Manipulating Light Duration and Intensity Using LEDs to Enhance Off-Season Yield of Hylocereus polyrhizus in a Tropical Area of Banyuwangi, East Java, Indonesia

This study aimed to examine the effect of light duration and Light Emitting Diode (LED) power on the production of red dragon fruit during the off-season. The experiment was conducted in Bulurejo, Banyuwangi, East Java, Indonesia, from March to June 2024 using a split-plot design. The main plot consisted of LED illumination duration (2, 4, and 6 hours), while the subplot consisted of LED power levels (6, 9, 12, and 15 watts). Observations included environmental parameters (temperature, humidity, and heat units), plant phenology (number of flowers and fruits), and fruit quality attributes (fruit weight, volume, sugar content, and anthocyanin content). Data were analyzed using analysis of variance (ANOVA) followed by appropriate mean comparison tests. The results showed a significant interaction between illumination duration and LED power on the number of flowers. Treatments of 4 hours (P2) and 6 hours (P3) illumination were able to significantly increase the number of fruits, while the use of 12-watt LED (D3) produced the highest results for number of fruits, fruit weight, and sugar content. The increase in light intensity proved to enhance photosynthesis, sugar accumulation, and fruit quality, although anthocyanin accumulation tended to decrease along with increasing productivity. Thus, the combination of 4–6 hours of illumination with 12-watt LED was the most optimal treatment to improve the productivity and quality of red dragon fruit during the off-season. This study demonstrates that optimizing both light duration and intensity can effectively enhance off-season productivity and fruit quality of red dragon fruit, providing a practical lighting strategy for tropical cultivation systems.