Received: 07-11-2019 / Accepted: 05-02-2020
The studywas aimed to establish atechnical protocol to extend the fruit harvest in Northern provincesfor off-season flowering of red-fleshed dragon fruit TL5 variety growingin Gia Lam, Hanoi. The study was conducted in 2 seasons of lighting, on October 20, 2016,and October 20, 2017. The lighting treatment used 60W incandescent light bulbs to supplement light from 10 pm to 3 am, in the 5 different lighting durations of 13, 16, 19, 22 and 25 nights. The experiment was arranged in RCBD, with 20 posts/treatmentforeach replication. The results showedthat in both seasons of lighting supplement, the treatments of lighting in 19, 22 and 25 nights were recorded with good flowering. The number of shoots per post-producing flower buds and number of stable flower buds per post in these lighting treatments reached 28.2-33.6 and 52.7-67.2 respectively, which were significantly different from those of the treatments with 13 and 16 nights of lighting. Actual yields in treatments of 19; 22 and 25 supplement nights reached 6.2 to 7.3 kg/post in both the 2 seasons, which were significantly different from those of treatments with fewer lighting days. Among the lighting treatments, the supplement in 22 nights was the most effective that the profits were increased to 150.8 million dong/ha in the first crop and 144.8 million dong/ha in the second crop.