Horticultural management practices for controlling fruit flies in mango and guava

A series of experiments were carried out in order to increase the production of quality mango and guava fruits in the Mymensingh region of Bangladesh through proper management of fruit flies. The research work was conducted at the Fruit Tree Improvement Project (FTIP), Bangladesh Agricultural University, Mymensingh during the period from January 2012 to December 2014. Fruit flies (Bactrocera dorsalis) are considered as serious pests that cause enormous losses to farmers in many countries of the world. Earlier reports suggest that frequent use of insecticides in controlling fruit flies did not result in sustainable management of this pest. Scores of problems are associated with sole reliance on chemical control such as residues of insecticides in crops, health risks for human, contamination of water and soil, insecticide resistance development and decrease in population of natural enemy. Hence, exploitation of fruit fly control through natural means merit investigation. The present experiments were conducted mainly to manage mango and guava fruit flies with emphasis on non-chemical means, and to improve the yield and quality of mango and guava through the use of proper horticultural management practices, and finally to recommend a package of integrated management for safe mango and guava production. Results of the experiments in relation to management practices revealed that bagging of fruits with perforated white polybag one month before harvest checked fruit fly infestation fully and produced almost 100 percent non-infested fruits per plant. Results of the experiments related to pheromone traps (methyl eugenol) on fruit fly control under open field condition suggested that around 90 percent non-infested mango and guava fruits were produced when pheromone traps were used. The results were further confirmed by conducting an experiment with artificial release of fruit fly in enclosed environment for mango. Almost 100 percent non-infested fruits were obtained from each plant when pheromone trap was used without fly, and it was around 94% with fly. Seasonal incidence of fruit fly was extensively investigated in the present study. Results showed that incidence of mango fruit fly was the maximum in the month of May, whereas for guava it was the month of June. Results from a combined experiment incorporating all the best findings and the benefit cost analysis revealed that perforated white polybag and pheromone trap were the best and appeared to be suitable for the management of mango and guava fruit flies. The preharvest fruit bagging technique has been found to be useful for extending shelf life of mango. The longest shelf life of 10.48 days was obtained from the fruits bagged with white polybag. Results indicated that preharvest proper management practices, especially fruit bagging with perforated white polybag and pheromone trap (One trap per plant) may be recommended for producing good results and safe mango and guava with longer shelf life and higher economic returns.