Biology Reference
In-Depth Information
Muskmelon Mosaic ¼ Squash Mosaic
Comovirus
Narcissus White Streak
Silver Leaf. Paper tips and white streaks in leaves
are primary symptoms, with wilting and falling
over of foliage long before harvest so bulbs are
small.
Causes decline combined with chocolate spot.
Transmission by aphids. Replant only the largest
bulbs.
Widespread on melon. First leaves have dark
green bands parallel with main leaf veins;
later leaves are mottled, sometimes deformed.
Transmitted by seed and sap;
insect vectors
unknown.
Muskmelon Vein Necrosis Carlavirus
Narcissus Yellow Stripe Potyvirus
Caused vein necrosis and leaf chlorosis on
cucumber and pea plants.
Strong yellow streaking and mottling of
foliage, often roughened near veins and with
a peculiar twist. Flowers are streaked.
Transmission by several species of aphids.
Select the best plants for a mother block, with
final selection during bloom; rogue plantings
early before symptoms are masked by hot
weather.
Mustard Mosaic
On black mustard, California. Small, brown local
lesions are followed by a general mottling.
Nandina Mosaic Potexvirus
Nasturtium Mosaic Potyvirus
Occurs in California; transmitted by mechanical
inoculation.
Vein clearing, ruffling and cupping of
young leaves, dark green vein banding in older
leaves, sometimes chlorotic spots or white
rings between veins. Flower color may be
broken, petals crinkled. Transmitted by several
aphids.
Narcissus Chocolate Spot
Often present with white streak in a decline
complex.
Nothoscordum Mosaic Potyvirus
Narcissus Flower Streak
False garlic (wild amaryllis) mosaic transmitted
through bulbs but not seed. Typical mosaic mot-
tling of foliage.
Strong breaking of flowers but normal foliage in
Oregon bulb crops.
Narcissus Mosaic Potexvirus
Oak Ringspot Virus
Widespread on narcissus, but with mild symp-
toms, seldom apparent before plants bloom; has
been confused with yellow stripe.
Caused mosaic, chlorotic ringspot and oak leaf
pattern on the older leaves.
