Black rot of mustard is caused by

Options

A. Colletotrichum falcatum
B. Xanthomonas oryzae
C. Xanthomonas campestris
D. Phytophthora infestans

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the causative agent of black rot in mustard plants. This is a specific plant disease that affects mustard and other cruciferous crops.

2. **Identifying the Disease**: Black rot is a significant disease that affects crucifer crops, which include mustard. It is important to know the pathogen responsible for this disease.

3. **Researching the Pathogen**: To answer the question, we need to identify the pathogen. Black rot of mustard is known to be caused by a specific bacterium.

4. **Naming the Pathogen**: The bacterium responsible for black rot of mustard is Xanthomonas campestris. This bacterium is known for causing various plant diseases, particularly in crops belonging to the family Brassicaceae (crucifers).

5. **Conclusion**: Based on the information gathered, the correct answer to the question is that black rot of mustard is caused by Xanthomonas campestris.

**Final Answer**: Black rot of mustard is caused by **Xanthomonas campestris**.

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