The document provides an overview of various tea diseases, their symptoms, life cycles, and management strategies. Key diseases discussed include algal leaf spot, brown blight, blister blight, and root rot, along with suggested control measures such as proper drainage, air circulation, and targeted fungicide applications. It emphasizes the importance of maintaining plant health and soil conditions to prevent disease onset and spread.

1. WELCOME

2. Mr. MAHESH P N
UHS16PGM758.
M.Sc.(Hort.)
Dept. of fruit science
Tea diseases and their
management
UNIVERSITY OF HORTICULTURAL SCIENCES,
BAGALKOT
COLLEGE OF HORTICULTURE, BAGALKOT
Presentation on

3. TEA
 B N: camellia sinensis
 2n : 30
 Origin: china

5. Algal leaf spot
CO:Cephaleuros virescens
Symptoms
•Leaves develop lesions that are roughly circular, raised and purple to reddish-
brown.
Life Cycle
•The alga produces microscopic, rust-colored, spore-like bodies on the surface
of the leaf spots, giving them a reddish tinge.
•The “spores” are dispersed by wind or rain.
•The alga may spread from leaves to branches and fruit.
•Poor soil drainage, imbalanced nutrition, and exposure to relatively high
temperature and humidity predispose tea plants to infection by algal leaf spot,
so it is important to strengthen the plant through proper cultivation and
fertilization.
•Most algal spots develop on the upper leaf surface. Older infections become
greenish-gray and look like lichen. Cephaleuros usually does not harm the
plant.

6. Management
•Avoid plant stress.
•Avoid poorly drained sites.
•Promote good air circulation in the plant canopy to reduce humidity and
duration of leaf wetness.
•Removal of infected portions by spraying of bordeaux mixture
•Destruction of affected plant portions
Improving the nutrient status of the soil by application of nitrogen, phosphorus
and potassium

7. Brown blight, grey blight
CO:Colletotrichum sp., Pestalotiopsis sp.
Symptoms
•Small, oval, pale yellow-green spots first appear on young leaves.
•Often the spots are surrounded by a narrow, yellow zone.
•As the spots grow and turn brown or gray, concentric rings with scattered, tiny
black dots become visible and eventually the dried tissue falls, leading to
defoliation.
•Leaves of any age can be affected.
Life Cycle
•The tiny, black spots on the lesions contain the fungal spores.
•Rain splash transports the spores from one plant or site of infection to another.
•If the spores land on a leaf, they germinate to start a new leaf spot or a latent
infection.

8. Management
•Avoid plant stress.
•Grow tea bushes with adequate spacing to permit air to circulate and reduce
humidity and the duration of leaf wetness.
•Spray Copper Oxy Chloride or Bordeaux mixture 0.1% during winter season
and Summer season
Brown blight Grey blight
Concentric rings Infected leaves

9. Blister blight
CO : Exobasidium vexans
Symptoms
•Small, pinhole-size spots are initially seen on young leaves less than a month
old.
•As the leaves develop, the spots become transparent, larger, and light brown.
•After about 7 days, the lower leaf surface develops blister-like symptoms, with
dark green, water-soaked zones surrounding the blisters.
•Following release of the fungal spores, the blister becomes white and velvety.
•Subsequently the blister turns brown, and young infected stems become bent
and distorted and may break off or die.

10. Life cycle
•The disease cycle repeats continuously during favorable(wet) conditions, and
the spores are readily dispersed by wind.
•Spores that land on a leaf with adequate moisture will germinate and infect it,
producing visible symptoms within 10 days.
•The fungus can directly penetrate the leaf tissue.
•The basidiospores have a low survival rate under conditions of drought or
bright sunlight.
•The life cycle of the fungus is 3–4 weeks.
Management
Removal of affected leaves and shoots by pruning and destruction of the same
have been recommended.
Spraying of Bordeaux mixture or Copper Oxy Chloride 0.1%
A mixture of 210g of Copper oxy Chloride + 210g of nickel chloride per ha
sprayed at 5 days interval from June to September and October to November
Spray Tridemorph at 340 and 560 ml/ha is satisfactory under mild and
moderate rainfall conditions

11. Horse hair blight
CO: Marasmius crinisequi
Symptoms
•Black fungal threads resembling horse hair are attached to upper branches
and twigs by small brown discs.
•The fungus penetrates and infects the twigs from the discs and produces
volatile substances that cause rapid leaf drop.

12. Life cycle
This pathogen is spread from infected twigs to healthy twigs by extending its
hair-like threads.
Management
•Remove a and destroy all crop debris from around plants
•Prune out infected or dead branches from the plant canopy

13. Camellia flower blight
CO:Ciborinia camelliae
Symptoms
Small, brown, irregular-shaped spots on the flower petals; whole flower turning
brown; flowers dropping from plant.
Comments
Disease emerges early in Spring during periods of high moisture.
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.

15. Twig dieback, stem canker
CO: Macrophoma theicola
Symptoms
•The first symptoms include browning and drooping of affected leaves.
•As the disease spreads into the shoots, they become dry and die.
•The entire branch can die from the tip downward.
•Dying branches often have cankers—shallow, slowly spreading lesions
surrounded by a thick area of bark.
Browning Dried leaves

16. Life cycle
•The fungus produces spores on small, pear-shaped pycnidia on dead branches.
•Spores are spread when splashed by rain and can survive for several weeks on
pruned branches left in the field.
•The fungus usually requires wounded plant tissue to gain entry and initiate
infection.
Management
•Plant in well draining, acidic soils.
•Remove diseased twigs by cutting several inches below cankered areas and
disinfecting them.
•Spray appropriate protective fungicides during periods of wet weather or natural
leaf drop to protect leaf scars from infection
Stem canker Infected field

17. Black root rot
CO: Rosellina arcuata
Symptoms
•The fungus originates from the dead heaped leaves of 5 – 7.5 above the soil
level. From there if spreads to roots region of tea bushes.
•When bark is removed star like growth of mycelium can be seen.
•At the surface of the soil the mycelium surrounds the stem and kills the bank
for the length of 7.5 – 10.0 cm.
•A swollen ring of tissue is formed round the stem above the dead patch.

18. Management
•Removal and destruction of infected plant.
•Clean cultivation with out fallen leaves
•Dig a drench around the infected bush to provide sunlight in the drench which
prevent the spread of mycelium.

19. Camellia dieback and canker
CO: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.
Comments
Fungus can enter plant through wounds.
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.

20. Root rot
CO:Phytophthora cinnamomi
Symptoms
Leaves turning yellow; poor plant growth; entire plant wilting; roots discolored;
rapid death of plant.
Cause
Oomycete
Comments
Disease emergence favors poorly drained, warm soils.
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.

21. Poria root disease (Red root disease)
CO: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.
Comments
Spread by mycelial strands in the soil.
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.

22. Journal of Plantation Crops, 2014, 42(3):341-347
Bioefficacy of certain chemical and biofungicides
against Hypoxylon spp. causing wood rot disease in
tea
Nepolean et al
The study revealed that, chemical fungicide (Benomyl or
copper oxychloride at 0.01%), botanical extracts at 10%
(A. nilagirica, H. argutus, Azadirachta and ‘Expel’) and
biocontrol agents (Bacillus sp., Pseudomonas sp. and T.
viride) were effective in controlling wood rot pathogen
under in vitro condition.

23. Pl. Dis. Res. 24 (2) : 182-183 (2009) Thakur et al
Contaf, a promising triazole fungicide against
blister blight of tea
The studies showed that Contaf (hexaconazole 5 EC), a promising
systemic triazole fungicide with low active ingredient having minimum
residual effect at low concentration 0.10 % was found to be effective to
keep the disease under control for quality tea production in Himachal
Pradesh. The test fungicide can further be evaluated at this
concentration to formulate the spray schedule with non-systemic
fungicide to avoid fungicidal resistance against the disease.

24. immunolocalization of chitinase in tea leaves was also done using
the chitinase PAb. B. megaterium has been found to be a good plant
growth promoter with the ability to increase growth of tea plants
along with a reduction of sclerotial blight disease which acts both
by direct and indirect mechanisms in the host.
Indian Phytopathology ; Vol 68 No 3, 2015
; PP: 237-247
Chakraborty et al
Bacillus Megaterium from Tea Rhizosphere Promotes Growth
and Induces Systemic Resistance in Teaagainst Sclerotium
Rolfsii

25. The aqueous solution of the antagonists which showed
maximum inhibition of the pathogen in vitro was applied under
field conditions as foliar spray. The percentage symptom and
senility index was found to be lowest in the plots sprayed
with A. niger followed by T. atroviride and T. citrinoviride,
respectively.
Journal of Biological Control ; Vol 26
No 4, 2012; PP: 341–346
Romila Thoudam et al
Control of Black Rot Disease of Tea, Camellia Sinensis (L.) O.
Kuntze with Mycoflora Isolated from Tea Environment and
Phyllosphere

26. THANK YOU