Minimizing weed competition through waterlogging in rice (Oryza sativa) under various soil types 

National rice production continues to be increased to meet the needs of food security in Indonesia. But in reality, every rice cultivation always raises the problem of weed disturbances. One way to control weeds can be through waterlogging. Waterlogging can suppress weed growth and increase rice yields. This study was conducted from August 2019-January 2020 at greenhouse conditions, Faulty of Agriculture, Universitas PGRI Yogyakarta. The study aimed at knowing the waterlogging period to minimize weed competition and increase the rice yield. This study was arranged in a completely randomized design (CRD) factorial with three replications. The first factor was the waterlogging period, which consisted of three levels : without waterlogging, 1-15 days after planting (DAP) and 1-30 DAP. The second factor was soil types, which consisted of four kinds : latosol, coastal sandy, volcanic and regosol soil. The weed observation was carried out at 60 DAP, and the rice was done at 104 DAP. The results showed that waterlogging could minimize weed competition in rice fields. Furthermore, waterlogging period of 1-30 DAP could inhibit the weed dry weight (WDW) and increase the leaf area index (LAI), shoot : root ratio (SRR), grain dry weight (GDW) and harvest index (HI) in different soil types. Waterlogging period of 1-30 DAP gave the highest GDW in latosol (7.5 t/ha), then decreased in volcanic (6.0 t/ha), regosol (5.9 t/ha) and the lowest in coastal sandy (4.8 t/ha). The research findings showed that waterlogging period of 1-30 DAP could minimize the weed competition and increase the rice yield. Thus, it was highly recommended to be practised as cultural weed control in rice cultivation. In future research, weed types that are tolerant to waterlogging treatment need to be combined with weeding treatment.
