Physiological effects and technical strategies of LED supplemental lighting for pitaya cultivation: a review.

Pitaya is a high-value perennial tropical fruit known for its nutritional and health benefits. It is now widely cultivated in many tropical and subtropical countries, offering strong economic returns. China ranks first globally in pitaya cultivation, which includes both open-field production in tropical and subtropical regions and facility-based cultivation in temperate zones. As a long-day, light-loving plant, pitaya can be produced year-round. However, during off-season cultivation in winter and spring, weak light conditions and limited daylight hours lead to low flowering and fruit-setting rates, resulting in reduced yield and quality, factors that significantly constrain the industry's development. The core technological challenge in achieving high-quality, high-yield, multi-cropping pitaya production lies in inducing abundant, high-quality blooms in a staged manner using LED artificial lighting. Based on current domestic and international research on the physiological mechanisms and technical strategies of light-induced flowering in pitaya, the effects of LED light supplementation on flowering and yield, along with relevant technical parameters, have been clarified. Practical applications have demonstrated the feasibility of using three-dimensional, precise LED supplemental lighting to regulate flowering and photosynthesis in both facility and open-field cultivation. This technology synergistically promotes both vegetative and reproductive growth, significantly improving flowering and fruit-setting rates, increasing single fruit weight, enhancing yield and quality, and boosting annual production efficiency. This article comprehensively summarizes the enhancement effects and physiological mechanisms of LED supplemental lighting on pitaya flowering regulation, focusing on light intensity, light quality, and photoperiod, within the context of international research. It also analyzes existing challenges and proposes strategies such as optimizing LED light source design, accurately planning supplemental light periods and durations, and establishing three-dimensional lighting methods. These strategies aim to improve the efficiency of LED lighting systems and provide a theoretical foundation for developing a precise and efficient pitaya LED supplemental lighting technology system. In conclusion, LED supplemental lighting promotes both the quantity and timing of pitaya flowering, as well as fruit yield and quality. Red, blue, and far-red light, combined with a photoperiod of 4-6 h, are recommended for effective application.