If current rains persist, farmers who do not harvest their maize early will incur huge losses due to rotting.

Early harvesting and proper drying ensures maize does not develop moulds

There is one issue farmers ignore every year at their own peril: Harvesting their maize on time and storing it in the right way to ensure the harvest is not infested or destroyed by pests. Proper drying also prevents the maize from being contaminated with toxins, the most dangerous of these being aflatoxins.


Current rains a threat to maize

Losses due to late harvesting and poor storage can be huge. Research has shown that for every 100 bags farmers harvest in Sub-Saharan Africa, 40 bags are lost due to rotting, especially during periods of heavy rains and also as a result of poor storage methods and handling. If the Meteorological Department weather forecast for the current short season rains is correct, farmers in all maize growing areas in the country now face a real threat of losing a lot of maize this season unless they harvest it on time.

All maize that was planted in April and May this year is due for harvest in the months of October and November.


Why harvest early?

Some varieties of maize open the husks (ears) when they reach maturity; if it is raining, the water enters the maize cob and the maize acquires a yellow colour and eventually starts rotting. When maize ears open, weevils and other pests gain easy access and start destroying the maize even before it is harvested. Maize that is left to stay in the shamba after it matures is also prone to fungal infestations.


Maize is ready for harvesting immediately the grains harden; any farmers can be able to check this and decide when to start staking the maize in readiness for harvesting. The farmers can also check the silky flowers on the tip of the maize cob- when the flowers turn black, the maize can be harvested as soon as possible.


Post harvest management

Dry your maize immediately after harvest while the maize is still on the cob. The maize should be spread on a tent on dry ground or paved, clean surface. All rotten maize cobs should removed and even those showing signs of weevil infestation. It is not advisable to store maize while on the cob for long. Research has shown that maize on the cob is more prone to weevil damage. Always shell maize immediately it is dry enough or when ready for long term storage.


Monitoring the moisture level

One of the most important steps a farmer needs to take after harvesting maize is to check the moisture level. Moisture is responsible for both rotting and attacks by moulds, which grow on the maize grains and produce aflatoxins. When maize is harvested early, the moisture content can be very high, sometimes as high as 37 per cent. The maize has to be dried until it attains a moisture level of 12 per cent, which is the recommended level for long-term storage.


A quick moisture test method

It is difficult for the majority of small-scale farmers to buy a moisture meter for measuring purposes. But there is a simple method every farmer can use for this purpose as outlined below:


• Put a handful of grains and ½ handful of salt in a dry soda bottle.

• Shake for 2-3 minutes and allow the grains to settle. If the salt sticks onto the walls of the bottle, it is a sign that the maize has moisture.

• Dry again and repeat the test until no salt sticks on the sides of the bottle. If not salt is seen on the bottle, this is a sign that the maize has dried adequately and can now be stored.

Tips on how to store your maize.

• The maize store should be properly cleaned. Remove undesired grains, cobwebs, and any other material in the store where pests can hide.

• Preferably, the shelled maize can be stored in airtight containers to prevent pests from getting into the maize and destroying it.

• Ensure the maize is harvested early before the husks open which allows water, weevils and moths to enter the maize cobs.

• Sort the maize before storage to remove any cobs that may be infested with weevils or moths.

• Shelled maize should be sun-dried for 3-4 days to bring the moisture content to 12 per cent, which is safe for long-term storage.


Try diatomite for maize storage

Once the farmers have taken all the measures we have given above, they still need to take care of the maize to ensure it is not infested by weevils, moths and other pests during long-term storage. The problem is that most of the storage pesticides in the market are no longer effective against pests such as the Larger Grain Borer (LGB) commonly known as Osama, which is very destructive.


Diatomite can solve the problem. Diatomite is a powder with very sharp particles that pierces all insects on contact; this dehydrates the insects killing them. Unlike chemical pesticides, no insect can resist diatomite.


Farmers are therefore assured of total protection of their maize from weevils and other damaging pests. Diatomite can protect your maize for up to 4 or 5 years without any pest damage. Farmers groups can organize themselves and buy diatomite as a group. It is only available at African Diatomite Industries in Gilgil. Farmers groups in Kirinyaga region are already buying it this way and dividing among themselves. Interested farmers groups can make orders directly from the company by calling – 0700 409 199 or 0722 277 120.