Growing Food: A Guide to Food Production

The optimum temperature for most insects attacking stored seed is between about
28 °C and 35°C. If the temperature rises much higher, insects normally either die or
cannot reproduce, so very dry seed can be stored at about 28°C for short periods to
minimise insect infestation. But even when the seed is dry insects can sometimes
multiply very rapidly, especially if the seed is not well cleaned and contains many
broken or damaged grains.

On a global scale post-harvest loss due to poor storage is estimated at around 5–10%,
representing many millions of tons of lost food. To reduce losses in storage, the storage
facilities should have as many of the features listed below as possible:

• an even, cool and dry internal atmosphere;


• protection against insects, rodents, birds, fungi and thieves;


• protection against rain and floods;


• constructions which are simple, cheap, preferably made from local materials, and
  most importantly, easy to thoroughly clean between harvests.

Types of Seed Store - seed stores can be either ventilated or non-ventilated:

1. Ventilated Stores
   Exposure to air means that the crop can continue to dry while in storage. Heating is
   also reduced since moulds (fungi) are less likely to multiply. On the other hand, the seed
   is exposed to insect, bird and other damage.
   Ventilated stores are most useful in humid regions, and are often used for storing
   maize cobs. As the climate or region becomes drier, less ventilation is necessary and
   also becomes increasingly inappropriate.


2. Non-Ventilated Stores
   These are normally used in drier regions, and the seed must be at or below its safe
   moisture content before it is stored. Non-ventilated stores have solid walls and close-
   fitting lids, which ideally are designed to allow for fumigation of pests if this should
   become needed.
   Seed is often also stored under the ground, where it is cooler.

Storing Seed (and food) in Sacks
There are four points to bear in mind:

1. The sacks should be well protected from rain, sun, insects, rodents etc., and—vitally—
   OFF THE GROUND. Pallets, and plastic (overlapped to avoid gaps) are ideal.


2. If possible use only clean, undamaged sacks to avoid losses from spillage and/or
   infestation by fungi and insects which may be present in the old sacks.


3. The sacks should be clearly marked (seed type, lot number etc).

regular inspection, and fumigation if necessary. Keep the store clean.

3. Observe all the normal rules applied to the storage of food in sacks, principally

102 TONY WINCH

5. Storage Facilities