Lowland Ecotype Cyperus rotundus L. Affects Growth and Yield of Rice under Flooded Conditions in the Philippines

Lowland ecotype Cyperus rotundus L. has been reported to infest irrigated lowland ricefields in the Philippines. Its effects on growth and yield of rice under flooded conditions are unknown. Two experimental runs were conducted a screenhouse determine C. with transplanted wet direct-seeded at sowing densities 0, 22, 44, 66, 88 initial germinating tubers m–2, as well its rice. Except for height, variables increased increase tuber densities. Compared 22 number off-shoots plus shoot root biomass 44–88 m–2 by up three times. Growth reduced weed. Grain was 14–38%, whereas that 11–28%. The estimated losses per weed plant 0.8 0.1% density approached zero (i) 75.7 66.1% infinity (a). Estimated 0.6 two i 63.8 100% a. Results suggest can grow reduce conditions. Although findings obtained conditions, results imply need developing holistic control strategy against