Adubação nitrogenada e diagnóstico do estado de nitrogênio nas culturas de abobrinha, abóbora tipo tetsukabuto e pepino

• Ano de defesa: 2011
• Autor(a) principal: Pôrto, Mônica Lima Alves
• Orientador(a): Puiatti, Mário
• Banca de defesa: Neves, Júlio César Lima , Vidigal, Sanzio Mollica
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Rendimento; Eficiência econômica; Índice SPAD; Clorofila; Nutrição mineral
• Palavras-chave em Inglês: Yield; Economic efficiency; SPAD index; Chlorophyll; Mineral nutrition
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1176

Despite zucchini, hybrid winter squash ( Tetsukabuto type) and japanese cucumber nutritional and commercial importance, few studies have been led with the nitrogen fertilization and nutrition these crops. Thus, it is necessary to determine the N requirement of these cultures, as well as indicate methods for nitrogen status diagnosis, contributing to rationalize the productive potential and exploration of these important cucurbits. This studie‟s objective was to evaluate the productive performance and nitrogen status diagnosis on plants of zucchini, hybrid winter squash ( Tetsukabuto type) and japanese cucumber as a function of the nitrogen fertilization. In 2009 and 2010, three experiments were carried out in the experimental area of Department of Crop Science, Federal University of Viçosa, at Viçosa, Minas Gerais State, Brazil. The first experiment was conducted in 2009 with zucchini plants ( Caserta‟ cv.), being carried out in field conditions in a randomized block design with five N doses (0; 50; 100; 200 and 400 kg ha-1), with four replications. The second experiment was conducted in 2010 with hybrid winter squash ( Tetsukabuto type) plants, being carried out in field conditions in a randomized block design, arranged in a 2 x 5 factorial design, with two nitrogen sources (ammonium sulphate and ammonium nitrate) and five nitrogen doses (0; 50; 100; 200 and 400 kg ha-1), with four replicates. The third experiment was conducted in 2010 with japanese cucumber ( Taisho‟ hybrid) plants under protected cultivation, being carried out in a randomized block design, arranged in a 2 x 5 factorial design, with two nitrogen sources (ammonium sulphate and ammonium nitrate) and five nitrogen doses (0; 75; 150; 300 and 600 kg ha-1), with four replicates. At the early flowering stage, total chlorophyll concentration, SPAD index and total N concentration in fourth leaf fully expanded from the apex of plants. After, the number of fruits/plant, average fruit mass and yield of the japanese cucumber were evaluated. There were no significant effects of nitrogen sources and of the interaction between nitrogen sources and nitrogen doses under the evaluated characteristics of hybrid winter squash ( Tetsukabuto type) and japanese cucumber. For the three species evaluated, all the productive characteristics increased following a quadratic model as a function of the N doses, being observed high economic response to N application. Nitrate accumulation in japanese cucumber ( Taisho‟ hybrid) fruits as a function of the N doses for two nitrogen sources evaluated was not verified. The maximum nitrate content observed in fruits of zucchini and hybrid winter squash ( Tetsukabuto type) doesn't represent risk for human health. For the three species evaluated, the total chlorophyll concentration, SPAD index and total N concentration in leaves increased following a quadratic model as a function of the N doses. Significant linear and positive correlation between the evaluated characteristics was observed. The results indicate that the SPAD index can be used for N status diagnosis on plants of zucchini, hybrid winter squash ( Tetsukabuto type) and japanese cucumber.