Australia
July 16, 2008
Source:
GRDC's The Crop Doctor
With no registered chemicals for
controlling bacterial diseases in oats, the most effective
options are a two year rotation that includes a non-cereal crop
and using certified clean seed.
Dominie Wright and Megan Jordan of the Department of Agriculture
and Food WA (DAFWA) investigated the main bacterial disease of
oats in WA and their Grains Research and Development Corporation
(GRDC) supported research diagnosed stripe blight infection on
leaf samples and in seed samples.
After primary infection in the grain oat or hay crop, secondary
infection occurs throughout the canopy.
The bacteria enter the plants through stomata on the leaves, or
through wounds and are spread by wind and rain. Insects will
also spread the disease if the plant is exuding bacterial ooze.
So far, stripe blight and halo blight have only been detected on
oats in WA, but halo blight is reported to have a wider host
range that includes wild oat, rye, barley, wheat, maize,
perennial ryegrass and most grasses, including prairie grass.
Ms Wright and Ms Jordan have developed a seed test to detect
stripe blight caused by Pseudomonas syringae pv. striafaciens.
The test can detect a level of one per cent infection in 250
grams of seed.
According to Ms Wright, more work is required to determine how a
one per cent infection in seed translates to loss of grain yield
or marketability of hay crops.
Although there is little published evidence of seed transmission
of stripe blight, she believes the pattern of spread and
occurrence in WA indicates seed-borne transmission. |
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The Crop Doctor is
GRDC Managing Director,
Peter Reading |
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