Effect of pruning and flower and fruit thinning on growth, yield and quality of 'PHM 99.1.1' late longan in Hung Yen province
According to statistical data in 2017, the area under longan in northern provinces was estimated at 35.6 thousand ha, with an average yield of 5.7 t ha‑1 and a productivity of 186.9 thousand t. Among the longan cultivars under cultivation in the North, the late cultivar PHM 99.1.1 is one of the important ones due to its valuable characteristics, such as stable fruit set rate, high yield, late harvest season and longer time to keep fruits on the tree than other cultivars. The late longan cultivar PHM 99.1.1 accounts for 55% of the total area of 3,904 ha under longan production in Hung Yen. In order to develop the intensive cultural protocol to improve the fruit yield and quality, the study on Effect of shoot pruning and flower and fruit thinning on growth, yield and quality of late PHM 99.1.1 longan in Hung Yen province was implemented in 2 years of 2017-2018. The study was conducted on an 8-year-old longan orchard, planted at spacing of 6×6 m in Hung Yen province. Results of the study show that application of shoot pruning, fruit and flower thinning affected the growth, fruit yield and quality of the cultivar. Pruning 25% branches that bore fruits in the previous season and heading off branches bearing fruits (at the position next to the fruit panicles); and thinning 10% flower clusters of the trees and fruit panicles promoted vegetative growth that enabled two formations of new shoots which produced higher fruit yield than that of the control without pruning. Yield with the pruning treatment reached 22.5 t ha‑1, with each fruit panicles of 1.2-1.3 kg in weight and fruits of high uniformity in appearance. Proportion of the edible fruit flesh accounted for 65.68% of the fruit weight, with Brix at 21.6%. Application of shoot pruning and flower and fruit thinning on late longan cultivar PHM 99.1.1 enabled higher income for farmers in Hung Yen province.
Hung, V.V. and Hung, N.Q. (2020). Effect of pruning and flower and fruit thinning on growth, yield and quality of 'PHM 99.1.1' late longan in Hung Yen province. Acta Hortic. 1293, 143-148
late longan cultivar 'PHM99.1.1', pruning, growth, yield, Hung Yen province