Mycotoxin contamination of food grains represents significant health and economic
challenges in developing countries as well as the developed world. Mycotoxinproducing
fungal species affecting maize mainly belong to the genera
Aspergillus
,
Fusarium
, and
Penicillium
.They pose serious phytopathological and mycotoxicological
risks both at pre-harvest and post-harvest stages. Maize in Kenya has been associated
with frequent outbreaks of aflatoxin contamination. A number of mycotoxin control
strategies both chemical and biological have been developed as potential tools for
mycotoxin control. A Laboratory based cross-sectional study was carried out in a
Mycology Laboratory at the Center for Microbiology Research in Kenya Medical
Research Institute, Nairobi, Kenya. A total of 138 maize samples obtained from
Machakos, Nairobi, Mombasa, Kitale and Kisumu were subjected to mycological
analysis. The samples were treated with the fungicides; Antracol (propineb), Milraz
(propineb700g/kg and Cymoxanil60g/kg), Mistress (Cymoxanil 8% and Mancozeb 64%)
and Victory (Metalaxy 80g/kg and Mancozeb 640g/kg.) before inoculation on
Sabourauds dextrose agar (SDA). Infestation rates on fungicide- treated and non treated
control maize kernels were scored. The susceptibility of the isolates to the four test
fungicides was determined by disk diffusion technique. All the maize samples were
infested by moulds and there was a significant difference in regional infestation rates
(p<0.05). Maize from Mombasa had the lowest infestation of 72.5% while Nairobi was
the highest with 99.1%. Fungi of the genera
Aspergillus,
Fusarium, and
Penicillium were
frequently isolated from the five regions. There was a significant reduction {p<0.05
(0.00)} of infestation rates on fungicide- treated maize compared to the untreated.
Generally, 26% (n=35) and 34% (n=47) of maize samples treated with Mistress and
Victory, respectively had 0% infestation while those treated with Milraz and Antracol
were 10% (n=14) and 14% (n=19), respectively. Some mycotoxigenic isolates were
found to be resistant to more than one of the test fungicides. However, their in- vitro
antifungal activity is of great importance and could further be evaluated to determine
their field efficacy for mycotoxin control in maize.
