Maize is the major staple food in Africa. In developing countries, post-harvest losses due
to insect pests are up to 40% of total production. Inert powders can be alternative tools
in integrated pest management programs of stored cereals. The aim of this study was to
assess the efficacy of ashes from cashew (
Anacardium occidentale
) branches, charcoal
powder, dried and milled
Eucalyptus citriodora
leaves, and diatomaceous earth (standard
check), for
Sitophilus oryzae control on stored maize grains. The experimental design
was completely randomized with 11 treatments and 4 replications. Insect introduction
was carried out immediately after treatment application and at 30 and 60 days after. The
mortality assessment was performed by counting the dead insects at 10 and 20 days after
each infestation. The emergence of
S. oryzae adults was also assessed at three different
times. The germination of treated grains was also evaluated. Data analysis was performed
on the SISVAR statistical package. Diatomaceous earth showed maximum control
efficiency (73.75%) at 10-day evaluation, reaching total control at a 20-day evaluation.
The remaining treatment control efficiency was below 50% in all concentrations and
evaluations. The lowest insect emergence rates were observed in grains treated with
diatomaceous earth or charcoal powder, which were more efficient than cashew ashes,
Eucalyptus citriodora, and untreated control. There was no significant effect of the tested
products on seed germination so, they can be used in smallholder farmers' grain storage.
The results allow us to affirm that
Eucalyptus citriodora charcoal powder, and cashew
ashes can be used to reduce
Sitophilus oryzae damage in traditional agricultural systems.
Considering the reduction in the
Sitophilus oryzae progeny, the potential use of charcoal
powder should be considered, given the efficiency compared to that of the diatomaceous
earth. Thus, the plant-derived products tested in this study has the potential to be used in
the integrated management of
Sitophilus oryzae in stored products.