Impact of organic nutrient management modules on growth, yield, fruit quality, and soil biochemical dynamics in Kinnow Mandarin (Citrus reticulata Blanco)

Abstract

A field study was conducted at the Agricultural Research Station, Sri Ganganagar, (Rajasthan) India, under AICRP on Fruits, to evaluate the effects of organic and integrated nutrient management modules on growth, yield, fruit quality, and soil–plant nutrient status in Kinnow mandarin (Citrus reticulata Blanco). The experiment, laid out in a randomized block design, comprised five treatments involving vermicompost and bio-inoculants, including Trichoderma harzianum, Pseudomonas fluorescens, Azotobacter chroococcum, and azadirachtin spray. Integrated organic treatments significantly enhanced vegetative growth, yield attributes, fruit yield, quality, and nutrient status. Treatment T4 (75% N through vermicompost + T. harzianum + azadirachtin + P. fluorescens) recorded the highest plant spread (5.10 m), girth (53.32 cm), canopy volume (67.36 m³), fruit weight (181.96 g), number of fruits per tree (409.37), and fruit yield (20.57 t ha–¹). Fruit quality improved with higher juice content (58.12%) and lower acidity (1.25%), while maximum total soluble solids (10.45 °Brix) were observed under T5 . Soil fertility and leaf nutrient composition were also significantly improved, with T4 recording the highest soil available N, P and K and corresponding increases in leaf nutrient content. The study highlights the potential of integrated organic nutrient modules for improving productivity, fruit quality, and soil health in Kinnow mandarin under semi-arid conditions.