Model Answer
0 min readIntroduction
Bunchy Top disease is a devastating viral disease affecting banana plants worldwide, particularly impacting the livelihoods of millions of farmers in South Asia. The disease is characterized by the production of numerous, small, non-productive inner leaves (creases) and a stunted plant growth. It is caused by the Banana Bunchy Top Virus (BBTV), transmitted through infected suckers and the banana aphid, *Pentalonia proxima*. Its prevalence poses a significant threat to banana production, necessitating effective management strategies. This response will outline the diagnostic symptoms, transmission mechanisms, and management practices for this critical agricultural concern.
Diagnostic Symptoms of Banana Bunchy Top Disease
The symptoms of Bunchy Top disease typically appear 6-12 months after infection. They progress gradually, and early detection is crucial for effective management.
- Creases: The most characteristic symptom is the proliferation of numerous, small, narrow, and crowded inner leaves. These are known as “creases.”
- Stunted Growth: Infected plants exhibit significantly reduced height and overall growth.
- Absence of Fruit: The plant fails to produce marketable bunches of bananas.
- Dark Green Leaves: The leaves are often a dark green color and may be slightly curled.
- Short Internodes: The distance between nodes (internodes) is reduced.
Mode of Transmission
BBTV is transmitted primarily through two routes:
- Vegetative Propagation: The virus is easily transmitted through infected suckers (daughter plants) during replanting. This is the most common mode of transmission.
- Banana Aphid (Pentalonia proxima): This tiny aphid acts as a vector, carrying the virus from infected plants to healthy ones. A single aphid can transmit the virus for its entire lifespan.
Management Practices
Effective management requires an integrated approach.
| Practice | Description |
|---|---|
| Quarantine & Eradication | Destruction of infected plants and surrounding plants (ring-fencing) to prevent further spread. |
| Use of Virus-Free Suckers | Planting only suckers from certified, disease-free sources. Tissue culture planting material is preferred. |
| Vector Control | Controlling banana aphid populations through insecticides (e.g., Imidacloprid) and biological control agents (e.g., parasitoids). |
| Roguing | Regularly inspecting fields and removing any suspected infected plants. |
| Crop Rotation | Rotating banana crops with non-host plants can help break the disease cycle. |
Government Initiatives
The Indian government promotes disease-free planting material through schemes like the National Mission on Sustainable Agriculture (NMSA), which encourages the use of tissue culture banana plants and integrated pest management practices. The Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) also supports irrigation infrastructure to enhance banana cultivation.
Case Study: Kerala’s Bunchy Top Control Program
Kerala, a major banana-producing state in India, has implemented a rigorous Bunchy Top control program. The program involves strict quarantine measures, distribution of virus-free suckers, and farmer training on disease identification and management. Regular surveillance and rapid response are key components. Despite challenges, the program has significantly reduced disease incidence in certain regions.
Conclusion
Bunchy Top disease presents a significant challenge to banana cultivation globally. Early detection, integrated management practices involving quarantine, vector control, and the use of virus-free planting material are crucial for mitigating its impact. Continuous research into BBTV and its vectors, coupled with farmer education and government support, is essential for sustainable banana production. A proactive and coordinated approach is vital to safeguard this important crop.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.