EFFECT OF POTASSIUM FERTILIZER ON THE GROWTH AND YIELD OF ONION

Abstract

Onion (Allium cepa L.) is a highly potassium (K) responsive crop and has been recognized as world most influential onion growth and production limiting factor over the world. Integrated influence of K yet to be tested in AEZ-1 especially in Dinajpur district of Bangladesh. Present research work was undertaken to know the effect of different levels of K on growth and yield of Onion in Dinajpur district. The experiment was laid out in randomized complete block design (RCBD) with three replications. The treatments consisted of seven (7) levels of K, T1= Control (Without K ), T2 = 100% (K) at planting, T3 = 75% (K) at planting + 25% (K) at 30 DAT, T4 = 50% (K) at planting + 50% (K) at 30 DAT, T5 = 25% (K) at planting + 75% (K) at 30 DAT, T6 = 0% (K) at planting + 100% (K) at 30 DAT, T7 = 50% (K) at planting + 25% (K) at 20 DAT + 25% (K) at 50 DAT. The recommended dose of Urea 240 kg, TSP 260 kg, B 2.5 kg, Zn 5 kg ha-1 was used in each treatment. Growth data were recorded at vegetative stage 15, 30, 45, 60, and 75 DAT at harvesting stage. Results at 75 DAT, T7 showed highest plant height (51.1 cm plot-1), bulb diameter (11.7 cm plot-1), average single weight (39.3 g plot-1) and total weight (0.93 kg plot-1) indicating that about split application of K fertilizer might be suggested for Onion cultivation in Dinajpur district. Similar further experiment was needed having K dose near 50% at planting + 25% at 20 DAT + 25% at 50 DAT to find out actual dose.