Effect of weed and nitrogen management practices on controlling weeds and enhancing the productivity of linseed (Linum usitatissimum L.) under utera conditions

A field experiment was executed during the Rabi season at CSKHPKV, Palampur, to evaluate the effects of different weed control and nitrogen management practices on weed control, yield, nutrient content, dehydrogenase activity and the oil content of linseed. The experiment was set up in the RBD with 3 replicates consisting of fifteen treatment combinations comprising five weed controls (viz. isoproturon 1.25 kg/ha, clodinafop propargyl + metsulfuron methyl 60+4 g/ha, clodinafop propargyl + carfentrazone ethyl 60+10 g/ha, hand weeding twice and weedy check) and three nitrogen levels (i.e., FYM 5 t/ha, 75 and 100% RDN). The soil texture at the experimental site was silty clay loam, acidic and medium in available nitrogen, phosphorus and potassium. The results showed that the use of clodinafop propargyl + metsulfuron methyl 60+4 g/ha significantly decreased the count and dry matter content of the total weeds at the maximum count and dry matter stage. However, 1.25 kg/ha isoproturon was likewise effective at significantly reducing the total weed count and was the next best at reducing the dry matter content of the total weeds. The effective control of weeds by the application of isoproturon at 1.25 kg/ha (Post.) significantly increased plant growth without any toxicity, which contributed to increased nutrient uptake and increased seed, straw and oil yields in the linseed treatment. Among the nitrogen levels, a considerably lower count and dry matter content of the total weeds were recorded in the 100% RDN plots, followed by the 75% RDN treatment. The application of 100% RDN resulted in significantly greater NPK uptake than did the other treatments, which contributed to considerably greater seed, straw and oil yields. Thus, the application of isoproturon at 1.25 kg/ha (Post.) with 100% RDN was proven to be the most effective at realizing higher seed and oil yields with better weed control in linseed plants grown under utera conditions.