Corn Diseases Flashcards
How much corn did MB produce in 2023?
11%
What are the symptoms of Gibberella ear rot?
Fusarium growth from the tip of the cob to slowly progresses down the cob as infestation progresses.
What mycotoxins are produced by fusarium graminearum and due to the disease gibberella ear rot?
Deoxynivalenol (DON)
Zearalenone (ZEN)
Where does infection usually occur for Gibberella Ear rot?
Usually through silks. sometimes through kernel wounds and systemically through wounds.
What is the most common mycotoxin in food and feed?
DON
What livestock is most sensitive to DON?
Swine
What are some negative effects of DON on swine and other young animals?
- Feed suppression
- Feed Refusal
- Reduced weight gain
- Impaired organ function.
How does the ZEN mycotoxin manifest in swine and dairy?
It affects estrogen activity leading to reproductive effects.
What are 3 effects that ZEN has on cattle?
- Infertility
- Reduced milk production
- Hyper-estogenism
What fungus causes Gibberella ear rot?
Fusarium graminearum
What fungus causes Fusarium ear rot?
Fusarium verticillioides
What is the symptom of fusarium ear rot?
Sporadic (Scattered) appearance of affected kernels.
What mycotoxin is produced by fusarium verticillioides?
Fumonisim (FB)
Which animals are affected by the mycotoxin FB?
Cattle, Swine, Sheep and Horses
What fungus causes Penicillium Ear Rot?
Penicillium
What are the symptoms of Penicillium Ear Rot?
Blue-green or greyish fungal growth on or in between kernels, usually near the tip of the cob.
What mycotoxin is produced by Penicillium Ear Rot?
Ochratoxin A
What livestock animals are affected by Ochratoxin A mycotoxin?
Swine and Poultry
What are the effects of Ochratoxin A on swine and poultry?
- Reduced feed intake, and dehydration.
- Growth retardation.
- Kidney Dysfunction
- Diarrhea and excessive urine production
- Reduces egg production
- Vomiting (Swine)
What is the causal agent of Aspergillus Ear rot?
Aspergillus flavus and Aspergillus parasiticus.
What are the symptoms of Aspergillus Ear rot?
Brownish, grey-green powdery mold on or in between kernels. Mold can develop anywhere on the ear however symptoms are often found at damaged areas.
What animals are affected by Aflatoxins?
Dairy cattle, Swine, Poultry, and Horses.
How much Aflatoxin gain are you not allowed to blend?
more gthan 20 ppb
What fungus is the causal agent for the common smut?
Ustilago maydis
What are the favorable conditions for the common smut?
25 - 35 degrees. High nitrogen and heavy manure are also favorable.
How can you control smut?
There is no chemical control for smut, but its spread can be controlled by removing galls before they mature and clearing corn litter each fall.
How can you control root diseases for corn?
Good soil drainage and fungicides.
What is the world’s most destructive corn disease?
Stalk Rot
What are the two types of stalk rot and what are they caused by?
Fusarium stalk rot by fusarium species and Anthracnose stalk rot by Colletotrichum species.
What is the sign for Stalk rot?
light pink to tan discoloration in or on the stalk.
What are the symptoms of stalk rot?
Shredding of the stem.
What are 4 management techniques for stalk rot?
- Use resistant hybrids.
- Crop Rotation
- Balanced N and K fertility.
- Sanitation, stress reduction such as pest control and reduced plant populations.
What are the 4 most common fungal plant pathogens that cause seedling rots and damping off?
Pythium, Fusarium, Rhizoctonia, and Penicillium.
What kind of a bacteria is Xanthomonas?
Gram negative
What kind of a bacteria is Clavibacter?
Gram positive
