Chemical control of loose smut of wheat (Ustilago segetum var. tritici) and its effects on seed yield

The investigation were carried out to evaluate the effect of three fungicides namely Bavistin (0.25%), Vitavax (0.25%) and Raxil (0.1%) on controlling the loose smut of wheat and to determine yield losses due to disease in five different cultivars. Among the five cultivars taken for study, highest diseased tillers/plot (in primed control) were recorded in cv. Sonalika (34.67 and 33.33) and lowest were observed in VL-421 (6.0 and 9.67) at 2% infection level in 2000–01 and 2001–02 respectively. Raxil showed best performance in controlling the loose smut disease and its eliminated the disease completely in all cultivars at all the infection levels except Sonalika at 2% infection level, where 3.67 and 1.93 diseased tillers were observed in 2000–01 and 2001–02 in Raxil treated plot. Vitavax (0.25%) was found to be second best fungicide in controlling the disease while Bavistin (0.25%) was not found promising. Maximum reduction in yield/ha was recorded in cv. Sonalika when compared to primed and unprimed control at 2% infection level. The yield/ha in unprimed control was recorded 41.40% q/ha and in primed control it was 29.0 q/ha. It is further interesting to note that the yield/ha was increased in the entire treated plot when compared with unprimed control. The increased in yield was maximum in Raxil treated plot when compared to Vitavax and Bavistin.