Uniform yellow tips of leaves with stripes running down the leaf blade. The leaf margins may become reddened or purple with age. The leaves are not killed by the infection but the whole plant may be dwarfed especially with early infection. Plant tops and roots may be stunted. Heads may be sterile. There are often patches of infection within the crop. Root stunting can cause a number of symptoms typical of water and nutrient shortages.
Species Affected:
Barley, Oats, Wheat.
Biology:
Caused by a group of closely related viruses that infect cereals and grasses.
It is transmitted by aphids with the Corn Aphid, Wheat Aphid, Oat Aphid or Rose Grain Aphid being the most common vectors.
It is not transmitted on seed or plant residues.
Epidemics are more common when Aphids have built up with cool summer weather and when volunteer cereals have survived over summer or there is infected perennial grasses close by.
Most damage when they invade young crops. Early sown crops in low rainfall areas and long season crops in high rainfall areas are usually the most susceptible because these correspond with the typically high aphid numbers present in autumn and spring.
Life Cycle:
Transmitted by Cereal Aphids usually early in the season in April/May or in spring in August.
Origin and History:
Distribution:
Usually patchy.
Significance:
Can cause significant yield losses and yield loss can occur with little apparent symptom.
Heavy yield losses are usually associated with early infections on early sown crops.