Effect of Imazethapyr 10% SL as Post Emergence Harbicide on the Growth and Yield of Groundnut (Arachis Hypogaea L.) in Mubi Adamawa State, Nigeria

A field experiment was carried out  at the Adamawa state university Department of Crop  Science Teaching and Research Farm during the rainy season of 2019 ,to Evaluate the Effect of Imazethapyr 10%  SL as post Emergence Herbicide on the Growth and Yield of Groundnut with the objective of selecting the minimum concentration of the herbicides that can control weeds without negatively affecting the growth and yield of groundnut. The treatments consisted of the following: T₁ = 75ml, T₂ = 100ml, T₃ = 125ml, T₄ = 150ml, T₅ = 175ml, T₆ = 200ml, T₇ = 225ml, T₈ = 250ml, T₉ = 275ml of imazethapyr dissolve in 16 liter sprayer while T₁₀ = Control (hoe weeding). The experiment was laid out in a Randomized Complete Block Design (RCBD) in three replicates, imazethapyr applied 35 days after sowing when the weeds were actively growing. Date collected was subjected to Analysis of Variance (ANOVA), significant means where separated using Duncan Multiple Range Test (DMRT) at P≤ 0.05.  The results shows significant difference across the levels of the herbicides for most of the growth character, the plot treated with T₇ (225ml/16l sprayer) performed poorly while the control T₁₀ (manual weeding) recorded higher growth rate at 2, 4, 6, and 8 Weeks After Treatment Application, higher number of leaves at 2, 4, 6, and 8, higher number of nodes 2, 4, 6, and 8. T₉ produces more number of immature pod at harvest (9.33) and fewer ischolar_main nodules per plant (25.00) compared with the other treatments and the control. The yield character such as yield per plot (kg), pod yield in kg/ha and harvest index does not vary across the treatments and the control. Significant positive correlation  was found between Pod yield in kg/ha with biological yield per plot (r=0.4608**), pod yield per plot (r=0.7220**), Harvest index (r=0.8373**), Number of matured pod per plot (r=0.6795**), number of pod per plot (r=0.6795**), Number of leaves at two weeks (r=0.4173**), number of nodes at four weeks (r=0.4018*), plant height at  two weeks (r=0.3772*) and plant height at  four weeks (0.4608**). Suggest that improvement in those characters will help enhance the yield of groundnut. It can be concluded that application of imazethapyr 10% SL at the  rate of 75-100ml/16 liter sprayer applied 35 days after sowing is recommended for managing complex weed flora and obtaining higher seed yield of groundnut in Mubi, and can serve as a substitute for manual weeding which is time consuming, laborious and expensive.