There are many causes of post-harvest loss in grains. These are along the value chain beginning right at preharvest time through harvesting till storage. At preharvest, for instance, post-harvest loss can occur when birds, insects and rain attack grains that have been left to dry on the field. During storage, post-harvest loss occurs when grains are infested with mould, the cause of aflatoxins.

What are Aflatoxins?

Aflatoxins are a family of toxins produced by certain fungi that are found on agricultural crops. These mouldy fungi are mostly found in grains such as maize, rice, groundnuts and other agricultural produce.

While aflatoxins cannot be seen with the naked eye, the presence of mould is an indicator. The main aflatoxin producing fungi is called Aspergillus flavus and aspergillus parasiticus.

Aflatoxin contamination in corn. Source, AgroNigeria

Causes of Aflatoxins

You are probably wondering where these fungi come from or how they even come about in the first place. First of all, aflatoxins producing fungi thrive in warm and humid environments. Aflatoxins can occur either at preharvest or post-harvest including during storage. When grains are not well dried, the high moisture content can encourage the growth of mould producing aflatoxin.

Causes of mould producing aflatoxins include insect damage to grains during preharvest drying and storage, storing grain at high moisture levels and unfavourable storage conditions such as a leaking roof of a warehouse.

Effects of Aflatoxins

The effects are numerous. Both to the grain and humans. The effect it has on the grains is that it causes post-harvest loss. Post-harvest loss refers to the decline in quantity and quality of a crop; in this case grains. When aflatoxin producing mould infest grains, they are rendered spoiled. This is because the grains become mouldy and unhealthy to consume.

This means those grains must be thrown away because their quality has been compromised. Thus reducing the quantity of the overall grains harvested or in storage.

To humans, aflatoxin in food can cause health complications such as cancers.

What can be done

It is important that farmers and commodity traders always keep the moisture content of their grains at the required level. Dried enough for storage and protected from insects and humidity. Our GrainMate Grain Moisture Meter makes it possible for farmers and commodity traders to measure the moisture content in their grains to ensure they are dry enough so they can reduce aflatoxins.

If you’d like to know more about post-harvest management and how to reduce losses in grains, download our GrainMate app for Android and get access to a wide variety of content on post-harvest management.