A new disease is apparently posing a threat to eucalyptus plantations in South Africa.
What is Ceratocystis wilt and canker?
Ceratocystis wilt of eucalypts is a fungal disease caused by a species of Ceratocystis. Different species of the fungus have been associated with wilt of eucalypts globally. The disease is considered to be one of the two most serious diseases of eucalypts in Brazil.
Infection by Ceratocystis sp. most commonly results in a rapid wilt and death of the entire tree. It may affect plants of all ages.
What are the symptoms?
Rapid wilting of leaves. This may start with a single branch, or the entire tree at once. Leaves stay attached to the branches. Lesions may or may not be present in the bark.
Cutting into the bark will reveal speckling/spotting in the bark. Cutting longitudinally through the bark into the wood will reveal brown streaks in the wood. Cross-cutting of the stem will reveal radiating patterns of wood discolouration/streaking.
Wilting and death of trees.
Selection and breeding of disease tolerant/resistant genotypes. Ceratocystis species require wounds for infection. Prevention of wounds will reduce chances of disease.