Canker

Causal organism – Xanthomonas bilvae

Symptoms:

  • Small, round, brown, water-soaked spots appear on the leaves.
  • Spots are initially < 1 mm but enlarge to 3–5 mm, turning brown, concave, with a slightly raised oily margin.
  • In severe cases, necrosis causes shot holes in the lamina, and the infection may spread to fruits, twigs, and thorns.
  • On fruits, small, circular, greyish, oily, water-soaked spots develop. These gradually enlarge, forming raised margins and eventually acquiring a cankerous appearance.

Management-  

Cultural MethodChemical Control
Remove and destroy all infected plant parts followed by spraying with Bordeaux mixture. Spray of Streptomycin Sulphate 90% + Tetracycline Hydrochloride 10% @ 0.2g/L dissolved in water fortnightly to control the disease.Spraying Bordeaux mixture 1:1:100