TY - EJOU AU - Viriyawattana, Nuttabodee AU - Sinworn, Surachat TI - Optimizing Cherry Tomato Growth under Heat Stress Using Semi-Enclosed Greenhouses and LED Spectra T2 - Phyton-International Journal of Experimental Botany PY - VL - IS - SN - 1851-5657 AB - High solar radiation during the Thai summer raises greenhouse temperatures to 33–41°C, exceeding the optimal range for tomato cultivation (15–25°C) and reducing yield and fruit quality. This study aimed to evaluate the effectiveness of combining daytime shading with evening supplemental light-emitting diode (LED) lighting to improve the growth, yield, and fruit quality of cherry tomato grown under heat-stress conditions. To alleviate excessive heat accumulation, a semi-enclosed greenhouse equipped with an 80% shade net was applied from 11:00 to 14:00, while supplemental LED lighting was provided from 18:00 to 22:00. Plants were exposed to red, blue, red–blue, and red–blue–white (3000 K) light spectra at intensities of 150 and 200 μmol m−2 s−1. Growth parameters, biomass accumulation, fruit yield, and fruit quality attributes were evaluated throughout the cultivation period. The results demonstrated that supplemental LED lighting significantly improved plant performance under shaded greenhouse conditions. Among all treatments, the combined red–blue spectrum (3:1) supplemented with white light at an intensity of 200 μmol m−2 s−1 produced the most favorable response. Plants grown under this treatment exhibited greater vegetative growth, increased shoot and root biomass, enhanced flowering and fruit set, and higher total fruit yield compared with the control treatment without supplemental lighting. In addition, fruit quality was improved, as evidenced by increased soluble solids content (°Brix), indicating enhanced sweetness and market value. The improved performance was attributed to increased photosynthetic efficiency and better light utilization during the evening period. These findings suggest that integrating daytime shading with targeted evening LED supplementation is an effective strategy for mitigating heat stress and maintaining high productivity of greenhouse-grown cherry tomatoes under tropical environmental conditions in Thailand. KW - Heat stress; semi-enclosed greenhouses; light-emitting diodes spectra DO - 10.32604/phyton.2026.086514