| AFFECTING LEAVES AND VINES: |
|
CONDITION
|
CAUSE
|
 |
Plants
wilt, foliage looks burned; preceded by pale green areas forming on
leaves |
Squash bug (Anasa
tristus
|
|
Sudden
wilting of a runner or part of a runner |
Squash vine borer (Melitta
satyriniformis)
|
|
Leaves
wilt, yellow, and curl |
High Aphid populations
|
|
Vines
wilt and die gradually, starting with newer leaves; no leaf yellowing
is present |
Bacterial wilt (Erwinia
tracheiphila)
|
|
Small,
pitted leaf holes on young plants |
Cucumber beetles (Acalymma
vittata)
|
|
Distorted,
Yellow spots on leaves with mottling and wrinkling of older leaves |
Mosaic viruses
|
|
Older
leaves mottled yellow between veins |
Downy mildew (Peronospora
effusa)
|
|
Powdery,
white spots on upper surface of leaves especially |
Powdery mildew
|
|
Leaf
spots that begin as water-soaked, then turn gray, die and drop out
leaving foliage with a shot-hole appearance |
Angular leafspot (Pseudomonas
syringae)
|
|
If
water-soaked, yellow spots turn brown |
Anthracnose
|
|
Dark
brown spots with concentric rings on older leaves first; vines
defoliate eventually |
Alternaria leaf
blight (Alternaria spp.)
|
|
| AFFECTING FRUIT: |
|
CONDITION
|
CAUSE
|
|
Small,
brown, angular fruit spots |
Angular leafspot (Pseudomonas
syringae)
|
|
Brown
and sunken zoned spots |
Alternaria (Alternaria
spp.)
|
|
Circular,
black, sunken cankers |
Anthracnose
|
|
Misshapen,
yellow mottled fruit, often with a bitter taste |
Mosaic virus
|
|
Fruit
wilts and shrivels |
Bacterial wilt (Erwinia
tracheiphila)
|
|
Fruit is
narrow at stem end |
Potassium deficiency
|
|
Fruit
has a dull bronze color |
Phosphorus deficiency
|
|
Fruit is
light colored |
Nitrogen deficiency
|
|
Dark
pitting of fruit |
Cold damage
|
