Pinto Bean Yield Increased by Chemical Control of Pratylenchus spp

Pinto bean yields and Pratylenchus spp. (nematode) population densities are reported for field plots pro-plant treated with nematicides in 1966 and 1968. Vidden-D (1,3-dichloropropene, 1,2-dichloropropane and related chlorinated hydrocarbons), Vortex (20% methyl isothioeyanate plus 80% chlorinated Ca-hydrocarbons), Telone PBC (80% dichloropropenes, 15% chloropicrin, and 5% propargyl bromide), Dasardt (0,0-Diethyl 0-[p-(methylsulfmyl)phenyl] phosphorothioate, and Dowfume MC-2 (98% methyl bromide plus 2% chloropierin) were used in 1966. Vorlex, Dasanit, and D-D (1,3-dichloropropene, 1,2-dichloropropane and related chlorinated hydrocarbons) were each used at two rates in 1968.Fumigated plot yields ranged 32-56% higher than control plots in 1966 and 11-80% higher in 1968. Significant yield increases were obtained for all fumigants except Telone PBC in 1966. In 1968 significant increases were obtained from use of the high rate (374 liters/ha) of Vorlex and low rate (8.4 liters/ha) of Dasanit. There was an inverse relationship between yield and numbers of Pratylenchus spp./g root on four sampling dates in 1968. A correlation coefficient of -.39 (P