field efficiency and safety. The results showed that, the EC50 of azoxystrobin, carbendazim, propiconazole were 0.53μg/m L, 0.38μg/m L and 0.12μg/m L, respectively. And the biological activity of propiconazole was significantly higher than the two other fungicides. Azoxystrobin, carbendazim and propiconazole effectively controlled Alternaria nelumbii, and the field efficiency increased with the increase of the dosage of fungicide applied. All of the fungicides exhibited no significant effect on the yield of Nelumbo nucifera Gaertn. Although some certain damage to sprout and growth of Nelumbo nucifera Gaertn was observed in the safety experiment,fungicide against Alternaria nelumbii usually applied in the floating period, at which time the Nelumbo nucifera Gaertn would grow strong enough to resist the side-effect of the fungicides.Residual trails showed that the half-life of azoxystrobin, carbendazim, propiconazole on the lotus leaf were 2.6~8.5 days, 7.6~12.8 days, and 4.5~8.4 days, respectively. After harvest, the residual of azoxystrobin, carbendazim, propiconazole was less than 0.01mg/kg and had no significant effect on the quality of the Nelumbo nucifera Gaertn.