Abstract
The research work was carried out on the pest complex of country bean and their damage potentiality and development of integrated pest management techniques against legume pod borer, Maruca vitrata in the Regional Agricultural Research Station and farmers field, Jessore from 2004 to 2008. Sixteen insect pests and one mite pest were recorded in the bean field, and they infested different plant parts of country bean observed during June - January, 2005 - 2007. The legume pod borer was found to be the most abundant and damaging pest among the insect pests of country bean, causing 18.8 and 34.3 per cent flower and pod damage respectively. Twenty one germplasm accessions of country bean reacted distinctly to Maruca vitrata with significantly different levels of infestation to flowers, pods and yield. Chela shim, Barinagar local, Sada kalai shim, BARI 1 and 2, BARI line 115, Bota shim, Bagarpara 2 and IPSA 2 were found to be tolerant to legume pod borer in respect of pod damage and pod yield. Hand picking and light trap as mechanical control measures were evaluated in the country bean fields, which acted differently to legume pod borer. Hand picking had better effect than light traping controlling this pest. Of four botanical crude seed extracts, Neem @150 g and 100g /L and Mahogni @ 100 g/L of water at 7 days intervals on the country bean showed better performance in the reduction of flower and pod damage with significantly higher yield of bean. Amamectin Benzoate @ 1.0 g/L was superior to all other insecticides in respect of toxic action on Maruca vitrata and it reduced 91 and 96 per cent flower damage in kharif and rabi seasons, respectively and the pod damage accounted for 77 and 83 per cent reduction in these seasons resulting 78 and 59 per cent increasing pod yield. Nineteen combinations of sex pheromone blends with components of (E,E)-10,12-16:Ald, (E)-10- 16:Ald, (Z)-9-16:Ald, (Z)-11-16;Ald and (E)-12-16:Ald and 18 combinations of floral blends of components such as (-) limonene, phenylacetaldehyde, methyl 2-methooxibenzoate and salicylaldehyde were evaluated to attract Maruca vitrata moths in traps in the farmers bean field with trap catches as high as 0.36 moths per trap per night showing no effect in any combination. Some IPM packages were effective in reducing flower and pod infestation and increasing pod yield against legume pod borer. The package 2 - hand picking and destruction of infested flowers and pods with larvae of legume pod borer and cutting of older leaves and twisted young twigs and integrated with spray of Amamectin Benzoate (Proclaim) 5SG @ 1 g per litre of water at an interval of 7 days had comparatively better performance in the reduction of 89.36 per cent flower and 80.53 per cent pod damage and 44.21 per cent pod yield increase. The IPM package 5 - hand picking and cutting as package 2 integrating with spray of Amamectin Benzoate (Proclaim) 5SG @ 1 g per litre and Neem seed extract @ 100 g per litre of water separately at every alternate schedule date at an interval of 7 days might be considered as another management strategy for legume pod borer providing with 74.44 per cent reduction of flower damage, and 53.50 per cent pod damage, and 32.75 per cent increase of pod yield.