Impact of Fertility Levels and Weed Management Practices on Weed Dynamics and Yield of Lentil (Lens culinaris Medikus) under Eastern U.P. Conditions

An experiment was conducted during the Rabi season of 2012-13 and 2013-14 to examine the effects of fertility levels and weed management practices on weed density, growth parameters and yield of lentil (Lens culinaris Medikus). The experiment was laid out in split-plot design comprising six main plot treatments viz. Control (F0), 100% RDF (F1), 75% RDF + 2% urea spray at pre-flowering and pod initiation stage (F2), 75% RDF + Plantgro 9 kg/ha at 35, 50 and 65 DAS as foliar spray (F3), 100% RDF + 2% urea spray at pre-flowering and pod initiation stage (F4), 100% RDF+ Plantgro 9 kg/ha at 35, 50 and 65 DAS as foliar spray (F5) and four sub-plot treatments viz. unweeded (W0), weed free (W1), pendimethalin 1 kg a.i./ha (W2), imazethapyr 37.5 g a.i./ha (W3). The major group of weeds found in the experimental field was Cyperus rotundus, Chenopodium album, Solanum nigrum and Cynodon dactylon. The results indicated that fertility levels and weed management had a significant effect on weed population dynamics and lentil crop. Higher yield attributes, yield and harvest index was recorded with the treatment 75% RDF + Plantgro 9 kg/ha. Higher grain yield (1283.08 kg/ha) was recorded with 75% RDF + Plantgro 9 kg/ha whereas straw yield (2140.64 kg/ha), net returns 23218.09 (Rs./ha) and B:C ratio (2.29) was obtained with 100% RDF+ 2% urea spray. The increase in yield was 11.41 % and 29.83% over 100% RDF + 2% urea spray and control respectively. Highest N, P, K uptake (50.08, 7.29 and 22.92 kg/ha) respectively was recorded with 75% RDF + Plantgro 9 kg/ha. Total weed count and dry weight decreased significantly with the application of post-emergence application of imazethapyr 37.5 g/ha and was comparable to pendimethalin 1 kg/ha. Highest weed control efficiency of 68.87% was recorded with imazethapyr 37.5 g/ha. Higher grain yield (1088.05 kg/ha), straw yield (2121.43 kg/ha), net returns 22625.76 and B: C ratio (2.35) was recorded with imazethapyr 37.5 g/ha. This treatment also recorded the highest N (39.84 kg/ha), P (4.88 kg/ha), K (15.93 kg/ha) uptake and protein content (22.72%) of lentil.