Cover crop and herbicides can control purple nutsedge (Cyperus rotundus L.) and increase crop yields in conservation agriculture-based crop rotations

• Published in: Crop protection 2025-01, Vol.187, p.106974, Article 106974
• Main Authors: Nath, C.P., Kumar, Narendra, Dutta, Asik, Hazra, K.K., Praharaj, C.S., Kumar, Deepak, Dixit, G.P.
• Format: Article
• Language: English
• Subjects: 2,4-D; agricultural conservation practice; Cajanus cajan; Cenchrus americanus; chickpeas; Cicer arietinum; cover crops; Cyperus rotundus; experimental design; field experimentation; glyphosate; Halosulfuron-methyl; India; irrigation; mung beans; Pearlmillet-chickpea; Perennial weed; pigeon peas; plant protection; Seasonal dynamics; Sesbania bispinosa; summer; Summer mungbean; Triticum aestivum; weed control; weeds; wet season; wheat; winter
• ISSN: 0261-2194
• DOI: 10.1016/j.cropro.2024.106974

Adoption of conservation agriculture (CA) practices can lead to the dominance of perennial weeds including purple nutsedge (Cyperus rotundus L.) in different agroecologies over time. Without effective management of this weed, successful adoption of CA in smallholder farming systems is rather unlikely. Therefore, we aimed to develop an integrated strategy for managing C. rotundus in CA-based crop rotations. This study encompassed a two-year (during 2020–21 and 2021–22) field experimentation at Kanpur, India with a split-plot design with three replications. The treatments included purple nutsedge management practices in main plot and crop rotations in sub-plot under CA platform (no-tilled with added crop residues). Six management options were adopted in the summer season (during April to June) as main plots that were super-imposed with two crop rotations such as pigeonpea (Cajanus cajan (L.) Huth) – wheat (Triticum aestivum L.) and pearlmillet (Pennisetum glaucum (L.) R.Br) – chickpea (Cicer arietinum L.) as sub-plot. Growing of cover crop Sesbania (Sesbania aculeata (Willd.) Pers.) during the summer season for 45 days followed by knockdown with 2,4-D 500 g a.i. Ha−1 (cultural management; Sesbania+2,4-D) and/or summer irrigation followed by application of halosulfuron-methyl 70 g a.i. Ha−1 at 20 days after irrigation (chemical management; halosulfuron-methyl) reduced the C. rotundus density by 37–42% and 23–64% over years, respectively, than conventional practice (ploughing during summer followed by irrigation and glyphosate 1.5 kg a.e. Ha−1 application). Besides, these practices could decrease 25–27% total weed density (p