Interferência intra e interespecífica de Urochloa decumbens e Synedrellopsis grisebachii

• Autor(a) principal: Martins, Pedro de Figueiredo Rocha Barbosa [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/135913; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/15-02-2016/000858191.pdf
• topic: Capim-braquiaria; Plantas - Competição; Erva daninha; Plantas - Desenvolvimento; Plantas; Plant competition

This study evaluates the coexistence of Urochloa decumbens (Surinam grass) and Synedrellopsis grisebachii (Cinderella weed). Two experiments were conducted: a replacement series, to determine intra and interspecific interferences of both species grown in monoculture and in coexistence, and a diallel replacement series using permeable and impermeable barriers between said species to evaluate allelopathic and general interference among them. In order to determine the critical population density to be used in the replacement series, 1, 2, 4, 8, 16, 24 and 32 plants were planted in the same box and harvested 40 days after, dried and weighted, to be analyzed trough regression analysis. Replacement series experiment used the percentage densities for Surinam grass and Cinderella weed of 100:0, 75:25, 50:50, 25:75 and 0:100. The above-ground parts were harvested, dried and analyzed through qualitative and quantitative methods. The diallel replacement series consisted of four or eight plants in sand-filled boxes on growth chamber environment, being the species grown in monoculture or coexisting with each other, and three treatments were analyzed: a permeable one, an impermeable one and one without barrier between the plants. Analysis of variance and ecological coefficient analysis were performed to determine the competitive capacity. 16 plants per vase were needed for the Surinam grass to achieve the critical population. Qualitative analysis show there is mutual harm to the dry matter allocation of both species. Quantitative analysis shows Cinderella weed as a better competitive species than signal grass during the initial growth phase, fact which may be caused on account of allelopathic processes