Curative and Residual Efficacy of Injection Applications of Avermectins for Control of Plant-parasitic Nematodes on Banana.

Studies were conducted to determine the curative and residual efficacy of avermectins at controlling plant-parasitic nematodes when injected into the pseudostem of banana, Musa acuminata cv. Cavendish. In addition, we determined the lowest concentration of avermectins that provided satisfactory efficacy as protectants when injected into banana pseudostems. Experiments were conducted with a root-knot nematode, Meleidogyne javanica, and the burrowing nematode, Radopholus similis. Injections (1 ml) of >/= 100 mug a.i./plant of abamectin into pseudostems were effective at controlling M. javanica and R. similis, and were comparable to control achieved with a conventional chemical nemaficide, fenamiphos, in a protectant assay. Abamecfin injections of 250 and 500 mug a.i./plant were effective at reducing nematode infections 28 to 56 days after inoculation. Abamectin was more effective than ivermectin at controlling nematodes after nematode populations were established in banana roots. Injections of between 100 and 1,000 mug a.i./plant were effective at controlling nematodes for at least 56 days after treatment. These studies confirmed earlier results and demonstrated that abamecfin has potential for controlling nematode parasites on banana when injected into the pseudostem.