Iron-deficiency symptoms are observed on some genotypes of potato (Solanum tuberosum L.) grown on high-pH and calcareous soils. seven potato cultivars differing in response to iron deficiency chlorosis (FeDC) were grown on high-pH (8.1), calcareous (38% calcium carbonate equivalent in surface 20 cm) and silty clay soil in the field (Beka'a Valley, Lebanon), to determine the effects of FeDC on tuber yield of cultivars sprayed with Fe. A significant interactions between cultivars and Fe spray treatment were noted for visual FeDC ratings and tuber yield. Even though only slight FeDC was noted on some cultivars receiving no Fe spray, tuber yields were significantly increased when sprayed with Fe. Some cultivars with moderate FeDC ratings did not show a significant increase in yield when sprayed with Fe while other cultivars did. Sprayed cultivars generally produced higher tube; yields than unsprayed ones. Indicating that Fe-deficiency chlorosis in the Mediterranean region may be a serious limitation to potato tuber yield.