author(s)
Nguyen Trinh Nhat Hang, Tran Thi My Hanh and Dang Quoc Chuong

abstract
The study investigated the damage situation of fruit borers on longan in Dong Thap, Tien Giang, and Vinh Long provinces and evaluated the effect of different fruit bagging materials on preventing harmful fruit borers and fruit quality of longan cv. Edor during 2019-2020. The experiment arranged in a randomized complete block design (RCBD) four replications and five treatments. The treatments were non-woven bag, Bikoo micro-hole bag, Agro-net bag (49 holes.cm^-2), white cotton bag, and control (uncovered fruits). The investigation indicated that fruit borers appeared and caused damage fruit from 2 weeks after fruit set to harvesting time. The percentage of infected fruit of longan orchards were high at 4 weeks after fruit set (1.75%) in Dong Thap, and in Tien Giang, Vinh Long provinces at 10 weeks after fruit set (1.46% and 2.04%, respectively). During 12 weeks from fruit bagging to harvest, bagging of fruits by four types of material did not damaged by fruit borers. However, control treatment increased the rate of infected fruits continuously (7.22% at harvest time). Agro-net bag (49 holes.cm^-2), Bikoo micro-hole bags, and white cotton bag were low fruit drop rate (30.73%, 30.65%, and 32.11%) when compared to control (47.14%). From the results obtained conclusion that application of fruit bags on longan cv. Edor was highly effective in preventing damage from fruit borers and ultimately production free from pesticides residues.