How to recognize and correct calcium deficiency in fruit

Calcium deficiency, or blossom-end rot, is a physiological disorder that occurs when the fruit does not receive enough calcium in its developing tissues, even if the soil contains seemingly adequate amounts. Calcium is relatively immobile within the plant, and its transport depends primarily on the flow of water to the tissues. Therefore, any situation that reduces or alters transpiration and water movement can contribute to the problem. Roots absorb calcium from the soil solution, and this calcium is transported mainly by the xylem to the aerial parts of the plant. During periods of rapid fruit growth, the demand for calcium increases, and imbalances can occur when the supply does not keep pace with development. Water stress, sudden fluctuations in soil moisture, excessive salinity, root damage, high concentrations of other cations that interfere with calcium absorption, and certain environmental conditions can all reduce the amount of calcium reaching the fruit. The problem is especially common when there is rapid fruit growth accompanied by an irregular water supply, since calcium cannot be easily redistributed from the leaves and other organs to the areas with the greatest need. For this reason, there is no infection, reproduction, or propagation phase typical of a pathogenic organism, but rather a gradual onset of the disorder when physiological and environmental conditions hinder the delivery of calcium to the young fruit tissues.