Effects of levels of nitrogen and potassium on yield and fruit maturation of irrigated guava trees in the São Francisco Valley

• Autor(a) principal: Lima,Maria Auxiliadora Coêlho de
• Data de Publicação: 2008
• Outros Autores: Bassoi,Luís Henrique, Silva,Davi José, Santos,Polyane de Sá, Paes,Prissila de Castro, Ribeiro,Paula Rose de Almeida, Dantas,Bárbara França
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista brasileira de fruticultura (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452008000100045
• topic: Psidium guajava L.; nutrition; maturity stages; fruit quality

Yield and physical and chemical characteristics of 'Paluma' guava fruit were evaluated as a function of the harvest at different maturity stages, under influence of nitrogen and potassium fertilization, in Petrolina, State of Pernambuco, Brazil. Fertilizer rates were 67 kg N + 33 kg K2O, 133 kg N + 67 kg K2O, 200 kg N + 100 kg K2O and 267 kg N + 133 kg K2O per hectare. Fruits were evaluated at maturity stages 2, 3, 4 and 5, established according to peel color. Higher doses of N and K induced higher yields. Nevertheless, fertilization with 200 kg of N + 100 kg of K per hectare improved fruit quality, delaying ascorbic acid breakdown and conserving pulp firmness. Main changes took place at maturity stages 4 and 5, when the fruit should present ideal conditions for consumption, namely the increase on soluble solids and soluble sugars content.