Optimizing Nutrient Integration for Enhancing Plum Growth, Fruit Yield and Leaf Nutrient Status

The addition of organic materials to the fertilization regime can be instrumental in reducing the amount of chemical fertilizers use, while maintain optimum nutrient status in the trees. The 2 year field experiment was conducted to evaluate the effect of different nutrient source combination in comparison to conventional recommendation on growth, fruit yield and leaf nutrient status of plum cv. ‘Black Amber’ grown in hills of Himachal Pradesh, India. Treatments included conventional fertilizers rate which are recommended to the farmer (NPK₁₀₀) compared with 10 treatment combinations with reduced rate of chemical fertilizer (NPK₈₀; NPK₇₀; NPK₆₀), organic manure (Farmyardmanure; Vermicompost) and microbial formulations (Biofertilizers; Jeevamrit). Data revealed that NPK₇₀ + 10% RDN through vermicompost + biofertilizer (T-6) and NPK₇₀ + 10% RDN through vermicompost + jeevamrit (T-7) yielded the best results in terms of shoot growth, leaf area, leaf chlorophyll content, photosynthesis rate, stomatal conductance and transpiration rate in both the years. Cumulative fruit yield peaked in T-7 by 6% over conventional rate NPK₁₀₀ (T-1); there were no difference in fruit yield between T-6 and T-7. Integrated fertilizers combination registered significant influence on the leaf nutritional status, but not consistent. The deviation from optimum (DOP) index revealed excess of leaf phosphorus and iron content with all the treatments application, while negative for other elements however, T-6 maintained a better nutrient status than other treatments. The treatment combinations T-6 and T-7 can be recommended to the farmers for maintaining nutrient balance, thereby ensuring sustaining crop production in subsequent years.