Interferência de plantas daninhas no desenvolvimento da soja resistente ao glyphosate

• Ano de defesa: 2008
• Autor(a) principal: Silva, Alexandre Ferreira da
• Orientador(a): Ferreira, Francisco Affonso
• Banca de defesa: Santos, Leonardo David Tuffi , Santos, José Barbosa dos , Procópio, Sérgio de Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Glycine max; Competição; Plantas daninhas
• Palavras-chave em Inglês: Glycine max; Competition; Weeds
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4483

The weeds interference on the soybean crop may cause serious yield reductions, as a consequence of its interference on the soybean growth and yield components. The knowledge of the period previous to the interference (PPI) of weeds has become of great practical importance in the cultivation of glyphosate-resistant soybean because it makes possible the application of the herbicide in post-emergency, in the appropriate moment. In order to obtain those information, three experiments were carried out, in low, average and high weeds infestation conditions, seeking to quantify the effect of weeds densities on RR-soybean culture during its development cycle. In the first experiment, it was determined the PPI; in the second the effects of weeds interference on the soybean production components: height, number of pods per plant, number of seeds per plant and weight of one thousand grains; and in the third, the coexistence period and weed infestation level effects on the soybean growth variables: plant stature, dry matter of the branches without leaves, dry matter of the leaves and branches, number of trifoliate leaves and leaf area. The experimental design adopted, for all of the experiments, was a randomized blocks, being the treatments constituted by the combination of ten weeds coexistence periods with the culture (0, 0-5, 0-10, 0- 15, 0-21, 0-28, 0-35, 0-42, 0-49 and 0-125 days). In a general way, the values of PPI varied according to the infestation level, indicating that the higher the infesting community density, the more intense it will be the weed competition on the culture and minor will be the time after emergency to begin its control. The yield components and the growth variables were shown sensitive to the interference imposed by weeds, being the number of pods per plant the more sensitive to the interference yield component.