Melanose of Citrus

Diaporthe citri

Description:

A fungal disease that causes tiny dark brown to red spots on leaves and fruit. In severe infections the dots may join to give an overall brown appearance or brown patches. The spots may be in streaks where water carrying spores has dribbled across the leaf or fruit. On fruit that is severely infected the skin may crack giving a "mud cake" or road map appearance and the fruit may be slightly deformed or stunted.

Species Affected:

Citrus.
Washington Navel and sour Oranges, Emperor Mandarins and Lemons are more susceptible than Grapefruit and Valencia Oranges.

Biology:

Favoured by temperatures around 250C and moist conditions.
Most common in older trees that have lots of dead twigs.
Grows on plant debris.

Life Cycle:

Origin and History:

Distribution:

Significance:

Management and Control:

Prune and destroy dead twigs and branches.
Remove debris from under trees.
Apply fungicides.

Related and Similar Species:

References:

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.