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.

 

Texto completo disponível apenas em PDF.

Full text only available in PDF format.

 

REFERÊNCIAS BIBLIOGRÁFICAS

Appleby, A.P.; Olson, P.D. & Colbert, D.R. (1976) Winter wheat yield reduction from interference by italian ryegrass. Agronomy Journal 68: 463-466.         [ Links ]

Bastiaans, L.; Kropff, M.J.; Goudriaan, J. & Van Laar, H.H. (2000) - Design of weed management systems with a reduced reliance on herbicides poses new challenges and prerequisites for modeling crop-weed interactions. Field Crops Research 67: 161-179.

Calado, J. (2005) - Estratégias para o Controlo de Infestantes em Sistemas de Baixo Custo nos Cereais de Outono-Inverno - O Caso do Trigo Mole (Triticum aestivum L.). Dissertação de Doutoramento. Universidade de Évora, Évora, 334 pp.

Carvalho, M.J.G.P.R. (1994) - A contribuição conjunta do melhoramento e da fitotecnia na produção de trigo em Portugal face à política agrícola comum. Melhoramento 33: 577-608.

Challaiah; Burnside, O.C.; Wicks, G.A. & Johnson, V.A. (1986) - Competition between winter wheat (Triticum aestivum) cultivars e downy brome (Bromus tectorum). Weed Science 34: 689-693.

Champion, G.T.; Froud-Williams, R.J. & Holland, J.M. (1998) - Interactions between wheat (Triticum aestivum L.) cultivar, row spacing and density and the effect on weed suppression and crop yield. Annals of Applied Biology 133: 443-453.

Christensen, S.; Rasmussen, G.; Olesen, J.E. & Jørgensen, L.N. (1996) - Weed management for integrated winter wheat production. In: Proceedings Second International Weed Control Congress, Copenhagen, pp. 1-7.

Cooser, N.D.; Gooding, M.J.; Thompson, A.J. & Froud-Williams, R.J. (1997) - Competitive ability and tolerance of organically grown wheat cultivars to natural weed infestations. Annals of Applied Biology 130: 523-535.

Froud-Williams, R.J. (1997) - Varietal selection for weed supression. Aspects of Applied Biology, 50 (Optimising cereal inputs: Its scientific basis): 355-360.

Instituto Nacional de Meteorologia e Geofísica (1991) - O clima de Portugal - normais climatológicas da região de “Alentejo e Algarve” correspondentes a 1951/80 - fascículo XLIX. 4, Lisboa. 98 pp.

Korres, N.E. & Froud-Williams, R.J. (2002) - Effects of winter wheat cultivars and seed rate on the biological characteristics of naturally occurring weed flora. Weed Research 42: 417-428.

Kropff, M.J.; Bastiaans, L. & Lotz, L.A.P. (1997) Systems approaches in weed management and the design of weed suppressing crop varieties. In: Expert Consultation on Weed Ecology and Management. Plant Production & Protection Division Food and Agriculture Organization of the United Nations, FAO, Rome, pp. 73-85.

Légère, A. & Bay, Y. (1999) - Competitive attributes of A. sativa, T. aestivum, and H. vulgare are conserved in no-till cropping systems. Weed Science 47: 712-719.

Lemerle, D.; Verbeek, B. & Martin, P. (1996a) Breeding wheat cultivars more competitive against weeds. In: Proceedings Second International Weed Control Congress, International Weed Science Society, Copenhagen, pp.1323-1324.

Lemerle, D.; Verbeek, B.; Cousens, R.D. & Coombes, N.E. (1996b) - The potential for selecting wheat varieties strongly competitive against weeds. Weed Research 36: 505-513.

Lemerle, D.; Gill, G.S.; Murphy, C.E.; Walker, S.R.; Cousens, R.D.; Mokhtary, S.; Peltzer, S.J.; Coleman, R. & Luckett, D.J. (2001) - Genetic improvement and agronomy for enhanced wheat competitiveness with weeds. Australian Journal of Agricultural Research 52: 527-548.

Maçãs, B.; Coutinho, J. & Dias, A.S. (1998) -Oportunidades para aumentar o potencial produtivo do trigo da região mediterrânica do Sul de Portugal. I - Produção de biomassa, componentes da produção e índice de colheita. Melhoramento 35: 5-18.

Martínez-Ghersa, M.A.; Ghersa, C.M. & Satorre, E.H. (2000) - Coevolution of agricultural systems and their weed companions: implications for research. Field Crops Research 67: 181-190.

Moreira, I. (1980) - Situação actual dos conhecimentos de biologia e ecologia das infestantes. In: I Congresso Português de Fitiatria e Fitofarmacologia. III Simpósio Nacional de Herbologia, Lisboa, 3, pp. 211-218.

Ramsel, R.E. & Wicks, G.A. (1988) - Use of winter wheat (Triticum aestivum) cultivars and herbicides in aiding weed control in an ecofallow corn (Zea mays) rotation. Weed Science 36: 394-398.

Singh, S.; Kirkwood, R.C. & Marshall, G. (1999) Biology and control of Phalaris minor Retz. (littlessd canarygrass) in wheat. Crop Protection 18: 1-16.

Weiner, J.; Griepentrog, H. & Kristensen, L. (2001) Suppression of weeds by spring wheat Triticum aestivum increases with crop density and spatial uniformity. Journal of Applied Ecology 38: 784-790.

Wicks, G.A.; Ramsel, R.E.; Nordquist, P.T.; Schmidt, J.W. & Challaiah (1986) - Impact of wheat cultivars on establishment and suppression of summer annual weeds. Agronomy Journal 78: 59-62.

Wicks, G.A.; Nordquist, P.T.; Hanson, G.E. & Schmidt, J.W. (1994) - Influence of winter wheat (Triticum aestivum) on weed control in sorghum (Sorghum bicolor). Weed Science 42: 27-34.

Zadoks, J.C.; Chang, T.T. & Konzak, C.F. (1974) - A decimal code for the growth stages of cereals. Weed Research 14: 415-421.

 

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

 

Recepção/Reception: 2006.11.16

Aceitação/Acception: 2007.06.25