Archives of Current Research International

This study evaluated the effect of herbicidal treatments on growth components, weed dynamics and yield in quinoa through a pot experiment conducted during the rabi season 2025 at the Instructional North Farm of Karunya Institute of Technology and Sciences, Coimbatore. The experiment followed a Completely Randomized Design (CRD) with twelve treatments and three replications, comparing different pre-emergence herbicides alone and in combination with post-emergence herbicides, along with weed-free check and unweeded control treatments. The results indicated that crop growth attributes varied significantly between treatments at later growth stages. At 30 DAS, the weed-free check (T₁₁) recorded the highest plant height (39.28 cm), which was statistically similar to pretilachlor at 750 g a.i. ha^-1 applied as pre-emergence (T₃) and butachlor (pre-emergence) @ 1000 g a.i. ha^-1 at 3 DAS + Metamifop @ 1000 ml ha^-1 as post-emergence at 25 DAS (T₉). At 60, 90 DAS and at harvest, the weed-free check (T₁₁) consistently recorded superior plant height (95.3, 136.0 and 158.9 cm) and dry matter production (18.9, 27.9 and 36.2 g plant^-1). Among the treatments sequential application of pretilachlor (pre-emergence) @ 750 g a.i. ha^-1 at 3 DAS + halosulfuron-methyl (post-emergence) @ 70 g a.i. ha^-1 at 25 DAS (T₁₀)  recorded lower total weed density (2.38, 8.74, and 8.46 nos. pot^-1), total weed dry weight (0.54, 4.86 and 4.19 g pot^-1) and higher weed control efficiency (78.32%, 68.79% and 74.96%) at 15, 30 and 45 DAS, respectively. The weed-free check(T₁₁) produced higher grain (39.5 g plant^-1) and straw yields (45.05 g plant^-1), which were statistically comparable to pretilachlor (pre-emergence) @ 750 g a.i. ha^-1 at 3 DAS + halosulfuron-methyl (post-emergence) @ 70 g a.i. ha^-1 at 25 DAS (T₁₀). In contast, the unweeded control (T₁₂) recorded the highest total weed density and weed dry weight, reduced crop growth and yield due to severe crop-weed competition. This study suggests that the sequential application of pretilachlor followed by halosulfuron-methyl has potential for effective weed management in quinoa under controlled conditions; however, further validation through field experiments is necessary before making broader agronomic recommendations.