Caused by : Alternaria macrospora
It is one of the major bacterial diseases that can be seen in cotton crop. This disease become more severe in 45-60 days old plants. It occurs in all the stages of cotton crop
SYMPTOMS
- We can observe small brown irregular or round spots on the leaves.
- Each spot is surrounded by concentric rings and has a lesion at the centre.
- Few spots coalescen(merge) together and leads to blighted appearance.
- The affected leaves become brittle and fall down
- Lesions are also be seen on the stem.
- In severe infestation, we can observe  spots on bracts and bolls too.
- This leads to loss of yield
MANAGEMENT
Use Prioxar @120ml/acre
Seed treatment using Streptocycline before sowing can control this disease
Spray COC or Mancozeb @ 2kg/ha