Quality of 'Fuji Suprema' apples influenced by long-term annual addition of phosphorus to the soil.

portuguesA adubacao com fosforo (P) em pomares de maca tem recebido menos atencao que adubacoes com nitrogenio e potassio. No Brasil, as informacoes sobre a resposta da macieira a adicao de P ao solo e escassa. O objetivo deste estudo foi avaliar o efeito a longo prazo da adicao anual de P ao solo na qualidade e composicao mineral de macas. O experimento iniciou em 2010, num pomar comercial localizado no municipio de Sao Joaquim, Sul do Brasil, com a cultivar ‘Fuji Suprema’, instalado em alta densidade (aproximadamente 2.000 plantas ha-1) em um solo Haplumbrept. Os tratamentos consistiram de 0, 40, 80, 120 e 160kg ha-1 P2O5 aplicados anualmente a partir de 2010, na superficie do solo ao longo da fileira das arvores. As avaliacoes foram realizadas nas estacoes de crescimento de 2012/2013 ate 2014/2015. Tres amostras de 10 frutos de cada unidade experimental foram colhidas. Uma amostra foi armazenada em uma câmara fria de atmosfera controlada por seis meses; os outros foram imediatamente avaliados quanto a firmeza, solidos soluveis totais, acidez titulavel (AT), cor da epiderme e as concentracoes de N, P, K, Ca e Mg na polpa dos frutos. A aplicacao de P ao solo afetou apenas a firmeza de polpa na colheita e AT apos seis meses de armazenamento na safra 2012/2013, bem como a firmeza apos seis meses de armazenamento na safra 2013/2014. Na safra 2014/2015, a adicao de P reduziu a cor dos frutos, mas apenas na colheita. A adicao de P ao solo afetou os niveis de P nos frutos da safra 2012/2013, bem como N e a relacao N / Ca de frutas na safra 2014/2015. Em geral, os atributos relacionados a qualidade dos frutos da cultivar Fuji Suprema foram ligeiramente afetados pela adicao anual prolongada de P ao solo. Palavras-chave: Malus x domestica Borkh; qualidade de fruto; adubacao fosfatada EnglishFertilization of apple orchards with phosphorus (P) has received less attention than with nitrogen and potassium. In Brazil, the information about apple response to soil P addition is meager. The objective of this study was to evaluate the long-term effect of annual soil P addition on quality and mineral composition of apple fruits. The experiment started in 2010, in a commercial orchard located in the Sao Joaquim, Southern of Brazil. The orchard consisted of ´Fuji Suprema’, planted in high-density on a Haplumbrept soil. Treatments consisted of 0, 40, 80, 120 and 160kg ha-1 P2O5 applied annually starting in 2010 broadcast over the soil surface along the tree row. Evaluations were performed from 2012/2013 through 2014/2015 growing seasons. We harvested three samples from each experimental unit. One sample was cold stored in a controlled atmosphere chamber for six months; the others were immediately evaluated for firmness, total soluble solids, titratable acidity (TA), skin color, and the concentrations of N, P, K, Ca and Mg in the fruit flesh. Application of P to the soil affected only flesh firmness at harvest and TA after six months of storage in the 2012/2013 season, as well as firmness after six months of storage in the 2013/2014 season. In the 2014/2015 season, the addition of P reduced fruit color but only at harvest. Addition of P to the soil affected the levels of P in the fruit in the 2012/2013 season, as well as N and the N/Ca ratio of fruit in the 2014/2015 season. Overall, attributes related to fruit quality of cultivar Fuji Suprema were slightly affected by long-term annual addition of P to the soil. Key words: Malus x domestica Borkh; fruit quality; phosphate fertilization