Effect of Some Organic and Mineral Fertilizer Applications on Growth and Productivity of Pomegranate Trees

Abstract

This investigation was carried out during 2007 and 2008 growing seasons on six years old Arabi-pomegranate trees, grown in sandy clay loamy soil in a private farm located at Alexandria-Matrouh road, to study the effect of different fertilizers i.e., minerals (Ammonium Sulphate, Potassium Sulphate and Calcium Super Phosphate) at rate of 100% or 50% of the recommended dose or organic (humic acid or compost solely) or their combinations on growth, fruit set, yield, fruit quality and leaf minerals content during both seasons of study. The obtained results showed that, vegetative growth, fruit set, yield as weight or number of fruits /tree as well as fruit quality (average fruit weight, diameter, length, TSS and anthocyanine) and leaf N content were, generally, improved under all treatments as compared with control in both seasons. While, slight effect on leaf P and K content were noticed. The studied treatments decreased juice acidity and did not significantly affect V.C. and tannins content in both seasons. The striking treatments 50% of the recommended rate of NPK + organic matter (compost or humic acid) were most effective in improving all parameters when compared with other treatments. It is worthy to note that, using 50% of the recommended rate of NPK + organic matter (compost at 25Kg/ tree or humic acid at 12.5 or 25g /tree) had a similar effect to the treatment 100% of the recommended rate of NPK solely. Hence, it could be concluded that fertilizing pomegranate trees with 50% of the recommended rate of NPK + humic acid at higher rate 25g/ tree is the promising treatment under the same condition of our study. Moreover, it reduced half the amount of the recommended mineral fertilizers as well as soil pollution.