ABSTRACT
The temperature and moisture content of bulk wheat, maize, and wheat bran stored in bins or
general stores (in sacks), in the Riyadh and Dammam provinces, Saudi Arabia, were surveyed
periodically during 1987 and 1988. The temperature of experimental and control bins of wheat
and maize increased in direct proportion to the length of the period of storage. This was true for
all heights inside the bins on the same date of observation, for each height on all dates and in
both provinces and years.
In the Riyadh province, temperature of the headspace air in all bins showed a trend to
increase with increasing period of storage. In the same storage plant, temperature at any
particular height inside a bin varied according to the type of grain and the year. Individual
variation between bins was also recorded.
Storage in bins increased the temperature of the stored grain above that of the environment
in both provinces and years. The temperature of stores in both provinces fluctuated in parallel
with that of the environment.
The moisture content of grain was significantly affected by height inside bins of experimental
and control wheat, year, period of storage and province. The moisture content of maize was
always higher than of control wheat.
In general, interactions between province (Riyadh and Dammam), year (1987 and 1988),
period of storage (six periods each year), type of commodity stored (wheat in experimental and
control bins, maize in a control bin and in general stores, and wheat bran in general stores),
storage site (inside bins or in general stores), height inside bin (7 heights inside each bin) and
identity of the bin were significant sources of variation in temperature and moisture content of
stored commodities. To predict pest infestation, storage conditions should be accurately
assessed with respect to these factors.