Pinto Bean Yield Increased by Chemical Control of Pratylenchus spp.

R. T. Robbins, O. J. Dickerson, J. H. Kyle


Pinto bean yields and Pmtylenchus 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 = 0.05) was obtained for samples taken 36 days after planting and -.52 (P = 0.01) for samples taken 30 days later. There was no significant correlation between yield and numbers of Pvatylenchus spp. recovered from the soil. Key Words: Pathogenicity, Nematicides, Population dynamies, Fumigation.

Full Text: