Indoor Toxicity and Field Efficacy of Five Strobilurins Fungicides against Phomopsis asparagi (Sacc.) Bubak.

[Objective] The study was to evaluate the indoor toxicity and field efficacy of five Strobilurins fungicides including pyraclostrobin 250 g/L EC, azoxystrobin 250 g/L SC, kresoxim-methyl 50% WG, picoxystrobin 22,5% SC and trifloxystrobin 50% WG against Phomopsis asparagi (Sacc.) Bubak, and to screen out effective fungicides. [Method] The toxicity was tested by mycelial growth rate method. The field trials were carried out by routine spraying method. [Result] The indoor toxicities successively were pyraclostrobin > kresoxim-methyl > picoxystrobin > trifloxystrobin > azoxystrobin. The EC% values were 6.102 9, 52.559 1, 83.825 7, 129.861 6 and 252.121 4 mg/L, respectively, all significantly higher than that of benzimidazole fungicide carbendazim (753.365 0 mg/L). The field efficacies successively were pyraclostrobin > kresoxim-methyl ≥ picoxystrobin ≥ azoxystrobin ≥ trifloxystrobin. The control effects were 81.20%, 77.95%, 74.80%, 71.69% and 68.54%, respectively, all significantly higher than that of benzimidazole fungicide carbendazim(48.27%). [Conclusion] The five Strobilurins fungicides all have good toxicity and field efficacy against P. asparagi. [ABSTRACT FROM AUTHOR]