CONSERVATION TILLAGE AND SEEDLING DISEASES IN COTTON AND SOYBEAN DOUBLE-CROPPED WITH TRITICALE

A double-crop rotation of cotton-triticale-soybean-triticale was grown for 4-5 yr in three experiments on loamy sand soil. Tillage treatment s were conventional (moldboard plowing 20-25 cm deep after burning tri ticale residues), no-till, row-till, and ridge-plant. Triticale residu es were managed by burning or cutting the straw short (20 cm) or tall (60 cm) at harvest. Population densities of Rhizoctonia solani anastom osis group (AG)-4 in soil after triticale were low to moderate and sim ilar among treatments. Population densities of Pythium spp, in soil we re high and variable among treatments. Root and hypocotyl disease seve rity in cotton and soybean seedlings was low to moderate each year. In most years and crops, tillage and residue management treatments did n ot influence seedling disease or inoculum densities of pathogens. When there were differences, burning triticale residues and moldboard plow ing improved seedling health.