Effect of Different Ratios of Ammonium N to Total N on Vegetative Growth and Mineral Element Composition in Apple Leaves (var. Golab and Granny Smith)

Appropriate nutrition is necessary for obtaining high quality crop. In this research، the effect of different NH4+ / NH4+ + NO3- ratios on vegetative growth and N، K، Ca، Mg، and Fe concentration in apple seedling leaf was studied. The NH4+ / NH4+ + NO3- ratios were (0. 03، 0. 07، 0. 10، 0. 14، and 0. 04 meq L-1). Nutrient solution pH was adjusted at 6. 5 ± 0. 1. The experimental design was randomized complete block and was performed in three replicates. The results of the evaluation indicated that the increase in ammonium concentration caused significant (at 5% level) increase in leaf area، stem length، branches current year length، moisture content، and iron concentration of leaf. However، stem diameter، calcium، potassium، and magnesium concentration of leaf showed significant decrease with increasing concentration of ammonium. Number and diameter of current year branches as well as total nitrogen concentration did not show significant differences under different NH4+ / NH4+ + NO3- ratios.