Alternaria leaf spot: Alternaria dianthi

Symptoms

• The chief symptom is blight or rot at leaf bases and around nodes, which are girdled.  Spots on leaves are ashy white. 
• The centre of old spots are covered with dark brown to black fungal growth. 
• Leaves may be constricted and twisted and the tip may be killed.
• Branches die-back at the girdled area and black crusts of conidia are formed on the cankers.

Spot on leaves	Spot on buds	Spot on flower buds

Management

• To reduce the disease incidence, humidity may be kept low by providing proper air circulation. 
• Disease-free planting material should be used. 
• Planting material should be dipped in Bacillus subtilis 2g/litre of water