Biology Reference
In-Depth Information
rings, or large translucent areas and small corky
pustules; fruit has surface rings. In the concave
gum strain, cavities develop on trunks and larger
limbs. The blind-pocket strain usually produces
troughlike depressions in bark, sometimes bark
scaling. The crinkly leaf strain, usually on lemon,
causes warping and pocketing of mature leaves,
and rough, bumpy fruit. Transmission is by bud-
ding or through natural root grafts.
Remove trees with advanced infection; use
budwood from trees known to be free from
psorosis. Sometimes bark can be scraped, going
several inches beyond the margin of affected
areas and painting the scraped areas with bor-
deaux paste.
are produced from main limbs and trunk. Trans-
mission is by melon and other aphids. Make new
plantings with stock-scion combinations known
to be resistant. Best rootstocks are sweet orange,
rough lemon, Rangpur lime, and sweet lime.
Citrus Vein Enation
In California on sour orange, Mexican lime, and
other citrus. Veins swell and enations develop on
lower surface. Transmission by grafts and aphids.
Citrus Xyloporosis
Cachexia. In Florida, chiefly on sweet lime root-
stock, but also on mandarins and some of the
tangelo oranges. Symptoms include stunting of
2-or 3-year trees, small yellow leaves, partial
leaf drop, early blooming and fruiting; horizontal
growth of branches in middle section of
trees; dieback, followed by decay of entire
trunk and roots. Fruits are more rounded, with
a thicker rind. Transmission is by budding, pos-
sibly through seed. Use resistant rootstocks, as
sour oranges of Israel and Bagdad, Valencia
orange.
Citrus Ringspot Virus
Caused epinasty, chlorotic flecks, leaf mottling
Ringspot and large irregular chlorotic pattern on
mature leaves of
Citrus
sp.
Citrus Stubborn Disease
Oranges have multiple buds, abnormal
branching, acorn-shaped fruit, which is sour and
bitter at the navel end.
Citrus Yellow Vein
Citrus Tatter Leaf Cappillovirus
In California on limequat. Petioles and veins are
bright yellow.
Reported from California and Texas on Meyer
lemon and lime. Blotchy spotting of younger
leaves and ragged margins.
Clerodendron Zonate Ring Spot
Citrus Tristeza Closterovirus
In Florida on “bleeding-heart” vine. Chief symp-
toms are cleared veins.
Quick Decline. In California, Florida, and Texas;
usually in trees on sour orange rootstock. First
symptoms are partial or complete suppression of
new flushes of growth. Older leaves are dull or
bronzed, later yellow. Defoliation continues pro-
gressively from base of twigs to tip. Rootlets and
then roots die. Limbs die back, and weak shoots
Clover Club Leaf
On crimson clover. Young leaves are light-
colored, have club leaf appearance due to
delayed opening. Yellow margins of
leaves
