Growth, yield and quality of sweet orange cv. Mosambi in response to INM in vertisols of central India

A field trial was conducted on 8-year-old sweet orange orchards grown on black soils. Different treatments involved application of FYM, vermi-compost, wheat straw and green manuring with sunhemp as singly or in combination with inorganic and biofertilizers like Azotobacter and PSB including control plots. The dose of organic manures was applied on nitrogen equivalent basis. The results indicated that maximum fruit yield coupled with an adequate tree volume of sweet orange is attainable through combined use of organics plus inorganic or bio-fertilizers. Combined application of these three classes of nutrient sources has proved far superior to their sole application. Application of FYM (to supply 50% N) along with 50% dose of inorganic fertilizers showed complete supremacy with benefit: cost ratio of 4.59. Green manuring with sunhemp along with 50% dose of inorganic fertilizers was also equally effective with highest benefit: cost ratio of 6.46. While substantial improvement in fruit quality could be achieved with the sole application of organic manures specially FYM.