• Worldwide distribution. On lemon, rough lemon and mandarin. Other species of citrus - grapefruit, orange and pomelo - are also susceptible, but less so. An important disease.
• The fungus distorts the leaves and makes the fruit unsightly. It stunts common rootstocks in the nursery, so they are difficult to bud.
• Similar to citrus canker (see Fact Sheet no. 091), except leaves are stunted, wrinkled with torn margins.
• Spread is by wind and rain, by insects, on nursery plants, and fruits.
• Cultural control: make nurseries at distance from production areas; prune to keep open canopy, and improve air circulation.
• Chemical: in the nursery, use copper or chlorothalonil at the beginning of leaf flushes.

Common citrus scab

Elsinoë fawcettii. The fungus has an asexual stage, Sphaceloma fawcettii; this is the stage that occurs throughout the Pacific. There are several strains of Sphaceloma fawcettii. Another species, Elsinoë australis is also known, which is more economically important but is less widespread.