EVALUATION OF FUMIGANTS AND NEMATICIDES FOR THE CONTROL OF ROOT-KNOT NEMATODES ON CARROT

A study was conducted to investigate the effectiveness of soil fumigants and oxamyl nematicide on root-knot nematode, Meloidogyne hapla. A loamy sand carrot field of Danvers 126 carrots with a high population of root-knot nematodes was used for the test. Treatments included: 1, 3-dichloropropene, oxamyl, sodium methyldithiocarbamate, and the combination of 1,3-dichloropropene and oxamyl or sodium methyldithiocarbamate and oxamyl. All treatments were replicated 4 times in a randomized complete block design. Carrots were evaluated for plant stand, vigor, root length, galling, marketable yield, and total yield. Tremendous differences in plant vigor of young plants were observed among treatments. All of the fumigant treatments were significantly better than the other treatments and resulted in high plant stands and increased root length. Only the fumigated treatments, with or without foliar applications of oxamyl, resulted in significant marketable yield increases. Oxamyl foliar applications are beneficial in reducing root-knot nematode populations levels and damage when applied 6 weeks after initial treatment but not when they are initiated 10 weeks after initial treatment.