Biology Reference
In-Depth Information
Soybean bud blight, due to Tobacco Ring Spot
Virus, is serious in the Midwest, causing losses
up to 100 %. Tip buds turn brown, dry brittle;
plant is dwarfed, produces no seed.
Sorghum Mosaic Potyvirus
Virus is one of the potyvirus complex infecting
tropical grasses.
Sparaxis Mosaic
Sorghum Stunt Mosaic
Nucleorhabdovirus
Strong leaf mottling and crinkling.
Transmitted by leafhopper,
Graminella sonora
,
only in temperatures below 38
C.
Spinach Blight
Caused by Cucumber Mosaic Cucumovirus.
Sowbane Mosaic Sobemovirus
Spinach Latent Ilarvirus
Occurred in Europe, South and Central American
region; found also in USA.
Transmitted by means not involving a vector.
Symptoms disappeared soon after infection.
Sowthistle Yellow Vein
Nucleorhabdovirus
Spinach Yellow Dwarf
Susceptible hosts are
Sonchus oleraceus
and
Lactuca sativa
.
In California, confined to spinach, with vein
clearing, curvature of midrib; young leaves with
mottling, puckering, curling, blisters; old leaves
with yellow blotches becoming necrotic. All vari-
eties are equally susceptible. Mechanical trans-
mission and by aphids.
Soybean Dwarf Luteovirus
There are two different strains of this virus;
dwarfing strain and leaf yellowing strain. Virions
occurred in cytoplasm and cell vacuoles of
phloem. Virus transmitted only by aphid vectors
in persistent manner.
Spring Beauty Latent Bromovirus
Soybean Mosaic Potyvirus
Symptomless; best serological test for identifica-
tion is double diffusion test.
Widespread on soybean. Leaves are distorted,
narrow, with margins turning down, some with
ruffling along main veins; plants are often
stunted, pods misshapen with fewer seeds. Trans-
mission by peach, pea and other aphids and in
seed. Control by roguing.
Squash Leaf Curl Bigeminivirus
It is probably the same as Muskmelon Necrotic
Mosaic Virus causing severe stunting and leaf
curl on plants from family Cucurbitaceae.
Soybean Yellow Mosaic
Squash Mosaic Comovirus
Soybean Yellow Mosaic is caused by the Bean
Yellow Mosaic Virus. Younger leaves show
chlorotic mottling, followed by necrotic spots.
On squash and muskmelon, mostly in California.
Foliage is severely mottled and malformed with
dark green blisters. Transmission by banded,
