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The use of fungicides must be economic and not harmful to the en-
vironment and end users.
Breeding for resistance is one of the most promising long-term strat-
egies. Sources of resistance in maize to
Fusarium
spp. and
Stenocar-
pella maydis
are currently being identified by the ARC-Grain Crops
Institute (ARC-GCI) and will become public domain.
Managing mycotoxicosis
More than one mycotoxin can be present in feed, thereby making it
difficult to rely on clinical signs alone. Certain mycotoxins are im-
munosuppressive, which may allow viruses, bacteria or parasites
to create a secondary disease and therefore mask the effect of the
mycotoxin alone.
When mycotoxicosis is suspected, corrective actions must be taken:
Remove the suspected contaminated feed and clean equipment,
storage facilities, or feeding bins with bleach.
Inspect feed, feeders, storage bins and other equipment for
caking, fungi or strange odours.
Analyse the affected feed and send it to a laboratory for a plant
pathologist to isolate and identify fungi.
When fungi are identified the associated mycotoxins can be
quantified. For example, when
Aspergillus flavus
is identified,
quantifications can be done for aflatoxins.
Consult your veterinary, some of the effects of mycotoxicosis
can be reversed while others can be fatal.
For more information contact Dr Belinda Janse van
Rensburg at 018 299 6100.
1: Groundnut overgrown with
A. flavus
.
Photo: Dr P.S. van Wyk
2: Maize ear infected with
F. verticillioides
.
3: Rat liver tumour due to
fumonisins.
Photo: Prof W.F.O. Marasas
4: Hole and lesions in the brain
of a horse.
Photo: Prof W.F.O. Marasas
5: Staggering due to brain
damage.
Photo
:
Prof W.F.O. Marasas
6:
F. graminearum
colonisa-
tion on a maize ear.
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