~ NUTRIENT MANAGEMENT FOR BANANA MUSA (AB GROUP) NJALIPOOVAN IN ONATTUKARA SOILS By INDIRA, M. THESIS submitted in partial fulfilment of the requirement for the degree DOCTOR OF PHILOSOPHY Faculty of Agriculture Kerala Agricultural University Department of Soil Science and Agricultural Chemistry COLLEGE OF AGRICULTURE Vellayani, Thiruvananthapuram 2003
CERTIFI CATE Certified that this thesis entitled "Nutrient management for banana Musa (AB group) Njalipoovan in Onattukara soils" is a record of research work done independently by Smt. Indira, M. under my guidance and supervision and that it has not previously formed the basis for the award of any degree, fellowship or associateship to ~ her. Q~~ tl#.ad/ Vellayani, Dr. C. SUNDARESAN NAIR 10-3-2003. (Chainnan,AdvisoryCommittee) AssociateDirector of Research Kera1aAgriculturalUniversity Vellanikkara,Thrissur-680 656
ABSTRACT Banana cv. Njalipoovan is a popular variety cultivated in homesteads of Kerala. The nutritional requirement of the cultivar has not yet been worked out. Field experiments were conducted at Onattukara Regional Agricultural Research Station, Kayamkulam in Alappuzha district during 1998-99 and 1999-00 to formulate an effective nutrient, management schedule for the cultivar in Onattukara soil. In addition to this a soil column study was undertaken separately to assess the leaching losses of nutrients in the soil and retention of applied nutrients at. different depths. Three levels each of nitrogen at 100, 200 and 300 g planrl, phosphorus at 100, 200 and 300 g plant-l and potassium at 200, 400 and, 600 g plan(l apart from nopoko (control) in each block were tested in confounded 33 factorial, confounding NPK in replication I and Np2K in replication II. Application of nitrogen at 300 g plant-l increased the growth attributes like height of the plant, girth of the pseudostem, total number of leaves and number of functional leaves. Nitrogen supply at higher rates reduced the total duration of the crop, increased the LAI and leaf emergence nite, dry matter accumulation in leaves, pseudostem, rhizome
and bunch. Yield attributes and bunch yield increased significantly upto 300 g N planrl. The quality of the fruit was favoured by the application of higher rates of nitrogen. N supplementation at higher rates was beneficial for the uptake of N, P, K, Ca and Mg and micronutrients such as Mn, Zn and Cu. It also enhanced the available N, P, K, Ca and Mg in soil. Supply of phosphorus at 200 g plant-i increased the above growth attributes at most of the stages. LAI in the early stages of growth was favoured by P supply at high rate. Phosphorus application at 300 g plant-i favoured dry matter accumulation in leaves, pseudostem, rhizome and bunch. Yield attributes and yield were high by applying phosphorus at 200 g plant-i. Fruit quality was not affected by the application of P. Higher rate of P2 5 enhanced the uptake of N, P, K, Ca, Mg and micronutrients. P nutrition increased the available Nand P content of the soil. Potassium nutrition at higher rates promoted all the above growth characters, leaf area, LAI and dry matter accumulation in different plant parts. Potassium applied at 400 g plant-i favoured the yield attributes and yield of crop. Application of K20 at 600 g plant-i yielded better quality fruits with appreciable total sugars, reducing sugars, sugar-acid ratio, pulp-peel ratio and shelf life. Higher rates of K20 enhanced the uptake of N, P, K and micronutrients like iron, manganese, zinc and copper. Potassium supply at 400 g planrl was beneficial in increasing the calcium and magnesium uptake by different plant parts. Application
of K20 at higher rates resulted in appreciable build up of N, P and K in the soil. The combination of N, P205 and K20 applied at 300:300:600 g plant-l had appreciably increased the growth characters, yield attributes, and nutrient uptake. It was comparable to that of N, P205 and K20 at 200:200:400 g planrl. The bunch yield obtained by the application of N, P2 5 and K20 at 300:300:600 g planrl was also comparable with that of 200:200:400 g planr1. However, mineral nutrition of N, P2 5 and K20 at 200:200:400 g planrl had given the maximum benefit-cost ratio of 1.96. Therefore it can be concluded from the study that application of N, P205 and K20 at 200:200:400 g plant-l is beneficial for getting higher yield and maximum economic returns.