Biology Reference
In-Depth Information
infected leaves turn yellow and drop. Petioles and
stems have corky, raised necrotic streaks; tops
may die. The disease is most severe in spring,
inconspicuous in summer. Transmission is by
grafting (not by knife preparing cuttings) and
probably by whiteflies.
than normal, turning bronze or reddish along
veins, yellow between veins.
Grapevine Stem Pitting Associated
Chlosterovirus
Geranium (Pelargonium) Mosaic
Virions (800 nm length) found in phloem, but
they are very difficult to extract from host tissue.
Virus
Leaf Breaking. Leaves smaller, with purple spot-
ting along veins, and suppression of horseshoe
pattern in foliage of some geranium varieties.
related
only
to Citrus
Tristeza
Closterovirus.
Gladiolus Mosaic
Grape Yellow Mosaic F Strain of
Grapevine Fanleaf Nepovirus
(Panachure)
Bean Yellow Mosaic Potyvirus.
▶
Yellowing of leaves of young shoots in some
varieties; various types of leaf mottling;
blossom shedding. Transmission by grafting
andinsoil.
Grapevine Fanleaf Nepovirus
Infectious degeneration in California; Court-nou
´
and Roncet in Europe. New growth is severely
stunted; leaves are dwarfed and puckered or with
deep indentations and folded like a half-closed
fan; fruit set is poor. The virus is present in soil
and can be transmitted, apparently, by nematodes.
Grape Yellow Vein ¼ Tomato
Ringspot Nepovirus
Can be transmitted by dagger nematodes.
Grapevine Fleck Virus
Guar Symptomless Potyvirus
Generally symptomless in most cultivars; trans-
mitted only by grafting.
Symptomless or caused mild green mottle on
Cyanopsis tetregonoloba
.
Grapevine Rupestris Vein Feathering
Marafivirus
Hellenium S. Carlavirus
On grape.
Hellenium and Impatiens strains differ in host
range and aphid transmissibility.
Grape Leaf Roll
Grapevine
Leafroll-Associated Closterovirus
¼
Henbane Mosaic
White Emperor Disease. In California, restricted
to Emperor variety. Fruit is greenish yellow or
pink rather than normal red; leaves are darker
Clearing or yellowing of veins of youngest
leaves, then a yellow mosaic and dark green
vein banding.
