The Pests & Diseases of Beets

Major Pests

• Major pests found on beets include beet leaf miners, aphids and flea beetles. Beet leaf miners are small whitish maggots that feed on leaf surfaces, causing winding trails in the leaf tissue. Removing and disposing of infected leaves control the maggots. Aphids are small, black insects that suck out the beet's fluids, causing curled, yellow leaves. Aphid infestations are treated with insecticides. Flea beetles are tiny, brown insects that chew holes in the leaves giving them a lacy appearance. They are destroyed by spraying pesticides, such as Sevin or Rotenone.

Minor Pests

• Minor pests found on beets include aster and beet leafhoppers. Leafhoppers are yellowish-green, winged insects that feed on the beet's foliage by sucking out the sap, causing leaves to curl. Spraying pesticides controls severe leafhopper infestations.

Fungal Diseases

• Beets infected by black root produce wilting foliage and black rotted roots, which are caused by a fungus that infects the soil. The disease is controlled by maintaining well-drained soil and rotating crops. Verticillium wilt is a fungal disease that attacks the beet's roots, causing the leaves to brown and wilt. Treatment is in form of fungicides. Downy mildew appears on the beet's leaves, causing them to thicken, pucker and curl. Powdery mildew causes a white coating on the leaves, causing them to yellow and die. Both conditions are controlled with fungicides.

Bacterial Diseases

• Beet leaf spot disease causes small, round brown lesions to appear on leaves and stems, making the entire beet inedible. Treatment for the bacterial disease involves removing and discarding infected plants and rotating crops. Beet mosaic disease causes yellowish spots on young leaves to appear as rings. Treatment involves spraying bactericides. Beet yellow stunt involves young leaves becoming dwarfed, twisted, malformed and spotted. Controlling the disease involves discarding infected plants.

Viral Disease

• Curly top disease causes young beet plants to die quickly. Once infected, young leaves roll inward and pucker, lesions appear, the veins swell and the plant wilts. Aster and beet leafhoppers are known to spread the virus. Removal of infected plants and controlling weeds, which harbor leafhoppers, prevents the spread of the disease.