be less wasteful, but labor constraints can lead to delays in
or failures to harvest; these, then, can result in signifi cant
postharvest losses. This appears to be undocumented.
DRYING
Most farmers in Africa, both small and large, rely almost
exclusively on natural drying of crops from a combination
of sunshine and movement of atmospheric air through the
product, so damp weather at harvest time can be a serious
cause of postharvest losses—measured losses in excess of
16 percent in Swaziland (De Lima, 1982). Grains should be
dried in such a manner that damage to the grain is minimized
and moisture levels are lower than those required to support
mold growth during storage (usually below 13–15 percent).
This is necessary to prevent further growth of a number
of fungal species that may be present on fresh grains. To
achieve this, the harvested crop may be left standing in the
fi eld, cut and left drying on the ground, or stooked. In some
places, the crop may be moved immediately from the fi eld to
a swept area of ground at the homestead (Figure 2.5) or to
racks or cribs that are specifi cally designed to promote drying