This document summarizes the grassy shoot disease of sugarcane, caused by the phytoplasma pathogen. It affects sugarcane throughout its growth stages and causes severe damage to ratoon crops. Initial symptoms include thin, white young leaves and profuse white or yellow tillering below. Later symptoms are stunted growth with reduced internodal length and axillary bud sprouting. The phytoplasma is transmitted by aphid vectors and spreads primarily through diseased setts and cutting knives. Control methods include using resistant varieties, rogueing infected plants, treating setts with heat, and spraying insecticides to control aphid vectors.

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Prof. Shubhangi Pradeep Patil,
Department of Botany,
Miraj Mahavidyalaya, Miraj
Grassy Shoot Disease of Sugarcane

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▪ Host- Saccharum officinarum (Sugarcane)
▪ Causal Organism: Phytoplasma

3. z Occurrence:
▪ Grassy Shoot disease is one of the most
important diseases caused by Phytoplasma and
affecting sugarcane crop throughout its crop
growth stages. It is observed in many states of
India. This disease causes severe damage to the
ratoon crop.

4. z Symptoms:
▪ Initial symptom appears in the young crop of 3 –
4 months age as thin papery white young leaves
at the top of the cane.
▪ Later, white or yellow tillers appear in large
number below these leaves (profuse tillering).
▪ The cane becomes stunted with reduced
internodal length with axillary bud sprouting.
▪ This disease appears in isolated clumps.

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Symptoms:
Whitening of leaf Profuse Tillering
Reduced Internodal Length Grassy Shoot

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Causal Organism:
▪ Phytoplasmas are obligate intracellular
parasites of plant phloem tissue and of the
insect vectors that are involved in their plant-
to-plant transmission. Phytoplasmas were
discovered in 1967 by Japanese scientists
who termed them mycoplasma-like
organisms.

7. z Disease cycle
▪ The primary spread of the phytoplasma is
through diseased setts and cutting knifes. The
pathogen is transmitted secondarily by aphids
viz., Rhopalosiphum maydis, Melanaphis
sacchari and M. idiosacchari. Sorghum and
maize serves as natural collateral hosts.
Rhopalosiphum maydis
Melanaphis sacchari

8. z Control Measures/ Disease Management
Cultural method:
•Growing resistant varieties viz., Co 86249, CoG 93076 and CoC 22
•Avoid ratooning if Grassy Shoot Disease incidence is more than 15 % in the
plant crop
•If disease symptoms are visible within two weeks after planting, such plants can
be replaced by healthy plants.
•Uprooted infected plants need to disposed of by burning them.
Physical method:
•Rogue out infected plants in the secondary and commercial seed nursery.
•Treat the setts with aerated steam at 50°C for 1 hour to control primary infection.
•Treating them with hot air at 540C for 8 hours and spraying twice a month with
aphidicides.
Chemical method
•Spray dimethoate @ 1ml in 1 litre of water to control insect vector
•Apply pesticide methyl-demeton @ 2ml/lit of water for controlling aphids.

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