Head blight is one of the most damaging wheat (Triticum aestivum) diseases, causing reduction of grain yield, grain quality, flour protein levels, seed germination and vigor, and production of micotoxins. Head blight is considered a floral disease because the fungus enters the host plant through the anthers during anthesis. Occurrence of head blight is conditioned by temperatures above 20 °C and wetness periods longer than 72 h. This research aimed at studying the timing during anthesis for fungicidal sprays, the effect of rates of fungicide and number of sprays on head blight control and on grain yield and quality. Uneven anthesis is the main cause for the low efficacy of fungicides in the field. Even six and seven sprays during anthesis did not eradicate the disease (maximum control of 91%). Two and three applications improved the disease control over one spray. On average, the fungicidal sprays controlled head blight by 67% and increased grain yield by 32%. These results showed that chemical control of head blight is useful and would be practical at full anthesis, with no rate reduction recommended.
