Effect of iron nano oxide concentration and application time on tuber yield and quality of potato

In order to investigating nitrate accumulation, tuber yield and protein variation, affected by different levels of iron nano oxide in different growth stages of potato, a factorial experiment was conducted based on RCBD with three replications during 2012 in Ardabil region. The first factor was iron nano oxide fertilizer at four levels including 0, 0.5, 1, 1.5 and 2 percent as well as normal iron oxide at 2 percent and the second factor was spraying stages (vegetative growth, beginning of tubering and tuber filling). Results showed that by iron nano oxide application, nitrate content of tuber decreased significantly and the least value was acquired in the interaction of spraying with 1.5 and 2 percent of iron nano oxide during tuber filling. The most leaf chlorophyll and average tuber weight was acquired in the interaction of spraying with 1, 1.5 and 2 percent during tuber filling and the most protein percentage of tuber by spraying with 1.5 and 2 percent of iron nano oxide during this period. Iron nano oxide levels of 1, 1.5 and 2 percent and spraying during tuber filling had the most tuber yield with a significant difference compared to other treatments. Additionally the application of normal iron oxide significantly increased tuber yield compared to control while it was in the same group with iron nano oxide levels of 0.5 and 1 percent. Regarding all traits measured, iron nano oxide concentration of 2 percent by spraying during tuber filling indicated the best result and is recommended to farmers.