Citrus stem end rot

Phomopsis citri

Symptoms:

  • Lesions: Affected fruits typically exhibit lesions or decay at the blossom end. The affected area becomes sunken, dark brown to black, and may extend into the fruit flesh.

  • Texture: The decayed tissue often has a mushy or watery texture, and in advanced stages, the decay can spread throughout the fruit.

2. Causal Agents:

  • Phomopsis citri: This fungus is one of the common causal agents of citrus stem end rot. It can infect citrus fruits during the postharvest period, especially under conditions of high humidity.

  • Lasiodiplodia theobromae: Another fungus associated with citrus fruit rot, causing decay at the stem end of the fruit.

3. Conditions Favoring Disease Development:

  • Humidity: High humidity levels during storage and transportation can create conditions conducive to the development of citrus stem end rot.

  • Injury: Fruits with wounds or injuries are more susceptible to infection. Damage during harvesting, handling, or transportation can provide entry points for pathogens.

4. Prevention and Management:

  • Proper Harvesting: Harvest fruits carefully to minimize injuries. Avoid dropping or causing mechanical damage to the fruits during the harvesting process.

  • Postharvest Handling: Implement good postharvest practices, including proper storage conditions with controlled humidity levels. Prompt cooling of fruits can also help reduce the risk of decay.

  • Fungicide Applications: In some cases, postharvest fungicide treatments may be applied to reduce the development of stem end rot. These treatments are often part of a comprehensive postharvest disease management program.

  • Sanitation: Keep storage and packing areas clean and free of decaying fruits, as this can help reduce the inoculum of the pathogens.

  • Temperature Management: Maintain proper storage temperatures to slow down the growth of fungi and reduce the incidence of decay.