Optimizing weed management in chickpea through planting date and fall-applied residual herbicides

Abstract Chickpea provides significant diversification benefits for semiarid cropping systems. However, the crop’s slow emergence and open canopy growth habit make it a poor competitor against rapidly growing weeds during the early season. In 2022 and 2023, field experiments were conducted at two sites, the Montana State University (MSU) Southern Agricultural Research Center, in Huntley, and the MSU Post Agronomy Farm, in Bozeman, to evaluate broadleaf weed management by integrating planting date and fall-applied,soil-active herbicides to chickpea. Application of dimethenamid at 950 g ai ha −1 + pendimethalin at 1.68 kg ai ha −1 , and carfentrazone + sulfentrazone at 238 g ai ha −1 resulted in better protection of yield against weeds and provided longer residual activity for control of kochia, redroot pigweed, and common mallow by reducing weed density to 10 to 20 plants m −2 compared with 50 to 70 plants m −2 in an untreated check. Pyridate (700 g ai ha −1 ) applied postemergence was required with these treatments to eliminate escaped weeds. Early planting provided an additional biomass reduction compared to late planting due to the crop emergence before or around the same time as the weeds. Planting date had no effect on weed density or grain yield in plots that received dimethenamid + pendimethalin and carfentrazone + sulfentrazone, suggesting that these herbicides can extend the planting date window. These herbicide programs and early planting can be integrated with other weed management tactics for additional weed management options in chickpea.