Sugarcane Leaf Scald Disease:
essential data |
Disease Name, Other
Names, Crops Affected Causative
Agent, Synonyms,
Description
of the Agent Symptoms Prevention
and Treatment
Other Comments |
| Disease name |
Sugarcane Leaf Scald Disease |
| Other Names |
None |
Causative Agent
|
Xanthomonas albilineans |
| Synonyms |
- Agrobacterium albilineans
- Bacterium albilineans
- Phytomonas albilineans
- Pseudomonas albilineans
|
| Crops Affected |
Sugarcane |
| Description of the Agent |
X. albilineans is a bacterium belonging to the biochemically
versatile gamma Proteobacteria. It is Gram negative (stains red in
the Gram stain), aerobic and does not form spores. It can survive
in cane stubble and on agricultural implements and these are an important
mechanism of spreading the disease. It can also survive in a number
of grasses, including elephant grass and may be transmitted from them
to sugarcane.
|
| Symptoms |
The disease can be latent, it can develop unseen for some time and
when symptoms first appear, the plant is already seriously infected.
The first sign of the disease is the development of "pencil lines"
of white with yellow borders following the veins on the leaf that
lead to necrosis (death) of tissue. The term "scald" for the disease
comes from areas of the leaf that loose their color and become a pale
green (chlorotic) as they fail to produce chloroplasts. As the disease
progresses, the vascular tissue involved in the transport of water,
nutrients and metabolites is damaged and leaves begin to die from
the edges towards the midrib.
The disease can prevent shoots from developing and in mature plants
it forces the development of side shoots that often die when still
small. |
| Prevention and Treatment |
The best response to the disease is the use of resistant
varieties of sugarcane. Seedlings can be decontaminated by a hot water
treatment (3h at 50°C) that is an extension of a method used to
control another sugarcane disease (ratoon stunting disease) Tools
such as cane cutting knives and harvesters must be sterilized with
a phenolic disinfectant such as Lysol, alcohol, or bleach if infection
is suspected. There are no treatments, such as antibiotics, for the
disease. |
| Other Comments |
The latency of the disease makes it a particularly dangerous
anticrop weapon as it can become well established before it is first
recognized in the crop. Crop losses can be severe and this is made
worse by the lack of a suitable treatment beyond prevention.
The disease attacks the vascular tissues: the vessels through
which water and nutrients flow around the plant.
|