Crescimento e acúmulo de nutrientes em bucha vegetal (Luffa cylindrica)

• Ano de defesa: 2007
• Autor(a) principal: Siqueira, Rosileyde Gonçalves
• Orientador(a): Santos, Ricardo Henrique Silva
• Banca de defesa: Fontes, Paulo Cezar Rezende , Lopes, José Flávio , Pedrosa, Marinalva Woods
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Luffa cylindrica; Nutrição mineral; Órgãos da planta; Exportação
• Palavras-chave em Inglês: Luffa cylindrica; Mineral nutrition; Plant organs
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4459

Plants present an average o 5% of mineral nutrients in its dry mass, but there area wide differences in nutrient accumulation among species, and the total nutrient amount required by crop depends on its productivity. Besides, the nutrient absorption varies according to plant development stage and it is enhanced by flowering and fruit formation and growth. The plant growth analysis allows the evaluation of the mass and nutrient accumulation progress in different plant organs. The goal of this project was to determine the growth and nutrient absorption in different organs of an access of Luffa cylindrica. The nutrient content in plant tissue and mass accumulation were determined at 30, 60, 90, 120, 150, 180, 210 and 240 days after transplant (DAT). Each plot presented two plants and the experiment was set up in completely randomized design and four repetitions, totalizing 32 plots limited by each trellis area. At each sampling date plants were cut at soil level and separated in leaves, stems and flowers and fruits, and determined the fresh mass. Samples of each plant organ were dried in oven and it was determined the dry mass and its nutrient content. The data was then submitted to analysis of variance and regression analysis. The maximum of total dry mass production occurred at 231.01 DAT, with and accumulation of 9.69 kg pl-1. The leaves dry mass represented 14.04%, the stems dry mass 27.34% and the flowers and fruits accumulated dry mass represented 58.51% of the total aboveground dry mass. Nitrogen and calcium were more accumulated in the leaves, while phosphorus, potassium, magnesium and sulfur were more accumulated in the flowers and fruits. Potassium was the macronutrient more absorbed by the plants, followed by nitrogen, calcium, phosphorus, magnesium and sulfur, in decreasing order. Iron and manganese were more accumulated in the leaves, while copper and zinc were more accumulated in flowers and fruits. Among the micronutrients, iron presented the highest absorption by the plant, followed in decreasing order by manganese, copper and zinc. In commercial fruits, the average length was 0.90 m, the top diameter average was 6.23 cm, the middle diameter average was 8.17 cm, the average basal diameter was 10.63 cm and the diameter uniformity was 1.30. At 240 DAT the fruits represented 80.3% of the total plant accumulated dry mass. Of the total nutrients accumulated by the plants at the end of the experiment, the fruits exported 40.0% of the nitrogen, 54.6% of the phosphorus, 60,1% of the potassium, 25.2% of the calcium, 50.8% of the magnesium and 57.0% of the sulfur. Potassium was the more exported nutrient by the fruits, presenting 93.77 kg ha-1 of K exported, followed by nitrogen (25.37 kg ha-1), phosphorus (15.46 kg ha-1), calcium (13.55 kg ha-1), magnesium (5.48 kg ha-1) and sulfur(3.54 kg ha-1). Iron (346.09 g ha-1) was the micronutrient more exported by fruits, followed by zinc (89.68 g ha-1), manganese (84.28 g ha-1) and copper (31.83 g ha-1).