Phytophthora infestans causes

Options

A. Early blight of Potato
B. Late blight of Potato
C. Green ear of Bajra
D. Downy mildew.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**:
- The question asks about the disease caused by *Phytophthora infestans*.

2. **Identifying the Options**:
- The options provided are:
- A) Early blight of potato
- B) Late blight of potato
- C) Green ear of Bajra
- D) Downy mildew

3. **Analyzing Each Option**:
- **Option A: Early blight of potato**:
- This disease is caused by the fungus *Alternaria solani*, not *Phytophthora infestans*. Therefore, this option is incorrect.

- **Option B: Late blight of potato**:
- This disease is specifically caused by *Phytophthora infestans*. Hence, this option is correct.

- **Option C: Green ear of Bajra**:
- This disease is caused by the fungus *Sclerospora graminicola*, which is different from *Phytophthora infestans*. Thus, this option is incorrect.

- **Option D: Downy mildew**:
- This is also caused by *Sclerospora graminicola*, similar to the green ear of Bajra. Therefore, this option is incorrect.

4. **Conclusion**:
- The correct answer is **B) Late blight of potato**, as it is the only disease listed that is caused by *Phytophthora infestans*.