Botrytis cinerea is a fungus that causes a commercially damaging disease in strawberries, known as Botrytis rot or gray mold.
The disease can infect strawberries in the field, as well as during transportation, can invade storage rooms, and can induce problems in the marketing of strawberry fruits.
Gray mold must be controlled during bloom and harvest periods, especially in cloudy, rainy, and cool weather temperatures.
During all stages of strawberry fruit development, gray mold may be present. The first symptoms appear as light brown lesions on the stem end of the fruit due to flower infection. Infected strawberries are usually covered with a fuzzy gray-brown coat of mold. Fruits that are completely rotted become dry and mummified.
- Exceeding the rate of use and application of certain fungicides during the propagating phase results in resistant populations and poor control with these fungicides in fruit production.
- Dense cultivation can higher the risk of getting gray mold problems.
- Plant in raised beds increases airflow resulting in lower disease levels.
- Manage plant spacing, for better disease management.
- Avoid over-fertilization, and schedule fertilizer programs according to plant stage.
- Avoid exceeding nitrogen use has shown a big effect on increasing gray mold especially when favorable weather conditions.
- Drip irrigation eliminates higher humidity levels.
- Removal of dead leaves and tissues may be beneficial in early spring, just prior to the bloom cycle.
- Infected berries should be removed while harvesting, to no risk of having infections in a storage room or transportation.
Well-timed sprays at first bloom are the most effective controlling gray mold disease. Multiple fungicides are well targeted to limit flower infection.
By Eng. Roy Ayek