| چکیده انگلیسی مقاله |
Determining deviation from optimum percentage (DOP) index and diagnostic recommendation integrated system (DRIS) index for evaluation of nutritional status of onion (Allium cepa L.) and also for comparison of these two procedures, leaf samples were collected from 50 fields and N, P, K, Ca, Mg, Fe, Mn, Zn, Cu and B concentrations were determined. On the bases of crop yield, the fields were divided into two groups with low and high yielding populations. DRIS norms were determined for the different nutrients ratios. DRIS indices were calculated to evaluate nutrients balances. The optimum concentrations as reference values were used for the calculating of DRIS indices. The optimum nutrients concentrations in leaf were calculated from relationships between DRIS index and nutrient concentrations considering the fitted models show points where the DRIS indices are equal to zero. The optimum macro nutrient concentrations were, 2.94, 0.27, 4.40, 1.82, and 0.25 % N, P, N, Ca, Mg, and for micro nutrients107, 50, 18, 13, 27 mg/kg for Fe, Mn, Zn, Cu, B, respectively.. On the bases of DRIS indexe means, the respective for requirement of micro nutrients and macro nutrients were Cu>Ca>K=Mn>P>B>Mg>Zn>N>Fe in low yielding farms. On the bases Means of DOP indexes, the respective for requirement of micro nutrients and macro nutrients were Ca>K>Cu>P>B>Mn>Mg>N>Fe>Zn in low yielding farms. Comparison of the DRIS indices for macro and micro nutrients with the DOP indices revealed that Ca, K and Cu were the most deficient elements in all low-yielding fields showing that both methods provide similar information in the interpretation of results of leaf analysis. To validate DRIS norms and verify the efficiency of DRIS and DOP as methods for improving the interpretation of analysis results of leaf, the fertilizer experiments should be conducted on onions in a low-yielding field. |