Description:
Honey coloured elliptical lesions occur on the lower stems within 4 cm of ground level causing stem breakage or bending. The lower leaf sheath normally needs to be peeled back to see the lesion. Young lesions may have a darker border but as they age they tend to go darker in the centre giving an eye-like appearance. Older lesions surround the entire stem and my be up to 4 cm long. A sooty mould is under the leaf sheath near where the stem is weakened. Stems fall in random directions which helps distinguish it from lodging due to wind.Species Affected:
Wheat is more susceptible than Barley.Biology:
Spread by air borne spores over long distances or raindrop splash from infected stubble.Life Cycle:
In cool, moist autumn conditions infectious spores are produced on infected cereal or grass stubbles. The spores are spread by wind to seedlings in neighbouring crops or by raindrop splash and direct contact onto seedlings growing in stubble. The spores invade the coleoptiles and leaf sheaths and the fungus grows through to the stem. Lesions can usually be seen by mid tillering to early stem elongation. The fungal growth shows as a sooty mould under the sheath and weakens the stem causing lodging. Spores survive over the summer in cereal and grass straw.Origin and History:
Distribution:Significance:
In severe infestations the whole crop may lodge before harvest.Management and Control:
Avoid continuous cereal rotations.Related and Similar Species:
References:Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 for more information.