| AFFECTING SEED, SEEDLING, AND WHOLE PLANT: |
|
CONDITION
|
CAUSE
|
 |
Wilted,
stunted plants and/or spotty, poor stands |
May be due to several
soil-dwelling pests including: Wireworm, Seed corn maggots, or,
less commonly, white grubs.
|
|
Wilting,
stunting, and poor germination |
Corn root worms
|
|
| AFFECTING LEAVES: |
|
CONDITION
|
CAUSE
|
|
Numerous
small holes, bleached out spots or stripes on leaves |
Flea beetles (Phyllotreta
spp.)
|
|
Ragged
leaf margins on young plants; plants cut at base of stem |
Cutworms (Noctuidae
spp.)
|
|
Holes in
leaves, shot-hole leaf injury |
Corn earworm (Heliothis
zea )
, European corn
borer (Ostrinia nubilalis) , or Armyworm (Euxoa
auxiliaris)
|
|
Round,
brown raised spots on leaves |
Rust
|
|
Mottled,
stunted new leaves; poor kernel formation at base of ear |
Maize dwarf mosaic
virus
|
|
White-black,
puffed-out growths on ears, tassels, and stems |
Smut (Ustilago maydis)
|
|
Older
leaves purple on young plants |
Phosphorus deficiency
|
|
Yellow
leaves, older first; stunted plants |
Nitrogen deficiency
|
|
Yellow,
curled leaves; stunted plants |
Aphids
|
|
| AFFECTING EARS: |
|
CONDITION
|
CAUSE
|
|
Irregular
ears with corky bands at the base of kernels |
Boron deficiency,
phosphorus deficiency, or potassium deficiency
|
|
Large,
chewed areas or dry, brown exposed kernels at the top of ear |
Birds
|
|
Hollowed-out
kernels in the upper half of the ear |
Sap Beetles
|
|
Damage
to developing kernels at ear tips |
Corn earworm
|
|
Bored
ears and stalks, with damage seen anywhere on ear (not just at tips) |
European corn borers
(Ostrinia nubilalis) and/or Armyworms (Euxoa
auxiliaris)
|
