Sclerotinia Symptoms in Lettuce: What You Need to Know

When it comes to lettuce production, Sclerotinia symptoms can be a major problem. This disease is caused by the fungus Sclerotinia sclerotiorum, which can infect a wide range of crops including lettuce, beans, and sunflowers. If you are a lettuce grower, it is important to understand what Sclerotinia is and how to recognize its symptoms.

What is Sclerotinia?

Sclerotinia is a fungal disease that can cause significant damage to lettuce plants. The fungus produces hard, black structures called sclerotia, which survive in soil for up to five years. These sclerotia can germinate and infect susceptible plants when conditions are favorable. Sclerotinia is favored by wet conditions and moderate temperatures, making it a common problem in many regions.

Symptoms of Sclerotinia in Lettuce

The symptoms of Sclerotinia in lettuce can be difficult to detect, especially in the early stages of infection. However, there are some key signs to look out for:

1. Water-soaked lesions on leaves: These will appear as small, water-soaked spots on the leaves of lettuce plants. As the disease progresses, the spots will enlarge and become necrotic (brown or black).
2. Stem rot: Sclerotinia can also infect the stem of lettuce plants, causing it to rot and become mushy.
3. White, cottony growth: In humid conditions, the fungus may produce a white, cottony growth on infected plant parts. This growth may also contain black sclerotia.

Preventing and Managing Sclerotinia in Lettuce

Preventing and managing Sclerotinia in lettuce requires a combination of cultural practices and fungicides. Here are some tips:

1. Plant resistant varieties: Some lettuce varieties are more resistant to Sclerotinia than others. Check with your local extension office or seed supplier for recommendations.
2. Practice crop rotation: Because Sclerotinia can survive in soil for several years, it is important to rotate crops to reduce the build-up of sclerotia.
3. Avoid overhead irrigation: Wet leaves provide ideal conditions for Sclerotinia to thrive. Instead, use drip irrigation or other methods that keep leaves dry.
4. Apply fungicides: Fungicides can help prevent Sclerotinia from infecting lettuce plants. Be sure to follow label instructions carefully.

Healthy Lettuce plants in a garden

The Bottom Line

Sclerotinia can be a serious problem for lettuce growers, but with proper management, it can be controlled. By understanding the symptoms of Sclerotinia and taking steps to prevent its spread, you can help ensure a healthy harvest of lettuce plants.

Lettuce diseases, Sclerotinia, plant pathogens, crop protection, lettuce production