Comparative Trapping Potentials of Different Pheromone-Incorporated Traps Against Fruit Fly and Estimation of Crop Water Productivity of Guava Under a High Efficiency Irrigation System
摘要
Fruit flies are notorious insect pests of guava and other fruit crops worldwide, resulting in substantial yield loss and also deteriorating fruit quality. Management of the fruit fly is mainly achieved through synthetic insecticides, but repeated use of the insecticides has resulted in environmental pollution, residual effects in fruits and resistance development. Pheromones are bio-derived substances that are safe to human health and possess no residual effects in fruits. The present study was carried out to assess the impact of modified pheromone traps against the fruit fly population in a guava orchard containing three varieties (‘Golden’, ‘Small Surahi’ and ‘Large Surahi’) having three plantation densities (dense 3 × 3 m, high dense 1.5 × 3 m and ultra-high dense 1 × 2 m) and three pruning levels (P.Ls), i.e. P.L1 = 4 ft, P.L2 = 5 ft and P.L3 = 6 ft. Two insecticides (dimethoate and malathion) and a plant oil (garlic, variety ‘G-1’) were incorporated in pheromone traps. Results of mean infested fruits per plant showed that maximum infestation (8.0 mean infested guava fruits) were observed in the case of the control in ‘Golden’ variety, while the lowest infestation (1.50 mean infested guava fruits) was recorded in the case of ‘Small Surahi’ at P.L1 under dense guava plantation. The infested fruits were comparatively greater in number in the case of malathion + methyl eugenol (M.E.) and garlic ‘G-1’ + M.E. pheromone traps than in dimethoate + M.E. In the case of guava planting densities and pruning levels, maximum infested fruits (6.82) were recorded in garlic ‘G-1’ + M.E. at P.L3 under ultra-high dense plantation, while comparatively lower infested fruits were recorded at the same pruning level under low and dense guava plantation at P.L1. Overall results revealed that dimethoate-incorporated traps were comparatively more effective than the other two pheromone traps. Results of the three pruning levels showed that P.L1 proved relatively more effective with the lowest than the other two pruning levels. The highest crop water productivity value (3.557 kg m−3) was recorded under drip irrigation in the case of P.L3 under dense plantation, while the lowest (0.365 k kg m−3) was recorded in the case of P.L1 under ultra-high dense plantation. From the results, it is concluded that modified pheromone traps could be effective in the integrated pest management (IPM) of fruit fly.