This work was carried out at Embrapa Agropecuaria Oeste, Dourados, MS in order to evaluate the efficiency of several fungicides, applied as seed dressing, in the control of damping-off caused by Rhizoctonia solani. Greenhouse testing was performed, using the cotton (Gossypium hirsutum) cv. DeltaOpal. Treated and untreated seeds with the fungicides were sowed in sand contained in plastic flats, placed in individual and equidistant wells, 3 cm deep. Inoculation with R. solani was done by the homogeneous distribution of the fungus inoculum onto the substrate. The fungus was grown for 35 days on autoclaved oat seeds and then ground to powder using a mill (1 mm). Nine grams of the fungus inoculum were put into each plastic flat. The effect of the fungicide treatment on initial and final seedling emergence was observed, with distinction to triadimenol + pencycuron + tolylfluanid and triadimenol + tolylfluanid, followed by carboxin + thiram, triadimenol and carboxin + thiram + carbendazim. The most efficient treatments in the control of cotton seedling pos-emergence damping-off were triadimenol + pencycuron + tolylfluanid, followed by triadimenol, triadimenol + tolylfluanid and carboxin + thiram. No phytotoxic effects were observed on cotton.
