Red rice (oryza sativa): competition studies for management decisions

Growth analysis and competition studies involving red rice and rice "Oryzica 1" were conducted at CIAT, Colombia, during 1989 and 1990. In competition red rice (2 biotypes) grew taller than Oryzica 1, but had similar leaf area. During the first 60 days after emergence (d.a.e.) Oryzica 1 tillered mor...

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Main Authors: Fischer, Albert J., Ramírez Suárez, A.
Format: Informe técnico
Language:Inglés
Published: International Center for Tropical Agriculture 1992
Subjects:
Online Access:https://hdl.handle.net/10568/72331
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author Fischer, Albert J.
Ramírez Suárez, A.
author_browse Fischer, Albert J.
Ramírez Suárez, A.
author_facet Fischer, Albert J.
Ramírez Suárez, A.
author_sort Fischer, Albert J.
collection Repository of Agricultural Research Outputs (CGSpace)
description Growth analysis and competition studies involving red rice and rice "Oryzica 1" were conducted at CIAT, Colombia, during 1989 and 1990. In competition red rice (2 biotypes) grew taller than Oryzica 1, but had similar leaf area. During the first 60 days after emergence (d.a.e.) Oryzica 1 tillered more than the red rice biotypes, but these continued to tiller after anthesis. Competitive effects differed for each red rice biotype. In field competition studies (1989) red rice was very competitive with rice: 5 and 20 red rice plants/m2 reduced rice yields by 40 and 60 respectively. Twenty red rice plants/m2 shattered 35 seeds/m2 before rice harvest, and contaminated harvested rice with about 1100 kg/ha of red rice grain. An infestation of 24 red rice plants/m2 reduced rice yields by 10 if allowed to compete during 40 d.a.e., and 75 after season-long competition. In 1990 red rice competition was stronger, and an experiment combining effects of red rice density and duration of competition indicated that 50 yield was lost when 24 red rice plants/m2 competed during 40 d.a.e. with Oryzica 1. Economic analysis using competition data indicated that with current prices in Colombia and given the high red rice competitiveness, herbicide control with glyphosate (2 kg ai/ha) followed by paraquat (0.75kg ia/ha) was economically justified even at very low red rice densities. The probability of justifying hand weeding practices was higher among low-yield-farmers, early weeding, and low labour costs.
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spelling CGSpace723312025-11-05T18:19:57Z Red rice (oryza sativa): competition studies for management decisions Fischer, Albert J. Ramírez Suárez, A. oryza sativa rice weeds biological competition weed control arroz malezas competencia biológica control de malezas Growth analysis and competition studies involving red rice and rice "Oryzica 1" were conducted at CIAT, Colombia, during 1989 and 1990. In competition red rice (2 biotypes) grew taller than Oryzica 1, but had similar leaf area. During the first 60 days after emergence (d.a.e.) Oryzica 1 tillered more than the red rice biotypes, but these continued to tiller after anthesis. Competitive effects differed for each red rice biotype. In field competition studies (1989) red rice was very competitive with rice: 5 and 20 red rice plants/m2 reduced rice yields by 40 and 60 respectively. Twenty red rice plants/m2 shattered 35 seeds/m2 before rice harvest, and contaminated harvested rice with about 1100 kg/ha of red rice grain. An infestation of 24 red rice plants/m2 reduced rice yields by 10 if allowed to compete during 40 d.a.e., and 75 after season-long competition. In 1990 red rice competition was stronger, and an experiment combining effects of red rice density and duration of competition indicated that 50 yield was lost when 24 red rice plants/m2 competed during 40 d.a.e. with Oryzica 1. Economic analysis using competition data indicated that with current prices in Colombia and given the high red rice competitiveness, herbicide control with glyphosate (2 kg ai/ha) followed by paraquat (0.75kg ia/ha) was economically justified even at very low red rice densities. The probability of justifying hand weeding practices was higher among low-yield-farmers, early weeding, and low labour costs. 1992 2016-02-29T17:15:46Z 2016-02-29T17:15:46Z Report https://hdl.handle.net/10568/72331 en Open Access application/pdf International Center for Tropical Agriculture Fischer, Albert J.; Ramírez Suárez, Alvaro. 1992. Red rice (Oryza sativa) : Competition studies for management decisions. Centro Internacional de Agricultura Tropical (CIAT), Cali, CO. 30 p.
spellingShingle oryza sativa
rice
weeds
biological competition
weed control
arroz
malezas
competencia biológica
control de malezas
Fischer, Albert J.
Ramírez Suárez, A.
Red rice (oryza sativa): competition studies for management decisions
title Red rice (oryza sativa): competition studies for management decisions
title_full Red rice (oryza sativa): competition studies for management decisions
title_fullStr Red rice (oryza sativa): competition studies for management decisions
title_full_unstemmed Red rice (oryza sativa): competition studies for management decisions
title_short Red rice (oryza sativa): competition studies for management decisions
title_sort red rice oryza sativa competition studies for management decisions
topic oryza sativa
rice
weeds
biological competition
weed control
arroz
malezas
competencia biológica
control de malezas
url https://hdl.handle.net/10568/72331
work_keys_str_mv AT fischeralbertj redriceoryzasativacompetitionstudiesformanagementdecisions
AT ramirezsuareza redriceoryzasativacompetitionstudiesformanagementdecisions