Effect of weed management on crop growth and yield of rice in organically grown transplanted aromatic rice-tomato cropping system

A field experiment was conducted at Instructional cum Research Farm, Indira Gandhi KrishiVishwavidyalaya, Raipur (C.G.) during kharif season 2022 and 2023. The soil of experimental field was neutral in reaction, medium in organic carbon and low in available nitrogen, low in available phosphorus and high in available potassium. Experiment was laid out in randomized block design with three replications, consisted of T₁- hand weeding (HW) twice at 20 and 40DAT, T₂- motorized weeder twice (single row type) at 20 and 40 DAT, T₃- motorized weedertwice (single row type) at 20 and 40 DAT+ one intra row HW at 20 DAT, T₄- mechanical weeding through Ambika paddy weeder at 20 and 40 DAT, T₅- mechanical weeding through Ambika paddy weeder + one intra row HW at 20 DAT, T₆- green leaf manuring (incorporation at puddling) + one HW at 20 DAT, T₇-10 days delayed planting with incorporation of emerged weeds, T₈- dense planting (closer spacing of 15 × 10 cm) and T₉- Weedy check. The weeds ofthe experimental site were dominated with grasses like Echinochloacolona, Cyanotis axillaris, broad leaves like Alternanthera sessilis, Celosia argentea, sedge like Cyperus sps. and otherweeds. Results revealed that all growth parameters and yield was highest in Hand weeding (HW)twice at 20 and 40 DAT which was at par with Motorized weeder twice (single row type) at 20and 40 DAT+ one intra row HW at 20 DAT. Similarly, total weed density and biomass at 90 DAT was also significantly reduced in these treatments to others. However, higher WCE (Weed control efficiency) at 90 DAT was noticed in this treatment than weedy check. Highest net return recorded under hand weeding (HW) twice at 20 and 40 DAT and B:C ratio recorded in Motorized weeder twice (single rowtype) at 20 and 40 DAT+ one intra row HW at 20 DAT. However, lowest net return and B:Cratio was noticed in this treatment than weedy check.