Compositional Nutrient Diagnosis (CND) Norms and Indices for Potato ( Solanum tuberosum L.)

A survey was conducted in potato fields for collection of leaf samples to establish nutrient concentration yield data bank. The data bank was used for developing multivariate compositional nutrient diagnosis (CND) norms for assessing the nutritional status of selected centres of potato growing fields. The mean N, P and K concentrations were 2.09, 0.25 and 4.16 %, respectively. The mean Ca (1.11%) concentration was twice higher compared to Mg (0.63 %) concentration. The mean values of Zn, Cu, Fe, Mn and B were 43.69, 31.24, 986.71, 192.76 and 59.98 ppm, respectively. The CND norms for V_N, V_P and V_K were 3.04, 0.94 and 3.73, respectively. The norm for Ca (V_Ca=2.45) and Mg (V_Mg=1.78) were much narrower compared to the absolute nutrient concentration. The norm for V_Zn, V_Cu, V_Fe, V_Mn and V_B were -3.24, -3.60, -0.23, -1.98 and -2.89respectively. The multivariate CND norms developed for ten nutrients proved to be an important tool for diagnosis of nutrient imbalance in potato. The nutrient indices developed indicated that Zn was the most common yield-limiting nutrient. The CND norms and the indices developed can be used for identifying the hidden hunger of various nutrients in potato for evolving nutrient management strategies.