This post was written by Nina Jovanovic, Jacob Ricker-Gilbert, Patrick Ketiem, Jonathan Bauchet and Vivian Hoffmann.

Improving food safety and reducing food loss and waste (FLW) are growing concerns in sub-Saharan Africa and the developing world. Aflatoxin is a fungal metabolite that contributes to both concerns. It is commonly present in the region’s staple crops like maize, rice, millet and groundnuts. Chronic exposure to aflatoxin is associated with liver cancer, immune suppression, child stunting and death, contributing to a significant public health burden in the developing world. The prevalence of aflatoxin contamination will only increase as the climate warms. Aflatoxin-producing fungi live in the soil and thrive in hot and humid conditions. They contaminate crops while they are still in the field and can continue to grow and produce aflatoxin during harvest, drying and storage. While the consumption of aflatoxin-contaminated food presents a serious threat to food safety, discarding contaminated food contributes to FLW.

The key to preventing aflatoxin contamination in Kenya is the implementation of good agricultural practices. With this in mind, Purdue University, in collaboration with the Kenyan Agricultural and Livestock Research Organization (KALRO), implemented a study in Meru and Tharaka-Nithi counties in upper eastern Kenya during the short agricultural season starting in October 2021. The project aimed to identify the effectiveness of two agricultural inputs intended to prevent aflatoxin contamination in smallholder farmers’ maize. The first input was Aflasafe, a new biocontrol product that is applied on the soil surface while the maize is still in the field (Figures 1 and 2). Aflasafe is not yet widely adopted by smallholder farmers in Kenya, despite its proven effectiveness in reducing aflatoxin contamination in maize through researcher-managed field trials. The second input was a 12 meters squared (m2) food safety-certified tarp for drying maize off the bare ground.

The study was implemented as a clustered randomized controlled trial (RCT) with a factorial design. We randomly assigned 1,920 households from 240 villages (8 households per village) to four experimental groups to estimate the effects of these inputs. The first group was control farmers who did not receive any agricultural inputs during the intervention, but were trained at the end. The second group of farmers received 4 kilograms (kg) of Aflasafe and training on its use. The third group received the drying tarp and training on its use, and the fourth group received both Aflasafe and the tarp and training on the use of both. This design allowed us to test the extent to which a preharvest input (Aflasafe) and a postharvest input (tarp) can prevent aflatoxin contamination when used separately and together. To obtain data on the effectiveness of distributed inputs, we collected maize samples from farmers and measured their aflatoxin level at harvest (March-April 2022) and in storage (May-June 2022). Maize samples were determined not safe for human consumption if the aflatoxin level was above 10 parts per billion (ppb), which is the Kenyan food safety limit for aflatoxin contamination of maize.

The study found that Aflasafe was the key input to lower aflatoxin levels. At harvest, being assigned to receiving Aflasafe (alone or together with a tarp) reduced the probability of having maize that was unsafe for human consumption by 44-47% compared to the control group, on average. Similarly, receiving Aflasafe (alone or together with a tarp) reduced the probability of having maize samples that tested above 10 ppb by 30-41% several months later when maize was in storage compared to the control group, on average (Figure 3).

After the aflatoxin testing results were known (May-June 2022), we offered all farmers the opportunity to purchase Aflasafe through an experimental auction to assess their demand for this input. We found that only 9% of respondents were willing to purchase Aflasafe at or above the commercial price of KSh 400 ($4) per 2 kg bag, while more than 30% of farmers wanted to pay less than KSh 250 ($2.50) for a bag. One potential reason for such low willingness to pay is that the effectiveness of Aflasafe is not directly observable, so farmers must incur an extra cost of KSh 800 ($8) per acre to purchase it without clearly seeing the benefit.

Our study clearly indicates that, even though Aflasafe is effective, its price needs to be lower for farmers to adopt it. This could be achieved by providing farmers with a time-limited subsidy for the input, and/or allowing multiple private sector companies to distribute Aflasafe to introduce competition that lowers the price. In addition, there is a need to invest in training farmers on Aflasafe. Providing reliable information on its effectiveness is a critical tool to counterbalance the lack of observable benefits to the product in order to increase households’ food safety and food security while reducing FLW.

This work was funded in whole or part by the USAID Bureau for Resilience and Food Security under Agreement # AID-OAA-L-14-00003 as part of Feed the Future Innovation Lab for Food Processing and Post-Harvest Handling at Purdue University. Any opinions, findings, conclusions or recommendations expressed here are those of the author alone. A portion of this work was also funded by the Jim and Neta Hicks Small Grant, Department of Agricultural Economics at Purdue University.