Effects of an Amino Acid-Based Micronutrient Formulation on Growth and Yield of Mandarin Orange (Citrus reticulata)

This study evaluated the impact of foliar application of an amino acid-based micronutrient formulation on the growth, yield, and quality of mandarin orange (Citrus reticulata). The field experiment (2022–2024) was conducted at Kelwad Farm, Maharashtra, India, on 6‑year-old trees under uniform orchard conditions. The formulation comprised naturally derived amino acids (cysteine, serine, glutamic acid, glycine, leucine, valine, arginine, etc.) combined with micronutrients (Zn 3%, Fe 2.5%, Mn 1%, B 0.5%, Mo 0.1%, Cu 1%, Mg 1%). Five treatments were compared, including a control (water spray), amino acids alone, micronutrients alone, a commercial formulation, and an in-house developed formulation (T5). The combined treatment (T5) significantly enhanced plant height (up to 27.8%), stem diameter (up to 30.5%), fruit weight (up to 39.7%), and fruit number (up to 31.1%) compared to the control. The improvement is attributed to the synergistic effect of amino acids and micronutrients that enhanced nutrient uptake, physiological efficiency, and metabolic activity. These results demonstrate that amino acid-based micronutrient formulations can effectively enhance growth and yield in mandarin orange while supporting sustainable nutrient management strategies in citrus cultivation systems.