By Hanks Saisai
Many farmers across Namibia have achieved substantial cereal grain yields due to the normal to above-normal rainfall received across the country. Currently, many smallholder farmers have commenced with threshing their grain for the common staple grains (Mahangu, Maize and Sorghum) and have engaged in preparations to store their grains for future use.
However, annually, numerous farmers experience post-harvest losses due to inadequate planning and preparation. To this end, to prevent post-harvest losses of grains, it is vital for farmers to understand the different strategies they can implement to mitigate the common causes of grain losses. The prevention of post-harvest losses can be managed by farmers by focusing on essential strategies, including properly drying grains before storage, ensuring safe grain storage, and effective transportation. Firstly, it is essential for farmers to sun dry their grains on raised platforms. The platform must first be cleaned to eliminate any conditions, such as the presence of moisture, which creates a conducive breeding environment for pests such as weevils that cause major post-harvest losses. Sun drying grains also prevents the formation of mould caused by fungi.
For this strategy to be effective, smallholder farmers can be assisted by extension officers to monitor moisture levels in the grains by using moisture meters before storage. Moreover, it is advised that at least 15% of the grains must be dry after being sampled by the moisture meter before the grains can be stored. The second strategy is for farmers to ensure that the storage facilities used to store the cereal grains are airtight and moisture proof to ensure the grains remain dry. Before grains are stored, it is advisable for farmers to apply eco-friendly pesticides that selectively target pests such as moths (Angoumois Grain Moth), scientifically known as Sitotroga cerealella), Rice Weevil (Sitophilus oryzae), Maize Weevil (Sitophilus zeamais), and beetles (mainly Lesser Grain Borer).
After fumigating silos, it is advised that farmers clean these storage facilities with plenty of water and allow them to dry properly. This will ensure that the grains are stored in a safe facility. Traditionally, farmers in remote areas make use of ash by placing it in grain silos to serve as a pesticide against weevils, moths and beetles. Wood ash acts as an abrasive that rubs against the exoskeleton of weevils, causing them to lose moisture, become dehydrated and eventually die. Additionally, ash applied at a rate of 5% of the weight of grains stored in silos, can create a less hospitable environment for weevils by making the grain surface less appealing for them to move around and lay eggs. Another strategy that can be used to prevent post-harvest losses of grains is to reduce the number of times the grains are handled during transportation. The more times grains are handled, the greater their exposure to contamination and moisture. This can easily accelerate the deterioration of high-quality grains.
Additionally, when grains are to be transported, it is advisable for farmers to store them in appropriate, durable, and secure packaging materials. Additionally, the surface on which the bags containing grains are loaded for transportation must always be dry and clean. Lastly, by training farmers on the importance of avoiding post-harvest losses, we can positively ensure that sufficient staple grains are available to meet daily household requirements. Moreover, government policies that integrate food loss reduction into national agricultural strategies and promote the establishment of silos and milling facilities in grain producing regions, can provide long-term benefits. Furthermore, stakeholder support to develop grain infrastructure in remote grain-producing regions of Namibia can ensure that grains are properly dried, stored and transported with minimal losses. By implementing these strategies, farmers and stakeholders can significantly reduce post-harvest losses, ensuring food security and minimizing waste.
Hanks Saisai is the Technical Advisor: Crops & Poultry at Agribank