Field Evaluation of Pesticides Applied to the Soil for Control of Insects and Nematodes Affecting Southern Peas in Georgia1

Abstract

Soil fumigants DD® Mixture (dichloropropane-chloroproene mixture), DBCP (1,2-dibromo-3-chloropropane), and potassium azide (KN3), and nonvolatile pesticides aldicarb, carbofuran, disulfoton, duPont 1410 (methyl N, N -dimethyl- N' -l (methylcarhamoyl) oxy)-1-thio-oxamimidate), fensulfothion ( O, O -diethyl O-[p -(methyl-(methylsutinyl) phenyl hosphorothioate), and prophos ( O -ethyl S, S -dipropyl phosphorodithioate), were evaluated as soil treatments in 19170 and 1971 for control of plant parasitic nematodes and insects affecting southern peas, Vigna sinensis (Torner) Savi, in southern Georgia. In 1970 plots treated yield carbofuran had significantly taller plants, greater yield, and fewer plants infested with beet armyworms. Spodoptera exigua (Hubner), than other plots. Plants growing in plots treated with KN3 and DBCP were completely free of root galls caused by root-knot nematodes, Meloidogyne incognito (Kofoid & White) nematodes. Split applications of chemicals (1/2 replant and 1/2 postplant) were less effective than applications of the entire dosage of chemical preor post-plant. In 1971 control of thrips, Frankliniella spp. was best, and yield was highest in plots treated with aldicarb. Yield decreases in 1970 were correlated with terminal growth infested with beet armyworms (r = -0.71). In 1971 yield decreases were correlated with thrips injury (r = -0.52) and numbers of root-knot nematodes per 150 cc soil (r = -0.33).