path-354 diseases of tomato

1. • Course No: PATH-354
Course Title: Diseases of Field & Horticultural
Crops & their Management
Credits: 2+1=3
Name of Topic: Diseases of Tomato
Prepared by: Ritesh sitaram londhe
AGL-028/2021

2. DISEASES
OF
TOMATO

3. Diseases of
Tomato
Cause
Early blight Alternaria solani
Leaf curl Gemini virus
Mosaic of
Tomato
➢Tobacco mosaic virus
(TMV)
➢Cucumber mosaic virus
(CMV)
➢Potato mild or latent virus.
➢Potato vein banding virus.
➢Tobacco acuba mosaic
virus
Fusarium wilt Fusarium oxysporum f. sp.
lycopersici
Damping off Pythium debaryanum
Late blight Phyotophthora infestans

4. EARLY BLIGHT
Symptoms:
➢ On leaf
Small, isolated, scattered spots
Circular to angular spots
Pale brown
➢ Fully developed spots
Irregular,
Brown to dark brown
Concentric rings
Coalesce to form large patches
Resulting in leaf blight

5. Symptoms…
➢ Lowest leaves :
Attacked first
Disease progresses upwards
➢ In severe cases of infection
Leaves dry up,
Shrivel
Drop off.
➢ The entire plant defoliated
➢ Zonate lesions :
On stems, petioles
Break at point of infection
EARLY BLIGHT

6. Symptoms…
➢ Calyx: Brown spots
➢ Fruits spots :
Green ripe stage,
Dark brown
Usually sunken
Enlarge to cover most of fruit
➢ Lesions on fruit at calyx end
Slightly dark,
Sunken,
Round to irregular
EARLY BLIGHT

7. EARLY BLIGHT

8. C
ausalorg
anism:A
lternariasolan
i.
D
iseasecycle/P
erpetu
atio
n:
➢P
.I:
M
yceliumorconidia
Infectedplan
td
ebris:driedleaves,seeds.
➢S.I:
Conidia
B
yw
ind,w
aterorrainsplash
es
EARLY BLIGHT

9. Epidemiology
➢Dryw
armw
eather
➢A
lternatingw
ithintermittentrains
➢Reductioninplantvigor
➢June-Julysowing,
➢W
eakoldplantspronetoinfection
➢Highsoilm
o
isture
➢Highhum
idity
EARLY BLIGHT

10. Control measures:
➢Maintainpropervigor
➢Useof diseasefreeseed
➢Removal &burningof cropdebris
➢Nursery&Fieldspraying:
Copperoxychloride0.3%
or Zineb0.2%or
Mancozeb0.25%.
EARLY BLIGHT

11. LEAF CURL
Symptoms:
➢ Dwarfing
➢ Puckering
➢ Twisting
➢ Curling
➢ Mottling
➢ Vein clearing
➢ Excessive branching
➢ Stunting of plant
➢ On lower side of leaves
Thickening of veins
Veins with small leaf like outgrowths (enations)
➢ Partial or complete sterility.
➢ Early infection : 92 % reduction in yield.
➢ Late infection at 35-55 days : 29-74 % yield loss

12. LEAF CURL

13. C
a
u
s
e
:G
e
m
i
n
iv
i
r
u
s(
T
o
b
a
c
c
oleafcurlvirus)
T
r
a
n
s
m
i
s
s
i
o
n
:
➢S
e
e
db
o
r
n
e
➢V
e
c
to
r:w
h
itefly
,B
e
m
is
ia
ta
b
a
c
i. M
a
n
a
g
e
m
e
n
t
:
➢R
o
u
g
in
g
,d
e
s
tru
c
tio
no
fa
ffe
c
te
dp
la
nts
.
➢U
s
eo
fs
y
s
te
m
icin
s
e
c
tic
id
e
s
LEAF CURL

14. MOSAIC OF TOMATO
➢Severalvirusesincitemosaic.Theyare
• T
o
baccom
o
saicviru
s(TM
V
)
• C
u
cum
b
erm
osaicviru
s(C
M
V)
• P
o
tatom
ildo
rlaten
tvirus
• P
o
tatoveinb
and
ingviru
s.
• T
o
baccoacub
am
o
saicvirus
➢T
o
baccom
o
saicviru
s(TM
V
):
• Longestlongevitya
m
o
n
gallplantvirusesknown.
• R
em
ainsactiveinp
lantjuiceupto25days

15. Symptoms:
• Y
oungerleaves
Light darkgreenmosaicmottle
Raiseddarkgreenarea
Distortedcrinkled.
Stuntedleaves
Distortedtoafanleaf ortendril like
• Thesymptomsvarydependingonstrainofvirus.
Somestrainscauseyellowingor
Leafmottling
Whichmayalsoaffect fruit.
MOSAIC OF TOMATO

16. Symptoms…
• Someotherstrains
Producestreaksymptoms
Stemorpetioles:longitudinalnecroticstreaks
Plantsarekilled
• At low
temperature Low
intensity
, Mottling
ismasked
Stunting
Distortionofleaves(leafbladereducedtofernlike)
MOSAIC OF TOMATO

17. Symptoms…
• Fruits:
Yellowchlorosis,
Necrosis
Distortion
Sunkenlesions
Internal necrosisor browning
MOSAIC OF TOMATO

18. Mode of spread Survival
• PI of TMV in tomato:
Plant debris
Manufactured tobacco products.
Seed transmitted
• The virus :
Seed borne
Sap transmissible
• Spread:
Implements
Cultural operations
By animals
By leaf contact
M
o
d
eo
fs
p
re
a
dS
u
rv
iv
a
l…
.
• T
r
a
n
s
m
i
s
s
i
o
n
:
M
e
c
h
a
n
ic
a
l m
e
a
n
s
:
C
o
n
ta
m
i
n
a
te
dh
a
n
d
s o
f
w
o
rk
e
rs
In
t
e
r-c
u
lt
u
rin
go
p
e
ra
tio
n
s
,
MOSAIC OF TOMATO

19. M
a
n
a
g
e
m
e
n
t
• D
estroycollateralh
o
sts
• D
estroydiseasedp
lants
• U
seviru
sfreeseed
• S
T
:10%T
ri-so
d
i
u
mo
rth
op
h
o
sph
atefo
r15-20m
in
utes
• H
eattreatm
entfo
r2-4d
aysat700
C
• C
ro
ssprotectio
n
:w
ithm
ildstrains
• A
voidu
sin
gtob
accop
rod
u
ctsinfield
• A
voidso
ilcon
tainin
fectedd
eb
ris.
• Eliminatechancesorspreadthroughman,animal,machinery
.
• Th
o
ro
u
g
hw
ashin
gofh
an
dsw
ithso
ap
.
MOSAIC OF TOMATO

20. ➢Tobaccoacubamosaicvirus:
• Astrainof tobaccomosaicvirus(TMV).
• Downwardcurlingof wholeleaf
• Leaf withslight turningdownat margins
• Surfaceof leaf
Rough, wrinkledorcorrugated.
• Chlorosisstartsassmall pinpointsof yellowareas
Graduallyspreads.
• Leavesbecomepaleyelloworwhite.
• Theplant isnot killedbut
Growthischecked&stunting.
MOSAIC OF TOMATO

21. ➢Cucumbermosaicvirus:
• Sometimesaffectstomatocrop.
• Shoestringlikefoliage,
• Dwarfingof plant,
• Necroticstreaks
• Fruit distortion
• Aphidbornebut short lived.
• Persistent inperennial weedhosts
MOSAIC OF TOMATO

22. ➢P
o
ta
to
m
o
s
a
ic
:
• W
h
e
nl
a
t
e
n
t
m
o
s
a
i
cv
i
r
u
s
o
f
p
o
t
a
t
o
i
st
r
a
n
s
m
i
t
t
e
d
t
o
t
o
m
a
t
oi
n
a
b
s
e
n
c
eo
f
t
o
b
a
c
c
om
o
s
a
i
cv
i
r
u
s
• V
e
r
ym
il
dd
iffu
s
em
o
ttl
e
• F
o
llo
w
e
db
yn
e
c
r
o
tics
p
o
ts
,
• M
il
dv
e
in
-c
le
a
r
in
g
m
o
t
t
l
eo
c
c
u
r
s
.
• S
y
m
p
t
o
m
sa
r
em
a
s
k
e
d
p
l
a
n
tc
o
n
t
i
n
u
e
st
oc
a
r
r
yv
i
r
u
sw
i
t
h
o
u
t
s
y
m
p
t
o
m
s
i
np
o
t
a
t
o
.
MOSAIC OF TOMATO

23. M
a
n
a
g
e
m
e
n
t
:
➢A
v
o
id
s
o
ilc
o
n
t
a
in
in
f
e
c
t
e
d
d
e
b
r
i
s
.
➢E
l
i
m
i
n
a
t
e
c
h
a
n
c
e
s
o
r
s
p
r
e
a
d
t
h
r
o
u
g
h
m
a
n
,a
n
i
m
a
l
,
m
a
c
h
i
n
e
r
y
.
➢U
s
e
s
e
e
d
f
r
o
m
d
is
e
a
s
e
f
r
e
e
p
la
n
t
.
➢T
h
o
r
o
u
g
h
w
a
s
h
in
g
o
fh
a
n
d
s
o
fw
o
r
k
e
r
s
w
i
t
hs
o
a
p
.
MOSAIC OF TOMATO

24. FUSARIUM WILT
Symptoms:
➢ Yellowing of lower leaves
➢ Discolouration of younger leaves
➢ Leaves droop,
➢ Wilt & die.
➢ May affect a few branches
➢ Plants or branches dry up.
➢ Vascular bundles become brown.
➢Plants stunted in growth
➢Fruits ripen prematurely

25. FUSARIUM WILT

26. Causalorganism:Fusariumo
x
y
s
p
o
r
u
mf.sp.lycopersici
Perpetuation:
➢Soil-borne&
seed-borne.
➢Survivesinsoilaschlamydospor
esor
A
ssaprophyticallyincropdebris
➢Spread:
S
eed
lin
g
sraisedinin
fecte
dso
il.
W
in
d
-b
o
rn
esp
o
res,
S
u
rfaced
rain
ag
ew
ater
A
g
ricu
lturalim
p
lem
e
n
ts
FUSARIUM WILT

27. Favourable conditions:
➢ Alternating high low soil temperatures
➢ High humidity levels.
➢ The optimum temperature : 280
c.
➢ Other favorable factors
• Light sandy soils,
• Low soil moisture
• Low ph,
• A low relative humidity
• Short day length.
• Root-knot nematodes
FUSARIUM WILT

28. M
a
n
a
g
e
m
e
n
t
:
➢H
e
a
l
th
ys
e
e
d
s
➢N
e
m
a
to
d
e
-fre
es
o
il.
➢S
T
:c
a
rb
e
n
d
a
z
i
m2
g
/k
g
➢S
o
ild
re
n
c
h
in
g
:c
a
rb
e
n
d
a
z
i
m0
.1%
,b
e
n
o
m
y
l0
.2
%
➢D
e
s
tro
yin
fe
c
te
dp
la
n
ts
FUSARIUM WILT

29. DAMPING OFF
Symptoms:
➢ Occurs in two stages
i) Pre-emergence phase
ii) Post-emergence phase.
➢ Pre-emergence phase:
• The young seedlings killed before reach to surface
• Complete rotting: radical, plumule
➢ Post-emergence phase:
• Occurs at or below ground level
• Tissue appear soft water soaked.
• Stem becomes constricted at base
• Plant collapses.
• Seedling toppling over
• Large patches of die seedlings
• Common in seed beds.

30. Causalorganism: Pythiumdebaryanum
Perpetuation/Modeof spread:
➢Survivesin formofoosporesormycelium
➢Survivesinsoil or seed.
➢PI : seed, soil.
➢SI: zoosporescarriedbyirrigation water.
Favorableconditions:
➢Excesssoil moisture
➢Highhumidity,
➢Overcrowding
DAMPING OFF

31. M
a
n
a
g
e
m
e
n
t
:
➢A
v
o
idw
a
te
r-lo
g
g
e
dlo
wlyin
gla
n
d
.
➢U
s
es
e
e
dfro
m
d
ise
a
s
efre
ea
re
a.
➢S
o
wo
nrais
e
ds
e
e
db
e
d
s
➢A
v
o
ido
v
er-cro
w
d
in
g
➢U
s
eoflig
h
ts
o
ilfo
rn
u
rs
e
ry
➢L
ig
h
tb
u
tfre
q
u
e
n
tirrig
a
tio
n
➢D
re
n
c
h
in
g:c
o
p
p
e
rfu
n
g
icid
ie
s
➢S
T
:T
h
ira
m
@
2to4g
m
/k
g
➢Soilt
re
a
t
m
e
n
t
:f
o
r
m
a
l
d
e
h
y
d
e(
F
o
r
m
a
l
i
n4
0
%
)
dilutedto5
0t
i
m
e
s
w
ithw
atero
r1
%
B
o
rd
e
a
u
xm
ix
ture
DAMPING OFF

32. L
A
T
EB
L
IG
H
T
:P
h
y
o
to
p
h
t
h
o
rainfe
a
ta
n
s
Symptoms:
➢Leaves
W
atersoakedlesions
W
ithfadedgreenpatches
Spreadfasttoentireleafpetiole
➢D
eadareasappearinleaftipm
argin
➢W
hitishgrow
thappearonleaves,
➢Killedordeadareabecom
edry
,

33. Symptoms….
➢ Fruits
Olivaceous greasy spots
Spots enlarge
Fruits remain firm;
If fruit is cracked a weft of fungus appear
Resulting in soft rot.
Perpetuation/Disease cycle:
➢P.I: dormant mycelium or oospores
➢Collateral host: potato, Pepper, egg plant.
➢S.I: sporangia or zoospores
L
A
T
EB
L
IG
H
T
:P
h
y
o
to
p
h
t
h
o
rainfe
a
ta
n
s

34. Favorable conditions
➢ Cool moist conditions
➢ RH: >90%
➢ Temperature:12-240
C
➢ The disease favored by
Moderate temperature
High relative humidity.
Cloudy weather
Rain fall with splashing rains.
L
A
T
EB
L
IG
H
T
:P
h
y
o
to
p
h
t
h
o
rainfe
a
ta
n
s

35. Management:
➢Regulatorym
easures
➢Selecthealthyplantingm
aterial
➢G
rowresistantvarieties
➢Prophylacticsprays
Metalaxyl(0.1%)orchlorothalonil(0.2%)or
B
M(1%) or copper oxychloride 0.3 %or
Zineb0.2%orM
ancozeb0.3%orR
idom
il
0.2%
L
A
T
EB
L
IG
H
T
:P
h
y
o
to
p
h
t
h
o
rainfe
a
ta
n
s

36. BUCKEYEROTOFTOMATO:
Phytophthoranicotianaevar.parasitica.
S
y
m
p
t
o
m
s
:
➢F
ru
its:
➢P
a
leb
ro
w
ns
p
o
ts
➢C
o
n
c
e
n
tricrin
g
so
nfru
its
➢E
n
tirefruitc
o
ve
re
d
➢B
u
tr
em
ai
nfirmunlessattackedb
ys
e
c
o
n
d
a
r
y
organism.
➢I
m
m
a
tu
refru
its:
➢Shrink

37. Modeof spread:
➢Soil borne-sporangia
➢Spreadbywind, water others.
Favorableconditions:
➢Water-loggedsoil
➢Fruitscomingin contact withsoil,
➢Highrainfall.
Management:
➢Croprotation,
➢Goodsoil drainage,
➢Spraydithiocarbomates,captafol, chlorothalonil etc
at regularintervals.
BUCKEYEROTOFTOMATO:

38. POWDERYMILDEW:
Leveillulataurica
➢Seepowderymildewofchilli
Bigbud: Mycoplasma-likeorganisms
Blossomendrot: