Corn Diseases

Question 1

Anthracnose

Answer 1

Fungus of corn

Leaf Blight, stalk rot

Spread via rain-splashed spores (local) from corn debris

Thrives in mild, wet;
Reduced-till, continuous corn
European Corn Borer Injury to stems

Resistant hybrids (1-2)
Bt (Corn-borer resistant) hybrids (1-2)
Crop Rotation (2)
Clean Plowing (2)

Question 2

Common Rust

Answer 2

Fungus on corn

Leaf Rust

Long distance airborne spores

Thrives in humid conditions, thunderstorms

Resistant hybrids (1)
Timely planting (2)

Question 3

Common Smut

Answer 3

Fungus on Corn

Galls on ears, tassels, leaves

Airborne and rain-splashed spores (in soil)

Injuries, DRY conditions

Resistant Hybrids (1)
Fertilize based on soil test (2)

Question 4

Eye Spot

Answer 4

Fungus on Corn

Leaf Lesions

Rain-splashed spores from corn debris

Thrives in Cool, wet;
Reduced Till, continuous corn

Resistant hybrids (1)
Crop Rotation (2)
Clean Plowing (2)

Question 5

Gibberella (red) Ear Rot

Answer 5

Fungus on cereals and grasses

Ear rot, Mycotoxins

Airborne spores (regional) from corn debris

Favored by moisture at silk emergence

Adapted, less susceptible hybrids (2)
Timely planting and harvest (3)
Fertilize based on soil test (3)
Reduce stresses (3)

Question 6

Gibberella Stalk Rot

Answer 6

Fungus on Cereals and grasses

Stalk Rot

Invasion via Roots or wounds (soil)

Favored by stressed plants

Apdapted, tolerant hybrids (2)
Timely planting and harvest (3)
Fertilize based on soil test (3)
Reduce Stresses (3)

Question 7

Gray Leaf Spot

Answer 7

Fungus on corn

Leaf lesions (matchstick)

Airborne spores (regional) from corn debris

Persistent dew, fog;
reduce till, continuous corn

Foliar fungicides (1)
Partially resistant hybrids (2)
Crop Rotation (2)
Clean Plowing (2)

Question 8

Northern Leaf Blight

Answer 8

Fungus on corn

Leaf lesions (cigar)

Airborne spores (long distance) from corn debris

Favored by humid and wet

Resistant hybrids (1-2)
Foliar fungicides (1-2)
Timely planting (2)

Question 9

Northern Leaf Spot

Answer 9

Fungus on Corn

Leaf lesions

Airborne spores (long distance)

Humid, wet

Resistant hybrids (1)
Timely planting (2)

Question 10

Seed Decay/ Seedling Blight

Answer 10

Fungi, Oomycete, Bacteria on many hosts

In soil; seed

Favored by cool, moist soil;
Poor quality seed

Protectant seed fungicides (1)
Good seedbed preparation (2)
Timely Planting (2)

Question 11

Stewart’s Leaf Blight

Answer 11

Bacterium on Corn

Leaf blight, systemic

Spread via corn flea beetle

Favored by mild winter before crop season

Resistant hybrids (1)