The diseases which commonly occur in tea can be classified into two broad groups, viz.,
(a) Primary diseases and
(b) Secondary diseases.
A disease which can cause death of the healthy tissues or the bushes even under the best growing conditions is called a primary disease. On the other hand, the secondary diseases are those which attack the bushes only after the health of the plants is impaired due to cultural and/or environmental stresses.
The primary and the secondary diseases can be further categorised into different groups on the basis of the site of first (major) infestation on the tea bushes as root diseases, stem diseases and leaf diseases.
Before going into details, let us have a look on the major tea diseases and their occurrence in different tea growing countries.
|Major Tea Diseases||Country|
|Leaf Diseases||Blister Blight||China, Taiwan, Japan, India, Indonesia, Sri Lanka, Malaysia|
|Red Rust||China, India, Indonesia, Sri Lanka, Malaysia, Central Africa, Uganda, Peru|
|Bird’s Eye Spot||China, Japan, India. Sri Lanka, Indonesia|
|Black Rot||India, Indonesia, Sri Lanka|
|Anthracnose||China, Japan, Taiwan|
|Reticular Blight||Japan, Taiwan|
|Scab||Malawi , Tanzania, Mozambique, Uganda, Brazil|
|Stem Diseases||Branch Canker||Japan, India, Sri Lanka, Indonesia, Taiwan, Malawi, Kenya,|
|Thorny Stem Blight||India, Sri Lanka, Indonesia, Malawi, Zimbabwe, Columbia|
|Wood-rot||India, Sri Lanka, Kenya|
|Collar Canker||India, Sri Lanka, Kenya|
|Die back||India, Sri Lanka|
|Pink Disease||Kenya, Burundi, Cameroon, Madascar|
|Root Diseases||Brown Root Rot||China, India, Sri Lanka, Indonesia, Malaysia|
|Red Root Rot||China, India, Sri Lanka, Indonesia, Malaysia|
|Diplodia Root Rot||India, Sri Lanka, Indonesia, Malaysia, Malawi|
|Black Root Rot||Japan, India, Indonesia, Malaysia, Central Africa|
|Root Splitting||India, Sri Lanka, Indonesia, Central Africa, Kenya, Malawi, Uganda, Zimbabwe|
|Pale Brown root rot||Malawi|