The Effect of Ammonium Nitrate Foliar Spray on Quantitative and Qualitative Parameters of Tomson Navel Orange

Foliar-nitrogen applied has the potential to become an important component in fertilizing programs for citrus in Iran, as it can reduce nitrate leaching into ground water. The goal of this research was to determine the most foliar concentration, ammonium nitrate application to “Tamson Navel “orange trees, for achieving the highest quantity and quality of yield. Foliar sprays were carried out, in two stages with concentration 0.4, 0.8 and 1.2 % and in three different concentrations, on 10 years old trees, grafted on sour orange rootstocks in Kotra Station of citrus Research Institute in Ramsar city. First stage applied in April with concentrations (0.25, 0.5 and 0.75 %) and second stage in the end July with concentrations (0.15, 0.35 and 0.45 %). Fruits were harvested in December as local common and determining the quantitative and qualitative (fruit diameter, fruit length, fruit weigh, fruit sink thickness, Vitamin C, total soluble solids, acidity and yield) parameters. The obtained results of statistical analysis showed that ammonium nitrate treatments at concentration of 0.8 and 1.2% had significant increase in yield and weight mean fruit in comparison to control treatment, respectively. Also, significant decrease in ratio sink thickness to diameter fruit in ammonium nitrate treatment with concentration of 0.4% was observed. The result indicated significant effect in total soluble solid to acidity ratio in ammonium nitrate treatments with concentration of 0.8% and 1.2%. In fruit length, fruit weight and ratio total soluble solids on acidity factors, treatment ammonium nitrate at concentration of 1.2%. Generally, treatment ammonium nitrate at concentration of 1.2% in almost factors measured had the best response and introduce as the best concentration.