Crop residues acting as mulches can influence weed seedling emergence and weed biomass. A field study was conducted to evaluat. The effect of rice residue amounts (0, 3, and 6 t ha-1) on seedling emergence of eight weed species in zero-till dry-seeded rice. The highest seedling emergence of spiny amaranth, southern crabgrass, crowfootgrass, junglerice, eclipta, goosegrass, and Chinese sprangletop was observed I. The absence of residue. Seedling emergence of these weeds declined with increasing residue amounts; however. The greatest and most substantial reductions in emergence occurred with 6 t ha -1 of residue. The presence of residue also resulted in less weed biomass than wit. The no-residue treatment. The emergence and biomass of threelobe morningglory seedlings, however, were not influenced by residue amounts. The use of residue also increase. The time taken to reach 50% of maximum emergence for some species, for example, spiny amaranth and Chinese sprangletop. The results of our study suggest tha. The use of residue at high rates can help suppress seedling emergence and growth of many weeds. However, there is a need to integrate other weed management strategies with residue retention to achieve season-long weed control.
Nomenclature: Spiny amaranth, Amaranthus spinosus L. AMASP; crowfootgrass, Dactyloctenium aegyptium (L.) Willd. DTTAE; southern crabgrass, Digitaria ciliaris (Retz.) Koel. DIGSP; junglerice, Echinochloa colona (L.) Link, ECHCO; eclipta, Eclipta prostrata (L.) L. ECLAL; goosegrass, Eleusine indica (L.) Gaertn. ELEIN; threelobe morningglory, Ipomoea triloba L. IPOTR; Chinese sprangletop, Leptochloa chinensis (L.) Nees. LEFCH; rice, Oryza sativa L.