Course Content
Common bunt of wheat
Angular leaf spot/ bacterial blight/boll rot/black arm of cotton
Rice tungro virus
Rice grassy stunt virus
Rice ragged stunt virus
Rice yellow dwarf disease
Learn crop diseases and their management with Braimy- B.Sc agriculture
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C/O: xanthomonas campestris pv malvacearum


Attack all stage of plant.

Seedling blight:

  • Small, water-soaked, circular or irregular lesions develop on the cotyledons.
  • Later, the infection spreads to stem through petiole and cause withering and death of seedlings.

Diseases of Cotton (GOSSYPIUM HIRSUTUM) and Management Strategies –

Angular leaf spot

  • Small dark green water soaked area developed on the lower surface of leaves.
  • Angular spot are restricted by vein and veinlet and spot are visible on both surface of leaf.
  • At lesion are older, they turn to radish brown color.

Bacterial Blight of Cotton | NC State Extension Publications

Vein blight or vein necrosis or black vein:

  • The infection of veins causes blackening of the veins and veinlets, gives a typical ‘blighting’ appearance. On the lower surface of the leaf, bacterial oozes are formed as crusts or scales.
  • The affected leaves become crinkled and twisted inward and show withering.

TNAU Agritech Portal :: Crop Protection

Black arm:

  • On the stem and fruiting branches, dark brown to black lesions are formed, which may girdle the stem and branches to cause premature drooping off of the leaves, cracking of stem and gummosis, resulting in breaking of the stem which hang typically as dry black twig to give a characteristic “black arm” symptom.

Bacterial Blight (Angular Leaf Spot, Black Arm) - UT Crops Pest Guides

 Square rot / Boll rot:

  • On the bolls, water soaked lesions appear and turn into dark black and sunken irregular spots.
  • The infections on mature bolls lead to premature bursting of bolls.
  • The bacterium spreads inside the boll and lint gets stained yellow because of bacterial ooze.

Cotton Boll Rot: Potential Implications of Bacterial Blight | Mississippi  Crop Situation

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