Control of Nematodes and Black Weevils in Plantains

Abstract

The burrowing nematode, Radopholus similis, and the black weevil, Cosmopolites sordidus, are the most important economic pests of plantain, Musa acuminata x M. balbisiana, AAB, in Puerto Rico. Research carried out by this Station has demonstrated that chemical control of nematodes increases plantain production and the useful life of the plantation. Similar results have not been obtained with the black weevil even when research has been conducted toward this goal. Several nematicide-insecticides for the control of both pests have been tested. At the Fortuna Substation five pesticides were evaluated: Carbofuran 5G and 10G, Fensulfothion 15G, Ethoprop 10G, and Aldicarb 10G. Carbofuran 5G was evaluated at the rate of 42 g/plant applied every 4 months. The other pesticides were evaluated at 56 g/plant applied every 6 months. At the Corozal Substation Aldicarb 10G was evaluated at 4 doses (10, 15, 30, 45 g/plant) applied every 4 and 6 months. Carbofuran 10G at 56 g/plant applied every 6 months was included for comparison. At the Fortuna Substation, where only one crop was harvested with no significant differences in yields, the majority of the pesticide treatments controlled the nematodes. The black weevil was controlled only with Aldicarb, Ethoprop, and Fensulfothion. At Corozal, where two crops were harvested, all treatments were significantly better than the control; with the control of nematodes and weevils there was an increase in yield and suckers. The most effective doses and frequencies for the control of both pests were Aldicarb 10G at the rate of 30 and 45 g/plant applied every 4 months and at 30 g applied every 6 months.