Barley Yellow Dwarf Barley yellow dwarf, also known as red leaf, is a virus disease that can cause serious damage to oats, wheat, barley, and many grasses. Leaves of oat plants infected with barley yellow dwarf turn red to purple in color and tend to twist or curl inward. The green tissue of diseased plants may be a darker green than that of healthy plants. Plants infected early may be severely dwarfed and premature death may result. The barley yellow dwarf virus is spread by aphids.
Aphids acquire the virus by feeding on infected plants.
From 1 to 4 days later the aphids are able to transmit the virus to healthy plants. The virus survives between small grain crops in a variety of annual and perennial grasses. No oat varieties that are highly resistant to barley yellow dwarf are known. Delaying planting until late fall or early winter to avoid high aphid activity may lessen the disease. E-mail William S. Gazaway , Extension Plant Pathologist, Auburn University, Alabama.