Effect of pre and post-emergence herbicides on growth and yield of horsegram [Macrotyloma uniflorum (L.) Verdc.]

Abstract

A field experiment entitled “Effect of pre- and post-emergence herbicides on growth and yield of horsegram [Macrotyloma uniflorum (L.) Verdc.]” was conducted during the post-kharif season of 2024 at the Research cum Instructional Farm, Barrister Thakur Chhedilal College of Agriculture and Research Station, Bilaspur (C.G.). The study was laid out in a Randomized Block Design with three replications and evaluated ten weed management treatments: (T1) Control, (T2) Weed free, (T3) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence, (T4) Oxyfluorfen (23.5% EC) @ 100 g a.i. ha-1 as pre-emergence, (T5) Imazethapyr (10% SL) @ 75 g a.i. ha-1 as post-emergence at 20 DAS, (T6) Quizalofop ethyl (5% EC) @ 50 g a.i. ha-1 as post-emergence at 20 DAS, (T7) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Imazethapyr (10% SL) @ 75 g a.i. ha-1 as post-emergence at 20 DAS, (T8) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Quizalofop ethyl (5% EC) @ 50 g a.i. ha-1 as post-emergence at 20 DAS, (T9) Oxyfluorfen (23.5% EC) @ 100 g a.i. ha-1 as pre-emergence + Imazethapyr (10% SL) @ 75 g a.i. ha-1 as post-emergence at 20 DAS and (T10) Oxyfluorfen (23.5% EC) @ 100 g a.i. ha-1 as pre-emergence + Quizalofop ethyl (5% EC) @ 50 g a.i. ha-1 as post-emergence at 20 DAS. The results revealed that the (T2) Weed free recorded the highest growth, yield attributes, grain yield, and gross returns, while among herbicidal treatments, (T7) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Imazethapyr (10% SL) @ 75 g a.i. ha-1 as post-emergence at 20 DAS and (T8) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Quizalofop ethyl (5% EC) @ 50 g a.i. ha-1 as post-emergence at 20 DAS were most effective in improving yield and controlling weeds. Although (T2) Weed free produced the maximum yield, the highest benefit-cost ratio was observed with (T7) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Imazethapyr (10% SL) @ 75 g a.i. ha-1 as post-emergence at 20 DAS followed by (T8) Pendimethalin (30% EC) @ 850 g a.i. ha-1 as pre-emergence + Quizalofop ethyl (5% EC) @ 50 g a.i. ha-1 as post-emergence at 20 DAS. These treatments efficiently suppressed broad-leaved weeds, grasses, and sedges, resulting in higher weed control efficiency and lower weed index. The study suggests that integrating Pendimethalin with either Imazethapyr or Quizalofop ethyl provides an economical and effective weed management strategy for horsegram under Chhattisgarh conditions.