Rapid correction of iron deficiency in peach trees by direct injection of ferrous sulfate into the trunk

Chlorosis caused by iron deficiency restricts the growth of plants on calcareous and alkaline soils. The aim of this study was to evaluate the effect of different application methods of FeSO4 on iron-deficient peach trees. The experiment was conducted for 2 years as a randomized complete blocks design with seven treatments including soil application (500 g tree−1), foliar spraying (0.5% solution, 21 liters tree−1) and trunk injection of 0%, 0.5%, 1%, 1.5% and 2% solutions of FeSO4 on eight-year-old trees. The application method had a significant effect on the characteristics of fruits and leaves. Injection of FeSO4 not only led to elimination of iron chlorosis by increasing chlorophyll and active iron contents of leaves but also increased fruit weight and volume, improved fruit yield and increased TSS content of fruits as compared to the control. On the other hand, soil and foliar application treatments did not have a significant effect on fruit weight, volume and yield. Foliar application increased the active iron content of the leaves but had no significant effect on their chlorophyll content. Based on the results, trunk-injection of FeSO4 is the most effective method for eliminating iron deficiency of peach trees on calcareous and alkaline soils.