CROP-SPECIFIC GROWTH RESPONSES TO LED OVEREXPOSURE: A STUDY ON Brassica rapa (PETCHAY) AND Ipomoea aquatica (WATER SPINACH)

Abstract

Urban farming and controlled-environment agriculture have become critical strategies for sustainable food production. This study investigates the effects of overexposing blue and purple LED light on the growth of Brassica rapa (petchay) and Ipomoea aquatica (water spinach) under controlled outdoor conditions. The research evaluated plant height, number of leaves, leaf length, and leaf width across three lighting treatments: natural sunlight, blue LED, and purple LED. Using one-way ANOVA and post-hoc analysis, significant differences were observed in selected growth parameters. Blue LED light significantly increased the plant height of Water Spinach (mean = 14.82 cm, p = 0.0339), while purple LED light significantly enhanced the number of leaves in Petchay (mean = 8.46, p < 0.001). No significant differences were found in leaf length and width across treatments for both crops. These findings suggest that specific LED wavelengths can improve particular growth traits depending on crop type. The study provides a basis for optimizing artificial lighting strategies in controlled agriculture and urban farming systems.