Interference and economic threshold of Brachiaria plantaginea and Ipomoea nil in the common bean crop/Interferencia e nivel de dano economico de Brachiaria plantaginea e Ipomoea nil na cultura do feijao comum

The researches about the impact of weed interference on crops are usually performed with a single weed species, when in reality there are numerous. The objective of this study was to evaluate the interference of Brachiaria plantaginea and Ipomoea nil on the grain yield of French beans (Phaseolus vul...

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Published inCiência rural Vol. 40; no. 8; p. 1675
Main Authors Vidal, Ribas Antonio, Kalsing, Augusto, Gherekhloo, Javid
Format Journal Article
LanguageSpanish
Published Universidade Federal de Santa Maria 01.08.2010
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Summary:The researches about the impact of weed interference on crops are usually performed with a single weed species, when in reality there are numerous. The objective of this study was to evaluate the interference of Brachiaria plantaginea and Ipomoea nil on the grain yield of French beans (Phaseolus vulgaris) and to determine the economic weed threshold (EWT) of each species on the crop. Two field experiments were conducted with bean cultivars 'IPR Grauna' (Black group) and 'UTF-06' (Carioca group) in coexistence with random proportions of mixed infestations of B. plantaginea and I. nil. Multiple regression models were used to determine the interference abillity of each weed species on crop productivity. The interference ability of each plant of I. nil corresponded to 2.6 and 0.25 of each B. plantaginea, dependent on the relative proportions on the weed community and on the conditions of each experiment. Cultivar 'IPR Grauna' showed higher competitive ability than 'UTF-06'. The EWT was dependent on the relative proportion of each weed species in the community and was reached under low infestation (<16 plants [m.sup.-2]) in all conditions tested and simulated. Key words: interspecific competition, mathematical simulations, weeds. As pesquisas acerca do impacto da interferencia das plantas daninhas sobre as culturas normalmente sao realizadas com uma unica especie infestante, quando na realidade podem ocorrer diversas. Os objetivos deste trabalho foram avaliar a interferencia de Brachiaria plantaginea e Ipomoea nil sobre o rendimento de graos do feijoeiro (Phaseolus vulgaris) e determinar o nivel de dano economico (NDE) de cada especie na cultura. Foram realizados dois experimentos a campo com as cultivares de feijao 'IPR Grauna' (Grupo Preto) e 'UTF-06' (Grupo Carioca) em convivencia com infestacoes mistas em diferentes proporcoes aleatorias das especies B. plantaginea e I. nil. Modelos de regressao multiplos foram utilizados para determinar a capacidade de interferencia de cada especie daninha sobre a produtividade da cultura. O impacto de interferencia de cada planta de I. nil correspondeu a 2,6 e 0,25 quando comparada a cada planta de B. plantaginea, dependente das proporcoes relativas na comunidade infestante e das condicoes de cada experimento. A cultivar 'IPR Grauna' apresentou maior habilidade competitiva do que 'UTF-06'. O NDE foi dependente da proporcao relativa de cada especie daninha na comunidade e foi obtido sob baixas infestacoes (<16 plantas [m.sup.2]) em todas as condicoes testadas e simuladas. Palavras-chave: competicao interespecifica, plantas daninhas, simulacoes matematicas.
ISSN:0103-8478
1678-4596