The effects of nitrogen, molybdenum, and cobalt application on pod yield and nutrient content of bean leaf (Phaseolus vulgaris L.)

Elements such as nitrogen (N), molybdenum (Mo), and cobalt (Co) are needed to improve the quantity and quality of beans. In order to study the effects of these elements on pod yield and concentration of nutrients in bean, a factorial pot experiment was conducted in 2016 in greenhouse conditions at University of Zanjan, using a CRD with three replications. The experimental factors consisted of four levels of N (50, 100, 150, and 200 mg/l), three levels of Mo (0.067, 0.2, and 0.6 mg/l), and Co (0.006, 0.06, and 0.3 mg/l). The results showed that the highest dry weight of pods was obtained from treatment of N100Mo0.2Co0.06 which was 34.05 g/pot and had no significant difference with N150Mo0.6Co0.06 treatment. The application of different levels of factors increased the concentrations of N, P, and Mg in bean leaves in treatments of N200Mo0.6Co0.3, N200Mo0.6Co0.006, and N150Mo0.6Co0.3 and the highest increase in concentrations of mentioned elements were 6.94, 0.91, and 0.41% respectively. However, the concentrations of K and Ca decreased as a result of the application of the factors. The highest concentrations of Fe, Mn, Cu, Mo, and Co bean were measured in treatments of N200Mo0.6Co0.006, N150Mo0.2Co0.006, N200Mo0.6Co0.3, N150Mo0.6Co0.3, and N150Mo0.067Co0.006 which were 490, 185.4, 8.26, 284.5, and 54.9 mg/kg, respectively. Overall, according to the results, N100Mo0.2Co0.06 is recommended for bean.