Determinants of smallholder farmers’ maize grain storage protection practices and understanding of the nutritional aspects of grain postharvest losses

Poor storage methods lead to high postharvest losses in maize, an essential staple in sub-Saharan Africa. Smallholder farmers’ knowledge and awareness of postharvest nutritional losses (PHNLs), practices regarding maize grain storage, and factors influencing use of improved storage protection practices were investigated in two districts in Zimbabwe through a cross-sectional field survey of 331 households randomly selected from lists of farmers’ names kept by local extension staff. A multistage sampling technique was used involving purposively selecting the study districts then randomly selecting the study wards, the villages and the households. Twenty eight key informant were purposively selected being officers and stakeholders working or residing in the two districts and involved in postharvest and nutrition issues. The most commonly used storage practices were the admixture of maize grain with synthetic grain protectant pesticides followed by storage of untreated grain in polypropylene bags. Highly toxic pesticides, such as Cabaryl 85 WP and Acetamiprid 20 SP, which are not registered for stored food grain treatment, were being applied by 14.6% of the farmers to protect their grain from insect attack. We developed a PHNL knowledge index that measured farmers’ nutritional knowledge and awareness of PHNL. Level of education and district positively correlated with farmers’ PHNL knowledge (p < 0.05), whereas the opposite was found for farmers’ age (p < 0.05). Multinomial logistic regression analysis showed that use of grain storage protection practices was positively related to farmers’ age, total maize grain production, education level and PHNL knowledge (p < 0.05). Older farmers were less likely to use non-recommended chemicals to protect their maize grain during storage. Farmers’ education level and total maize grain production were positively associated with higher use of synthetic pesticides, while PHNL knowledge was associated with the use of traditional grain protectants (p < 0.05). Training on grain storage management, especially safe grain storage protection practices and PHNLs, is essential to contribute towards household food and nutrition security.