Weed management in adzuki bean: a review

Adzuki bean is a niche market, high-value field crop suited to the temperate growing regions of the world. Adzuki bean lacks early season vigour and thus early season weed control is critical for profitable production. Efficacious application of preplant incorporated (PPI), preemergence (PRE), and, to a lesser degree, postemergence (POST) herbicides have been documented, however, the number of registered herbicides is currently limited due to the sensitivity of adzuki bean crops. In addition to the currently registered products, the literature shows the potential utility of cloransulam-methyl or halosulfuron applied PPI and (or) PRE, and imazamox or acifluorfen applied POST in adzuki. Furthermore, growers should avoid atrazine, metribuzin, EPTC, pethoxamid, pyroxasulfone, clomazone, flumioxazin, sulfentrazone, alachlor, dimethenamid-P, and S-metolachlor applied PPI and (or) PRE, and halosulfuron, thifensulfuron-methyl, and bentazon applied POST, due to poor adzuki bean tolerance to these herbicides. While crop tolerance research represents a growing body of work, there is a paucity of available weed control data to assist growers. The persistence of volunteer adzuki bean is a significant hurdle for adzuki bean growers. However, crop and herbicide mode-of-action rotation, in combination with early-season [PPI and (or) PRE] control, have demonstrated success. There is an ongoing need to evaluate weed control and expand the number of registered herbicides for adzuki bean growers.