Journal of Crop and Weed 7(2): 100-103 (2011) Influence of biofertilizer and inorganic fertilizer in pruned mango orchard cv. Amrapali S. KUNDU, P. DATTA, J. MISHRA, K. RASHMI AND B. GHOSH Department of Fruits and Orchard Management Bidhan Chandra Krishi Viswavidyalaya Mohanpur-741252, Nadia, West Bengal, India Received:l 1.05.2011, Revised: 23.09.2011, Accepted: 29.09.2011 ABSTRACT An experiment was carried out at Horticultural Research Station of Bidhan Chandra Krishi Viswavidyalaya (Agriculture University), West Bengal, India during 1005-07 to find out the effect of biofertilizer and inorganic fertilizer in Amrapali mango trees of JO years old which were planted in the year 1995 at 5m x 5m spacing and subsequently pruned during January, 2004 at 2.5 m height. Three levels of inorganic fertilizers (100% NPK, 75% NPK and 50% NPK) were applied alone and also in combinations with different bioferti/izers (Azotobacter, Azospirillum and VAM). Among sixteen treatments, all the inorganic and biofertilizer combinations exhibited profound effect on growth, yield and fruit quality and leaf mineral composition than inorganic fertilizer alone. However, the efficiency of inorganic fertilizer at three levels was more when supplemented with both Azotobacter and VAM. Higher fruit yield was obtained when the plants were treated with 100% NPK + Azotobacter + VAM (98.l kg/plant) or 75%NPK + Azotobacter + VAM (93.5 kg/plant) as compared to much lesser yield (60 Kg/plant) with 100% NPK. It was concluded that the treatments 100%NPK + Azotobacter + VAM and 75% NPK + Azotobacter + VAlvf were effective and may be adopted to improve the vegetative growth and productivity with quality fruits. Key words: Fmit quality, growth, leaf mineral composition, yield Mango (Mangifera indica L.), the King of fruits, is the most important fruit in the tropical and subtropical region of the world. The nutritional anp. economic importance makes mango very popular over the world. Amrapali is a mango hybrid (Dashehari x Neelum) and gaining popularity for its dwarf stature and regular bearing in nature. Amrapali has already occupied a major area in newly planted mango orchard in West Bengal and replacing the traditional cultivars. Nutrition of trees is an important part of mango orchard management practices and fertilizer is one of the major inputs accounting for nearly 35 percent of the cost of cultivation. Indiscriminate use of inorganic chemical fertilizers resulted in high amount of chemical residues in field as well as in the crop produces leading to various environmental and health hazards along with socio-economic problem. Again the increasing cost of fertilizer and global concern of ground water pollution through leaching from the soil are discounting the use of fertilizers. So, it is necessary, to maintain the soil fertility and plant nutrient supply to an optimum level for sustaining the desired crop productivity through optimization of the benefits from all possible sources of plant nutrients in an integrated manner (Chundawat, 2001). Biofertilizers are the living organism which add, conserve and mobilize the plant nutrients in the soil. Biofertilizer based on renewable energy source are cost effective supplement to chemical fertilizers and can help to economize on the high investment needed for fertilizer use (Motsara et al., 1995). The beneficial effect ofbio-fertilizers is now well established in fruit crops like papaya (Sukhade et al., 1995) and banana (Gogoi et al., 2004). However, very little work has been done on the use of biofetilizers in mango. With these backgrounds the present experiment was Email: skundubckv@rediffmail.com designed with the objective to supplement the use of ever increasing costly chemical fertilizers with the incorporation of biofertilizers that could ensure eco- friendly environment. MATERIALS AND METHODS The experiment was carried out at Horticultural Research Station of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India during 2005-07 to find out the effect of biofertilizer and inorganic fertilizer on 10 years old Amrapali mango trees which were planted during 1995 at 5mx Sm spacing and subsequently pruned during January, 2004 at 2.5m height. The research station is located at 22 °43' N latitude and 88°34. E longitude, having an altitude of 9.75m above mean sea level. The experiment was laid out with sixteen treatments and three replications with completely randomized design. Three levels of inorganic fertilizers (100% NPK, 75% NPK and 50% NPK) were applied alone and also in combinations with different biofertilizers viz., Azotobacter, Azospirillum and vesicular arbuscular mycorrhiza (V AM). The plant fertilized with 100% NPK revealed lOOOg nitrogen, 500g phosphorous and lOOOg potassium. Inorganic or chemical fertilizers were applied to the concerned plants according to their levels of treatments in two splits - once after fruit harvest (August) and another at pea stage of fruit (March). However, full dose of phosphorous and potassium and 50 % of nitrogen were given after harvest and remaining 50% of nitrogen was given at pea stage. Biofertilizers @250g each was incorporated to the concerned plant in the month of October by thoroughly mixing with 10 Kg of FYM. Both inorganic and biofertilizer were applied in a ring 1