Critical timing of weed removal in dry bean as influenced by the use of preemergence herbicides

Abstract The critical timing of weed removal (CTWR) is the point in crop development when control must be initiated to prevent yield loss due competition. A field study was conducted 2018 and 2020 near Scottsbluff, NE, determine how use preemergence herbicides affects CTWR dry bean. experiment arranged as a split plot, with herbicide treatment main sub-plot factors, respectively. Herbicide treatments consisted no-preemergence application, or pendimethalin (1,070 g ai ha –1 ) + dimethenamid-P (790 applied preemergence. Sub-plot included season-long weed-free, at: V1, V3, V6, R2, R5 bean growth stages, weedy control. four-parameter logistic model used estimate impact time removal, for all response variables including yield, plants m row, number pods per plant, seeds pod, seed weight. based on 5% reduction estimated range from V1 stage [(16 d after emergence (DAE)] R1 (39 DAE) treatment. In preemergence-applied treatment, began at R2 (47 DAE). Number row reduced delayed beyond season. prevented plant 2020, pod 2020. 2018, by 73% no applied, compared 26% soil-active preserved potential.