Halo Blight of Oats
Pseudomonas syringae pv. coronafaciens

Description:

Light green, water soaked spots, up to 1 cm diameter, appear initially and enlarge to oval spots with a yellow centre and a yellow green halo. As the disease progresses, the spots merge into brown irregularly shaped blotches. The leaves may wither and die, starting from the tip.

Species Affected:

Oats.

Biology:

Survives on crop residues and seed.

Spread by raindrop splash, direct contact and aphids or other insects.

Moist weather favours disease spread and warm dry weather stops spread.

Life Cycle:

Origin and History:

Distribution:

Significance:

Management and Control:

Plant resistant varieties. See Disease Susceptibility of Oat Varieties.

Plant clean seed.

Avoid planting into Oat stubble.

Burn, bury or graze Oat stubbles.

Related and Similar Species:

References:

1207

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 for more information.