Effect of UMAR-SRImat on weed management, number of tillers and plant height of MR219 rice in System of Rice Intensification (SRI)

System of Rice Intensification (SRI) is an innovation in rice farming cultural practice for increasing the productivity of water, capital, labour and land. SRI is all about altering the management of soil, water, rice plants and nutrients. However, weeds growth is one of the major problems of SRI due to alternate wetting and drying (AWD) and wide planting spacing (25 × 25 cm or more). Thus, if weed management is not being attempted it will lead to harmful competition between the weeds and the rice plants for water, nutrients, solar radiation, carbondioxide and space. Currently, manual weeder is being used to remove the weeds up to 40 days after transplanting (DAT) which is labour intensive, while motorized weeder reduces the intensive labour but cannot be able to remove the weeds up to 40 DAT as practiced by farmers. This research was designed to determine the effectiveness of SRImat known as "UMAR-SRImat" on weed control, and to determine the influence of UMARSRImat on number of tillers and plant height. The experiment was laid out using randomized complete block design (RCBD) with four treatments [without soil cover (T1), SRImat (T2), UMAR-SRImat without LGE (T3) and UMAR-SRImat with LGE (T4)] and three replications. Weed density (WD), weed dry weight (DW), weed dry weight ratio (DWR), summed dominance ratio, plant height and number of tillers were examined and recorded from the treatment plots for analysis. The dominant weed class associated with SRI were sedges, due to higher summed dominance ratio (SDR) followed by grasses and broadleaves, respectively. The effectiveness of UMAR-SRImat mulched was 100% (WCE) at 20 DAT and 99.64% at 40 DAT. The research exposed the opportunity of UMAR-SRImat mulch in controlling weeds up to 40 DAT with higher plant height and larger number of tillers at 30 and 50 DAT.