Management of Banana Pseudostem Weevil – A Biological Approach

Abstract

The production and productivity of banana is governed by many biotic and abiotic factors. Among biotic factors, incidence of insect-pests is considered as one of the major hindrance in successful cultivation of banana. In India, about eight pests commonly infest the banana crops; but of these, the banana stem weevil (Odoiporus longicollis) is cosmopolite's insect pest that threatens the banana cultivation. The most common management practices followed for managing this pest includes cultural practices and application of insecticides. An attempt was made to manage this insect pest using biocontrol agents with the following treatments: Beauveria bassiana (1 x 107 spores/mL) spray at 5th, 6th and 7th months after planting; Metarrhizium anisopliae (1 x 107 spores/mL) spray at 5th, 6th and 7th months after planting; swabbing B. bassiana on the pseudostem at 5, 6 and7 mo after planting; swabbing M. anisopliae on the pseudostem at 5, 6 and7 mo after planting; Heterorhabditis indica spray at 5, 6, 7 mo after planting; stem trap swapped with B. bassiana @ 10mL/trap at 5 mo after planting; stem trap swapped with H. indica @ 1 x 109 IJS /mL at 5th month after planting; insecticidal check - chlorpyrifos (0.1%) and untreated Control. Three years of experimentation resulted that among the bio-agents, application of B. bassiana was found to be the most effective in reducing the population of banana stem weevil. Amongst the treatments, swabbing B. bassiana on the pseudostem at 5, 6 and7 mo after planting showed the best result followed by stem trapping of banana stem weevil swapped with B.bassiana @ 10mL/trap at 5 mo after planting. There was 59.31 and 69.78 per cent reduction in psuedostem infestation over control at 7 mo after planting and at harvest, resp. in the best treatment. However, insecticidal spray out yielded all the treatment in reducing the pest incidence and increasing the yield of banana.