This bacterial disease is particularly damaging to vinifera grapes and interspecific hybrids. The major symptom is fleshy galls on the lower trunk near the soil. Galls may also form up to 3 feet high on trunks and canes and on below-ground plant parts.
Initially, galls are cream-colored and fleshy, but later they turn brown and woody. Affected vines appear weak, and portions of the vines above the galls may die. They may also be more prone to freeze injury. Young vines may be girdled by galls in one season. The crown gall bacterium lives in the soil and enters the plants through wounds caused by freeze injury, mechanical damage, grafting or insect damage. Crown gall may be confused with natural callus growth at graft unions.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.