WEED MANAGEMENT IN WHEAT-MUNGBEAN-RICE CROPPING PATTERN UNDER CONSERVATION AGRICULTURE IN DROUGHT-PRONE AREAS

Abstract

Conservation Agriculture (CA) is promoted as a sustainable alternative to systems involving conventional tillage. Adoption of CA changes weed dynamics and communities and therefore necessitates adjusting weed control methods. A field experiment was conducted at Regional Wheat Research Centre, Bangladesh Agricultural Research Institute, Rajshahi, Bangladesh to develop sustainable and effective weed management strategies for Wheat-Mungbean-T. Aman rice under CA systems. Four weed management treatments (WM1: Pre-plant herbicide (Glyphosate: Roundup) for wheat + Pre-plant herbicide (Glyphosate: Roundup) followed by (fb) Pre-emergence herbicide (Ethoxysulfuron: Sunrise) for mungbean + Pre-plant herbicide (Glyphosate) followed by (fb) post-emergence herbicide (Bensulfuron methyl and Acetachlor: Nirmul-18WP) for rice; WM2: Post-emergence herbicide (Carfentrazone-ethyl + isoproturon: Affinity) for wheat + Post emergence (Fenoxaprop-p-ethyl: Whipsuper) for mungbean + Post-emergence (Bensulfuron methyl and Bispyribac Sodium: Serious Plus 30 EC) for rice; WM3: One hand weeding at 25-30 DAS for wheat, 15-20 DAS for mungbean and 30-35 DAS for rice; and WM4: No weeding as control) were compared for five tillage options (ZT: Zero Tillage, ST: Strip Tillage, Permanent Raised Bed (PRB), PTOS: minimum tillage and CT: Conventional tillage). The study identified a significant effect of tillage treatments on wheat and mungbean; however, non-significant effect was observed on T. Aman rice. The ST and PRB gave a higher grain yield of wheat (4.01 and 4.07 t ha−1, respectively) compared to ZT (3.73 t ha−1). The highest yield of all component crops of Wheat-Mungbean-T. Aman rice pattern was attained from weed management treatments WM1 and WM2. Both the treatments also had the lowest weed population and dry weed biomass. Treatment PRB and ST with WM2 offered higher yield, gross margin and gross return for all the crops of wheat-mungbean-T. aman rice pattern compared to the other treatments.