Neck rot

Botrytis allii refers to a species of fungus that causes the disease commonly known as neck rot in onions and other Allium crops. Here is an informative description of Botrytis allii, including its appearance, identification, and management:

Botrytis allii:

Appearance: Botrytis allii primarily affects Allium crops, such as onions, garlic, leeks, and shallots. The disease manifests as a rotting of the neck or bulb tissue. Initially, infected tissues may appear water-soaked or have a brown discoloration. As the disease progresses, a fuzzy gray mold develops on the affected tissues, giving it a characteristic appearance. The infected bulbs may become soft and show signs of decay.

Identification:

1. Neck Rot: The most characteristic symptom is the rotting of the neck or bulb tissue, usually starting at the top of the bulb.
2. Water-Soaked Appearance: Initially, infected tissues may exhibit a water-soaked appearance, which can progress to a brown discoloration.
3. Gray Mold: Fuzzy gray mold develops on the affected neck or bulb tissues, especially under high humidity conditions.
4. Soft Bulbs: Infected bulbs may become soft and show signs of decay, affecting their overall quality.

Management:

1. Cultural Practices:

   • Proper Spacing: Ensure proper spacing between plants to improve air circulation and reduce humidity around the plants.
   • Avoid Overhead Irrigation: Minimize moisture on plant surfaces by using drip irrigation or watering at the base of the plants. This helps create conditions less favorable for fungal development.

2. Sanitation:

   • Remove Infected Plant Material: Promptly remove and destroy infected plant material, including bulbs and debris, to reduce the inoculum source.

3. Fungicide Application:

   • Copper-Based Fungicides: Copper-based fungicides may help in managing Botrytis allii. Consult with local agricultural experts for recommended fungicides and application schedules.

4. Storage Conditions:

   • Proper Storage: Store harvested bulbs under dry and well-ventilated conditions to minimize the risk of fungal growth.

5. Resistant Varieties:

   • Plant Resistant Varieties: Where available, consider planting onion or Allium varieties that are known to be resistant to Botrytis allii.