Weed Colonization of Experimental Gaps in the Gaps in the Canopy of a Wheat Crop.

• Autor(a) principal: LEWIS, J. P.
• Data de Publicação: 1991
• Outros Autores: LEGUIZAMON, E. S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/105814
• topic: Disturbance; gaps; weed colonization; weed community; wheat crop

Gaps of different sizes were opened in the canopy of a wheat crop by removing all above ground vegetafion in, August and October. Half of the gaps opened in. August were reopened in October. Composition of the weed community and abundance of individual species were measured in. September and in. November just before crop harvest. In September there were very litde differences between treatinents, and in November the most important differences were due to time of gap opening but not between gaps of different: sizes. Most weed species are synchronous with the crop and are well adapted to coexist with it, so there is a marked negative effect of late opening of gaps on most of them. Gaps have a positive effect on weeds asynchronous with the crop and perhaps on. rarities, Le. species which are neither constant nor abundant.