|
|
Flavescence
dorée - Grapevine flavescence dorée phytoplasma
Annemiek
Schilder, MSU Plant Pathology |
| Home > Scouting guide> flavescence doree |
| Flavescence dorée
infects only vinifera grapes and interspecific hybrids. Labrusca cultivars
are resistant. Symptoms usually appear the year after infection and either
get progressively worse until the vine dies or disappear in an apparent
recovery. Symptoms include delayed or no bud break and progressively shortened
internodes. In summer, vines take on a weeping posture, and shoots become
rubbery and fail to lignify. Characteristic black pustules may be seen
in longitudinal rows near the bases of shoots. The leaves have golden
yellow or reddish patches and curl downward. Growing points become necrotic,
and flowers and fruit clusters shrivel up and fall. The pathogen overwinters
in infected canes and is spread by a leafhopper. Symptoms may resemble
those of certain virus diseases or potato leafhopper damage. |
 |
 |
| Photo:
http://www.APSnet.org |
Black
pustules in rows. Photo: http://www.APSnet.org |
|
|
