Step 1: Understanding black rot in cabbage.
Black rot, a severe bacterial disease caused by Xanthomonas campestris pv. campestris, significantly impacts crucifer crops, leading to substantial reductions in head quality and yield.
Step 2: Resistant variety selection.
- Pusa Mukta has been specifically developed to resist black rot. - Pusa Ageti and Pusa Drum Head are widely used but lack black rot resistance. - September is also a non-resistant variety.
Step 3: Conclusion.
Therefore, Pusa Mukta is the identified black rot resistant cabbage variety.
Final Answer: \[\boxed{\text{Pusa Mukta is resistant to black rot disease.}}\]