Unraveling the roles of natural biostimulants and GA₃ in regulating physiological, biochemical, and nutritional adjustments in Mandarin

Climate change is a key factor affecting the citrus growth, quality, and yield. The research was designed to evaluate the comparative effect of the foliar treatment of various bio-stimulants (Kamab-26, Seamaxx, and Isabion) and gibberellic acid (GA 3 ) on the growth and fruit attributes (plant height, leaf area, canopy volume, fruit size, fruit weight, rag weight, peel weight, peel thickness, viscosity), ionic (N, P, and K), physiological (Chlorophyll contents, photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency) and biochemical [total soluble sugars (TSS), titratable acidity (TA), Juice contents, antioxidant, phenolic content, reducing, and non-reducing sugars] attributes of Kinnow. The treatments were designated as T 0 (Control), T 1 ( Kamab-26), T 2 (Isabion), T 3 (Seamaxx), and T 4 (GA 3 ) and were applied three times before flowering, at the fruit set period, and at the pre-mature stage under a randomized complete block design (RCBD). Each treatment was replicated three times. The statistically significant ( p ≤0.05) results were shown by all the bio-stimulants, but T 1 ( Kamab-26) treatment indicated the most significant improvement in growth yield, physiological, biochemical, fruit quality, and ionic attributes, whereas other treatments showed a non-significant behavior. Overall results suggested a beneficial effect of bio-stimulants, particularly Kamab-26 and GA 3 , which helped in improving citrus growth, yield, physiological, biochemical, ionic, and fruit quality parameters.