Survey of N and population on spud fertilizer uptake and protein

In order to the study of the Influence of nitrogen and population on spud N uptake and protein, a factorial experiment based on randomized complete block design was carried out in Ardabil region in 2009 with three replications. Factors were nitrogen fertilizer levels (0, 80, 160 and 200 kg/ha nitrogen) and plant densities (5.5, 7.5 and 11 plant/m2). Results showed that most N uptake by plant aerial parts were observed at 200 kg ha-1 nitrogen, 11 plant m-2 and 200 kg ha-1 nitrogen, 5.5 plant m-2, respectively. With increasing nitrogen application up to 160 kg ha-1, N uptake by tuber, number of tuber, tuber dry weight and mean tuber weight was increased. The highest number, dry weight and yield of tuber and protein yield per unit area and the lowest mean tuber weight and protein percent per plant were achieved in population of 11 plant/m2. With increasing nitrogen application up to 80 kg/ha, number, dry weight, yield and protein content of tuber per unit area and mean tuber weight per plant, were increased. So, utilization of 80 kg/ha net nitrogen to achieve highest yield and lowest nitrate accumulation, 11 plant/m2 to gain seed tuber according to reducing tuber weight and size and 7.5 plant/m2 to eating utilizations, is recommended.