Effects of Crotalaria juncea green manure on weed dynamics in transplanted rice-based systems were investigated in a field study conducted over two cropping seasons, 2016 and 2017, at Ludhiana, India.  The major weed species in the field, during the green manuring phase, included Cyperus rotundus, Digitaria ciliaris and Eleusine indica. The use of cover/green manure crops and their residues to suppress weeds has shown potential to manage weeds. In this context, green manuring/cover cropping has great potential and is feasible in a rice-wheat system in northern India as there is a 45 to 60 days' fallow period between wheat harvest and transplanting of rice. C. juncea with 50 and 100 kg seed ha-1 recorded significantly lower density and biomass of aerobics weeds and weed density as compared to without green manure in both years; GM with 100 kg seed ha-1 had a more suppressing effect on weeds than green manuring with 50 kg seed ha-1. The residual effects of weed control treatments, applied during 2016 to succeeding transplanted rice crops, did not have any specific trend on weed density in 2017. The major weeds in green manuring crop were C. rotundus, D. ciliaris and E. indica. But in transplanted rice, Echinochloa colona, E. crus-galli and Leptochloa chinensis were major weeds