Sugarcane Grassy shoot and Ratoon stunting diseases
1. GRASSY SHOOT AND RATOON STUNTING
DISEASES OF SUGARCANE
COURSE TEACHER:
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)
STUDENT:
Mr. VASANTHAKUMAR M
ID. NO. 2016021050
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
6. SIGNIFICANCE OF THE DISEASE
Grassy Shoot disease is one of the most important
diseases caused by Ca. Phytoplasma.
It is observed in many states of India.
This disease causes severe damage to the ratoon
crop.
7. ECONOMIC LOSS
Its reduced germination of setts from diseased
canes.
Stunted growth and poor juice quality.
Infections upto 10% do not cause significant
reduction in yield and number of milleable canes.
The threshold level for yield reduction is 15%
infection.
8. DISTRIBUTION
It was first noticed in india in 1919 in Maharashtra.
Subsequently found it was in Andra Pradesh, Tamil Nadu,
Orissa, Bihar, Uttar Pradesh, Punjab, and Rajasthan also.
Outside india, its reported from Myanmar, Sri Lanka, and
Sudan.
9. SYMPTOMS
Profuse tillering and grassy apperanance of the stools.
Shoots growing from diseased setts remain stunted.
The leaves are narrow and small, like grass leaves.
The canes are thin with short internodes, giving a
bunchy or grassy appearance to the clump.
10. SYMPTOMS
The leaves of infected plants do not produce
chlorophyll, and therefore appear white or creamy
yellow.
The leaves appear yellowish and in some cases may
be entirely devoid of any pigment (white leaf).
This symptoms can be seen prominently in the
stubble crop.
The lateral buds sprout before the normal time on
growing cane.
11. SYMPTOMS OF GRASSY SHOOT DISEASE
Grassy Shoot Disease in sugarcane ...agropedia.iitk.ac.in
13. SYSTEMATIC POSITION
Domain : Bacteria
Phylum : Tenericutes
Class : Mollicutes
Order : Acholeplasmatales
Family : Acholeplasmataceae
Genus : Ca. Phytoplasma
Species : oryzae
14. CAUSAL ORGANISM
Its caused by Phytoplasma.
One of the destructive pathogens of sugarcane.
Phytoplasmas are spreading at an alarming rate,
adversely affecting yield of sugarcane crop.
15. PATHOGEN CHARACTER
Phytoplasmas, formely called Mycoplasma like
organisms (MLOs).
Its large group of obligate, intracellular, cell wallless
parasites.
Its found in the sieve cells of infected plant.
Two types of bodies are noticed, spherical bodies of
300-400 nm diameter and filamentous bodies of 30-53
mm diameter.
16. TRANSMISSION
The grassy shoot disease is primarily transmitted
through the diseased seed material and perpetuated
through ratooning.
This disease is also transmitted by
a) Mechanically by Cutting knife,
b) Insects
-Leaf hopper-Saccharosydne saccharivora
-Aphids -Melanaphis sacchari
c) Dodder.
17. TRANSMISSION
Aphids - Melanaphis sacchari
Optimum acquisition feed period is 15 mins.
Single infected aphid can transmit the
pathogen, optimum number is 15.
Transmission is non persistent manner.
The pathogen has been transmitted from sugarcane to
sorghum and from sorghum to sugarcane by using
aphids.
Sorghum is also natural host of the GSD
phytoplasma.
20. DISEASE MANAGEMENT
Phytosanitary control measures are important.
Grow resistant varieties viz., Co 86249, CoG 93076,
Coc 22.
Use of healthy diseased free planting material
collected from seed nursery for planting.
21. DISEASE MANAGEMENT
Heat therapy: seed/planting material should be treated
with hot water (50oC for 120 Min.) or moist hot air
(54oC for 2½ hrs.) that eliminates the Pathogen from
diseased seed materials.
Ratooning of affected crop must be avoided.
Crop rotation may be employed to reduce inoculum
in the field.
22. DISEASE MANAGEMENT
Roguing of affected stools and destruction – Mass
eradication may help consistent reduction in
inoculum in the area.
Control of insect pests.
Set treatment with 500-ppm solution of ledermycin
(an antibiotic) before planting.
24. SIGNIFICANCE OF THE DISEASE
This is one of the major causes of degeneration,
deterioration, or “running down” of several
commercial varieties of sugarcane.
It occurs not only in India but also atleast in 40 other
countries that grow sugarcane and is considered most
important disease.
Because of its cryptic and chronic nature it is cited as
an example of typical endemic disease.
25. ECONOMIC LOSS
Its caused by poor germination, extra cultivation cost
in removal of weeds, low yield of canes, and loss of
ratooning capacity of the cane.
Extent of loss depends on the cultivar and its growing
conditions.
The loss is increased many fold when RSD occurs
along with the mosaic disease of the same crop.
Yield losses from 5-60% depending on the
susceptibility of the variety and the weather
conditions.
26. DISTRIBUTION
RSD is found in all districts in eastern Australia, but
it has not been found in Western Australia.
The incidence of the disease is associated with the
degree to which control measures are followed.
Generally, RSD is present in fewer than 5% of fields
in Australia, although in some districts RSD
incidence is much higher.
27. SYMPTOMS
RSD produces no easily visible symptoms other than
stunting.
Diseased fields often have an ‘up-and-down’ appearance
due to differing levels of stunting in adjacent stools.
The only other visible symptoms are red-orange dots or
‘commas’ in the vascular traces in the nodal tissue (which
can be seen when stalks are sliced open with a sharp
knife), and a faint pink discoloration of the growing point
of young plants.
28. SYMPTOMS OF RATOON STUNTING DISEASE
Ratoon stunting disease in sugarcane ...agropedia.iitk.ac.in
29. SYMPTOMS OF RATOON STUNTING DISEASE
Ratoon stunting disease in sugarcane ...agropedia.iitk.ac.in
30. CULTURE OF Leifsonia xyli
http://agritech.tnau.ac.in/crop_protection/images/sugarcane_diseases/5.3.jpg
31. MICROSCOPIC VIEW OF Leifsonia xyli
http://agritech.tnau.ac.in/crop_protection/images/sugarcane_diseases/5.4.jpg
32. CAUSAL ORGANISM
Domain : Bacteria
Phylum : Actinobacteria
Order : Actinomycetales
Family : Microbacteriaceae
Genus : Leifsonia
Species : L. xyli
Subspecies: L. x.subsp. xyli
33. CAUSAL ORGANISM
The disease is caused by the bacterium Leifsonia xyli
subsp. xyli (Davis et al.).
It infects the xylem (water transport) vessels of the
sugarcane plant.
The bacterium is rod shaped, typically with a slight
bend and measures 0.25-0.5 μm by 1-4 μm.
34. PATHOGEN CHARACTER
The organism that causes RSD is, Leifsonia
xyli subsp. xyli, a small aerobic bacterium.
The genus of the pathogen was previously
called Clavibacter.
36. SPREAD
The two primary methods of spread of the disease are
by planting infected cuttings and by use of
contaminated cutting implements.
The bacterium is highly contagious and can be spread
for many metres down a row after a planter or
harvester cuts a diseased stalk or plant.
The recirculating fungicide spray system on planting
machines can carry the bacteria and spread the
disease.
38. CULTURAL METHOD
Select healthy setts for planting.
Field should maintain at proper sanitation.
Ungerminated setts should be removed and fill the
gap with new setts which should be treated before
planting.
39. MECHANICAL METHOD
Treat the setts with hot water at 50°C for about 2
hours this gives 100 per cent control.
A temperature higher than this would kill the cane
and lower temperature than the specified enables the
pathogen to survive.
Aerated steam therapy eliminates the pathogen from
the infected canes.
Use of disinfectants to clean seed cutting tools which
would reduce the chance of spread of pathogen from
the infected to healthy setts.
40. CHEMICAL METHOD
Chemical disinfectants that may be used on cane
cutting knives includes, Lysol, Dettol, ethanol, Mirrol
and Roccal. Atleast 5 minutes of contact with the
cutting surface is needed to assure disinfection.
