咯菌腈与戊唑醇复配对小麦赤霉病菌的增效作用研究

研究旨在明确咯菌腈和戊唑醇复配剂抑制小麦赤霉病菌菌丝生长的最佳药剂配比。采用菌丝生长速率法测定了咯菌腈、戊唑醇及其复配剂对小麦赤霉病菌的有效抑制中浓度(EC₅₀)。采用wadley的增效比率法,评价了复配剂的增效作用。结果显示,咯菌腈和戊唑醇对小麦赤霉病菌的EC₅₀值分别为0.0205 μg/mL和0.1704 μg/mL;复配剂咯菌腈:戊唑醇的质量比在40:1,20:1,10:1,5:1,1:1,1:5,1:40时,SR值为0.54~1.28,呈相加作用;复配剂的质量比在1:10,1:20时,SR分别为1.56和1.62,呈增效作用。咯菌腈:戊唑醇的质量比在1:20时,SR值最大,为最佳增效作用比例。本试验为小麦赤霉病的防治及延缓戊唑醇的抗性产生提供了理论依据。

Synergistic Effect of Fludioxonil and Tebuconazole Against Fusarium graminearum

The purpose of this study is to determine the highest synergy ratio (SR) of the mixture of fungicide fludioxonil and tebuconazole that inhibited the mycelial growth of Fusarium graminearum. The effective concentration of 50% (EC₅₀) of fludioxonil, tebuconazole and their mixtures against F. graminearum isolates were determined by mycelium growth rate method. The SR of the mixture of the fungicide fludioxonil and tebuconazole was determined by Wadley’s SR method. The synergistic ratio of the mixture of the fungicide fludioxonil and tebuconazole was evaluated. The results showed that the EC₅₀ value of fludioxonil and tebuconazole against F. graminearum was 0.0205 μg/mL and 0.1704 μg/mL, respectively. When the mass ratio of the mixture of fludioxonil and tebuconazole was 40:1, 20:1, 10:1, 5:1, 1:1, 1:5 and 1:40, the SR range was from 0.54 to 1.28, which showed additive inhibition. When the mass ratio of the mixture of fludioxonil and tebuconazole was 1:10 and 1:20, the SR was 1.56 and 1.62, respectively, which showed synergistic inhibition. When the mass ratio of the mixture of fludioxonil and tebuconazole was 1:20, the SR value was the highest, which was the best synergistic ratio. These results could provide a theoretical basis for the control of wheat scab and delaying the development of tebuconazole resistance.