Abstract:
Control of the storage pest Larger Grain Borer (LGB) (Prostephanus
truncates) and aflatoxin contamination by the mould Aspergillus spp. are the
major challenges to maize storage in Africa. In this study, the effect of
hermetic storage on LGB and Aspergillus spp. during maize storage was
evaluated. A 2 x 3 factorial experiment of two storage atmospheres (hermetic
and non-hermetic) and infestation levels (LGB, Aspergillus spp. and
uninfected control) were evaluated during the storage of ‘Obatampa’ maize.
LGB and Aspergillus spp. were each introduced into 1.5 kg of the maize
grains in hermetic and non-hermetic bags and stored alongside uninfected
grains of same weight. Oxygen depletion in the hermetic bags was significant
(p = 0.012) while temperature in both hermetic and non-hermetic bags
remained fairly constant at 26.99 ºC and 27.4 ºC, respectively. Relative
humidity, moisture content, grain damage and weight loss percentages were
significantly different in the various bags (p < 0.001). There was 100 % LGB
mortality in the hermetic storage after 52 days. Aspergillus flavus
contamination in the non-hermetic bags was highly significant compared to
the hermetic bags (p = 0.002). The aflatoxin group B2 was found in both
storage systems. While the aflatoxin group G1 was not detected, the G2 group
was only detected at the concentration 0.1 ppb in the hermetic storage. The
double layer hermetic SuperGrainbag better preserved the quality and shelf
life of the maize grains and maintained seed viability (p < 0.001) much longer
than the non-hermetic polypropylene bag.
