Population dynamics and management of major insect pests of strawberry Fragaria ananassa Duch and phalsa Grewia asiatica L

Abstract

newline The thesis embodies the results of experimentation made on population dynamics and management of major insect-pests of strawberry (Fragaria x ananassa Duch.) and phalsa (Grewia asiatica L.) carried out during cropping seasons of 2018 and 2019 at Chatha Farm, SKUAST- Jammu. Studies revealed that the infestation due to major pests viz., aphids (Chaetosiphon fragaefolii), whiteflies (Bemisia tabaci), and Red-vented bulbul (Pycnonotus cafer) and Yellow vented bulbul (Pycnonotus goiavier) on Strawberry and fruit flies (Bactrocera dorsalis, B. zonata) and leaf-rolling weevil (Pseudallapoderus sissus) on phalsa wherein, leaf-rolling weevil (Pseudallapoderus sissus) and Hesperid caterpillar (Odontoptilum angulate) were recorded for the first time on phalsa crop in India. The data on population dynamics revealed that the peak aphid population on strawberry during 12th standard week whereas, fruit fly population on phalsa peaked during 24th standard week. newlineCorrelation studies revealed that highly significant and positive correlation existed between weekly mean relative humidity morning with aphid (0.487**) and whitefly population build up (0.434**), respectively. The overall impact of weather factors on population buildup of aphid and whitefly on strawberry was 51.10 and 51.80 percent, respectively for both the years. Screening of eight varieties of strawberry against aphid revealed that Festival was found to be superior in obtaining maximum yield/plot in Kg (13.94) however, in terms of healthy fruits percentage obtained per plot, Chandler was found to be the best (88.53 percent). The screening of strawberry varieties for resistant reaction revealed that Chandler, Camarosa and Vimosine varieties as moderately resistant against aphid population in the field conditions. The treatment Imidacloprid 17.8SL was found significantly different from all other treatments in reducing the percentage aphid population over control. The pooled data on insecticide evaluation recorded lowest number of mean populations of aph