Chemical control of Fusarium head blight on wheat

The effects of different chemical substances on infection and mycotoxin production of Fusarium culmorum in winter wheat cultivars were investigated in Field trials during 2 years. Spray treatments of the cvs. 'Kontrast' and 'Agent' with the fungicide tebuconazole either 2 days before or 2 days post inoculation reduced of the disease index of the spikes by 61-89 % and the toxin deoxynivalenol (DON) in the grain by 50-70 % as well as increased grain yield by 9-19 % in comparison to the untreated control. Application of metconazole in the cvs. 'Kontrast', 'Agent' and 'Piko' 2 days before inoculation led to decreases of the disease index by 68-71 % and the DON content in the grain by 61-69 % and increased grain yield by 6-9 % compared with the untreated plants. The application of the fungicidal substances chlorothalonil, prochloraz and benomyl 2 days before inoculation did not satisfactorily control the pathogen. Treatment of the plants with azoxystrobin reduced the disease index of the spikes, but the content of DON determined in the grain was higher than in the untreated control. Application of piperonylbutoxide, a possible inhibitor of trichothecene biosynthesis, increased the efficacy of the fungicides in the cv. 'Agent'.