Impact of some organic acids on correcting iron chlorosis in two soybean genotypes grown in calcareous soil

Iron chlorosis is widespread in many plants grown in calcareous soil and induces economic losses in crop production. In Egypt, this phenomenon commonly occurs, particularly in the north-western coastal zones adjacent to the Mediterranean Sea. The remedy of iron chlorosis is accordingly crucial. Two experiments were carried out in a greenhouse to evaluate some organic acids for enhancing the Fe status and correcting iron chlorosis in two soybean genotypes. Results showed that the ameliorative effect of organic acids depends on its type, level added, soybean genotype and Fe levels. Citric and salicylic acid were more pronounced in improving the dry matter, chlorophyll content, ferrous leave content, Fe and Zn uptake by two soybean genotypes. Therefore, they were better suited for iron chlorosis recovery than caffeic acid. Also, salicylic and citric acid increased Fe-59 content in shoot and the percentage of Fe derived from fertilizer (y% for crawford and clark genotype, respectively.