Rotting of tomato’s ends is a sign of blossom-end rot, and is usually caused by calcium deficiency. Blossom-end rot develops when tomato’s demand for calcium outstrips the supply in the soil. This may be caused by low calcium level in the soil, excessive soil moisture or fluctuation due to overwatering.
A water-soaked spot at the blossom end of a tomato fruit is a typical symptom of blossom-end rot. The disease can also occur in other crops, including cucumber, melon fruits, pepper, eggplant and squash. This is essentially a physiological disorder as a result of calcium imbalance within the crop. When vegetables and fruits are unable to get sufficient calcium from the soil, the tissues on the blossom end of the fruit break down.
In some cases, calcium may be present in the soil, but is tied up in the soil chemistry because of very low pH. Similarly, drought stress and/or moisture fluctuations reduce uptake of calcium into the plant. In addition, excessive nitrogen fertilizer causes rapid vegetative growth, causing slow uptake and movement of calcium into the plant. Damage becomes visible when fruits are about half their full size. The water-soaked parts expand and become dark brown and leathery, then begin to rot.
Blossom-end rot is managed by maintaining a consistent level of moisture throughout the fruit’s growing season. Tomato Rot Stop may be used to prevent calcium deficiency. Keeping garden records helps in discovering crop varieties susceptible to blossom-end rot.