EVALUATION OF FOLIAR FUNGICIDES FOR CONTROLLING FUSARIUM HEAD BLIGHT OF WHEAT

Fusarium head blight of wheat causes significant reductions in yield, test weight, and seed quality and may be associated with mycotoxin con tamination of grain. The objective of this study was to evaluate certa in fungicides for effects on head blight severity, deoxynivalenol leve l, yield, and test weight under conditions of high disease pressure in the field. Fungicides (benomyl, chlorothalonil, fenbuconazole, flusil azole, myclobutanil, potassium bicarbonate, propiconazole, tebuconazol e, thiabendazole, and triadimefon plus mancozeb) were applied to wheat cv. Florida 302 at heading stage in 1992 and 1993. Plots were inocula ted three times with macroconidia of Fusarium graminearum and misted t o promote severe head blight epidemics. Head blight incidence was rate d at the soft dough stage. Grain yield, test weight, and deoxynivaleno l level were determined after harvest. The fungicides tested did not r educe head blight incidence or deoxynivalenol level and did not increa se yield or test weight. Prospects for chemical control of head blight are poor.