Aumento da eficiência fotossintética com o fornecimento de iluminação complementar em feijoeiro

Abstract

Supplementary lighting with LEDs has emerged as a promising technology to enhance photosynthetic efficiency and plant growth in controlled environments. This study aimed to evaluate the effects of different durations of nighttime supplementary lighting with pink LED on the growth of common bean plants (Phaseolus vulgaris L.). The experiment was conducted between October and November 2025, using five treatments: 1 h, 2 h, 3 h, and 4 h of supplemental lighting, as well as a control without LED. Plant height was measured weekly and analyzed using ANOVA followed by Tukey’s test. The results showed a significant effect of treatment, evaluation date, and the Treatment × Date interaction, indicating that plant response is influenced both by illumination duration and developmental stage. The 2-hour treatment showed the greatest mean final height (21.6 cm), outperforming the control (10.0 cm) and the other treatments. Energy cost analysis demonstrated that using 10 W LEDs resulted in a total expenditure of less than R$ 1.00 for the entire experimental period, highlighting an excellent cost–benefit ratio. Although plant height does not directly indicate productivity, the findings suggest that moderate nighttime supplementary lighting can promote early vegetative development in common bean plants. It is concluded that supplemental LED lighting is an efficient and low-cost strategy for use in controlled cultivation environments. Further research should evaluate its effects on yield, biomass accumulation, and physiological performance.