INFLUENCE OF NEMATICIDE APPLICATION ON THE SEVERITY OF THE ROOT-KNOT NEMATODE FUSARIUM-WILT DISEASE COMPLEX IN COTTON

Eight cotton cultivars, with and without aldicarb treatment, were eval uated for their effect on the severity of the root-knot nematode-Fusar ium wilt disease complex in cotton. A randomized complete block design with a split-plot arrangement of treatments was used with cotton cult ivars as the main plots and nematicide treatments as the subplots. Res ults in 1994 and 1995 were similar. Yield of lint, boil weight, and wi lt and root-gall ratings were different among cultivars and between ne maticide treatments both years. Increased lint yield and boil weight, and reduced root-gall and wilt ratings were associated with applicatio n of aldicarb. Increased lint percentage was associated with applicati on of aldicarb in 1994, but not in 1995. Fiber micronaire, elongation, uniformity, and strength were different among cultivars, but not betw een nematicide treatments. Fiber length (UHM; Upper-Half Mean) was dif ferent among cultivars and was higher in the aldicarb-treated plots in both years. Numbers of Meloidogyne incognita second stage juveniles a nd eggs extracted from soil samples were lower in the aldicarb-treated plots in July, but not at harvest, both years. Population densities o f M. incognita were not different among cultivars, except the mid-seas on sample in 1995.