Fight against gray mold

What is gray mold? Gray mold, mainly caused by the fungus Botrytis cinerea, is a very common disease. A gray downy growth covers affected buds, flowers, or fruits. If left unchecked, the disease can then spread throughout the plant. Small black structures, called sclerotia, are sometimes found, which are the fungus's storage organs. These can survive in the soil for up to 5 years! Under what conditions does gray mold appear? Botrytis is a saprophytic fungus that generally feeds on dead tissue. However, it can attack healthy plants under certain conditions. Injuries and stress are entry points for the disease. Flowers and fruits are mainly affected when they grow in humid conditions. Gray mold can appear throughout the year! Humid, mild weather with temperatures between 15-20°C are ideal for it. In some plants, such as strawberries, botrytis can act latently. It enters through the flowers and colonizes the developing fruit. Symptoms are then only visible when the fruit begins to ripen...and rot. Which plants are affected? This disease is frequently found on shrubs and small fruits such as apples, grapes, strawberries, blackcurrants, raspberries, and gooseberries. It also affects vegetable plants (cucumbers, peas, squash, eggplants, lettuce, tomatoes, etc.) and ornamental plants (dahlias, roses, hydrangeas, pelargoniums, cyclamens, etc.). How to combat gray mold? Space them out. Sow or plant plants well apart to promote air circulation. Do not leave any dead plant debris (fallen leaves, fruit, etc.) or contaminated plant debris nearby. Quickly remove affected leaves, buds, and flowers. Do not put them in the compost. Rotate: Sclerotia can be stored in the soil for 5 years and could contaminate future crops. Avoid watering at the end of the day, as humidity levels will remain high throughout the night and encourage fungal attack. Watering is best done early in the morning, as humidity will decrease more quickly during the day. Make clean cuts when pruning. Also, always place the blade of the tool (pruning shears, pruning shears, etc.) on the side of the plant for a better cut. Boost your plants' defenses with decoctions of horsetail, comfrey, nettle, and fern purines.