vegetables

52
R&D
Farm Productivity,
Resource Use
& Management
Vein-clearing symptoms of a sweetpotato virus on an indicator plant, Ipomoea setosa.
Sweetpotato project showing steady progress
AUSTRALIAN SWEETPOTATO GROWERS INC. AND THE QUEENSLAND DEPARTMENT
OF AGRICULTURE AND FISHERIES ARE NEARLY HALFWAY INTO A RESEARCH PROJECT
FOCUSING ON MANAGING SWEETPOTATO VIRUSES AND DEVELOPING PLANTING BED
AND VIRUS MANAGEMENT GROWER GUIDES. THERE HAS BEEN SUCCESS SO FAR, WITH
SWEETPOTATO GROWERS ACTIVELY ENGAGING IN THE PROJECT.
Sweetpotato viruses can
have a major impact
on the yield and quality of
sweetpotatoes in Australia.
There are currently five
main viruses known to occur
in Australia. Sweetpotato
feathery mottle virus (SPFMV)
and Sweetpotato leaf curl
virus (Begomovirus group) are
both common. Sweetpotato
virus G (SPVG), Sweetpotato
chlorotic fleck virus (SPCFV)
and Sweetpotato collusive virus
(SPCV) are rare.
In response to this, the
Australian Sweetpotato Growers
Inc. in association with the
Queensland Department of
Agriculture and Fisheries,
is conducting a project
commissioned by Horticulture
Innovation Australia. Entitled
Sweetpotato project, the
research focuses on managing
sweetpotato viruses in Australia
as well as developing new virus
diagnostics and plant bed
management in the industry.
Most plant viruses are
transmitted between plants
by sap-sucking insects, which
are called vectors. SPFMV and
SPVG are aphid-transmitted,
while Begomoviruses are spread
by whiteflies. Vectors of SPCFV
and SPCV are currently unclear.
Apart from cropped
sweetpotatoes, other plants
are important in the life cycle
of many viruses and their
vectors. Both viruses and
vectors are able to survive
adverse conditions and
between crop cycles in
weeds, volunteer crop plants,
abandoned crops and discarded
sweetpotatoes. Infected plants
cannot be cured.
The most critical strategy
for managing sweetpotato
viruses is using clean planting
material sourced from a
reliable supplier. The key to
managing sweetpotato viruses
in commercial crops is reducing
the probability and rate of
virus re-infection. This can be
achieved in the following ways.
Be vigilant in maintaining
nursery beds as virus- and
vector-free as possible.
Ensure no sweetpotato
plants or materials (apart
from current nursery beds or
growing commercial crops)
exist on-farm. This means
removing old crops and
volunteer plants, including
dump sites for reject roots.
As far as practical, eliminate
weeds related to
sweetpotatoes and vegetation
that supports vector insects
around the farm.
Report any unusual plant
symptoms to appropriate
agencies, as there are
important sweetpotato virus
diseases not currently in
Australia that could severely
impact the industry.
The Sweetpotato project has
already demonstrated significant
value to Australian sweetpotato
growers, who have been
engaged in the project since its
inception.
This project had two major
achievements during the
2014/15 season – not only were
grower guides on management
of sweetpotato-infecting viruses
and planting bed management
prepared, but the project
achieved significant levels of
attendance at industry targeted
extension events.
The planting bed and virus
management grower guides
developed under this project
are a valuable resource for both
growers and researchers. Both
guides are informative and easy
to read and will no doubt be
highly useful reference tools for
years to come.
Coupled with these guides
have been extension events