Scald of Barley

Rhynchosporium secalis

Description:

Initially appears as water soaked areas on the leaf, sheath or stem that turns grey green then develops bleached centres with a dark brown rim and often with a yellow halo. The upper stem rarely has lesions. Heads and grain can be affected when rain falls after heading.

Species Affected:

Barley, Barley Grass.

Biology:

More common in wet conditions with early sown crops.
Survives on residues of Barley and Barley Grass.
Spores are spread by raindrop splash from the residues to the plant and then from plant to plant.
Can be seed borne.
Varieties differ widely in their tolerance and the tolerance appears to differ between seasons and regions.

Life Cycle:

Origin and History:

Distribution:

Most common in South Australia.

Significance:

Foliar fungicides are usually only economical on crops with a yield potential of more than 3 t/ha.
It causes most damage in seasons with frequent rain on early sown crops in paddocks with infected Barley or Barley Grass residues in the medium to high rainfall areas.

Management and Control:

Sow resistant varieties. Forrest is resistant. O'Connor is moderately resistant. See HYPERLINK \l "_Disease_Susceptibility_of_Barley Va" Disease Susceptibility of Barley Varieties.

Burn, bury or graze infected Barley and Barley Grass straw.
Use a seed treatment or flutriafol(Impact®) on fertiliser in furrow to control early infections. Economic responses have been recorded in the higher rainfall areas.
Don't use seed from areas where head infection has occurred.
For early infections use a foliar fungicide at the 6-7 leaf stage of the crop. Economic responses may be achieved on crops with a yield potential of more than 2 t/ha.

Related and Similar Species:

Halo Spot of Barley (Pseudoseptoria stomaticola)

References:

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.