about diseases of sugarcane

1. BACTERIAL,VIRAL & PHYTOPLASMAL
DISEASES OF
SUGARCANE AND THEIR
MANAGEMENT
BY
Abhijithv
ROLL NO:2012-20-105

2. INTRODUCTION
• Sugarcane is not only cash crop for the growers, but
it is main source of white crystal sugar. It also
provides grower with a very good substitute of sugar
as ‘gur’ and ‘khandsari’ (brown sugar).
• Sugarcane tops serve as fodder for cattle, baggage
and leaf trashes as fuel, stubble and roots as organic
manure and crop residues as mulch and compost.
• It may also be kept in mind that sugarcane leaves
are used as substrate for the artificial cultivation of
edible mushrooms.

3. • There are many constrain, including the heavy losses,
caused by a number of diseases to the sugarcane
crop.
• More than 50 diseases are reported in sugarcane,
fungi, bacteria, viruses and nematodes cause the most
destructive diseases.
• These all diseases are injurious in some areas, in
some years and on some plant parts.

4. FUNGAL DISEASES

5. WHIPSMUT
(Ustilago scitaminea)
Symptoms:
• The affected canes
produce long, black
whip-like and coiled or
curved shoots, which
are covered with a thin
silvery membrane,
containing masses of
chlamydospores of the
fungus.

6. •The smutted shoots may arise from the top of the cane or
from lateral buds. Later on that membrane ruptures and
releases a multitude of spores, which contaminate soil and
the standing crop.
•In certain cases, the infected plants remain stunted in
growth with increased tillering of little value. The diseased
plants are unfit for use.
Perpetuation:
•The disease is carried over from year to year by ratooning
or planting sets taken from smutted shoots of cane. Soil
borne infection may also takes place, while wind
disseminates disease.

7. Control:
Following measures are suggested for prevention as well as
control of the disease:
1) Sets from smutted canes should not be used for planting.
2) Seed-sets should be disinfected either in 0.1% mercuric
chloride or formaline solution for 5 minutes followed by 2
hours covering under a moist cloth. The other effective
chemicals available in market may also be used.
3) Hot water treatment of sets at 52°C for 18 minutes can
help eliminate the internal infection.
4) Smutted plants should be rouged out and burnt before the
bursting of the spores.
5) Ratooning of the diseases crop should be discoursed.
6)Use of resistant varieties should be encouraged.
7) Planting should be done in healthy soil.
8) Autumn planting of sugarcane should be avoided.

8. RredRot
(Colletotrichum falcatum)
Symptoms:
• The disease first
appears as red bright
lesions on mid rib of
leaves and shows
itself as drooping
and changing of
colour of upper
leaves.

9. • Withering of the leaves proceeds downwards. Usually third
or the fourth leaf from the top is affected and shows drying
at the tip.
• The pith becomes red and later on brown. In sever cases
complete destruction of the stools is brought about.
Perpetuation:
• The disease is perpetuated from year to year by planting
sets from infected canes and also through the fungus that
remains viable on diseased canes lying in the field or
ratooning of the crop.
Control:
• Non ratooning and use of resistant varieties are
recommended. Disinfecting of sets with effective and easily
available chemicals.

10. BACTERIAL DISEASES

11. RATOON STUNTING
• PATHOGEN: Clavibacter xyli
subsp. xyl (Xylem limited
fastidious bacteria)
• HOST: Sugarcane

12. SYMPTOMS
• stunted growth of clumps
• reduced tillering,
• Thin stalks with shortened internodes and yellowish
foliage (mild chlorosis).
• Coryneform Xylem limited fastidious bacteria infects the
vascular bundles of canes . When mature canes are split
open, vascular bundles appear discolored.

13. • In young canes, pink colour in the form of minute pin
head like areas near the nodes.
• reduced length, girth and the number of canes per clump

14. Transmission
• The disease spreads through use of diseased setts.
• spreads through cane harvesting implements
contaminated with the juice of the diseased canes.
• Maize, sorghum, Sudan grass and Cynodon are some of
the collateral hosts of the pathogen.

15. Management
• Grow setts from disease free field.
• Remove and burn the clumps showing the disease
• Sterilization of cutting knives with spirit or any other
antiseptic solution
• Hot air treatment of setts at 52˚ C for 8 hours or hot
water treatment at 52˚ C for 2 0 minutes or aerated
steam treatment at 50˚ C for 1 hour.

16. RED STRIPE
(Xanthomonas Rubrilineans)
• Symptoms
• Appears in may
• Leaves show red streaks

17. • Control
• Rogue out and bum affected plants if small in number
• Otherwise discard tile whole field
• Fresh sowings are done with resistant varieties in well
drained soils

18. LEAF SCALD
( Xanthomonoas albilinean)
• Leaf scald was first recognized as a bacterial disease of
sugarcane in the 1920s.

19. SYMPTOMS
• The most typical symptom is a white pencil line streak
about 1–2 mm wide on the leaf that extends from the
midrib to the leaf margin running parallel to the veins
• A diffuse yellow border of varying widths runs parallel
to the pencil line streak. The pencil line may have areas
of reddish discoloration along part of its length
• later, necrosis develops from the leaf tip or leaf margin,
and finally extends the entire leaf (Figure 2). Leaves
look burned and curl inward, giving the foliage a
scalded appearance, hence the name for the disease

20. • partial or complete chlorosis of the leaf blade

21. • Causal Agent
• In the early stages of infection, the leaf scald bacterium
is restricted to the xylem elements of the vascular
bundles in the white pencil line streaks. It is generally
not found in the surrounding chlorotic leaf tissues. A
phytotoxin called albicidin has been isolated from
chlorosis-inducing strains of X. albilineans. This
phytotoxin inhibits chloroplast differentiation and thus
disrupts photosynthesis. In the late stages of infection,
the pathogen exits the xylem and invades other tissues,
causing the appearance of lysigenous cavities in the stal

22. GUMMING DISEASE
(Xanthomonas vasculorum)
• 2ND Disease to be natal

23. SYMPTOMS
• There are two phases mild and accute
the symptoms of mild is on leaves
• Yellow stripes with varying length and upto 1/8 of an
inch in width develop from infection site to both the tip
and base of leaf following venation
• Sometimes infection passes from leaf to stem by way of
leaf sheath and get advanced
• If LS of stem taken slow oozing of yellow red gum from
cut ends of vascular part of stem

24. • If accute
• Cavities are formed in softer parts in the vicinity of
growing point
• These are filled with gummy material
• Chlorosis in the form of white pathes-is a
secondary symptom due to toxin produced by
bacteria

25. TRANSMISSION
• By planting infected setts
• The bacteria ooze from infected plant is carried out to
healthy plant by wind,rain through small injuries in
leaves

26. CONTROL
• Growing resistant varities
• It is difficult o control disease by eradication or roguing
if advanced

27. RED STRIPE
(Xanthomonas Rubrilineans)
• Symptoms
• Appears in may
• Leaves show red streaks

28. • Control
• Rogue out and bum affected plants if small in number
• Otherwise discard tile whole field
• Fresh sowings are done with resistant varieties in well
drained soils

29. VIRAL DISEASES

30. SUGARCANE MOSAIC VIRUS (SCMV, Potyvirus group)
Symptoms:
• Mottling of young
crown leaves
showing a definite
pattern of alternating
dark and light green
coloured patches of
varying size and run
parallel to the midrib
of leaf.

31. Transmission:
Transmitted through mosaic infected sets and an aphid.
Alternate hosts:
Maize and sorghum.
Control:
Planting virus free sets and avoid ratooning of diseased
crop.

32. PHYTOPLASMA DISEASES

33. GRASSY SHOOT DISEASE
• Pathogen: Phytoplasma
• Hosts: Sugarcane

34. SYMPTOMS
• proliferation of tillers, which give it typical grassy
appearance, hence the name grassy shoot disease.
• The plants appear bushy and ‘grass like’ due to
reduction in the length of internodes,
• premature and continuous tillering.

35. • The leaves of infected plants do not produce
chlorophyll, and therefore appear white or creamy
yellow.
• The leaf veins turn white (Albino) first as the
phytoplasma resides in leaf phloem tissue. include leaf
chlorosis,
• no cane formation.

36. TRANSMISSION
• Transmitted via seed setts/planting material
• by phloem feeding vectors as aphids
• Phytoplasma infection also spreads through insect
vectors

37. Management
• Control vector by spraying Malathion or Dimethoate @
2ml/lt
• Plant disease free setts
• Remove and burn the infected clumps periodically
• Avoid ratooning in problem areas
• Hot Water Treatment (HWT) of setts at 52˚ C for
30min or Aerated Steam Therapy (AST) at 50˚ Cfor 1hr
followed by steeping in fungicidal solution of
carbendazim @ 0.05% for 15 minutes.

38. Thank You