Effects of applications of a complex and N-Ca fertilizer on leaf and fruit nutrient concentrations and some fruit quality parameters in two apple cultivars

Abstract

The aim of this research was to study the effects of application of ‘hydrocomplex’ (H) and ‘Norway nitrate’ (NN) fertilizers on leaf and fruit nutrient concentrations and some fruit quality parameters in the following apple (Malus domestica Borkh) cultivars (cvs.): Golden Delicious and Black Ben Davis. Applications of 50 kg NN, 75 kg NN, 50 kg NN plus 50 kg H and 75 kg NN plus 25 kg H per 0.1 hectare significantly increased leaf Ca concentration of the cv. Golden Delicious in comparison with the control in the July 15 sampling period. Boron concentration of leaves of the cv. Black Ben Davis increased steadily throughout the season. Applications of 75 kg H and 75 kg H plus 25 kg NN per 0.1 hectare significantly increased fruit B concentration of the cv. Black Ben Davis at harvest. The ratios N/Ca, K/Ca and K + Mg/Ca in fruit were calculated for all treatments. Applications of 25–75 kg NN, 25–75 kg H as well as the combination of the two fertilizers decreased the ratios N/Ca, K/Ca and K + Mg/Ca of fruits of the cvs. Golden Delicious and Black Ben Davis in comparison with the control at harvest. Applications of 50 kg (ΝΝ), 75 kg (Η), 25 kg (ΝΝ) plus 75 kg (H) and 75 kg (NN) plus 25 kg (H) per 0.1 hectare significantly increased soluble solids of fruits of the cv. Golden Delicious at harvest.