Field experiments were conducted on weed control in rice-blackgram at Annamalai University Farm, Annamalainagar, India during 1999–2000. Among the rice weed control measures, hand weeding twice recorded the least weed counts (19.0 m−2) and weed dry matter production (300.2 kg ha−1) with maximum rice grain yield (5.91 t ha−1), which was at par to incorporation of 10 t pressmud ha−1 + 1 t Azolla ha−1 (5.72 t ha−1). The later had positive carry over effect on weed control in succeeding black gram also.
