Optimizing Citrus aurantifolia (Christm. Swingle) Production Through Integrated Irrigation and Growth Regulation Strategies

Optimizing irrigation and the targeted use of plant growth regulators are key strategies to improve productivity in citrus systems under water-limited conditions. This study evaluated the effects of three irrigation levels (4.44, 5.18, and 7.77 mm day−1) combined with variable doses of naphthaleneacetic acid (NAA) and gibberellic acid (GA3) on physiological and productive responses in Citrus aurantiifolia. The treatment with 7.77 mm irrigation and moderate doses of NAA (100 mg L−1) and GA3 (80 mg L−1) increased yield by 38% (6.2 kg/plant), and it enhanced photosystem II photochemical efficiency (Fv/Fm = 0.82), chlorophyll index (SPAD = 62), and fruit weight by 15%. In contrast, high hormone doses under water deficit reduced leaf water potential and impaired physiological performance, leading to lower productivity. These findings support the combined use of regulated deficit irrigation and hormonal biostimulation as a sustainable strategy to enhance key lime yield and resource efficiency in semi-arid environments.