ECOFRIENDLY MANAGEMENT OF CUCURBIT FRUIT FLY ON BITTER GOURD

Abstract

A field experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University to find out the effective as well as hazards free management practice(s) of cucurbit fruit fly infesting bitter gourd cultivated during Kharif I season (February 2016 to June 2016). The experimental treatments were T1 comprised of setting up of pheromone trap replaced at 1 month interval, T2 comprised of setting up of poison bait trap @ 2 gm Sevin 85 WP mixed with 100 g mashed sweet gourd and 10 ml molasses replaced at 4 days interval, T3 comprised of spraying of Spinosad @ 0.08 ml per liter of water at 7 days interval, T4 comprised of bait spray @ 10 ml molasses and 1 ml Malathion mixed with 1 liter of water @ 7 days interval, T5 comprised of the combination of T1 and T2; T6 comprised of the combination of T1 and T3; T7 comprised of the combination of T1 and T4; T8 comprised of spraying of Neem oil @ 3 ml neem oil and 10 ml Trix mixed with 1 liter of water @ 7 days interval, and T9 comprised of untreated control. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Pheromone trap in combination with poison bait trap (T5) contributed to produce the highest number of fruit at early (26.67 fruit/plot), mid (37.33 fruit/plot) and late (27.00 fruit/plot) fruiting stage; total weight of fruit (838100 gm/plot) and reduced the maximum fruit infestation over control at early (94.23%), mid (94.48%) and late (85.05%) fruiting stage. The highest yield (24.03 t/ha) was recorded in T5 which contributed to increase the highest yield (163%) over control. The yield of bitter gourd was negatively correlated with the fruit infestation by number at early, mid and late fruiting stage (r = 0.795, r = 0.910 and r = 0.937, respectively). The fruit yield was strongly and positively correlated with the length (r = 0.972), girth (r = 0.938), single fruit weight (r = 0.931) and number of fruit per plant (r = 0.932), i.e., yield of bitter gourd increased with the increase of the length, girth, single fruit weight and number of fruit per plant. The poison bait trap was more effective than pheromone trap in terms of capturing adult fruit fly per trap throughout the cropping season, where in case of poison bait trap the average number of adult fruit flies captured per trap was 32.6 and in case of pheromone trap this number was 17.49 fruit flies per trap. The higher temperature (35oC) negatively affected the capturing of adult fruit fly for poison bait trap because of drying up of bait materials, but not affected on the adult capturing capacity of pheromone trap. The highest benefit cost ratio (43.20) was also found for T5 and the lowest BCR (14.91) for T8..Considering the social acceptance and environmental safely point of view, T5 comprising pheromone trap along with poison bait trap was the most effective management practices in reducing the fruit fly infestation. Thereby increasing the yield of bitter gourd.