Variability of weed infestation in two wheat varieties (Triticum Aestivum L.). II - as influenced by their weed competition characteristics

José Manuel Godinho Calado^{1 (2)}, Gottlieb Basch^{1 (2)}, Mário de Carvalho^{1 (2)}

RESUMO

Culturas e/ou variedades competitivas com as plantas infestantes são auxiliares relevantes para a gestão da infestação. Assim, neste trabalho, procurou-se verificar a relação da taxa de afilhamento e da altura das plantas do trigo mole com a infestação.

As observações e verificações foram realizadas durante quatro anos (1996/97 a 1999/00), a partir de um ensaio de datas de sementeira e de controlo das infestantes em duas variedades de trigo mole (Sever e Centauro) instalado na Herdade da Revelheira, concelho de Reguengos de Monsaraz.

De acordo com a análise dos resultados, constatou-se que, perante níveis elevados de infestação, a taxa de afilhamento e a altura das plantas de trigo variaram inversamente com o número de plantas infestantes da classe Monocotiledónea e directamente com a produção de grão e de biomassa da cultura. Por isso, conclui-se que as características referidas (afilhamento e altura das plantas) se relacionam positivamente com a capacidade das plantas de trigo competirem com a flora infestante.

Palavras-chave: capacidade competitiva do trigo, gestão de plantas infestantes.

ABSTRACT

Weed competitiveness of crops and/or varieties can be an important tool for weed management. In this study, the effect of plant height and tillering capacity of two wheat varieties was analyzed regarding their contribution to weed competitiveness.

The observations were carried out over four years (1996/97 to 1999/00) in a field trial on seeding dates and weed control in two wheat varieties (Sever and Centauro) on the “Herdade da Revilheira”, municipality of Reguengos de Monsaraz.

The results show that the two parameters plant height and tillering rate are positively related to crop yield and that there is a negative correlation with the number of weeds, especially grass weeds. Thus it can be concluded that the characteristics of plant height and tillering rate are positively related to the capacity of the wheat crop to compete with weed infestation.

Key-words: weed competition, weed management, Wheat morphology.

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¹Universidade de Évora, Departamento de Fitotecnia, Apartado 94, 7002-554 Évora; E-mail: jcalado@dfit.uevora.pt.

² Instituto de Ciências Agrárias Mediterrânicas. Apartado 94, 7002-554 - Évora E-mail: icam@uevora.pt

Aceitação/Acception: 2007.06.25