Sugarcane diseases slide collected and edited by Syed Zahid

1. Sugar Crop diseases
Syed Zahid Hasan

2. Red rot of sugarcane
CO: Colletotrichum falcatum
 Red rot is one of the oldest known
diseases of sugarcane
 It occurs in most cane-growing countries
 Complete loss to cane production in
case of severe epidemic condition
 It continues to be a threat in certain
subtropical countries

3. Symptoms
A) Symptoms on the leaves
 First symptoms are seen after the rainy
season when plant growth stops and
sucrose formation begins
 Loss of color and drooping of the 3rd or 4th
leaves are the earliest symptoms
 Red patches with ash colored centre
develop on the mid-rib of leaf
 The entire top become wither

4. Loss of color and
drooping of the
3rd or 4th leaves
Red patches
with ash colored
centre develop
on the mid-rib
Entire top
become wither
3rd
4th

5. B) Symptoms on the canes
 The infected cane become shriveled and
such canes lighter in weight and easily
broken
 When the diseased canes are splitted
open longitudinally, characteristic red
tissues are seen which are intermingled
with white tissues in the pith and
vascular region
 The cavities filled with grayish or white
mycelium are found in the pith and minute,
velvety, dark dots (acervuli of the fungus)
are formed near the nodes of the diseased
canes and also in shrunken areas

6. Red tissues which
are intermingled
with white tissues
in the pith and
vascular region
Cavities filled
with grayish or
white mycelium
in the pith and
minute, velvety,
dark dots near
the nodes

7. Favorable conditions
 Rain and irrigation water (carrying out
fungus or infectious material from one
plant to another or one field to the other)
 Presence of Wind and insects (Stalk borer,
moth borer, sugarcane weevil)
 Injury to sugarcane setts

8. Disease cycle

9. Control measures
 Diseasefreecane should be used as setts
 Diseasedplantsshould be dug out & burnt
 Low lying areas avoided forcultivation
 A2-3 years rotationshouldbe followed
 Ratooningshouldbe avoided
 Use of resistantvarieties,eg. Iswardi2/54,Iswardi-16,iswardi-17,etc
 SettstreatmentwithBavistin DF orKnowin50WPorAimcozim50WPor
Agben 50WPorForastin50WPor Genuine50WPor Cindazim50WP
orAgridazim50WPor Nayan 50WPor Evazim 50WPor Haydazim 50WP
or Gilzim50WPorOrgazim50WP@ 1glitof water
 Application of the above mention fungicides @ 2ml/lit of water at 12-15
days interval for2-3 timesin the field

10. Smut of sugarcane
CO: Ustilago scitaminea
 It causes 10-25% yield loss in
severe infections
 Ratoon crop may suffer more

11. Symptoms
 The most recognizable diagnostic feature
is the emergence of a “smut whip”
 Spindle leaves are erect before the
whip emerges
 Affected plant may produce tiller profusely
with the shoots being more spindly and
erect with small narrow leaves
(i.e., the cane appears “grass-like”)

12. Emergence of a
“smut whip”
Spindle leaves
are erect
before the whip
emerges
Affected plant produce tiller
profusely & grass-like
appearance

13. Favorable conditions
 Infected setts (Primary spread of the
disease)
 Wind (secondary spread by teliospore)

14. Control measures
 Smuttedwhipsfromthe fieldshould be removed very carefullyandburnt
 Avoid of practiceof ratooning
use resistantcultivars
 The smuttedcanes should not be usedas settsforplanting
 Settstreatedwith0.25%AgallolorAretanor inBM(4:4:50) for 5 min
 Settsalsobe treatedwith0.1%Hgcl2 or1% formalinsolutionfor5 minutes
and followedby covering undermoist cloth for2 hours
 Soaking of cane settsin solutionof triadimefonfungicide@ 2ml/litofwater

15. Wilt of sugarcane
CO: Fusarium sacchari
 It causes 10-15% yield loss in
epidemic areas

16. Symptoms
 The earliest symptom of the disease is the
stunting & unthrifty appearance of a few
isolated plants or small groups of plants
at half grown stage of the plants
 The most striking symptom is the yellowing
and or withering of the top when the crop is
getting ready for harvesting. The canes
become light and hollow
 The splitted cane shows brick red color
with individual vascular strands. There are
no white transverse bands as seen in the
red rot disease

17. Stunting & unthrifty
appearance of affected cane
Splitted cane
shows brick
red color with
individual
vascular
strands
Yellowing
and or
withering
of the top

18. Favorable conditions
 Infected setts
 injuries to setts
 Biotic stresses like nematode, root borer,
termite, scales, mealy bugs etc
 Abiotic stresses like drought and
water logging condition
 Moisture stress coupled with high
temperature and low humidity reduces
plant resistance to wilt

19. Control measures
 Crop debris should be destroyed
 Healthysettsshould used forplantation
 Proper maintenanceof soilmoistureand fertilitycanreduce the
disease incidence
 Settsshould be takenfromborer infestationfreecanes
 Ratooning shouldbe avoided
 A2-3 years croprotationshould follow
 Applicationof boron and manganese canreduce thewiltincidence
 SettstreatmentwithBavistin DF orKnowin50WPorAimcozim
50WPor Forastin50WPorGenuine50WPorCindazim50WP@
1glit ofwater
 Applicationof the above mentionfungicides@ 500g/hain the field

20. Pineapple disease of sugarcane
CO: Ceratocystis paradoxa

21. Symptoms
 Typical disease symptoms are detected in
setts after 2-3 weeks of planting
 Destroy the central soft portion i.e. paren-
chymatous tissues of the internodes by
rotting and then damages the buds
before germination
 The rotten portion become red and emits
a characteristic smell of pineapple
(production of ethyl acetate by the fungus)
 If germinates, the shoot may die after
reaching a height of one feet

22. Destroy the
central soft
portion by
rotting and
become red

23. Favorable conditions
 Infected setts
 injuries to setts
 Stalk damaged by borers, rat damage
or any such injuries
 Drought accelerates the damage

24.  Plantinghealthysetts
 The cutends of the settsshould paintedwithfungicidal
solutionorby coulter
 Settsshould be treatedin hotwaterat52°C for 30 minutes
 Setts treatment with Bavistin DF or Knowin 50WP or Aimcozim 50WP
orForastin 50WPor Genuine 50WPorCindazim50WP@1glitof water
 Applicationof the above mentionfungicides@ 500g/hain the field
Control measures

25. Ratoon stunting of sugarcane
CO: Clavibacter xyli or
Leifsonia xyli subsp. Xyli
 It causes yield reduction upto 40%

26. Symptoms
 The diseased cane usually show stunted
growth, reduced tillering, thin canes with
shortened internodes & yellowish leaves
 The typical symptoms of ratoon stunting
disease are found only after splitting
the cane longitudinally like two types
of discoloration are seen in the pith
 In mature canes, orange red discoloration
of vascular bundles seen at the nodes
In young canes, pink color can be seen
at the nodes

27. Affected cane show stunted
growth, reduced tillering,
thin canes with shortened
internodes yellowish leaves
Orange red
discoloration
of vascular bundles
at the nodes in
mature cane
Pink color at the
nodes in young cane

28. Favorable conditions
 Infected setts
 Harvesting implements (if
contaminated with the juice
of diseased canes)

29.  Using the disease free setts. Raising of
disease free setts in nursery by the
following measures-
 Proper drainage and optimum dosages of
fertilizers & irrigation should be provided
 Timely hoeing and weeding
 Weak plants should be uprooted & burnt
 Rouging of stools showing symptoms of wilt,
red rot and smut should also be done
 Any sett that fails to germinate within a
reasonable period should dug out and removed
 Setts should be treated in hot water
at 52°C for 30 minutes
 Use disease resistant varieties for cultivation
Control measures

30. Red stripe/ top rot of sugarcane
CO: Xanthomonas rubrilineans

31. Symptoms
 Initially water-soaked yellowish stripes
occur on leaves, later become dark red
 In severe infection, lateral buds show
reddening, terminal buds and spindle
leaves may die and causing top rot
 The vascular bundles exude foul smelling
yellowish gum on cut

32. Initially water
soaked yellowish
stripes
Dark red stripes

33. Favorable conditions
 Infected setts
 Wet seasons
 water stress due to drought &
water logging
 low temperatures

34. Control measures
 Systematic cutting down and burning of
the affected shoots (reduces the spread
of the disease)
 Disease resistant varieties should be used

35. Mosaic of sugarcane
Cause: Sugarcane mosaic virus
Vector: Different species of aphids
 In mosaic susceptible varieties the
yield loss could be upto 10%

36. Symptoms
 The most important symptom is the
appearance of pale green patches or
blotches in the green surface of the leaf
 These patches are not uniform in
size and shape
 Usually the patches are oval to elongated
and parallel to the midrib
 The youngest unfolded leaves show the
mottling very clearly while the symptoms
are not very clear in the older leaves

37. Appearance of
pale green
patches or
blotches in the
green surface
of the leaf

38. Control measures
 Healthy setts should be used for planting
 Disease free nursery can be raised by
treating the setts with hot water
 Systematic rouging should be followed if
the incidence is not very high
 Alternate hosts should be destroyed
 Disease resistant or tolerant varieties
should be used

39. White leaf of sugarcane
CA: Mycoplasma like organism (MLO)
Vector: Leafhoppers and psyllids

40. Symptom
 Initially, a single white or cream line parallel to
the midrib occurs, which can be seen from either
side of the blade
 Later, several straight white to light green to
yellow stripes develops parallel to the midrib
extending along the entire leaf length
 A mottled pattern of normal or light green dot,
spot, streak or patch may develop on a white
background, varying in size and shape
 The typical symptoms of sugarcane white leaf
(SWL) disease are total chlorosis of the leaf and
proliferation of tillers

41. White leaf
symptom
Chlorosis of the leaf and
proliferation of tillers
White leaf
symptom
in field

42. Control measures
 Healthy setts should be used for cultivation
 Malathion should be sprayed @ 0.16%
during early stage of crop growth to
control insect vectors
 Sett should be treated with hot water
at 54°C for one and half hours

43. Grassy shoot
CA: Mycoplasma like organism (MLO)
Vector: Aphids
 In severe cases, yield loss
could be up to 40%
 Its severity will be more
in ratoon crops

44. Symptoms
 Profuse tillering and bunchy or grassy
appearance of the stools are the main symptom
 Shoots growing from diseased shoots remains
dwarfed or stunted
 The leaves appear yellowish and in some cases
may entirely devoid of any pigment (white leaf)
 Leaves exhibit straight, narrow, long, white or
light green or yellowish streaks

45. Profuse tillering and
bunchy or grassy
appearance of the stools
Leaves exhibit
straight,
narrow, long,
white or light
green or
yellowish
streaks
Devoid of any
pigment (white leaf)

46. Favorable conditions
 Disease infected setts

47. Control measures
 Healthy setts should be used for cultivation
 Malathion should be sprayed @ 0.16%
during early stage of crop growth
 Sett should be treated with hot water
at 54°C for one and half hours

48. Thanks To All