不同杀菌剂对水稻稻曲病菌的室内毒力及田间药效

摘要

The toxicities of 19 fungicides and the mixture difenoconazole validamycin A against Ustilaginoidea virens were tested in laboratory by detecting mycelial growth rate,and eight fungicides with better efficacy were selected to test in fields.The results showed that propiconazole,trifloxystrobin,prochloraz,tebuconazole,picoxystrobin,azoxystrobin and difenoconazole had stronger inhibition on mycelial growth,and the EC50 values were 0.025 4,0.032 8,0.041 8,0.045 1,0.082 6,0.100 1 and 0.148 2 mg · L-1,respectively.The mixture of difenoconazole and validamycin A combined with the ratio of 1 ∶ 2 had obvious efficiency on Ustilaginoidea virens,with the 174.78 and the EC50 0.226 3 mg · L-1.Field tests revealed that 43％ tebuconazole SC,25％ azoxystrobin SC,25％ prochloraz EC,8％ validamycin A 4％ difenoconazole WP and 25 ％ propiconazole EC had better control effect,which were 83.27 ％,82.76 ％,82.73 ％,80.66 ％ and 80.35 ％,respectively.%采用生长速率法测定19种杀菌剂和苯醚甲环唑·井冈霉素A混配剂对水稻稻曲病菌的室内毒力,选择其中较好的8种药剂进行田间防效试验.结果表明:丙环唑、肟菌酯、咪鲜胺、戊唑醇、啶氧菌酯、嘧菌酯和苯醚甲环唑对稻曲病菌菌丝的抑制作用较强,EC50值分别为0.025 4、0.032 8、0.041 8、0.045 1、0.082 6、0.100 1和0.148 2 mg· L-1;苯醚甲环唑和井冈霉素A按1∶2的比例混配增效作用非常明显,混剂共毒系数为174.78,EC50值为0.226 3 mg·L-1；43％戊唑醇SC、25％嘧菌酯SC、25％咪鲜胺EC、8％井冈霉素A·4％苯醚甲环唑WP和25％丙环唑EC田间防效较好,分别为83.27％、82.76％、82.73％、80.66％和80.35％.