Sclerotinia stem rot

Sclerotinia sclerotiorum:

Sclerotinia sclerotiorum is a fungal pathogen that causes diseases commonly known as white mold or Sclerotinia stem rot. It affects a wide range of crops, including vegetables, oilseeds, and ornamentals. The pathogen is known for producing sclerotia, which are hard, survival structures enabling it to persist in the soil and debris.

Hosts:

1. Oilseed Crops: Sclerotinia stem rot is a significant concern in crops like soybeans and sunflowers.
2. Vegetables: Various vegetables, including lettuce, carrots, and beans, are susceptible to white mold.
3. Ornamental Plants: Certain ornamental plants can also be affected.

Symptoms:

1. White Mold: The disease is characterized by the development of a white, cottony mold on infected plant tissues.
2. Lesions: Lesions may appear on stems, leaves, and sometimes on flowers.
3. Sclerotia Formation: The pathogen produces small, hard, black sclerotia that can survive in the soil.

Identification:

1. White Cottony Growth: The presence of the characteristic white mold on plant tissues is a key identification feature.
2. Sclerotia: Detection of small, hard, black sclerotia in or on infected plant tissues or soil.

Management:

Cultural Practices:

1. Crop Rotation: Rotate crops to reduce the risk of disease buildup in the soil.
2. Spacing: Ensure proper plant spacing for good air circulation and reduced humidity.
3. Avoid Overhead Irrigation: Minimize leaf wetness, as the pathogen thrives in moist conditions.

Fungicide Application:

1. Foliar Fungicides: Application of fungicides, especially during periods of high humidity, can help manage white mold.
2. Timing: Fungicides are often more effective when applied preventatively or at the early stages of disease development.

Resistant Varieties:

1. Plant Resistant Varieties: Utilize plant varieties that are bred for resistance or tolerance to Sclerotinia sclerotiorum.

Sanitation:

1. Remove Infected Residues: Collect and destroy infected plant residues to reduce the overwintering source of the pathogen.

Regular Monitoring:

1. Scouting for Symptoms: Regularly monitor crops for early symptoms of white mold, especially during conditions conducive to disease development.

Post-Harvest Measures:

1. Proper Storage: Ensure proper storage conditions for harvested crops to minimize the risk of post-harvest infections.