Grapevine Virus A (GVA) and Grapevine Virus B (GVB)
Hosts
The natural host range of GVA and GVB is grape, Vitis vinifera.
Symptoms
Grapevine Virus A (GVA) and Grapevine Virus B (GVB) are also called vitiviruses and
are associated with the rugose wood complex diseases. Grapevines affected by this
complex exhibit pitting and grooving under the bark. These viruses are generally transmitted
by propagation of infected material.
Symptoms associated with GVA include reddening of leaf margins and petioles, poor
vigor, and leafroll. The plant may exhibit swelling at the graft union and stem cracking.
Ungrafted vines may be infected with GVA, but do not show visual symptoms. GVB causes
corky bark, which can be seen when the bark on the trunk is removed. GVB only occurs
in grafted vines.
Control
Growers should plant certified, disease-free plants. Pruning tools should be disinfected
with a bleach solution (1 part household bleach, 9 parts water) between cuts. Infected
plants should be removed and discarded.