Molibdênio pode substituir adubo nitrogenado de cobertura em feijoeiro de alta produtividade na Zona da Mata de Minas Gerais

• Autor(a) principal: Sapucay, Moryb Jorge Lima da Costa
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4569
• topic: Phaseolus vulgaris L.; Molibdênio no feijoeiro; Nitrogênio no feijoeiro; Phaseolus vulgaris L.; Molybdenum in bean; Nitrogen in bean; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

In areas cultivated frequently with common bean at Zona da Mata of Minas Gerais state, Mo application on foliage have been used instead of N topdressing to sustain yields around 2000 kg ha-1. However, there is a doubt about the effectiveness of this technology in higher yield conditions. The objectives of this work were: 1) determinate the maximal rate of N topdressing in which common bean respond to molybdenum fertilizer; 2) verify if the Mo fertilization replace the N topdressing in high yielding conditions. The experiments were conducted at three municipalities of Zona da Mata: Coimbra, Oratórios, and Viçosa. They were installed on April or May of 2011. The treatments were arranged as a 5 x 2 factorial: 0, 30, 60, 90 and 120 kg ha-1 of N and 0 and 80 g ha-1 of Mo. N as urea was applied the following way: 30 = at sowing, 60 = 30 (sowing) + 30 (15 days after emergence - DAE), 90 = 30 (sowing) + 30 (15 DAE) + 30 (25 DAE), 120 = 30 (sowing) + 45 (15 DAE) + 45 (25 DAE). Mo was applied as sodium molybdate solution onto the foliage at V4 stage. In order to reach the first objective, the effect of Mo was evaluated at each N rate. In order to reach the second objective, the ten treatments formed by the combination of N and Mo factors were considered. In this case, Dunnett test was utilized in order to compare the association of 30 kg ha-1 of N at the sowing + Mo with each other treatments. The cultivar Ouro Vermelho was used. A randomized complete block design with four replications was used. The highest yields were 3437, 2185 and 3270 kg ha-1 at Viçosa, Oratórios, and Coimbra, respectively. In Viçosa, differently from the others municipalities, N and/or Mo did not affect yield. In Coimbra, Mo increased yield when zero (level of 30 kg ha-1 de N) or 30 kg ha-1 de N topdressing (level of 60 kg ha-1 de N) was used. In Oratórios and Coimbra, plants sprayed with Mo and fertilized with N at sowing yielded as much as plants fertilized with N topdressing at a rate of 90 kg ha-1. Results suggest that common bean can respond in yield to Mo even when N topdressing of 30 kg ha is used and that Mo can replace topdressing N for yield levels of up to 3000 kg ha-1.