Which of the following fungi is found useful in the biological control of plant disease

Options

A. Mucor
B. Trichoderma
C. Penicillium notatum
D. Phytophthora

Answer

To answer the question "Which of the following fungi is found useful in the biological control of plant disease?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Options**: The question presents several fungi as options. We need to evaluate each one to determine which is useful in biological control.

2. **Evaluate Mucor**:
- Mucor is a type of black bread mold that belongs to the class Phycomycetes and the group Zygomycetes.
- It is primarily a saprophytic fungus and does not play a role in biological control as it can also act as a parasite.
- **Conclusion**: Mucor is not used for biological control.

3. **Evaluate Trichoderma**:
- Trichoderma species are known for their beneficial role in agriculture.
- They inhabit the root ecosystems of various plants and help curb plant pathogens by secreting certain chemicals.
- Trichoderma is actively used in integrated pest management programs alongside bacteria and viruses to promote organic farming.
- **Conclusion**: Trichoderma is useful in biological control of plant diseases.

4. **Evaluate Penicillium notatum**:
- Penicillium notatum is famous for being the source of the antibiotic penicillin.
- While it has significant medical importance, it does not have a role in biological control of plant diseases.
- **Conclusion**: Penicillium notatum is not used for biological control.

5. **Evaluate Phytophthora**:
- Phytophthora is a pathogenic fungus known for causing diseases such as late blight in potatoes and tomatoes.
- It is not beneficial for biological control; rather, it is harmful to plants.
- **Conclusion**: Phytophthora is not used for biological control.

6. **Final Answer**: Based on the evaluations, the only fungus that is useful in the biological control of plant diseases is **Trichoderma**.