Effects of late‐season fungicide sprays on yield of winter wheat

SUMMARY Sprays of broad spectrum fungicides were applied to winter wheat between the start of flag leaf emergence and the milky ripe stage of grain development in 118 experiments between 1970 and 1978. Although diseases were generally sHght, an average yield response of 0·185 t/ha (3·31 per cent) was recorded. Sprays apphed before the start of flowering gave the largest responses of up to 0·218 t/ha. Only those sprays applied between flag leaf emergence and the in‐boot stage showed evidence of an increasing yield response as the yield of untreated plots increased. The 1000‐grain weight of treated plots showed an increase of 1·9 per cent over untreated plots.