Weed Flora of Different Farm Blocks in Block-1 of Muda Rice Granary in Peninsular Malaysia

A survey on the major weed flora of rice fields in Block-1 of Muda rice granary area, Peninsular Malaysia, indicated there were 28 weed species belonging to 15 families in this area. Of these, 13 species were broad-leaves, six grasses, six sedges, and three aquatics. Sorenson s Index of Similarity (S) indicated that at least 24.2% of the listed species occurred in five blocks. Oryza sativa complex (padi angin) and Echinochloa crus galli appeared wide spread species in all blocks, but were most abundant in block AI, BI and DI having a greater proportion of severe infestations (scores of 3 to 5: 31%-50% weed cover). Leptochloa chinensis was the most frequent and abundant species in block AI and EI having the severity score of 3, i.e. 30% and 20% (score of 2) weed coverage in block BI and CI, respectively. Other weed species such as Ischaemum rugosum, Fimbristylis miliacea, Scirpus grossus, Sphenoclea zeylanica and Cyperus difformis were having 20% (score of 2) weed coverage. The hierarchy of weed type based on the percentage of field infested ratio was in the order of: grasses (G) broad-leaved weeds (BL) sedges (SG) aquatics (AQ) in all blocks with a slight difference in block AI, where sedges were dominant instead of broad-leaved weeds, aquatic weeds were totally absent and grasses were predominant as compared to other blocks.