EFFECT OF TWO ROOTSTOCK SELECTIONS ON THE SEASONAL NUTRITIONAL VARIABILITY OF BRAEBURN APPLE

A fertigation trial was carried out over two growing seasons in 2001/2002 (wet summer) and 2002/2003 (wet spring) in an apple orchard plot (Braeburn variety) located in the central south region of Chile. The orchard was established in 1991 and two subsections were selected for evaluations, each with M-111 and seedling rootstocks. Four sampling points were selected in each sector and each one was composed of two trees, selected by statistical chemical soils uniformity. At harvest in each growing season 40 fruits per sample point were collected, and their peel and pulp were analyzed. Additionally, 40 fruits per sample point were stored for 60 days in cool storage to evaluate bitter pit incidence. Results indicated that neither the yield nor nutritional concentration of tissues were not affected by rootstocks. In peel, N, P, Ca and Mg highest content, and B lowest content were obtained during 2001/2002. On pulp, K, Mg and B highest content and P lowest content were obtained during 2002/2003. A high incidence of Bitter pit was observed during the second growing season. Results obtained suggest a seasonal incidence on fruits nutritional content, which would affect their post harvest qualit