Effect of weed management practices and fertility levels on growth, nutrient uptake and yield of groundnut (Arachis hypogaea L.)

Arachis hypogaea is an energy-dense oilseed crop yet cultivated on low-fertility soils. Among the several constraints, weed infestation and improper nutrient management are the most widespread and essential for its low productivity. A field experiment was carried out in 2020 and 2021, using four levels of fertility and four methods for controlling weeds, resulting in sixteen different treatment combinations tested three times in a factorial randomized complete block design. The weed control techniques included W1- Pendimethalin application at 0.75 kg per hectare as a Pre-emergence (PE), W2- Pretilachlor application at 0.5 kg per hectare as a Pre-emergence (PE), W3-Manual weeding (20 and 40 days after sowing: DAS), W4-Twin wheel hoe at 20 days after sowing followed by (fb) hand weeding at 40 days after sowing and four fertility levels includes T1-100 % recommended dose of fertilizer (N:20::P205:40::K2O:40), T2- 75 % RDF + 5 FYM t ha-1 , T3- 50 % RDF + 10 FYM t ha-1 , T4- control. Amongst the weed control methods, the use of twin wheel hoe at 20 days after sowing fb hand weeding at 40 days after sowing reported the highest dry matter accumulation per plant (35.5g), Crop growth rate (20.4 g m-2 day-1 ), nutrient uptake by crop (191.9 kg ha-1 ), NUE, agronomic use efficiency, yield and benefit-cost ratio. Among the different fertility levels, the highest dry matter accumulation per plant (39.7 g), crop growth rate (22.8 g m-2 day-1 ), nutrient uptake by crop (202.4 kg ha-1 ), pod yield and haulm yield. As a result, weeds like Echinochloa colonum, Elusine indica, Digitaria ciliaris, Dactylotenium aegyptium, Celosia argentea, Cyperus rotundus, Borreria hispida, Cleome viscosa, Croton sparsiflorus, Phyllanthus niruri and Physalis minima were effectively prevented from growing by using a twin wheel hoe at 20 DAS and manual weeding at 40 DAS. This improved the growing conditions for crops. The maximum net return and cost-benefit ratio were achieved with 50 % RDF + 10 FYM t ha-1 application.