Bio-friendly management of Guava fruit fly (Bactrocera correcta Bezzi) through wrapping technique.
Fruit fly (Bactrocera correcta Bezzi) is the major pest of Guava grown in Baruipur region of West Bengal, contributing upto 90% yield loss. The present study was undertaken during 2011-12 at farmers' field to validate the wrapping of individual fruits at tree and to standardize the wrapping material and the correct technique of wrapping. Performance of nine different types of wrapping materials (butter paper bag, polypropylene bag of 20 µ gauge with and without paper piece inside, non-woven poly fabric bags of white, green and blue colour with 20 gsm and 40 gsm thickness) along with two chemical approaches were studied against untreated control. Fruit fly infestation varied between 1.32% and 17.31% in all treatments using wrapping materials and 13.14% in case of combined use of pheromone trap (Bacu lure) and Dichlorvos spray as compared to 21.71% in sole use of Dichlorvos and 66.67% in control plots. Wrapping resulted in increased weight of individual fruits (112.58 g in butter paper bag compared to 68.40 g in control). Wrapping with transparent polypropylene bags (20 µ gauge) with partial paper cover inside, resulted in lowest yield loss (1.66%), earlier fruit maturity, better fruit quality (in respect of colour and glossiness), highest market price ('30 per kg) and highest net profit (1.357 lakh/ha). This material is durable enough to be reused for 4-5 times. The partial paper cover helped to prevent scorching injury to the fruit as well as to control the humidity inside the polypropylene bag.