White blisters are usually a sign of fungal or bacterial infection, which can be detrimental to your seedlings' health. Here are some steps you can take to address this issue:
Identify the cause: Examine the white blisters closely to determine if they are a symptom of a specific disease or infection. Common culprits include powdery mildew, white mold, and downy mildew.
Improve air circulation: Ensuring proper airflow around your seedlings can help reduce humidity and the likelihood of fungal or bacterial infections. Space your plants adequately, and consider using a fan to promote air circulation.
Monitor temperature and humidity: Keeping the environment around your seedlings at the optimal temperature and humidity can help minimise the risk of infections. Generally, seedlings thrive in temperatures ranging from 18°C to 24°C. Use a hygrometer to monitor humidity levels and aim to keep them below 70%.
Water correctly: Overwatering can create a damp environment that promotes fungal growth. Water your seedlings sparingly and avoid wetting the foliage. Watering from the bottom can help prevent water from splashing onto the leaves.
Sanitise tools and containers: Clean and sanitise all gardening tools, pots, and trays to prevent the spread of disease. Use a solution of 1 part bleach to 9 parts water to disinfect the tools and surfaces.
Use fungicides or organic treatments: Apply fungicides or organic treatments, such as neem oil or potassium bicarbonate, according to the product instructions, to control the infection.
Remove infected plants: If the infection is severe, it might be necessary to remove and dispose of infected seedlings to prevent the disease from spreading to healthy plants.
