EFFECT OF WATERLOGGING ON WEED SEED GERMINATION AND GROWTH IN LOWLAND RICE.

Weed control is needed to avoid competition in early rice growth. A weed control method is waterlogging. The study aimed to investigate the effect of waterlogging on weed seed germination and growth in lowland rice. This research was arranged in a completely randomized design (CRD) factorial and three replications. The first factor was waterlogging, which consisted of three levels: without waterlogging, 1-15 days after planting (DAP), and 1-30 DAP. The second factor was focused on two different soil types: latosol soil (LS) and regosol soil (RS). The results showed that waterlogging could inhibit seed germination of weed in RS but not in LS. In this study, waterlogging of 1-30 DAP inhibited weed dry weight higher than 1-15 DAP in both soil types. Waterlogging of 1-30 DAP decreased the weed dry weight by 87.2% in LS and 97.3% in RS than without waterlogging. Waterlogging could change the summed dominance ratio (SDR) of weed species. The research findings show that the waterlogging period of 1-30 DAP effectively inhibits the weed seed germination and growth in RS, but in LS could extend. We recommend that waterlogging period of 1-30 DAP can be applied for weed control in lowland rice. [ABSTRACT FROM AUTHOR]