Integrated nutrient management in mango.
Bhargava B. S.
Author Affiliation: Maharashtra State Grape Growers Association, Manjri Farm P.O., Solapur Road, Pune - 412 307, India.
Scientific Horticulture 10 : 1-43
Abstract : Mango grown in 14,86,900 hectare area producing 1,05,03,500 tonnes of crop annually with an average production of 7.06 tonnes per hectare. To harvest optimum yield, good quality fruits of mango, we need 74?345 tonnes of nitrogenous, 44?607 tonnes phosphatic and 93?675.7 tonnes of potassic fertilizers nutrients in 0.80:0.48:1.00 ratio as compared to N:P2O5:K2O 7.20:2.66:1.00, being consumed by all agricultural, horticultural, plantation crops. Plant density, perennial nature, bud differentiation, root distribution and quality consideration demand special care, in nutrient management using modern methods of diagnosis such as leaf and soil analysis along with soil test, crop response correlation in mango. Use of organic manures and bio-fertilizers increase use efficiency of chemical fertilizer and improve the quality of fruits. Mango crop is either unbalanced fertilizer or not fertilized adequately giving rise to nutrient deficiency and hidden hunger or toxicity of some elements such as Al and Fe in acid soils of Ratnagiri. Mango crop normally do not express nutrient disorders and it can be assessed only by chemical analysis of index tissue - the leaf. Rational fertilization can be made based on native fertility of soil, climatic zone, nutrient removal by the crop, rate of growth and plant reserve. Necessary care is required in nutrient management in acidic, alkaline, sodic soils especially under arid climate. In mango, quality of fruits is more important and hence balanced nutrient management has a leading role to play to get excellent quality of fruits for domestic market as fresh fruits (extracting pulp or making mango leather) as well as for export. For a well grown tree of 10 years and above 50 kg N, 30 kg P2O5 and 63 kg K2O per hectare per year need to be applied coupled with required secondary nutrients such as Mg, S and micronutrients like Zn, Fe and others like Mn or B as indicated by leaf analysis with a support of soil analysis to get full benefit of primary nutrients and higher nutrient use efficiency. To assess the nutrient need, leaf nutrient guide for Alphonso cultivar of mango has been developed, according to which N may be in the range of 0.78 to 1.65%, P 23 to 33 mg%, K 0.77 to 1.73%, Ca 0.76 to 1.63%, Mg 0.40 to 0.65%, S 35 to 1312 mg%, Fe 657 to 961 ppm, Mn 14 to 408 ppm, Zn 78 to 18.3 ppm and Cu 14.3 to 17.8 ppm. On maintaining the required nutrient status on 5-month-old leaf the growers may get yield from 5.3 to 7.4 tonnes per hectare. The case study indicated that there was deficiency and hidden hunger for N, P, K, Mg, S, Zn and B even in moderately to relatively high yielding mango orchards of Ratangiri and therefore the yield level can further be increased to 15 to 20 tonnes per hectare on observing integrated nutrient management. Leaf nutrient norms were also developed for Rajapuri cultivar (1.41% N, 87 mg% P, 1.51% K, 1.89% Ca, 0.34% Mg, 140 mg% S, 101 ppm Fe, 114 ppm, Mn, 16 ppm Zn, 19 ppm Cu will give 2.0 to 7.5 tonnes mango fruit per ha) in tribal area of southern Gujarat and Totapuri cultivar (1.18% N, 105mg% P, 0.81% K, 2.58% Ca, 0.52% Mg, 181 mg% S, 67 ppm Fe, 116 ppm Mn, 29 ppm Zn, 5.50 ppm Cu, which will give yield of 10.5 to 12.7 tonnes yield per ha) of mango in Dharmapuri district of Tamil Nadu and discussed in details in the paper.