Effect of additional lighting for off-season production of dragon fruit

An investigation was carried out on the effects of additional LED lighting on dragon fruit yield, quality, and growth patterns during off-season flushes during 2020–2022. Each LED bulbs of 7, 9 and 12 watts were used during two-time intervals i.e. 4.30 to 8.30 pm and 06.30 to 10.30pm constituting 7 treatments including control with four replications. The application of 12W LED lighting from 4:30 pm to 8:30 pm significantly increased the number of fruits, with 10.61 and 10.69 fruits per pillar observed in the first and second flushes, respectively. This lighting regime also resulted in the longest (9.09 cm) and widest (7.18 cm) fruits considering both the flushes. Overall, total yield reached 6.01 kg per pillar, equating to 9.61 tons per hectare. The quickest floral bud formation (15.18 days) and highest ascorbic acid content (up to 7.98 mg/100g pulp) were also observed with the 12W LED lighting in the same time range. Light intensity readings, taken from various distances, peaked at 1002.57 LUX at 30 cm from the source. Additionally, some fruit quality traits, such as total soluble solids and sugar content, showed significant variation with lighting intensity, though titratable acidity and sugar types were unaffected.