| AFFECTING LEAVES: |
|
CONDITION
|
CAUSE
|
 |
Yellow,
dwarfed young leaves, bushy growth, purpled leaves |
Aster yellows (Phytoplasma)
|
|
Yellow
leaves, older first; stunted plants |
Nitrogen deficiency
|
|
Yellow-bronze,
curled leaves; bushy top growth |
Aphids
|
|
Dark
spots with yellow borders |
Cercospora leaf blight
(Cercospora spp.) if younger leaves are affected. Alternaria leaf
blight (Alternaria spp.) if older leaves are affected.
|
|
Seedlings
clipped off at soil line |
Cutworms (Noctuidae
spp.)
|
|
Poor
seedling emergence |
Crusted soil; high
temperatures
|
|
| AFFECTING ROOTS: |
|
CONDITION
|
CAUSE
|
|
Roots
chewed, meandering scars allon root with a rusty-red color |
Carrot rust fly (Psila
rosae)
|
|
Yellow,
stunted plants that wilt during bright, hot days and recover at night |
Usually a sign that
roots are injured. Pull up plant and check roots for Wireworms or
Root-knot nematodes (see below)
|
|
Small,
irregular holes scattered over surface of root; Damage usually occurs
later in the season and is worse in dry years. |
Wireworms
|
|
Bumps on
roots and deformed carrots |
Root-knot nematodes
(Meloidogyne spp.)
|
|
Jagged
cracks, water-soaked appearance |
Freezing injury
|
|
Forked
roots |
Can occur if soils
are heavy, compacted, or stony; if root tips are injured; if roots are
overcrowded.
|
|
Dark
tunnels, often in a zig-zag pattern, on upper and outer part of root |
Carrot weevil (Otiorynchus
spp.)
|
|
Internal
cavity spot |
Calcium deficiency
|
|
Spindly,
short roots |
Can be caused by
potassium deficiency or excessive heat
|
|
Poor
color and taste |
Caused by magnesium
deficiency, phosphorus deficiency, low temperatures and excessive heat
|
|
Small,
woody, hairy, pale roots |
Carrot yellows (Phytoplasma)
|
|
Green
shoulders |
Exposure to sunlight
|
