Page |1
Corn Diseases and Insect Pests in Missouri
Questions and Correct Answers/ Latest
Update / Already Graded
source of fusarium pathogen for corn seedlings
Ans: soil
type of pathogen that fusarium on corn seedlings
Ans: fungi
ID fusarium on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: root turns brown and has wet, rotted appearance,
seedlings yellow, wilt and die. brown sunken lesions on
mesocotyl
ID pythium on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: yellow, wilt and die. brown sunken lesions on
mesocotyl
roots: soft, dark-colored rot
All rights reserved © 2025/ 2026 |
, Page |2
source of inoculum for pythium on corn seedlings
Ans: soil
type of pathogen pythium on corn seedlings
Ans: fungi
type of pathogen is rhizoctonia on corn seedlings
Ans: fungi
source of inoculum for rhizoctonia on corn seedlings
Ans: soil
ID rhizoctonia on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: root turns brown and has wet, rotted appearance,
seedlings yellow, wilt and die. brown sunken lesions on
mesocotyl
ID bacterial leaf streak
Ans: narrow leaf lesions with wavy edges
All rights reserved © 2025/ 2026 |
, Page |3
between the veins
yellow, tan, brown, or orange
bright yellow halos when backlit
type of pathogen from bacterial streak
Ans: bacteria
source of inoculum for bacterial streak
Ans: corn residue
spread by splashing rain and wind driven rain
needs to be wounded to be infected
ID goss' wilt
Ans: wilting of plants
oblong or elongated lesions of water-soaked, grayish-green
tissue that progress to long dead streaks with wavy margins
sticky exudate in the streaks
freckles in the streaks
type of pathogen for goss' wilt
All rights reserved © 2025/ 2026 |
, Page |4
Ans: bacteria
source of inoculum for goss' wilt
Ans: corn residue
enters through wounds
host plants green foxtail, barnyardgrass and shattercane
ID holcus spot
Ans: small, oval to elliptical water-soaked lesions on leaves
later lesions become dry and turn light brown with a reddish
margin
type of pathogen for holcus spot
Ans: bacteria
source of inoculum for holcus spot
Ans: spread by wind-driven rain or splashing rain
outbreaks frequently occur after a rainstorm
ID stewart's wilt
All rights reserved © 2025/ 2026 |
Corn Diseases and Insect Pests in Missouri
Questions and Correct Answers/ Latest
Update / Already Graded
source of fusarium pathogen for corn seedlings
Ans: soil
type of pathogen that fusarium on corn seedlings
Ans: fungi
ID fusarium on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: root turns brown and has wet, rotted appearance,
seedlings yellow, wilt and die. brown sunken lesions on
mesocotyl
ID pythium on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: yellow, wilt and die. brown sunken lesions on
mesocotyl
roots: soft, dark-colored rot
All rights reserved © 2025/ 2026 |
, Page |2
source of inoculum for pythium on corn seedlings
Ans: soil
type of pathogen pythium on corn seedlings
Ans: fungi
type of pathogen is rhizoctonia on corn seedlings
Ans: fungi
source of inoculum for rhizoctonia on corn seedlings
Ans: soil
ID rhizoctonia on corn seedlings
Ans: seeds: soft and brown, visible fungi
seedlings: root turns brown and has wet, rotted appearance,
seedlings yellow, wilt and die. brown sunken lesions on
mesocotyl
ID bacterial leaf streak
Ans: narrow leaf lesions with wavy edges
All rights reserved © 2025/ 2026 |
, Page |3
between the veins
yellow, tan, brown, or orange
bright yellow halos when backlit
type of pathogen from bacterial streak
Ans: bacteria
source of inoculum for bacterial streak
Ans: corn residue
spread by splashing rain and wind driven rain
needs to be wounded to be infected
ID goss' wilt
Ans: wilting of plants
oblong or elongated lesions of water-soaked, grayish-green
tissue that progress to long dead streaks with wavy margins
sticky exudate in the streaks
freckles in the streaks
type of pathogen for goss' wilt
All rights reserved © 2025/ 2026 |
, Page |4
Ans: bacteria
source of inoculum for goss' wilt
Ans: corn residue
enters through wounds
host plants green foxtail, barnyardgrass and shattercane
ID holcus spot
Ans: small, oval to elliptical water-soaked lesions on leaves
later lesions become dry and turn light brown with a reddish
margin
type of pathogen for holcus spot
Ans: bacteria
source of inoculum for holcus spot
Ans: spread by wind-driven rain or splashing rain
outbreaks frequently occur after a rainstorm
ID stewart's wilt
All rights reserved © 2025/ 2026 |
