The smuts of crop plants are caused by

Options

A. Puccinia
B. Cystopus
C. Ustilago
D. Agaricus

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the cause of smuts in crop plants. Smuts are diseases that affect plants, particularly crop plants and grasses.

2. **Identifying the Nature of Smuts**: Smuts are fungal diseases characterized by the accumulation of fungal spores in soot-like masses, known as sori. These sori can form in various parts of the plant, including seeds, leaves, stems, flowers, and bulbs.

3. **Recognizing the Pathogen**: Smuts are caused by specific genera of fungi that act as obligate pathogens to plants. This means they rely on living plant tissues to grow and reproduce.

4. **Identifying the Correct Genus**: The genus responsible for causing smuts in crop plants is Eustylo. A specific example of a species within this genus is Ustilago, which is known to cause smut diseases in crops like maize, wheat, sugarcane, and sorghum.

5. **Evaluating the Options**: The options provided include various genera of fungi:
- **Option 1: Pikaenia** - Known for causing rust diseases.
- **Option 2: Cystopus** - Known for causing white rust.
- **Option 3: Eustylo** - Correct answer, as it causes smut diseases.
- **Option 4: Agaricus** - Known for edible and non-edible mushrooms.

6. **Conclusion**: Based on the information gathered, the correct answer to the question is **Option 3: Eustylo**.

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