Late leaf spot

Causal Agent:

• Fungal Pathogen: Cercospora personata is a fungal pathogen that causes Cercospora leaf spot, primarily affecting various leguminous crops.

2. Host Range:

• Leguminous Crops: The pathogen commonly infects leguminous plants, including soybeans (Glycine max), peas (Pisum sativum), and other related species.

3. Symptoms:

• Leaf Lesions: Initial symptoms manifest as small, angular lesions on the leaves.
• Lesion Color: Lesions progress to tan or light brown, often with a reddish-purple border.
• Coalescence: Lesions may coalesce, leading to extensive blighting of the foliage.

4. Disease Cycle:

• Survival: The fungus can survive in infected crop residues, acting as a source of inoculum for subsequent infections.
• Infection: Infection occurs through spores (conidia) produced on infected plant material or within pycnidia (fruiting bodies).
• Spread: Conidia are dispersed by wind, rain, or physical contact, initiating new infections on healthy plants.
• Favorable Conditions: Warm and humid conditions promote disease development.

5. Identification:

• Angular Leaf Spots: Identification involves recognizing the angular lesions with a characteristic tan to light brown color.
• Purple Border: The reddish-purple border around the lesions is a distinguishing feature.
• Microscopic Examination: Microscopic examination may reveal the presence of conidia and pycnidia.

6. Management:

• Resistant Varieties: Planting crop varieties with some level of resistance to Cercospora personata is an effective strategy.
• Crop Rotation: Avoiding consecutive cultivation of leguminous crops in the same field can help reduce the pathogen's survival.
• Fungicide Applications: Fungicides may be applied preventively or curatively, especially during periods of high disease pressure.
• Sanitation: Proper removal and destruction of infected crop residues can reduce the source of inoculum.

7. Importance:

• Economic Impact: Cercospora leaf spot caused by Cercospora personata can result in reduced yields and affect the quality of leguminous crops.
• Global Distribution: The pathogen is found in regions where susceptible crops are cultivated.