Investigating the effects of different sources of fertilizer on iron concentration in leaf and quantitative characteristics of Asgari grapes in Si-Sakht region

Askari grape is one of the dominant cultivars and main sources of income for the people of Dana city. The usage of this grape cultivar is as table, unripe grape juice, juice and raisins. Lime over 60% of the soil is one of the main problems of vineyards in the region. High lime increases the amount of grape leaf chlorosis and reduces the quantitative and qualitative characteristics of grapes. Iron deficiency is one of the main problems in calcareous soils. In order to investigate the effects of different fertilizer sources on quantitative characteristics of grapes and iron concentration in leaves, an experiment was conducted in the form of a randomized complete block design with four repetitions during two successive growth season. The treatments included control (distilled water), urea 5000 mg/liter, ammonium sulfate 5000 mg/liter, 50 gr of iron chelate as soil application. The results of the composite variance analysis of yield, cluster length, cluster weight and total soluble solids (TSS) of the fruit showed that the effect of fertilizer treatments and also the interaction effect of year and fertilizer treatment on these traits were not significant, but according to the comparison of the means , iron chelate increased yield, cluster weight and leaf iron content by 8, 3.6 and 61% respectively. Also, ammonium sulfate increased yield, cluster length and leaf iron content by 25.3, respectively. 5 and 30.8 percent. The results of the variance analysis of the iron content in leaves showed that the effect of fertilizer treatments on this characteristic is significant at the probability level of 1%. Iron chelate treatment increased the iron concentration in grape leaves by 61% compared to the control. Iron chelate in the amount of 50 gr as soil is recommended to increase the amount of iron in leaves and the quantitative and qualitative