Air
Explanation
Citrus canker is a highly contagious plant disease caused by the bacterium Xanthomonas citri. It affects all types of citrus trees, including lime, oranges, and grapefruits, leading to significant economic losses in agriculture.
Detailed Analysis:
- Mode of Transmission: According to standard biological classifications, the primary mode of transmission for Citrus canker is Air. The bacteria are spread from tree to tree by wind, rain splash, and overhead irrigation. Wind-driven rain is the most critical factor in the natural spread of the pathogen over short distances.
- Mechanism: The bacteria enter the plant tissues through natural openings (stomata) or wounds caused by insects or mechanical damage. Once inside, they multiply and cause characteristic lesions.
- Symptoms: The disease manifests as raised, corky, crater-like lesions on leaves, stems, and fruits. These lesions can cause leaf fall and premature fruit drop.
Key Takeaway:
Citrus canker is a bacterial disease primarily transmitted through air (wind and rain splash).