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Questions and Answers
What characteristic distinguishes the conidia of Cercospora personata?
What characteristic distinguishes the conidia of Cercospora personata?
- It is elongated and lacks septa.
- It is larger than other conidia.
- It is uniformly rounded.
- It is septate and has 3-4 septa. (correct)
Which symptom is associated with early leaf spot infection caused by Cercospora arachidicola?
Which symptom is associated with early leaf spot infection caused by Cercospora arachidicola?
- Fungal growth on stems and seeds.
- Yellowing of the entire leaf.
- Brown-coloured round or oval spots. (correct)
- Large black spots with a yellow halo.
What is one method to manage early infections of tikka disease in groundnuts?
What is one method to manage early infections of tikka disease in groundnuts?
- Using Bordeaux mixture as a spray.
- Pruning infected parts of the plant. (correct)
- Planting new crops without treating the soil.
- Applying chemical pesticides directly to seeds.
Which control measure is effective for managing late tikka disease of groundnut?
Which control measure is effective for managing late tikka disease of groundnut?
What color are the lesions caused by Cercospora personata on infected groundnut leaves?
What color are the lesions caused by Cercospora personata on infected groundnut leaves?
What species of Cercospora is responsible for Early leaf spot in groundnut?
What species of Cercospora is responsible for Early leaf spot in groundnut?
Which morphological feature distinguishes Cercospora arachidicola from Cercospora personata?
Which morphological feature distinguishes Cercospora arachidicola from Cercospora personata?
What is the approximate yield loss in groundnut crops due to Tikka disease?
What is the approximate yield loss in groundnut crops due to Tikka disease?
Which of the following statements is true about the conidiophore of Cercospora arachidicola?
Which of the following statements is true about the conidiophore of Cercospora arachidicola?
Which crop is primarily affected by Tikka disease?
Which crop is primarily affected by Tikka disease?
What color are the conidia of Cercospora personata?
What color are the conidia of Cercospora personata?
What distinguishes Late leaf spot from Early leaf spot in terms of visual symptoms?
What distinguishes Late leaf spot from Early leaf spot in terms of visual symptoms?
How does Cercospora personata differ in its growth compared to Cercospora arachidicola?
How does Cercospora personata differ in its growth compared to Cercospora arachidicola?
Flashcards
Tikka Disease
Tikka Disease
A fungal disease affecting groundnut (peanut) plants, caused by two species of Cercospora fungi: C. arachidicola and C. personata.
Early Leaf Spot
Early Leaf Spot
Symptoms caused by Cercospora arachidicola, characterized by small, brown, round or oval spots with a yellowish halo on groundnut leaves.
Late Leaf Spot
Late Leaf Spot
Symptoms caused by Cercospora personata, characterized by large, dark black spots on leaves, stems, seeds, and shells of the groundnut plant.
Conidia
Conidia
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Conidiophore
Conidiophore
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Causal Organism of Tikka Disease
Causal Organism of Tikka Disease
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Mycelium of Cercospora arachidicola
Mycelium of Cercospora arachidicola
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Mycelium of Cercospora personata
Mycelium of Cercospora personata
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Haustoria of Cercospora arachidicola
Haustoria of Cercospora arachidicola
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Haustoria of Cercospora personata
Haustoria of Cercospora personata
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Study Notes
Tikka Disease of Groundnut
- Tikka disease, also known as leaf spot disease, is caused by two species of Cercospora: Cercospora arachidicola and Cercospora personata.
- It affects groundnut crops in many countries, including the US, China, and India.
- The disease can reduce crop yields by approximately 22%.
- Cercospora arachidicola causes early leaf spot, characterized by small, brown spots with yellow halos.
- Cercospora personata causes late leaf spot, characterized by numerous, larger, black spots which are more damaging.
Distribution
- The disease is widespread in tropical regions with significant groundnut production.
Morphological Features
-
Mycelium:
- C. arachidicola mycelium is dark brown and intracellular (grows inside plant cells).
- C. personata mycelium is brown/black, initially intercellular (between cells), then intracellular.
-
Haustoria:
- C. arachidicola lacks haustoria.
- C. personata has branched haustoria.
-
Conidiophore:
- C. arachidicola conidiophores are yellowish-brown, geniculated (bent), and septate (divided by cross-walls). They are 22–44 μm long and 3–5 μm wide.
- C. personata conidiophores are light brown, geniculated, and aseptate (no cross-walls). They are 25–54 μm long and 5–8 μm wide.
-
Conidia:
- C. arachidicola conidia are hyaline (pale yellow), cylindrical, and septate (with 1–12 septa). They are 38–108 μm long and 6–8 μm wide. The shape is truncate at the base and subtruncate at the apex.
- C. personata conidia are short, cylindrical, septate (3–4 septa), rounded at one end and tapered at the other. They are 18–60 μm long and 6–11 μm wide.
Symptoms
- Early leaf spot (C. arachidicola): Brown or oval spots with yellow halos.
- Late leaf spot (C. personata): Large, dark, black spots on leaves, stems, seeds, and shells.
Management
- Early infection management methods include:
- Crop rotation
- Eradication of infected plants
- Pruning infected parts
- Seed treatment with sulfuric acid or copper sulfate solution
- Seed dressing with Agrosan GN
- Late infection management relies on fungicides, like Bordeaux mixture.
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