Pulse Crop Tolerance and Weed Control with Fall‐Applied Soil‐Residual Herbicides

CORE IDEAS: Limited weed control tools is a challenge for pulse production in the northern Great Plains. Soil‐applied residual herbicides are an important component of integrated weed management programs. Most herbicide programs adequately controlled kochia and Russian‐thistle in the pulse crops. Season‐long control of kochia and Russian thistle in dry pea, lentil, and chickpea. Weed management is a challenge for pulse producers in the northern Great Plains (NGP). Multi‐location trials were conducted in Montana to evaluate crop safety and weed control in spring‐planted pulse crops from soil‐residual herbicides applied the previous fall in postharvest wheat (Triticum aestivum L.) stubble. Dry pea (Pisum sativum L.), lentil (Lens culinaris L.), and chickpea (Cicer arietinum L.) were planted the subsequent spring in herbicide‐treated plots. Metribuzin (210 or 420 g ha⁻¹), flumioxazin (107 or 214 g ha⁻¹), pyroxasulfone (119 or 238 g ha⁻¹) + carfentrazone (8 or 16 g ha⁻¹), pendimethalin (532 or 1064 g ha⁻¹) + dimethenamid‐P (945 or 1890 g ha⁻¹), sulfentrazone (164 or 328 g ha⁻¹) + carfentrazone (18 or 36 g ha⁻¹), sulfentrazone (101 or 202 g ha⁻¹) + metribuzin (151 or 302 g ha⁻¹) applied the previous fall had no significant visual injury (≤8% early‐season) or yield reductions in dry pea and chickpea. However, sulfentrazone‐based programs caused unacceptable crop injury (up to 75% early‐season) and yield reductions in lentil. Unacceptable early season injury and yield reductions were observed in pulse crops with thiencarbazone + isoxaflutole‐based programs. Metribuzin or pyroxasulfone + carfentrazone at twice the recommended fall‐use rate(s) and flumioxazin, sulfentrazone + carfentrazone, or sulfentrazone + metribuzin even at the recommended fall‐use rate(s) provided 75 to 99% end‐season control of kochia [Kochia scoparia (L.) Shrad.] and Russian‐thistle (Salsola tragus L.). These herbicide programs will provide new tools for weed control in pulse crops.