Avena sterilis ssp. ludoviciana (Durieu) Control in Wheat Through Integration of Tillage, Seeding Rate, and Herbicide Application

Avena sterilis ssp. ludoviciana (Durieu) is a problematic weed in the wheat crop of Australia. Pinoxaden is an effective herbicide for the control of this weed. However, late cohorts of A. ludoviciana escape from the early application of pinoxaden and produce seeds. This research investigated the integrated effect of tillage systems (no-tillage and conventional tillage), seeding rates (100 and 200 seeds m(-2)), and weed control treatments (nontreated control and pinoxaden application at Z12 and Z33 stages of wheat) on Avena ludoviciana control and wheat yield. The wheat yield remained similar in no-tillage and conventional tillage systems; however, the no-tillage system helped in reducing A. ludoviciana seed production by 28% compared with the conventional tillage system. In the nontreated control, the increased seeding rate of wheat reduced A. ludoviciana biomass and seed production by 33 and 66%, respectively, compared with the low seeding rate. These results suggest that a high seeding rate could be useful in the organic production of wheat. Application of pinoxaden at Z12 and Z33 stages of wheat resulted in an improvement in grain yield by 170 and 150%, respectively, compared with the nontreated control. At both seeding rates, the application of pinoxaden at the Z33 stage of wheat reduced weed seed production by 99% compared with the nontreated control. These results implied that the delayed application of pinoxaden at the Z33 stage of wheat effectively reduced weed biomass and seed production of A. ludoviciana without compromising grain yield as the yield in this treatment was similar to the pinoxaden application at the Z12 stage.