Category : Other
Algal leaf spot
Cephaleuros virescens
Symptoms
Gray, green or tan raised spots or blotches with green margins on leaves
Cause
Algae
Comments
Management
Avoid overhead irrigation which can spread the disease; provide adequate space between plants to maximize air circulation around foliage; avoid wounding plants; prune out diseases parts of plants by cutting 6 inches below any visible symptoms; application of appropriate protective fungicides should be made in Spring when old leaves drop from plants
Category : Fungal
Blister blight
Exobasidium vexans
Symptoms
Small, pinhole-size spots on young leaves; spots become transparent, larger, and light brown; blisters on underside of leaves; dark green, water-soaked zones surrounding blisters; blisters may be white and velvety or brown; young stems bent and distorted, may break off or die
Cause
Fungus
Comments
Management
Plant tea varieties which are less susceptible to the disease; apply appropriate foliar or systemic fungicides to protect the plants
Camellia dieback and canker
Glomerella cingulata
Symptoms
Leaves suddenly turning yellow and wilting; branch tips dying; gray blotches on bark and stem which develop into sunken areas (cankers); cankers girdling the stem; parts of plant above cankers losing vigor, wilting and dying; symptoms more pronounced during hot, dry weather
Cause
Fungus
Comments
Management
Plant in well draining, acidic soils; remove diseased twigs by cutting several inches below cankered areas and disinfecting tools between cuts; apply appropriate protective fungicides during periods of wet weather or natural leaf drop to protect leaf scars from infection
Camellia flower blight
Ciborinia camelliae
Symptoms
Small, brown, irregular-shaped spots on the flower petals; whole flower turning brown; flowers dropping from plant
Cause
Fungus
Comments
Management
Remove all infected flowers from plants; remove all crop debris from around plants; soil drenches with appropriate fungicides can help to reduce the intensity of the disease
Horse hair blight
Marasmius crinis-equi
Symptoms
Black threadlike structures resembling horse hair attached to upper branches of plant by small brown discs; leaves drop rapidly from plant
Cause
Fungus
Comments
Management
Remove a and destroy all crop debris from around plants; prune out infected or dead branches from the plant canopy
Poria root disease (Red root disease)
Poria hypolateritia
Symptoms
Yellowing foliage; wilting and/or sudden death of part of plant; withered leaves remain attached to the plant for several days; uprooting the bush reveals whitish mycelium and red discoloration of the roots
Cause
Fungus
Comments
Management
Remove any visibly infected bushes and any adjacent plants which are showing signs of yellowing; remove any stumps or trees within infested area; all living and dead roots which are about pencil thickness or more should be removed from the site by digging using a fork; all material collected should be destroyed by burning; bushes surrounding the infested area should be treated with an appropriate fungicide applied as a soil drench; cleared site should be planted with grass for a period of two years before tea is replanted
Root rot
Phytophthora cinnamomi
Symptoms
Leaves turning yellow; poor plant growth; entire plant wilting; roots discolored; rapid death of plant
Cause
Oomycete
Comments
Management
Disease is difficult to manage once plants become infected so control methods should focus on protecting plants; always plant tea in well-draining soils which are not as favorable for the survival of the pathogen; application of appropriate fungicides can help to protect plants from infection