Weed Vegetation of Direct Seeded Ricefields in Muda Rice Granary Areas of Peninsular Malaysia

A survey was carried out at heading stage of direct seeded rice to determine the major weed flora in Muda area, Kedah, Peninsular Malaysia. Thirty five weed species belonging to 17 families were identified in this area. Of these, 15 species were broadleaves, 10 sedges, 6 grasses and 4 aquatics. According to % field infestation and infestation rating score the six most widespread and abundant species were Oryza sativa complex (weedy rice), Leptochloa chinensis, Echinochloa crus-galli, Ischaemum rugosum, Fimbristylis miliacea and Ludwigia hyssopifolia. The hierarchy of weed type according to % field infested ratio was in the order of grasses (G)> broadleaved weeds (BL)> sedges (SG)> aquatics.