Ring Spot of Wheat
Brown circles 1-4 mm diameter with tan to yellow to centres and yellow halo usually on a green leaf blade. In severe cases the tip of the leaf may turn may be completely yellow with brown rings.
Occasionally it may cause Black Point or blackening of the embryo area of the seed.
Thin spiky, black fungal structures up to 4 mm long can often be seen on the soil surface growing from previously infected grass residues or grain. These produce spores that infect the leaves of adjacent crop plants.
Species Affected:Wheat, Oats, cereals and grasses.
Biology:Occurs on most grass species.
Life Cycle:Origin and History:
Usually fairly evenly distributed through the crop.
Very common in southern Australia.
Significance:Rarely causes economic damage.
Management and Control:Control grasses in the year before sowing Wheat.
Use rotations where Wheat follows a broad-leaved crop.
Related and Similar Species:Common Leaf Spot of Wheat (Drechslera verticillata)
Wirrega Blotch (Drechslera wirreganensis)
Collated by HerbiGuide. Phone 08 98444064 or www.HerbiGuide.com.au for more information.