Daily Nation Newspaper

ECONOMIC LOSS Reducing losses in harvested maize

- By MAKELI PHIRI

THE government is talking about buying one million tons of maize from our farmers. Maize is our staple food. In the past the maize plant has been modified so that it is able to increase the yield. This increase in yield has often been lost after production due to insufficie­nt attention and/or to poor understand­ing of some of the basic properties of the crop.

Losses always begin while the crop ripens in the field through insects, rodents and other mammals that attack the crop before harvest. And not forgetting birds. And during drying on the farm further losses are encountere­d and also through contaminat­ion by various bio – chemical toxins, insect fragments and mammalian urine and feces.

When it comes to environmen­tal conditions the temperatur­e and humidity including moisture content add further to losses during drying and storage.

Maize or grain is a living entity. When unprocesse­d, it maintains its life processes. Meaning it respires, that is it able to take in oxygen from the air and converts the stored nutrients inside the seed or grain into carbon dioxide, water and heat which it releases into the air. Therefore, in the process of respiratio­n, dry matter and grain quality are lost by the formation of carbon dioxide, moisture and heat. However, when the grain is kept cool and dry the rate of respiratio­n is very low. In total absence of oxygen, respiratio­n in the seed or grain stops and the grain or seed dies, this means it loses its viability.

The maize grain stored in higher temperatur­e would make the seed or grain to respire and spoil quicker equally would favor the multiplica­tion and increase activity of insect pests causing further deteriorat­ion of the grain. Moisture content of below 12% makes the maize grain to stop respiratio­n increasing the grains storage life.

The above factors therefore, stress the importance of quickly drying grain after harvest and keeping it cool in storage, otherwise biological activity will result in rapid spoilage of the stored maize.

We are harvested talking about the maize crop our

staple food. To reduce therefore, the incidences of spoilage and deteriorat­ion, the farmer must make sure that the following conditions are satisfied.

The grain must have safe moisture levels often below 12%

Stored maize grain must be healthy with minimum of broken or bruised kernels, damaged grain gets attacked easily by insect pests.

The grain must be clean and free from contamifor storage

nation by foreign matter, mammalian and insect excrements facilitate infestatio­n of the grain by spoiling moulds.

Must be free from all stages of insect pests since these eat and grain.

Maintain cool temperatur­e for safe storage. But do our farmers do this when storing grain for the future?

With the anticipate­d bumper harvest. The storage agencies must guard quickly destroy

the grain from insect activity. Insects are very sensitive to storage temperatur­es of around 19 degrees Celsius. This means that whenever the storage temperatur­e is above 19 degrees Celsius, there is a risk of grain spoilage due to insect heating. National reserve food storage facilities are able to maintain storage temperatur­es of below 19 degrees Celsius because they have the means. But this option cannot work with at small

Any stored maize grain must at all levels be prevented from economic loss. This denotes a reduction in monetary value of the product as a result of loss either in quantity or quality of the product.

scale level. As long as variations of temperatur­es between night and day are above 19 degrees Celsius would mean problems with insect infestatio­n on stored maize would be prominent.

Any stored maize grain must at all levels be prevented from economic loss. This denotes a reduction in monetary value of the product as a result of loss either in quantity or quality of the product.

Next week we shall look at the main levels of maize grain loss of harvested grain.

 ??  ?? As long as variations of temperatur­es between night and day are above 19 degrees Celsius would mean problems with insect infestatio­n on stored maize would be prominent.
As long as variations of temperatur­es between night and day are above 19 degrees Celsius would mean problems with insect infestatio­n on stored maize would be prominent.

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