Tea Disease Management

Definition
Plant Pathology
Pathology derived from two Greek words; 1) Pathos = Suffering, 2)
Logos = Discourse or to speak. So, Plant Pathology is therefore, a
discourse on the suffering plants.
Thus, Plant Pathology is a subject that deals with the-
 The living entities and environmental conditions that cause disease in
plants;
 The mechanisms of disease development;
 Interactions between the pathogens and the diseased plant and
 The methods of controlling a disease either before or after it develop
in a plant.

Causing of diseases
Parasitic or
pathpogenic
Non-Parasitic or
Non- pathpogenic
Physiological or
Deficiency
Fungi
Bacteria
Virus
Nematode
Algae
Michoplasma
Environment
(Drought, Hail
damage, Chemical
injury, Heat etc.)
Lack of specific
nutrients-Nitrogen,
Phosphorus, Iron etc.

Disease Causing Agents
Host
Pathogen Environment
Disease
Triangle
Fig. Disease Triangle

Disease Causing Agents
Interaction Between the agentsInteraction Between the agents
1 2
3
1
3 2
1
3
2
No
Disease
No Disease
No Disease
1
2
3
Disease
Occur
1= Host
2= Pathogen
3= Environment

Pathogenesis
The process or chain of events whereby disease development take
place is called pathogenesis.
Inoculation Incubation Penetration
MultiplicationInfection
Symptom
development
Fig. Flow chart of Pathogenesis

Pathogen causes diseases in plants by-
 Weakening the host by continuous absorbing
food from the host cells.
 Disturbing the metabolism of host cells through
toxin secretion.
 Blocking the vascular system.
 Lysis & disintegration the cell contents.

Effect of Disease
 Photosynthesis is reduced
 Normal Physiology is disturbed
 Efficiency of nutrient and moisture uptake is reduced
Ultimately Low Production

Common Tea Diseases
Gall Disease
Dieback
Blister blight
Grey-Brown blight
Red rust (Epiphytic)
Black rot
Red rust
Horsehair blight
Thread blight
Branch Canker
Collar rot
Charcoal stump
rot
Violet root rot

Crop loss in tea due to Diseases
In general about 10-15%
Specific (preliminary observations)

Red rust 18-20%

Gall disease 20-25%
(Sometimes could be 100%)

Horse hair blight 11-13%

Macrophoma 15-25%

Black rot 25-35%
(Depends on the severity and age of the plant)

Die Back of Tea (Colletotrichum gloeosporioides)
• The fungus attack tender shoots, soft stem and leaves.
Symptom:
 At first the disease appears as small brownish spot on the soft stem/
host tissues.
 Gradually the spot enlarge with a yellow zonation.
 Later on the lesion becomes dark brown.
Disease lesion advances both in upward and backward direction from the
point of infection.
 In case of severe infection, young seedlings may die within two
weeks time.1-2 years old branches shrivel and turn rapidtl brown to
black and finally die.

Infected Tea Shoots:

Time of outbreak:
Field observation reveals that with the onset of winter as the host plant
shows dormancy the pathogen also ceases its activities and remains
dormant. The disease is found to occur during the month of July –
October when the climate is very hot and humid.
Transmission:
conidia produced numerous acervuli on infected shoots during wet
weather, acervuli are round,or irregular in shape and easily
disseminated by leaf and stem fluttering by wind, rain water splash/
dew/ other insects, etc.
Pre disposing factors:
Humid weather.

Control:
Mechanical
As soon as the disease is noticed in the field, infected twigs
should be cut, collected and removed.
Chemical
Spraying the plants immediately after pruning with a
solution of copper oxychloride. The treatment may be
repeat later in dry season when severe moisture-stress
first develop.

Blister blight (Exobasidium vexans)
Symptom:
 Appearance of mature small yellow spots on the under
surface of affected leaves.
 Concave on the upper surface and convex on the under
surface.
 Produce characteristic white wooly powder mass of the
spores on the under surface of the leaves.
 With maturity blister turns brown to black, leaves wither and
die.

Infected Tea Plant:

Time of outbreak:
 Appears during the later part of the season (October
– January).
Transmission:
 By wind
 During plucking – Clothes, buskets hand etc.
 Dew/ water splash.
Pre disposing factor:
 Dense shade,
 Cool weather.

Control:
Mechanical
If the disease is restricted in a small area, collect and
destroy disease shoots.
Chemical
Spray the affected areas especially on stems with
Macuprax 16 WW @ 2.24 Kg. / ha or Champion
77WP @ 2.24 Kg. / ha or any 50% Copper fungicides
@ 2.80 Kg. / ha mix in 1000 Litres of water. One
repeat application may be given with Knowin 50 WP
or any 50% Carbendazim @ 750g / ha mix in 1000
Litres of water after a fortnight if needed.

Grey blight (Pestalotia theae)
The disease is very common on mature leaves and is secondary
in nature. Other leaves may be attacked when the plant
become weak due to following reasons:

Lack of nitrogen,

Red spider and Jassid attack,

Sun scorch (which is extremely important)

Lack of shade,

Hail damage,

Drought etc.

Symptom:
 The disease appears as small brownish spot on the upper
surface of the leaves.
 The spots enlarge slowly.
 These spots may be of various size, shape with an irregular
out line.
 Later the spot look dark brown in color with a grayish
appearance at the centre and are surrounded by narrow
concentric zonation at the leaf margin.

Control
Cultural
 Provide shade
 Irrigate the soil when necessary
 Apply fertilizers.
Chemical
Spray the affected areas with Knowin 50 WP or any 50%
Carbendazim @ 750g / ha mix in 1000 Litres of water. One
repeat application may be given after a fortnight if needed.

Brown blight (Colletotrichum camelliae)
Symptom
 Yellow brown to chocolate brown spots appear at the margin of
leaves that resemble to sun scorch.
 Small minute black dot like fruiting bodies are produced on the
affected area.
Pre disposing factors
The pathogen can be infected leaves where plants become weak due
to the attack of

Red spider mites

Jassid

Sun scorch or any other mechanical injury which creates
wound on leaf surface.

Control
Mechanical
 If the disease is restricted in a small area, collect and
destroy disease shoots.
Chemical
Spray the affected areas with Knowin 50 WP or any
50% Carbendazim @ 750g / ha mix in 1000 Litres of
water. One repeat application may be given after a
fortnight if needed.

Gall
(Fusarium
oxysporum)
GALL (Fusarium oxysporum)
Galls have been found to
develop at-
 The base of leaf
petioles,
 leaf scars,
 on pruning cuts,
 at the base of young
succulent shoots,
 in between nodes and
 at the axial of branches

Gall (Fusarium oxysporum)
Symptom
 Small pear shaped gall (outgrowth) appears on the
infected area.
 Initially galls look smooth, green in colour. Outer surface
become rough, crinkle, and distorted giving the gall a
rough surface.
 Growth of Infected leaves and shoots become severely
restricted.
 Emergence and sprouting of new shoots stops absolutely.
 Within two to three months time the infected shoots dies
& dry up.

Symptom on twigs and other parts

Gall
Pinkish white
mycelium developed
Leaves and
twigs dried
due to Gall
infection
Growth of Infected
leaves and shoots
become severely
restricted.

Control
Cultural
 Pruning is one of the best and effective methods to
control the disease efficiently.
 Never left the infected sections un-pruned
 Never allow repeated skiff operations in the
infected sections
 Augment the pruning operation depending on the
disease severity.

Control
Chemical
Spray the affected areas especially on stems after
pruning with Macuprax 16 WW @ 2.24 Kg. / ha or
Champion 77WP @ 2.24 Kg. / ha or any 50%
Copper fungicides @ 2.80 Kg. / ha mix in 1000
Litres of water. One repeat application may be given
with Knowin 50 WP or any 50% Carbendazim @
750g / ha mix in 1000 Litres of water after a

Red rust (Cephaleuros parasiticus)
 Red rust disease is one of the major and most common
diseases of tea in Bangladesh, N.E India and Sri-lanka. The
disease is secondary in nature.
 The disease caused by Algae Cephaleuros parasiticus Karst
 = Cephaleuros virescens Kunze
Parts affected
 Plants of all ages may be attacked by the disease.
 The disease may be developed on stems, leaves and seed
capsules.
 Depending on the parts affected and infection nature, the
disease could be classified into two types.
a) Epiphytic (when the causal organism infects only the
leaves and seeds) and
b) Parasitic (causal organism infects stems and branches)

Symptom Epiphytic Red rust:
 This type of Red rust is always found on the upper surface
of the leaves and seed capsules.
 Small dull brick red colored circular to semi-circular spots
appear on the surface of infected parts.
 As the time passes, these small circular spots become
thick, enlarge gradually and give a slightly swollen
appearance on the upper surface of the infected plant parts.
 At this stage of growth, the margin of spots looks purple in
colour.Sometimes a watery green ring of tissues surrounds
the disease spots.
 In case of seed infection, fruiting bodies are found to
develop only on the upper surface of the seed coat

Symptom
Parasitic Red rust
 The algae can infect the branches at any stage of growth.
 The bark of the shoots is cracked, green stems become woody,
drier and finally die.
 With the advancement of time, variegated leaves show chlorosis
and gradually variegated area of the leaves dries out.
 Affected branch produces dense growth of tiny hairy structures,
which are purplish to dark red in colour.
 When numerous dark hairy structures of fruiting bodies are
produced on patches, it gives a rusty appearance to the affected
area from where it is named as Red rust.

Yellow VariegationDisease Cycle

Time of Occurrence:
 The disease first appears in the field in between mid March to
mid April depending on the first shower of monsoon.
 Generally Symptom on the leaves are noticed in the field just
within the fortnight of first rainfall.
Disease transmission:
 On maturity of the sporangium, spores are liberated.
 These spores are transmitted from one place to other place or
one plant to the other plants by means of
a) Rain,
b) Water splash,
c) Wind driven rain, fluttering of leaves through rain water
etc.

Pre-disposing factors of the Disease:
 Un-shaded or inadequately shaded tea.
 Bushes which receive an adequate annual application of
nitrogenous fertilizers are less prone to Red rust disease.
 There is less Red rust disease on tea which is applied with a
balance mixture of Potash than the tea grown under less
potash.
 Tea plants grown in alkaline soils are more prone to Red
rust attack.
 Teas grown on soils, which are poorly aerated or
waterlogged, are always very susceptible to Red rust attack.
 Low fertility
 Hardpan

Control:
Cultural:
 Establish good shade
 Remove Water logging conditions
 Improve nutrient status
 Correction or raising of pH
 Irrigate drought prone areas
 Apply mulching to conserve moisture
 Use Crotalaria anagyroides , not Bogamedeloa
 Lopping of Bogamedeloa

Control:
Chemical
77WP @ 2.24 Kg. / ha or any 50% Copper
fungicides @ 2.80 Kg. / ha mix in 1000 Litres of
water. One repeat application may be given with
Knowin 50 WP or any 50% Carbendazim @ 750g /
ha mix in 1000 Litres of water after a fortnight if
needed.

Black rot (Corticium invisum)
 One of the important diseases of mature tea.
 Caused by the two different species of fungus- Corticium
theae and C. invisium
 Both fungus produces same affect.
 Maintenance foliages are severely damaged.
 If not properly controlled it may cause 50% of shoot
reduction.
Symptom:
 Similar to those caused by sun- scorched except leaves appear
dull, but in sun scorched leaves look dark brown.
 Appear in patches look as a mixture of brown, yellow- brown
to chocolate brown and greyish white spots.

Symptom
 As the disease intensity increases, spots gradually enlarge with
an irregular size and shape.
 During wet weather, diseased patches look black.
 Affected leaves remain hanging with the branches or other
leaves by means of fungal mycellium.
 Fungus produces visible cord on the stem.
 Sporulation of fungus produce a white powdery appearance on
the under surface of green leaves.

Time of outbreak:
 In the month of May – June and remain in the field up to
October – November
Transmission:
 Air born spores dispersal occurs due to leaf flattering and
contact during wing.
 Water splash driven by strong wind.
 Plucking cloths, busket etc.
 Heavy shade
 Cool humid weather
 Through litters if not removed and cleaned properly.

Control
Cultural
 After pruning, litters should be cleaned and removed from
the bush. Never allow them to remain on the top of the
bushes.
 Over dense shades should be removed.
 Pruning litters, debris of the black rot infected area should
not be taken to an area which is Black rot free.
 A heavily infected black rot area should be given cut back or
low pruning operation. This may reduce the disease intensity
due to removal of infection source from the bush due to low
pruning.

Control
Chemical
Spray the affected areas with Knowin 50 WP or any
50% Carbendazim @ 750g / ha mix in 1000 Litres of
water. One repeat application may be given after a

Horse hair blight (Marasmius equicrinus)
 Horse hair blight is one of the severe of mid-canopy
diseases.
 The disease is caused by the fungus Marasmius equicrinis
Mull.
 It is very common in mature and old tea plantations.
 The disease is perennial in nature, thrives and persists for
years after years on the same bush or section if not
controlled properly.
 Crop loss varies with the intensity of the disease. In
general, crop loss is about 15-17%, but during favorable
conditions, crop loss could be more than 30%.

Symptom
 Symptom produced by the disease are difficult to recognize,
except that the appearance of infected bush become weak
and unthrifty.
 When observed carefully, black shining fungal threads or
mycelial cords are found to grow on the infected bushes.
 As the fungi closely resemble to the horsehair, hence it is
called horsehair blight.
 The disease develops on the dead leaves and twigs, which
remains on the soil or on bush frame after pruning
operations especially in the skiffed area.

Symptom
 Gradually spreading of the bush is arrested. As a result,
the active photosynthetic area of the bush is reduced.
 Also solar radiation can not reach to the effective depth of
the bush and results poor photosynthesis.
 Fungus remains attached to the bush frame and derives its
nourishment by means of haustoria.

Infected Tea Bush

Time of occurrence
 The disease is perennial in nature. Once enter into the bush
frame remains years together on the bush if not controlled.
 Usually more active during damp, warm and humid weather
(June to August).

Disease transmission
 One of the peculiarities of this fungus is that it does not produce
any spores. Transmission of the pathogen is mainly through
hyphal fragmentation, which occurs during pruning. Once fungal
cords or mycelium are broken these are transmitted from bush to
bush through following manners:
 Strong air current
 Rain water splash, wind driven rain
 Pruning litters
 Agricultural tools
 Pucker’s plucking basket and clothes.

 Heavy shade
 Poorly ventilated damp sections, where the air circulation is
restricted by jungles
 Kunchi area
 Bamboo grooves close to tea
 Leftover pruning debris on the bushes
 Bad drainage system.

Control
Cultural
 Bamboo grooves near the sections should be cleared and
kept clean. This will reduce the chance of fresh infection as
well as disease transmission.
 Heavy shade, damp, warm and humid weather is one of the
important predisposing factors. If there are excess shade
trees especially in kunchi area, those should be removed.
 Sections where removal of shade trees is not possible,
thinning of shade canopy may be done through lopping of
branches particularly with the onset of monsoon.

Control
Cultural (Contd)
 Surrounding jungles near the infected sections should be
cleaned.
 Never allow infected pruning litters to remain on the top of
the bushes,
 If possible, collect the infected pruning litters separately and
destroy them as far as possible,
 Never allow the workers to carry infected pruning debris
from one section to the other, particularly, from and infected
to a disease free sections.

Control
Chemical
77WP @ 2.24 Kg. / ha or any 50% Copper fungicides
@ 2.80 Kg. / ha mix in 1000 Litres of water. One
repeat application may be given with Knowin 50 WP
or any 50% Carbendazim @ 750g / ha mix in 1000
Litres of water.after a fortnight if needed.

Thread blight (Marasmius pulcher)
 Attack all tea from 3 years upward.
 Appears year after on the same bush.
Symptom:
 Fungus produces chalky white branching threads on the
stem.
 Fungal mycelium grow underside of the leaf, the affected
leaves darken, wither and turn brown.
 Gradually the affected leaves die and remain hanging on the
stems with fungal mycelia or threads.
 Infection occurs through leaf scar (hail) on the stem.

Symptom

Time of out break:
 Especially during rainy season.
Transmission:
 Direct contact year after year on same bush.
 Fungal fragmentation carried through winds or air
currents.
Source of infection:
 Old infection carried over from season to season by
means of threads which remain dormant during cold
weather.

 Heavy shade
 Damp, cool, humid weather.
Control
Cultural
 Regular cleaning after pruning.
 Reduction of over dense shade in the affected area.
 Clearing of jungles adjoining the tea to facilitate air circulation
to remove cool damp weather.

Chemical
77WP @ 2.24 Kg. / ha or any 50% Copper
fungicides @ 2.80 Kg. / ha mix in 1000 Litres of
water. One repeat application may be given with
Knowin 50 WP or any 50% Carbendazim @ 750g /
ha mix in 1000 Litres of water.after a fortnight if
needed.

Branch canker (Macrophoma theicola)
 Most widely prevalent stem disease of tea and shade trees/ forest
plants.
 The fungus is a wound parasite and enters in the bush frame
through wounds.
Symptom:
 Bark of affected plants split, as the disease proceeds down to the
frame from point of infection.
As the time passes bare wood may become covered with a fresh
coating of re- generated bark formed by vigorous callus growth
from the edges of splited area.

Symptom
 The fungus slowly and gradually extended down and kills the
branches one by one & reaches the collar region.
 The affected wood turns yellowish, soft and decays.
 As the fungus grows slowly – with in 8-15 years ultimately
the affected bush dies.
 In case of young plants they may dies with in 2-3 years time.

Time of outbreak:
 Following pruning operation (December – January).
Transmission:
 Wind born spores
 Irrigation water splash
 Dew and wind driven rain

Source of infection
 Previously infected forest plants
 Infected shade trees
 Old infection remaining in the field.
 Especially during pruning operation, fruiting bodies ruptures, spores
adhere to the agricultural tools.
 Care less pruning
1. Splits thick branches
2. Creating undesirable open wound.
 Failing to trim off broken tea bush branches after falling old shade trees
during their removal/ collecting fire wood.
 Injuring branches during cattle trespass.
 Hail damage.

Control
Cultural
 Careful removal of all dead wood from the bush at each
pruning.
 Infected woods should be collected separately during pruning
and should be removed/ burnt.
Chemical
 All cuts and wounds, especially on the thicker branches should
be smooth off with a sharp knife and then painted with-
I. Caustic wash solution
II. Copper fungicide
III. Bordeaux mixture

Collar rot (Phomopsis theae)
 Seen mostly in young tea
 Pathogen invades the stem mostly through open
wounds.
Symptom
 Chlorosis
 Wilting
 Smaller branches become srinkle
 Profuse flowering
 Canker on stem
 Defoliation

Pathogen invade
stem mostly through
open wound
Smaller in girth, ring
of callus growth,
pushes the bark up,
Collapse
Portion
Exposed
wood

Predisposing Factors
• Planting in gravelly soil
• Mulching closer to collar
• Wounds caused by weeding implements
• Fertilizer application close to collar
• Pegging
• Surface watering

Control Measures:
1. Preventives
 Avoid planting susceptible clones in gravelly soil
 Improve organic matter of marginal soil
 Use plants with good root system
 Avoid other predisposing factors
2. Curatives
 Removal of affected portion by pruning along with healthy
portion & pasting with Bordeaux paste.
 Spraying with systemic fungicides during draught period-
should be directed the collar & frame of bush only.

Charcoal Stump rot (Ustulina deusta)
 It is one of the important and serious root diseases of tea.
 It can attack both young and mature tea.
 The disease appears during and after rainfall.
Symptom
 Attacked bushes look sickly.
 Leaves loose their freshness, become flaccid, droopy and
color turns green to reddish.
 Leaves gradually wither and dry.
 Plant dies suddenly.

Symptom
 The fungus develops charcoal like black encrustation on the
root surface.
 In case of severe attack black, hard charcoal like encrustation
can also be seen at collar region above the soil surface.
 When shaken the infected bush, leaves remain firmly attached
with the branches.
 If bark remove white fan shaped mycelium can be seen on the
wood.

Black encrustation

Time of out break:
 The disease appears during and after rainfall.
Transmission:
 Soil born in nature
 Spread by means of lateral root contact.
 Termite can also play an important role in
transmission of the disease.

Source of infection
 Diseased woody materials remain in the field during removal
of shade trees.
 Root debris left during uprooting operations become infected
and severe as infection foci.
 If root debris is not removed properly while uprooting the
dead infected tea bush, they can also serve as infection foci.
 Infected shade trees like- Albizzia chinensis, A.
odoratissima, A. procera, Derris robasta, Tephrosia candida
etc.

Control
 Uproot a complete ring of apparently healthy surrounds at the same
time.
1. Incase of square planted uproot 09 bushes for one affected bush
2. Incase of hedge planted uproot 09 bushes for one affected bush
3. Incase of triangle planted uproot 07bushes for one affected bush
 All dead woody materials encountered during the uprooting
operation should be completely removed from the soil.
 Formalin treatment.
 The areas should then be put under a green crop at least a year,
preferably 2 years.
 Where disease occurs in small patches, mark out and remove all
bushes therein with their roots.

Violet root rot (Sphaerostibe repens)
 The disease is found on all type of soils but common on stiff
clayey soils.
 The disease can attack plants of all ages starting from 2 years.
 The disease is unreported on the hills.
Symptom
 Leaves of infected plants turn yellow.
 Droop and become flaccid.
 Often leaves fall off while still green.
 Often surrey vinegar smell may be found in the infected areas.

Symptom:
 Roots become ink black
or light violet in color.
 When bark is removed,
the wood surface is found
to be covered with irregular
purplish strands of fungus.
Transmission:
 By means of
drainage water.
Fungal
Mycelia

 Water logging
 Water logging conditions are mainly due to-

Flood

Low lie of the land with high water table.

Faulty drainage.

Back feeding or collapsing of drains during rain.

By cheeling soil from around the collar of the plant
 Poor soil aeration
 Hard pan

Control
Cultural
 Improve soil accretion by proper drainage.
 Maintain the drains in working condition.
 Do not cheel away soils from the base of the tea
bushes with out proper replacement.
 While deepening the drains care should be taken not to
pile the soils around the collar of the bushes.

 Cultural Control / Management
 Physical Control / Management
 Biological Control / Management
 Chemical Control / Management
 Integrated Disease Management
Disease
Management
Principles
Cultural
control
It is the control of Pests and Diseases
through timely manipulation /
augmentation of regular farm
operations.

 Land preparation
 Shade management
 Cleaning ,Sanitation and Jungle
clearing
 Pruning and Plucking
 Nursery soil and bed preparation
 Selection of planting materials (Pest and
Disease free)
 Rehabilitation
 Destruction of alternate hosts
 Wind belts
Components of
Cultural
control
(Tea)

Cleaning, Sanitation and
Clearing of Jungles
Blister blight, Black rot, Horse
hair blight, Thread blight
Destruction of alternate
hosts/ control of weeds
Dieback, Red rust, Black rot,
Macrophoma
Shade Management
Blister blight, Grey blight, Brown
blight, Dieback, Macrophoma,
Thread blight, Horse hair blight
Management of drainage
systems
Red rust , Violet root rot

Land preparation
Charcoal stump rot,
Violet root rot,
Weeds
Plucking (removal of
foliar pests and diseases)
Blister blight
Dieback
Replanting and soil
rehabilitation
Charcoal stump rot and
Violet root rot


Environment friendly

No risk of health hazard

No risk of MRL problem

Less costly

Compatible with IPM
Advantages of Cultural control (Tea)

It is the removal of infected
plant parts / organisms my
hand and destroy them as
soon as possible (Die back,
Blister blight, Flush worms in
the nursery)
Physical or Mechanical
control (Tea)
Advantages
• Environment friendly
• No risk of health hazard
• No risk of MRL problem
• Less costly
Disadvantages
The technique can not be applied
over a large area.

It is the use of living organisms
(Fungi, Bacteria, Viruses,
Actinomycetes, Nematodes,
Insects and other living
organisms) to control pests and
diseases.
Biological Control
Advantages
• Environment friendly
• No risk of health hazard
• No risk of MRL problem
• No risk for pollinators
Disadvantages
• Action is slow, Alone is not
sufficient
• Costly
• Compatibility problem

Chemical control Use of standardized chemicals against
specific pests and diseases
Advantages • Most effective
• Quick control
•Costly,
•Risk of environmental pollution
•Risk of MRL problem
•Availability of pesticides
•Storage problem
•Availability of equipment
•Require technical skill
•Effect on non-target species specially
parasitoids, pathogens and pollinators
•Influence of climatic factors on efficacy
•Chance of development of resistance
Advantages

Application Technology
Choice of Pesticides (Fungicide)
The pesticide to be used are to be chosen carefully particularly in
relation to the disease or pest and economic returns involved.
Main requirements of a satisfactory pesticide should be:
 High level of performance in the field which will be
determined by inherent toxicity, ready availability of the active
principle, adequate coverage, initial retention of the pesticide
applied and tenacity of the residue.
 Low phytotoxicity
 Low level of toxic hazards to animals and men including
operator and
 Stability in storage as well as after dilution to the desired
strength.

It is the process through which
one can identify, select and
implement actions to achieve
desired goal, objectives and
aims.
Planning
Step- 1: Identify-
Diseases
1. Observe Symptom and
damage (crop loss) by
carryout disease survey.
2. Note presence of pathogenic
structures.
3. Nature of the diseases/
pathogen
4. Find out the location (Upper
canopy, mid canopy or lower
canopy).

Step- 2:
• Select approved and right type of pesticides
(Fungicides)
• Procure pesticides (Fungicides) from registered
dealer
• Procure spray machines
• Calibration of sprayer/ machines
• Selection of trained or train operators
• Scheduling of spraying program (Regular
Problems)
• Consider cost effectiveness
• Should not be phytotoxic
• Should not impart off flavour, taint or residue in
made tea

1. Spraying operation should not be
carried out in hot sunny days.
2. Spraying operation should be
preferably conducted during
morning; before 10 am and in the
afternoon after 4 pm, when the
wind is calm. In contrast, between
10 am to 4 pm there is a risk of air
turbulence.
3. Spraying should be directed
towards the branches of mid and
lower canopy of the infected
bushes.
4. Apply fungicides only when it is
essential.
5. Avoid repeated exposure of same
chemicals
6. Always buy pesticides from
registered dealers
Few important
messages to be
considered while
spraying-

Cleaning of
sprayer:
1. Empty the tank of remaining
chemical and drained them on
wasteland where the chemical will
not contaminate irrigation cannels,
streams or cropland or spray the
remaining pesticide on a crop for
which the pesticide is appropriate.
2. Fill the tank 1/3 full with detergent
solution, shake vigorously and
then operate the pump several
times while spraying the rinse
solution. Pour out the remaining
rinse solution.
3. Fill the tank with clean water,
operate the pump and spray it.

Spraying Schedule
Months Weeks Nature of Spray & Cult.Oper Name of Diseases
Jan I, II and III Cleaning, Sanitation (particularly in LP &
MP areas) and General Spray in Pruned
area
HH,TB,MPH,Gall
April II General RR,Hail MPH
May II & III Spot RR & BR
June I General DieB, RR & BB
Sept. II Spot BR
Oct. II Spot BR & BB (if
infestation occurs)
Dec. II & III Cleaning, Sanitation (particularly in LP &
MP areas) and General Spray in Pruned
area
HR,TB,MPH,BR and
Gall

Pruning and Disease Management
Pruning is an essential cultural operation of tea cultivation that is
done to convert the plants into a bushy frame. This cultural
operation has tremendous influences on the micro climate and
disease incidence. Besides, the micro climate change , both in
cutting and removing of foliages have manifold effects
particularly on the disease-

Incidence,

Disease development,

Multiplication of pathogen,

Perpetuation of pathogen and

Dissemination of pathogen

Depending on the type of pruning operations given, certain
parts of top canopy/ mid canopy foliage are always cut and
removed every year, impact of which may be visualized into
two ways-
1. Positive Impact

Provide opportunities to reduce & control most of the
perennial diseases by automatically removal of diseased
parts.

2. Negative Impact

When infected plants are given different pruning operations,
diseased materials are also cut into numerous tiny
individuals which in turn serves as fresh source of infection.

When pruning is done, bush becomes more exposed to some
pathogens. In some particular cases, if pruning litters are not
removed and clean properly, this will further aggravate.

In addition, pruning tools sometimes carry the diseased
propagules from infected bushes to healthy one and helps
the disease transmission.
** So, it is very important to have clear ideas on different diseases
that are affected by pruning.

During LP and MP pruning operation-
All upper canopy and more or less mid canopy diseases (like-
Die-Back, Blister Blight, Gall, Red rust, Black rot, Horse hair
blight, Thread blight, Macrophoma etc are removed
During DSK and MSK pruning operation-
All upper canopy diseases- Die-Back, Blister Blight, Gall,
Red rust (Epiphytic) and also somewhat mid canopy-Black
rot, Thread blight etc. are removed.

Management options

Never allow pruning litters to remain on the bushes.

Collect, remove and destroy them as far as possible.

Lung pruning is not advisable in the sections where plants
are infected by these diseases.

Do not allow the laborers to carry pruning litters from
infected section to disease free sections.
****These will help in reducing the intensity of diseases,
consequently frequency of pesticide application will
be minimized.

Diseases Parts affected Pre-disposing factors Management
options
Target site
Gall
Die-Back
Blister
blight
Grey-
Brown
blight
Tender shoots,
petiole, leaf
scars
Tender shoots,
leaves,
Asillary buds
Two & a bud,
Soft shoots
Mature &
Maintenance
leaves
Low temp,Heavy
shade, Insufficient
sunlight
Warm humid
condition,
Insufficient shade
Heavy shade, Low
temperature
RM/JAS/Sun
scor./Lack of Shade/
Hail/ Poor Nutrients
Cultural &
Chem
Chem
Cultural &
Chemical
Chem
Absolutely
Upper Canopy
Upper Canopy
Upper Canopy
(both surface
of the leaves)
Upper & Mid
Canopy
Disease management option matrix

DiseasesDiseases Parts affectedParts affected Pre-disposing factorsPre-disposing factors Mgt.optionsMgt.options TGTG
Red rustRed rust Two & Above twoTwo & Above two
years old branchesyears old branches
Poor nutrient, low pH,Poor nutrient, low pH,
lack of shade, waterlack of shade, water
logging, bad drainage,logging, bad drainage,
drought,drought,
MainlyMainly
Cultural +Cultural +
ChemicalChemical
Mid
Canopy
Black rotBlack rot Mature andMature and
maintenancemaintenance
leaves,leaves,
Dense shade, KunchiDense shade, Kunchi
area, Poorly ventilatedarea, Poorly ventilated
damp sections, Left overdamp sections, Left over
pruning debris on thepruning debris on the
bushes, Bamboo grovesbushes, Bamboo groves
close to tea, Badclose to tea, Bad
sanitation, Watersanitation, Water
logging, Repeated skifflogging, Repeated skiff
operations in infectedoperations in infected
sectionsection
MainlyMainly
CulturalCultural
(During(During
Pruning)Pruning)
Phase wisePhase wise
………………PlusPlus
ChemicalChemical
Mid
Canopy
ThreadThread
blightblight
Mature andMature and
leaves, branchesleaves, branches
Mid
Canopy
HorseHorse
hairhair
blightblight
Mature andMature and
leaves, branchesleaves, branches
Mid
Canopy

Diseases Parts affected Pre-disposing factors Mgt.options TG
Branch
Canker
Above 3-5
years old
branches /
Base of YT
Mechanical injuries by:
Cheeling, Sickling, Hail
damage, Blunt pruning
cuts, Raged surface
Cultural and
Chemical
Mid
Canopy
Collar rot Collar region Faulty plantings, Faulty
manuring, Undecomp.
Mulch materials
Cultural and
Chemical
Lower
Canopy
Violet root
rot
Root zone Faulty drainage and
water logging,
Depression at the base of
Young plants….
Cultural Lower
Canopy
Charcoal
stump rot
Root zone Infected shade tree,
forest and tea root debris
left in the field
Cultural and
Chemical
Lower
Canopy

Tea Disease Management

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