Effect of integrated nutrient management on leaf nutrient content, fruit yield and fruit quality of Nagpur mandarin

This study was conducted at the Research Farm of ICAR- Central Citrus Research Institute , Nagpur, Maharashtra during 2019-20. This was the experimentation to establish, how much inorganic chemical fertilizers in form of RDF can be saved through application of microbial consortium different modules of INM. The experiment was conducted with a total of five treatments viz., T₁ - 100% RDF (600 g N - 200 g P₂O₅ - 300 g K₂O - 200 g ZnSO₄ - 200 g FeSO₄ - 200 g MnSO4 tree^-1 year^-1 ), T₂ - 45% RDF + 45% vermicompost + microbial consortium, T₃- 40% RDF + 40% vermicompost + microbial consortium, T₄ -35% RDF + 35% vermicompost + microbial consortium and T₅-30% RDF + 30% vermicompost + microbial consortium replicated four times on a soil taxonomically classified as Vertic Ustochrept under randomised block design. The highest total nitrogen concentration (2.42 %), total phosphorus (0.12 %) and total potassium (1.42 %) in leaf was recorded under treatment T₃ - 40% RDF + 40% vermicompost + microbial consortium. Leaf highest micronutrient concentration of Cu (11.2 ppm) was recorded under treatment T₃ -40% RDF + 40% vermicompost + microbial consortium and Zn (25.2 ppm), Mn (69.4 ppm) and Fe (118.1ppm) at fruit development stage were recorded under treatment T₂ - 45% RDF + 45% vermicompost + microbial consortium. The yield was significantly highest under treatment T₄ - 35% RDF + 35% vermicompost + microbial consortium (582 Number of fruit tree^-1). The results obtained in the present investigation regarding fruit quality indicated the superior fruit quality parameters such as juice content (43.92 %), TSS (8.17°Brix), ascorbic acid (33.84 (ml gm^-1) were though recorded under T₄ - 35% RDF + 35% vermicompost + microbial consortium and different integrated nutrient management, but statistically non-significant with other treatments ,thus suggesting the saving of 40% chemical fertilizers with usage of INM strategy.