Chemical Control of Coffee Nematodes in Seedbeds in Puerto Rico

Abstract

Pre-plant soil treatments with granular formulations and foliar sprays with the nematicides phenamiphos (Nemacur), oxamyl, (Vydate) and fensulfothion (Dasanit) reduced populations of Meloidogyne incognita and Pratylenchus coffeae in coffee (Coffea arabica L.) cv. Puerto Rico Selecto roots. Significant (P = 0.05) increases in growth and development of the treated plants were obtained in the greenhouse. Best results were obtained with 11.20 kg ai/ha of phenamiphos applied to the soil 15 days prior to planting, combined with foliar sprays of 1.12 kg ai/ha of the same systemic nematicide 15 days after transplanting or two foliar sprays with 0 .56 kg ai/ha applied at intervals of 30 days; 0.56 kg ai/ha of oxamyl applied to the foliage 30 and 60 days after transplanting; and 4 granular soil applications of 300 mg of fensulfothion at 30-day intervals. Dipping roots in a solution containing 400 p/m of phenamiphos and 600 p/m of oxamyl also reduced nematode populations in roots and soil. Significant differences in root-knot index were found among those treatments and the controls, but plant growth was not affected. The higher dosages (2.24 kg ai/ha) of phenamiphos and fensulfothion when applied to the leaves twice after transplanting were phytotoxic to the coffee seedlings resulting in early defoliation, but not killing the plants.