Apple fruit quality, yield and leaf macronutrients content as affected by fertilizer treatment

Abstract

During two years we have investigated main fruit quality traits, yield and leaf nutrient content at 120 days after full bloom (DAFB) of 'Idared' and 'Melrose' apples on M. 9 rootstock when fertilized with complex NPK (15: 15: 15) alone, and mixture with natural zeolite (Agrozel) and/or cattle manure. Results showed that fruit quality has been strongly affected by cultivars, whereas fertilizer treatments influenced only yield per tree. Moreover, significant impact of cultivar and fertilizer treatment on leaf P, K and Mg was found. Leaf of 'Melrose' contained higher P and K content, and lower Mg content than those of 'Idared'. In 'Melrose', NPK alone increased leaf P, whereas in 'Idared', mixture of NPK+Agrozel and NPK+Manure promoted leaf P, K and Mg content. According to DOP and SDOP indexes, excessive leaf Mg content was found, and deficiency of the rest of nutrients. 'Melrose' exhibited better balanced nutritional values for nutrients as compared to 'Idared', whereas NPK+M promoted better balanced nutritional values than other treatments.