Background: Groundnut or peanut (Arachis hypogaea L.) is known as the “King of Oilseeds” which belongs to family Fabaceae (Leguminosae). It is highly susceptible to weed infestation because of its slow initial growth up to 40 DAS and small foliage cover. However, study on use of mechanical weed control methods with different fertility regimes for improving the productivity of groundnut was limited. Therefore, the objective of this study was to find a suitable method for optimising the productivity of groundnut. Methods: A field experiment was conducted at Odisha University of Agriculture and Technology, Bhubaneswar for two consecutive years of 2020 and 2021. The field experiment comprised 16 treatment combinations of four weed management practices and four fertility levels. The weed management practice included W1-Pre-emergence (PE) application of pendimethalin @ 0.75 kg ha-1, W2-Pre-emergence (PE) application of pretilachlor @ 0.5 kg ha-1, W3-Manual weeding (20 and 40 DAS), W4-Twin wheel hoe at 20 DAS followed by (fb) hand weeding at 40 DAS and four fertility levels includes T1-100% RDF (20:40:40) (N: P205: K2O kg ha-1), T2- 75% RDF + 5 tonnes FYM ha-1, T3- 50% RDF + 10 tonnes FYM ha-1, T4- without fertilizer + without FYM. Result: Amongst the weed management practices, use of twin wheel hoe at 20 DAS followed by hand weeding at 40 DAS significantly reduced the weed density, weed dry weight, weed index and recorded the highest weed control efficiency (69.8%). Highest weed index (32.9) was recorded with the application of pretilachlor @ 0.5 kg ha-1 (PE), which was followed by weed index of (28.5) with application of pendimethalin @ 0.75 kg ha-1 (PE). The fertilizer management practice with application of 50% RDF + 10 tonnes FYM ha-1 gave the highest yield and considerably reduced the total weed density, weed dry weight and recorded the maximum weed control efficiency (71.8 % at harvest). We suggest that weed management with twin wheel hoe at 20 DAS followed by hand weeding at 40 DAS along with application of 50% RDF + 10 tonnes FYM ha-1 as the most effective strategy for controlling the weed menace in groundnut with the highest weed control efficiency.

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 W 1 - Pendimethalin application at 0.75 kg per hectare as a Pre-emergence (PE), W 2 - Pretilachlor application at 0.5 kg per hectare as a Pre-emergence (PE), W 3 -Manual weeding (20 and 40 days after sowing: DAS), W 4 -Twin wheel hoe at 20 days after sowing followed by ( fb ) hand weeding at 40 days after sowing and four fertility levels includes T 1 -100 % recommended dose of fertilizer (N:20::P 2 0 5 :40::K 2 O:40), T 2 - 75 % RDF + 5 FYM t ha -1 , T 3 - 50 % RDF + 10 FYM t ha -1 , T 4 - 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 (35.5 g), 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.