Temporal changes in weed population and biomass in unweeded broadcast seeded, wetland rice and field corn
1996
Paller, E.C. Jr. | Angela, C.J. | Blancaver, M.E.A. | Malenab, E.T. (Philippines Univ. Los Banos, College, Laguna (Philippines))
Changes in weed population and biomass in unweeded broadcast-seeded, wetland rice and field corn were monitored at 15, 30, and 45 days after sowing (DAS) for 3 seasons. Experiments on broadcast-seeded, wetland rice were conducted during the 1994 wet and dry seasons, and 1996 dry season; 1994 dry seasons, and 1994 and 1995 wet seasons for field corn. The major weed species at 15 DAS in rice were Echinochloa glabrescens Munro H. Hook f., Leptochloa chinensis (L.) Nees, Cyperus difformis L., and Fimbristylis littonalis Gaud. In corn, the major weed species were Rottboellia cochinchinensis (Lour.) W.D. Clayton, Cleone rutidosperma D.C., Cyperus rotundus L. and Amaranthus spinosus L. weed pressure varied with season. For 3 seasons, weed population in broadcast-seeded, wetland rice increased at 15 to 30 DAS but decreased at 30 to 45 DAS, population reduction from 30 to 45 DAS ranged from 15 to 84 percent. However, weed biomass increased from 15 to 30 DAS
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