Causal Agent: 

Fungi Cercospora canescens)

Characteristic Symptoms:
Leaf spots are circular to broadly irregular, reddish brown.
During heavy infestation, the leaves have leathery, dark-reddish-purple appearance.
Under warm and wet conditions, the lesions coalesce and the leaves may appear blighted.
Conditions for Disease Development:
The disease is common in humid tropic and subtropical regions.
The pathogen survives between crops on crop debris.
Conidia/spores are air-borne and are disseminated by wind, rain splashes, tools/implements and field workers.
Infection requires free water and is favoured by temperatures between 26-32°C, in which the disease develops rapidly with new infections occurring every 7-10 days.
Management and Control:
Good field sanitation (i.e., remove and destroy infected plants/plant parts) can help eliminate inoculum sources in the field.
Crop rotation with non-host crops for 2-3 years will ensure elimination of inoculum in crop residues.
A regular spray program of copper-based fungicides (e.g. Cupravit®, Super BlueⓇ, Vitigran blueⓇ, FunguranⓇ, KocideⓇ, Hydroxide superⓇ) and chlorothalonil (e.g. Daconil®, Agronil®, Yoda®, Rover®, Yoda 500Ⓡ) may help reduce incidence and severity especially when crops are susceptible and conditions are favorable for disease development.
Use resistant varieties, if available.

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