Resposta do feijoeiro ao molibdênio em mistura com glyphosate no plantio direto

• Autor(a) principal: Damato Neto, José
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4530
• topic: Feijão; Molibdênio; Glyphosate; Plantio direto; Bean; Molybdenum; Glyphosate; No-till; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

Experiments were carried out at the Experimental Station of Coimbra, Minas Gerais, of the Department of Plant Science of the Universidade Federal de Viçosa to study the effect of Mo in mixture with glyphosate, applied on corn and brachiaria straw on bean plant crop under no-till system. Two field assays were carried out, the first on brachiaria straw and the second on corn straw. The experiment was set up in split-plots, with the plots consisting of five doses of molybdenum (0, 100, 200, 400 and 800 g ha-1), applied in combination with the a desiccating herbicide (glyphosate) and the split-plots consisting of two doses of molybdenum (0 and 100 g ha-1), applied via the leaves on the bean plant, in the DBC, with four repetitions. Each split-plot was composed by five 5 m long, 0.5 m spaced lines of bean plant, cultivar Ouro Vermelho. Molybdenum foliar fertilization was carried out at stage V4, with sodium molybdate (39% of Mo) being the source of Mo. The content of chlorophyll was evaluated in the third completely expanded leaf from the apex (index leaf), through the SPAD index (Soil Plant Analyses Development), with three readings per leaflet being carried out in ten leaves randomly selected from the split-plot plants. The contents of N, P, K, Ca, Mg, S, Mn, Zn, Cu and Mo were evaluated in the leaves and grains under laboratory conditions. The number of plants per hectare (NP), number of pods per plant (NPP), number of grains per pod (NGP), mass of 100 grains (MG) and yield (Y) were later determined. The bean plant cultivated on the brachiaria straw absorbed MO applied on the latter, combined with glyphosate, increasing its yield. The content of Mo in the leaves increased in response to the application of the micronutrient, in mixture with glyphosate. Its concentration was even greater in the grains, when Mo was also applied via the leaves. The foliar content of nitrogen increased with the application of Mo mixed with glyphosate, when the micronutrient was not applied on the bean plant leaves, presenting a behavior similar to the SPAD index. When, besides the mixture of Mo with glyphosate, the former was applied via the leaves on the bean plants, these two factors decreased slightly. P content in the grains reduced when Mo was applied via the leaves. The content of K in the grains increased with the increase of the molybdenum dose, applied together with glyphosate on the brachiaria straw. On the other hand, when the bean plant was cultivated on the corn straw, the number of pods per plant (NPP) increased in response to the application of the Mo mixtures with glyphosate, when there was no foliar application of Mo on the bean plant. The foliar content of Mo was higher in the treatment Mo was applied on the bean plant leaves, regardless of the dose of this micronutrient, mixed with glyphosate. The content of Mo in the grains increased linearly with the increase of the micronutrient dose, applied together with glyphosate. The SPAD index was not altered, regardless of the Mo dose applied together with glyphosate, and/or applied via the leaves on the bean plant.