Mycorrhizal association in soybean and weeds in competition/Associacao micorrizica em soja e plantas daninhas em competicao

• Published in: Acta scientiarum. Agronomy 2016-04, Vol.38 (2), p.171
• Main Authors: Fialho, Cintia Maria Teixeira, da Silva, Gustavo Soares, Faustino, Lais Araujo, de Carvalho, Felipe Paolinelli, Costa, Mauricio Dutra, da Silva, Antonio Alberto
• Format: Article
• Language: Spanish
• ISSN: 1679-9275
• DOI: 10.4025/actasciagron.v38i2.27230

The purpose of this study was to evaluate the effects of mycorrhizal association on the interference of Bidens pilosa, Urochloa decumbens and Eleusine indica on soybean culture in two conditions: a) plants competing without contact with roots of another species; b) with contact between roots. At 60 days after planting, growth, nutrient accumulation and mycorrhizal colonization of soybean and weeds were evaluated. The contact between roots of soybean plant and weed species increased the negative interference effects for both species, with less growth and nutrient accumulation. With the individualization of roots, higher competition occurred for soil resources up to 60 days of coexistence between species. In competition with soybean, Bidens pilosa and Urochloa decumbens stood out in accumulation of most nutrients without differing from when cultivated in monocultivation. The increase of the soybean mycorrhizal colonization was 53, 40 and 33% when in competition with Urochloa decumbens, Eleusine indica and Bidens pilosa species, respectively. A positive interaction occurred for soybean mycorrhizal colonization and competing plants irrespective of weed species or root contact. Keywords: Bidens pilosa, Urochloa decumbens (Syn. Urochloa decumbens), Eleusine indica, arbuscular mycorrhiza fungi. Objetivou-se neste trabalho avaliar os efeitos da associacao micorrizica na interferencia de Bidens pilosa, Urochloa decumbens e Eleusine indica sobre a cultura da soja em duas condicoes: a) plantas competindo sem contato entre raizes de outra especie b) com contato entre raizes. Aos 60 dias apos o plantio, foram feitas avaliacoes do crescimento, acumulo de nutrientes e colonizacao micorrizica da soja e plantas daninhas. O contato entre as raizes de plantas de soja e das especies daninhas aumentou os efeitos negativos da interferencia para ambas as especies, com menor crescimento e acumulo de nutrientes. Com a individualizacao das raizes, maior competicao estabeleceu-se pelos recursos do solo ate os 60 dias de convivencia entre cultura e especie competidoras. Em competicao com a soja, B. pilosa e U. decumbens destacaram-se no acumulo da maioria dos nutrientes nao diferindo de quando cultivadas em monocultivo. O aumento da colonizacao micorrizica da soja foi de 53, 40 e 33% quando em competicao com U. decumbens, E. indica e B. pilosa, respectivamente. Ocorreu interacao positiva para a colonizacao micorrizica da soja e das plantas competidoras independente da especie daninha