Influence of previous crops and fungicide seed treatment in the incidence and control of damping-off caused by Rhizoctonia solani in cotton seedlings under greenhouse conditions

ABSTRACT The aim of this study was to verify the influence previous crops and fungicide seed treatment in incidence control damping-off caused by Rhizoctonia solani cotton seedlings under greenhouse conditions. This experiment carried out during two years at Embrapa Western Agriculture, Dourados, Mato Grosso do Sul State, Brazil. In addition (treated untreated seeds) fallow, following cover were tested as crops: black oats, millet, corn, forage sorghum, soybean, common beans, crotalaria (Crotalaria juncea), brachiaria (Urochloa ruziziensis) + juncea). mixture used seeds triadimenol pencycuron tolylfluanid (50 50 30 g a.i./100 kg seeds). Seeds from sown soil contained plastic trays pots; placed individual equidistant 3cm-deep wells. Inoculation R. obtained homogeneously distributing fungal inoculum onto substrate surface (2.5g/tray 0.34g/pot). fungus grown for 35 days on autoclaved oat subsequently ground powder using a mill (1mm). Damping-off daily evaluated seventh day after sowing. There significant effect interaction x (P<0.05). efficient controlling seedling its potentiated when grasses crops. Use such ruziziensis), corn sorghum crops, besides significantly contributed smaller population soil, which resulted lower rates damping-off. On other hand, continuously, well legumes soybeans, juncea) cotton, consistently associated with higher damping-off, contributing increase or least maintenance soil. highest percentages observed plots continuous cultivation without treatment. present results reinforce need improving adopting integrated management programs areas infested solani.