Agricultural crops :: Cereals :: Maize
Aspergillus rot / Aflatoxin contamination rot: Aspergillus flavus and
A. parasiticus
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Symptoms:
- Appears as an olive-green mould on the kernels from the tip of the ear
- Fungal spores appear as powdery and may disperse like dust when you pull back the husk
- Fungus produces a mycotoxin known as aflatoxin (B1, B2, G1 and G2)
- Aflatoxin affects grain quality and marketability, as well as livestock health if the grain is consumed
- Aflatoxin is extremely carcinogenic and most countries have regulations (20 ppb)
Favourable condition:
- During hot, dry years on stressed plants
- Feeding damage from ear-invading insects and injury by birds or hail
Mode of Spread:
- The fungus survives in soil or crop residue and infects ears during late silking
- Spores are spread by wind and insects and infection takes place through wounds or the silks
Management:
- Maize must be dried to below 14 percent moisture
- Reduce the stress to the crop during harvesting
- Avoid wound in kernels by insects/birds
- Appropriate fertility to the crop
Cob contamination by Aspergillus |
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