| AFFECTING LEAVES AND STEMS: |
|
CONDITION |
CAUSE |
 |
Young
leaves turn yellow between veins |
Iron deficiency,
usually on soils with high pH
|
|
Younger
leaves pale, terminal buds die |
Calcium deficiency
|
|
Leaves
on young plant are purple |
Phosphorus deficiency
|
|
Older
leaves pale, small, general yellowing |
Nitrogen dificiency
|
|
Older
leaves turn yellow between veins while veins remain green, then become
bronzed |
Potassium deficiency
|
|
Yellow,
mottled leaves; curling and malformation giving terminals a fernlike
appearance |
Mosaic virus
|
|
Black to brown angular to circular small spots (without concentric zones). |
Bacterial Spot
|
|
Brown
spots, distorted leaves and stems; stunted and sticky leaves covered
with a black film |
Aphids
|
|
Leathery,
black-brown spots with concentric rings; lower leaves and stems
affected first; occurs during humid/wet, warm conditions |
Early blight
|
|
Black-green
water soaked areas on older leaves, branches, and stems, usually in
humid/wet cooler weather (60-70° F.) |
Late Blight
|
|
Small
to large round holes in leaves, plants and leaflets stripped |
Colorado Potato
Beetle
|
|
Whole
leaves consumed |
Tobacco hornworms
|
|
Small
pitted holes, shot-hole injury |
Flea beetles (Phyllotreta spp.)
|
|
Leaves
have irregular chew holes giving the leaves a ragged appearance |
Cabbage Looper
|
|
| AFFECTING WHOLE PLANT: |
|
CONDITION |
CAUSE |
|
Yellowing
and “flagging” of shoots and leaves at base of plant first. Cross
section of infected stem has reddish-brown vascular system. Occurs when
temperature is 80-90° .F |
Fusarium wilt
|
|
Yellowing
and gradual wilting; leaf margins curl upwards; light brown
discoloration of vascular system. Occurs at 68-75° F. |
Verticillium Wilt
|
|
Young
plants cut off at soil line |
Cutworms
|
|
Whole
plant yellows, wilts and dies. Check roots. |
If galls on roots up
to 1 inch in diameter, Root-knot nematodes
|
|
| AFFECTING FRUIT: |
|
CONDITION |
CAUSE |
|
Large
chunks of green fruit consumed |
Tobacco and tomato
hornworm or Colorado
potato beetle
|
|
Small
holes on fruit surface with a messy, watery, rotten internal cavity.
Fruit appears to collapse like a balloon |
Tomato fruitworm,
also called Corn earworm
|
|
Dark
pinpricks surrounded by light areas; white, spongy area below spots |
Stink bugs
|
|
Scarring
and malformation of fruit, especially at blossom end |
Catfacing
|
|
Yellow
or white blister-like patch on fruit, usually on side exposed to the sun |
Sunscald
|
|
Yellow
streaks or shoulders; uneven fruit ripening |
Mosaic virus
|
|
Fruit
cracks at stem end radially or in concentric circles around shoulders |
Cracking, due to
uneven irrigation
|
|
Black
sunken area at blossom end of fruit; often seen in first ripening
fruit; hard, dark area inside fruit |
Blossom end rot
|
|
Gray to
brown blotches develop on the surface of green fruit with internal
browning and uneven ripening |
Graywall
|
|
Sunken,
dry spots with concentric rings near stem end |
Early blight
|
|
Water-soaked
spots, enlarging to large brown areas that remain firm |
Late blight
|
