Effect of weed management and nitrogen levels on nutrient (N) use efficiencies of onion crop

Abstract

Application of weed management treatments under varying levels of nitrogen is important in better onion (Allium cepa L.) production. Uptake of nitrogen (N) by onion plant is dependent upon many factors including type of weed species, intensity and the rate N fertilizer. To understand interactions among onion, applied N, and weed management is important in developing management strategies. A field experiment was conducted at SKN College of Agriculture, Jobner for two consecutive years during Rabi 2016-17 and 2017-18 to find out the efficient weed management in onion under varying levels of nitrogen. Among the different weed management treatments weed free check i.e. twice hand weeding treatment recorded significantly higher agronomic efficiency, apparent recovery of N and physiological efficiency of N to rest of the treatments except application of pendimethalin (PP) + oxadiargyl at 40 DAT or application of pendimethalin (PP) + 1 HW at 40 DAT, being statistically at par with each other. Similarly, highest agronomic efficiency, apparent recovery of N and physiological efficiency of N were obtained with 100 kg N ha-1 and declined with further increase in dose of N.