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 ΣDOP 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.