The efficacy of foliar applications of oxamyl were evaluated for the management of Meloidogyne incognita on cotton in Mississippi. Two tests were established in Leflore County on a fine sandy loam soil (56.8% sand, 37.8% silt, 5.3% clay, pH 5.4 and 0.3% OM) naturally infested with M. incognita. Oxamyl was applied as a foliar spray at 0.14, 0.27, or 0.53 kg a.i./ha to cotton plants that had reached the sixth true leaf growth stage. A second oxamyl application was applied 14 days after the first treatment at the same rates. All oxamyl treatments also received aldicarb at 0.59 kg a.i./ha at planting. Controls consisted of aldicarb alone, disulfoton (an insecticide) and an untreated control. Oxamyl reduced M. incognita numbers at 79 days after planting in Test 1 and 63 and 72 days after planting in Test 2 compared to aldicarb at 0.59 kg a.i./ha alone or the controls that received neither material. Average reniform population densities in oxamyl-treated plots were 38.3% and 44% lower than with aldicarb alone and the controls, respectively. Cotton plant height was greater in plots that received oxamyl at all rates than in the controls. Cotton in oxamyl plus aldicarb and aldicarb alone treatments produced more bolls per plant and had a greater total boll weight than disulfoton or the untreated control. Seed cotton yields were greater in oxamyl-treated plots than for disulfoton-treated and the untreated control.
