Field efficacy of hermetic and other maize grain storage options under smallholder farmer management

Household grain storage continues to be of paramount importance in improving food security in sub-Saharan Africa (SSA) where maize post-harvest losses of 10-20% are reported. On-farm trials to compare alternative solutions for reducing household maize storage losses were conducted in the 2014/15 and 2015/16 storage seasons in two contrasting agro-ecological zones in the Hwedza district of Zimbabwe. A wide range of treatments including a commercial synthetic pesticide composed of fenitrothion 1% and deltamethrin 0.13%, unregistered but commonly used botanical pesticides (Aloe ash, Colophospermum mopane leaves, Eleusine coracana (rapoko) chaff, and Ocimum gratissimum), hermetic storage facilities (metal silos, GrainPro Super Grain Bags (SGB) IVR™, Purdue Improved Crop Storage (PICS) bags), and storage bags with deltamethrin incorporated into their fabric, were evaluated. The results demonstrated the superiority of hermetic storage facilities (PICS bags, SGBs, and metal silos) in suppressing insect pest build-up, insect grain damage and weight loss in stored maize grain. A newly introduced synthetic pesticide on the Zimbabwean market which has pirimiphos-methyl 1.6% and thiamethoxam 0.36% was also evaluated in the 2015/16 season and was found to be highly effective. The following grain storage technologies: hermetic metal silos, SGB bags, PICS bags, and the pesticide pirimiphos-methyl 1.6% and thiamethoxam 0.36% are therefore recommended for smallholder farmer use to reduce stored grain losses due to insect pests.