Phoma rot

Phoma destructiva

Appearance:

Phoma destructiva is a fungal pathogen that causes a disease known as Phoma stem canker in various crops, including oilseed rape (canola). The disease primarily affects the stems and pods of the plant. The characteristic symptoms include the formation of elongated, dark brown to black lesions on the stems. These lesions often have a sunken appearance and may be surrounded by a pale margin. As the disease progresses, the affected stems can become brittle, leading to lodging and reduced yield.

Identification:

  1. Lesions on Stems: Look for elongated lesions on the stems of oilseed rape plants. These lesions are often dark brown to black in color.
  2. Sunken Appearance: Lesions may appear sunken, and the affected areas can become brittle.
  3. Pale Margin: Lesions are often surrounded by a pale margin, providing a distinctive appearance.
  4. Pod and Seed Infection: In advanced stages, the disease can spread to pods and seeds, affecting the overall quality of the crop.

Management:

  1. Cultural Practices:

    • Crop Rotation: Implement a proper crop rotation strategy to reduce the buildup of the pathogen in the soil.
    • Adequate Spacing: Plant crops with adequate spacing to promote air circulation and reduce humidity around the plants.

  2. Fungicide Application:

    • Fungicidal Sprays: Application of fungicides, especially those effective against Phoma destructiva, can be part of an integrated disease management strategy. Consult with local agricultural experts for recommended fungicides and application schedules.

  3. Resistant Varieties:

    • Plant Resistant Varieties: Where available, consider planting oilseed rape varieties that are known to be resistant or tolerant to Phoma stem canker.

  4. Regular Monitoring:

    • Scouting Fields: Regularly monitor oilseed rape fields for early symptoms of Phoma stem canker, and initiate control measures promptly if symptoms are detected.

  5. Timely Harvest:

    • Harvest at the Right Time: Timely harvest can help reduce the risk of disease spread and minimize losses.

  6. Sanitation:

    • Remove Infected Crop Debris: Promote field cleanliness by removing and destroying infected crop debris.