Response of micropropagated ‘Robusta’ banana to varying combinations of N, P, K nutrition in lateritic soils of coastal Orissa

To optimize the productivity of micropropagated banana in the lateritic soils of Orissa, an experiment on effect of graded doses of nitrogen, phosphorus and potassium on growth and yield of Robusta cultivar was conducted. Three factor experiment comprising of 0, 100, 200 and 300 g of each of nitrogen and potassium and 0, 50 and 100 g phosphorus per plant was laid out at 1.5 m spacing in Randomized Block Design with three replication. In the first and second crop, maximum plant height (164.03 and 131.86 cm) at shoot emergence was observed at 300 g nitrogen, 100 g phosphorus (152.44 and 132.04 cm) and 300 g potassium (145.81 and 131.00 cm). Pseudostem circumference, canopy spread and leaf size increased by 300 g nitrogen, 100 g phosphorus and 300 g potassium per plant per crop. Maximum bunch weight (16.54 and 12.04 kg) was recorded at 300 g nitrogen, 100 g phosphorus (13.93 and 10.29 kg) and 300 g potassium (13.5 and 9.89 kg) in first and second crops, respectively. Cumulative bunch weight (first crop + second crop) of 28.61 kg, 24.22 kg and 23.39 kg was recorded at 300 g nitrogen, 100 g phosphorus and 300 g potassium with an estimated cumulative fruit yield of 127.14, 107.63 and 103.95 t/ha, respectively. Interaction effects of different nitrogen, phosphorus and potassium doses were significant for bunch weight. Maximum cumulative (first+ second crop) bunch weight (46.9 3 kg) was recorded with combined dose of 300 g nitrogen, 100 g phosphorus and 300 g potassium per plant/crop with estimated fruit yield of 208.57 t/ha. Higher doses of nitrogen were observed to reduce the crop cycle interval from first to second crop. Significant improvement in TSS content and pulp/peel ratio of fruits was observed due to NPK nutrition. The dose of 300 g N and K₂O each and 100 g P₂O₅ per plant per crop was observed to be optimum for micropropagated “Robusta” banana under irrigated, low fertility, lateritic soil conditions of coastal Orissa.