Fruit yield and composition in orange trees cv. 'Lane Late' in response to nitrogen fertilization in Sandy Typic Hapludalf soil/Producao e composicao de frutos de laranjeira cv. 'Lane Late' em resposta a adubacao nitrogenada em um Argissolo Vermelho

• Published in: Ciência rural 2017-03, Vol.47 (3)
• Main Authors: Brunetto, Gustavo, Cella, Cesar, Miotto, Alcione, Girotto, Eduardo, Lorensini, Felipe, Brackmann, Auri, Ceretta, Carlos Alberto, Schorr, Marcio Renan Weber, Both, Vanderlei, Ambrosini, Vitor Gabriel
• Format: Article
• Language: Portuguese
• ISSN: 0103-8478
• DOI: 10.1590/0103-8478cr20140869

Little is known about the impact of N fertilization on fruit production and composition in orange groves grown in soils with low or medium organic matter content in Rio Grande do Sul (RS). This study aimed to evaluate how N fertilization of orange trees cv 'Lane Late ' in a sandy soil may interfere in fruit yield and composition of fruit and juice. The experiment was conducted with orange trees cv. 'Lane Late ' growing in Sandy Typic Hapludalf soil, in Rosario do Sul (RS). The plants received applications of 0, 20, 40, 60, 80, 100, 120, 140 and 160kg N ha-1. Total N in leaves, number of fruits per plant, yield, fresh weight, fruit diameter, peel thickness, percentage of fruit juice, peel color, juice color, ascorbic acid content, total soluble solids (TSS) and total titratable acidity were evaluated in 2010/2011 and 2011/2012 crops. In the first crop, especially yield, number of fruits per plant, TSS content in fruit juice and ratio decreased with increasing N rate applied. However, in the second crop, the total titratable acidity of the fruit juice prominently increased with the dose of N applied. In both crops, results were highly influenced by rainfall distribution, which affect the plant physiology, soil N dynamics and, consequently, probability of response to N applied and the loss of mineral N in the soil. Key words: nitrogen, leaf analysis, fruit quality, Citrus sinensis L. O impacto da adubacao nitrogenada na producao e composicao de frutos em pomares de laranjeiras cultivados em solos com baixo ou medio teor de materia organica do RS e pouco conhecido. Este trabalho objetivou avaliar como a adubacao nitrogenada, em solo de textura arenosa, pode interferir na producao, composicao de frutos e do suco em laranjeiras cv. 'Lane Late'. O experimento foi conduzido em um pomar de laranjeiras cv. 'Lane Late ' instalado sobre um Argissolo Vermelho, em Rosario do Sul (RS). As plantas foram submetidas a aplicacao de 0, 20, 40, 60, 80, 100, 120, 140 e 160 kg ha-1 de N. Nas safras de 2010/2011 e 2011/2012 foi avaliado o teor total de N em folhas, o numero de frutos por planta, a producao, o peso fresco e diametro de frutos, espessura da casca, porcentagem de suco nos frutos, cor da epiderme e do suco, os valores de vitamina C, solidos soluveis totais (SST) e acidez total titulavel. Na primeira safra, especialmente a producao, o numero de frutos por planta, o teor de SST no suco e o ratio diminuiram com o aumento da dose de N aplicada. Mas, na segunda safra, de