Lime‐induced chlorosis still today places limits on cultivation and optimum production of many fruit tree species, even in only slightly calcareous soil. Research must, therefore, be directed towards new selections of rootstocks and/or cultivars tolerant of this abnormal soil condition. In addition, it is necessary to evaluate the possibility of adopting physiological parameters, such as root cation exchange capacity (CEC) for a rapid screening of new selections. This physiological indicator, when used together with other evaluation parameters, such as vigor, clorophyll and mineral content, allowed to obtain a reliable identification of the most tolerant rootstocks. The aim of the present work was, therefore, to assess whether this parameter can discriminate among Myrobalan clones and GF 677 rootstock as regards iron (Fe) efficiency. This method is based on the assumption that the root system is the plant component playing the most fundamental role in allowing Fe utilization.