Canker: Xanthomonas campestris pv citri
Symptoms
- Acid lime, lemon and grapefruit are affected. Rare on sweet oranges and mandarins.
- Affects leaf, twig and fruits. In canker, leaves are not distorted.
- Lesions are typically circular with yellow halo; appear on both sides of leaf, severe in acid lime (difference from scab) When lesions are produced on twigs, they are girdled and die.
- On fruits, canker lesions reduce market value.
Management
- Streptomycin sulphate 500-1000 ppm; or Phytomycin 2500 ppm or Copper oxychloride 0.2% at fortnight intervals.
- Control leaf miner when young flush is produced.
- Prune badly infected twigs before the onset of monsoon
| Initial symptom on leaves | Advanced symptom |