Barley Yellow Dwarf

Your lawn may be harboring a plant pandemic that’s killing your corn. That disease is called barley yellow dwarf (BYDV). More than 20 different aphid species spread this viral disease, and it is found around the world.

Healthy green wheat (left) next to wheat infected with barley yellow dwarf (USDA ARS) Public Domain

Barley yellow dwarf host plants

Barley, corn, and the ryegrass and fescue in your lawn are not the only plants that can become infected with this disease. All members of the grass family (Poaceae) are susceptible.This means that your millet, oats, rice, rye, ryegrass, sorghum, sugarcane, and wheat can also become infected with barley yellow dwarf.  It is the costliest disease worldwide of all cereal crops. ​

Oats infected with barley yellow dwarf (Agronom) CC BY-SA 3.0

Barley yellow dwarf symptoms

This disease is tricky to identify. It looks similar to root and crown diseases, nutrient deficiencies, environmental stresses, and wheat streak mosaic. Closer inspection of unhealthy-looking patches in your lawn or grass family crops may reveal purple, red, orange, or yellow discolorations. These discolorations are seen from the tip downward and from the edges to the midrib. Infected leaves are often shorter, stiffer, and more upright than healthy leaves. Stunting is common due to shortened internodes. You may also see serrations along leaf edges and some infected plants start growing into a corkscrew shape.

Wheat plant infected with the barley yellow dwarf virus (William M. Brown Jr., Bugwood.org) CC BY 3.0 US

Barley yellow dwarf prevention

Fungicides are ineffective against barley yellow dwarf. Instead, good cultural practices are your best plan of attack. Since aphids are the vectors for barley yellow dwarf, planning your planting schedule around aphid migrations can help reduce the likelihood of disease occurring. I know that aphid migrations aren’t usually mentioned on the evening news. But regularly monitoring your plants for aphids will make it very clear when they arrive and start reproducing. Planting seeds at times when aphids and seedlings are less likely to occur at the same time will help reduce disease. These other tips will also help keep your garden plants healthy:

• Plant resistant cultivars.
• Eliminate grassy weeds and volunteer cereals.
• Spray heavy aphid infestations with insecticidal soap.
• Encourage beneficial predators and parasitic wasps with insectary plants.