Screening of Combination of Flumetralin and Fungicide to Control Cotton Fusarium wilt
In order to screen the combination of flutenide and fungicide for effective controling of cotton Fusarium wilt and determine the optimal ratio of agents,Fusarium oxysporum,the pathogen causing cotton wilt,was taken as the research object,the growth rate method was used to measure the indoor toxicity of fungicide,Wadley's synergistic ratio method was used to evaluate the synergistic effect of the compounds,and the indoor pot experiment was conducted to verify the effect of the compounds on cotton Fusarium wilt.The results showed that the effective inhibitory medium concentration(EC50)of flufluenil,pyrimethil,Bacillus subtilis and flutamide were 0.219,0.725,6.013 and 55.971 mg·L-1,respectively.Compound of flufenamide and fluoxonitrile showed synergistic effect when the compound ratio was 10∶1.The compound of flutenediamine and Bacillus subtilis showed synergic effects when the compound ratio was 10∶1,3∶1,1∶2 and 1∶3,and the synergic effect was the highest when the ratio was 1∶2.While the compound of flutamide and pyrimethanil showed no synergistic effect.Pot experiments showed that the disease index was the lowest when flutenediamine was mixed with Bacillus subtilis with the ratio of 1∶2,and the control effect was 77.11%,which was significantly better than other combinations.In conclusion,the combination between flutamide and Bacillus subtilis with the ratio of 1∶2 could be used for preventing cotton Fusarium wilt.Above results provided technical guidance for prevention and control of cotton Fusarium wilt.