VEGETOS : Une revue internationale de recherche sur les plantes

Impact of Weather Parameters on Major Insect Pests of Okra Prevailing Western Uttar Pradesh

Lok Nath, C S Prasad, G N  Tiwari and Amit Kumar

Biotic and abiotic factors limit the productivity of okra including insect pests like jassid, Amrasca bigutulla bigutulla, whitefly, Bemisia tabaci, Helicoverpa armigera, red spider mite Tetranychus sp., leaf roller Sylepta derogata and shoot and fruit borer Earias vittella. The high population of 10.76 jassids/leaf was observed on 3rd week of August (34th SW) during the first year and 8.96 jassids/leaf during the second year on 4th week of August (35th SW). The maximum level of whitefly population 10.52 flies/leaf was recorded on 2nd week of August (33rd SW) during first year. During second year the maximum population of 11.66 flies/leaf was recorded in 3rd week of August (34th SW). Jassid and white fly population with temperature (maximum, minimum and average), rainfall, sun shine hours and RH showed non-significant positive correlation during both the years. The highest population of red spider mite, 37.89 mites/leaf in 40th SW during 2005 and 40.83 mites/leaf were recoded in 39th SW during 2006. Temperature showed significant negative coefficient of correlation while RH, rainfall and sun shine hours showed non-significant positive relationship. The maximum level of 1.20 H. armigera/plant in 37th SW in 2005 and 1.0/plant was observed in 38th SW during second year. Significant positive coefficient of correlation was recorded between rainfall and H. armigera population during 2005. The rolled leaves gradually increased and reached to its maximum level of 2.80/plant and 1.60/plant in 39th SW during both the years. The larvae of S. derogata showed non-significant positive relationship with RH, rainfall and sun shine hours respectively and non-significant negative relationship with temperature. The maximum damage 43.52% and 42.31% in 41st SW during both the years was caused by Earias vittella. The temperature with per cent fruit damage showed significant negative relationship during 2005 and 2006 and RH showed non significant positive relationship with this pest