Effects of Graded Micronutrient Supply on Morphological, Nutritional, and Biochemical Traits of Fig ( Ficus carica L. ‘Sarılop’) Saplings

This study examined the effects of graded micronutrient supply on the morphological, nutritional, and biochemical responses of ‘Sarılop’ fig (Ficus carica L.) saplings grown under controlled greenhouse conditions. Three-year-old saplings received iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) at four supply levels: zero supply, half-strength, full-strength, and double-strength using a modified Hewitt nutrient solution. Responses were strongly element- and trait-specific. Fe supply progressively increased sapling height and stem diameter and significantly affected catalase (CAT) activity, which showed a nonlinear response, reaching its highest value (9.34 U mg−1 protein) at double-strength supply. Copper significantly affected chlorophyll b, which reached a maximum of 2.28 mg g−1 fresh weight at the full-strength treatment. Zinc supply was associated with increased leaf number up to the full-strength level and a pronounced increase in starch accumulation, whereas Mn significantly affected sapling height and leaf Mn concentration. Total superoxide dismutase (SOD) activity was not significantly affected by Cu, Zn, or Mn supply. Overall, the findings indicate that micronutrient supply during the sapling stage influences vegetative growth and biochemical responses in fig trees, providing controlled physiological evidence relevant to nursery-stage nutrition strategies.