Chickpea producers currently have no POST applied herbicides labeled for broadleaf weed control and rely heavily on PRE herbicides to manage weeds. Severe crop losses from broadleaf weed competition and harvest losses from weeds impeding harvest can occur when PRE herbicides perform poorly. Chickpea tolerance to POST applications of acifluorfen at 0.42 kg ai ha-1 and fomesafen at 0.28 kg ai ha-1 was tested at two sites in 2015. In 2016, both herbicides were tested on chickpeas when applied alone and in combination with pyridate at three sites. Acifluorfen and fomesafen injured chickpeas from 8 to 25% at 1 week after treatment (WAT) and 3 to 8% at 4 WAT in 2015 and from 16 to 40% at 1 WAT and 2 to 36% at 4 WAT in 2016. Pyridate applied POST at 1.00 kg ai ha-1 did not injure chickpeas or reduce yields. When pyridate was tank mixed with either acifluorfen or fomesafen, chickpea injury increased, but chickpeas recovered and yielded similar to nontreated checks or pyridate-treated plots. A low rate of metribuzin at 0.06 kg ai ha-1 tank mixed with pyridate had little impact on chickpea injury or weed control. In 2015, Russian thistle was controlled 100% by acifluorfen and fomesafen at Prosser at 28 DAT and both herbicides controlled the weed only 63% at Wilbur at 25 DAT. In 2016, all herbicide treatments reduced broadleaf weed densities equally ranging from 95 to 100% at Paterson, 50 to 100% at Prosser, and 78 to 98% at Wilbur. Chickpea yield was similar among POST herbicide treatments in all site-years. Acifluorfen, fomesafen, and pyridate have potential to improve control of susceptible broadleaf weeds that escape PRE herbicides chickpea production, but the potential for crop injury with acifluorfen and fomesafen warrant further evaluation.

Field studies were conducted in 2003 and 2004 near Scottsbluff and Sidney, NE, to identify efficacious chemical weed-control options for irrigated and dryland chickpea production. Weed control had a greater relative effect on chickpea yield in the irrigated system than the dryland system, with yield from the hand-weeded check exceeding the nontreated check by 1,500% in the irrigated system and 87% in the dryland system. Imazethapyr, applied preemergence at the rate of 0.053 kg ai/ha, reduced plant height, delayed plant maturity, and caused leaf chlorosis. At Scottsbluff, preplant-incorporated ethalfluralin caused significant crop injury in 2003, but the ethalfluralin treatment also maintained weed densities 4 wk after crop emergence that were not significantly different than the hand-weeded check at both locations in 2003 and 2004. Treatments containing sulfentrazone provided a similar level of weed control but without any evidence of crop injury. Pendimethalin and pendimethalin + dimethenamid-P applied preemergence provided acceptable weed control in the irrigated system, where water was applied within 4 d after herbicide application, but did not provide acceptable control in the dryland system.