Efficacy of Two Fungicides in Controlling Fusarium Wilt Caused by Fusarium oxysporum f. sp. cepae in Welsh Onion

Abstract

The efficacy of drip irrigation of two fungicides in controlling Fusarium wilt caused by Fusarium oxysporum f. sp. cepae in Welsh onion before transplanting was evaluated in the fields from 2014 to 2018.Several trials were conducted for each fungicide, and the data were analyzed by meta-analysis. An integrated risk ratio (the ratio of incidence on treated plants to incidence on non-treated plants) after treatment with mandestrobin flowable was 0.11 (95% confidence interval 0.06–0.21), indicating that the fungicide was effective against this disease. However, an integrated risk ratio after treatment with triflumizole wettable powder was 0.67 (95% confidence interval 0.41–1.10), indicating that the fungicide was not effective against this disease. The effect of fungicide application on the growth of Welsh onion was also evaluated. In three-year trials from 2015 to 2017, application of mandestrobin flowable inhibited plant growth in 2017.