Translocação do glyphosate em biótipos de plantas daninhas e características competitivas do azevém

• Autor(a) principal: Ferreira, Evander Alves
• Data de Publicação: 2008
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1086
• topic: Lolium multiflorum; Resistência; Radioquímico; Capacidade competitiva; Lolium multiflorum; Resistance; Radiochemical; Competitive capacity; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

The objective of the present work was to evaluate glyphosate translocation in Lolium multiflorum and Conyza bonariensis biotypes, resistant and susceptible to that herbicide, as well as to evaluate competitive capacity of italian ryegrass biotypes. For that, four experiments were accomplished. In the first and in the second, it was applied 14C-glyphosate in the first leaf with visible ligule in L. multiflorum biotypes and in the third knot leaf of C. bonariensis, with the purpose of evaluating the translocation of the product. In the third experiment, the glyphosate was applied in both italian ryegrass biotypes. After ten days, plants shoots and roots were collected and dried in stove, to obtain macronutrients tenors. In the fourth experiment, the competitive capacity of the italian ryegrass biotypes was evaluated with the culture, 50 days after emergency, being determined tillers number, plants height and leaf area. On that same occasion, shoots and roots of wheat plants and resistant and sensitive italian ryegrass biotypes were collected, being determined the dry matter of root, stem and leaves (in separate parts). The following variables in wheat and in italian ryegrass biotypes were evaluated: culture growth rate, specific leaf area and leaf area index. Results of the first and the second experiment demonstrated higher glyphosate retention in the treated leaf of resistant L. multiflorum and C. bonariensis biotypes. Regarding the third rehearsal, in the herbicide presence, the sensitive biotype presented smaller phosphorus tenor in shoots and in the whole plant. Resistant and sensitive biotypes, without herbicide application, presented higher total-N and inorganic- N tenors in shoot and in the plant as a whole. The susceptible biotype presented higher absorption capacity and macronutrients accumulation than the resistant when both were not treated with herbicide, evidencing its higher competitiveness. In the fourth rehearsal, plant height, dry matter and leaf area of susceptible italian ryegrass biotypes presented smaller reduction with the increment on plants density per area in relation to the resistant biotypes. Regarding the competition of italian ryegrass biotypes with wheat plants, negative effect on the crop was also observed, when it was under interference of the sensitive biotype.