• Small, pinhole-size spots are initially seen on young leaves less than a month old.
• As the leaves develop, the spots become transparent, larger, and light brown.
• After about 7 days, the lower leaf surface develops blister-like symptoms, with dark green, water-soaked zones surrounding the blisters.
• Following release of the fungal spores, the blister becomes white and velvety.
• Subsequently the blister turns brown, and young infected stems become bent and distorted and may break off or die.
  

Life cycle

• The disease cycle repeats continuously during favorable(wet) conditions, and the spores are readily dispersed by wind.
• Spores that land on a leaf with adequate moisture will germinate and infect it, producing visible symptoms within 10 days.
• The fungus can directly penetrate the leaf tissue.
• The basidiospores have a low survival rate under conditions of drought or bright sunlight.
• The life cycle of the fungus is 3–4 weeks.

• Removal of affected leaves and shoots by pruning and destruction of the same have been recommended.
• Spraying of Bordeaux mixture or Copper Oxy Chloride 0.1%
• A mixture of 210g of Copper oxy Chloride + 210g of nickel chloride per ha sprayed at 5 days interval from June to September and October to November
• Spray Tridemorph at 340 and 560 ml/ha is satisfactory under mild and moderate rainfall conditions

Content validator:
Dr. M. Deivamani, Assistant Professor, Horticulture Research Station, Yercaud-636602.