Botrytis cinerea, couramment appelé pourriture grise ou moisissure grise, est un champignon qui provoque une maladie nuisible chez les fraises au niveau commercial.
La maladie peut infecter les fraises dans le champ ou pendant leur transport. Elle peut envahir les salles de stockage et causer des problèmes qui affectent la commercialisation des fraises. La moisissure grise doit être contrôlée pendant les périodes de floraison et de récolte, surtout lorsque le temps est nuageux, pluvieux et plus ou moins froid.
Gray mold must be controlled during bloom and harvest periods, especially in cloudy, rainy, and cool weather temperatures.
Symptômes
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.
Management
- 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.
Fungicide recommendation
Well-timed sprays at first bloom are the most effective controlling gray mold disease. Multiple fungicides are well targeted to limit flower infection.
- Luna Sensation is the most innovative fungicide used to prevent Botrytis rot in strawberries (at the flowering stage) and extends the shelf-life post-harvest.
- Nativo WG provides good control of Botrytis rot while controlling another range of diseases (Rusts, leaf spots, powdery mildew)