Moisture and seed carbonization

Abstract

In recent years the multidisciplinary approach of modem archeology has involved an increasing number of botanists in the recovery, identification, and interpretation of seeds from archeological excavations. These seeds are frequently carbonized. This is particularly true of tell archeology of the Middle East, where usually the concern is the origin and early development of agriculture. In many reports and discussions that treat this subject, the size of carbonized grains from various sites is used to support species or wild from cultivated form determinations. Also carbonized modem forms have been used as reference collections. Concern about relatively small size differences being given appreciable weight in such diagnosis has led to this study of the effect of moisture percentage at carbonization on the size of carbonized grain. Two lots of 10 seeds each of Triticum dicoccum Schrank., T. manococcum L., T. aestivum L., Hordeum vulgare L., and H. distichon L. were adjusted to 11 and 15 per cent moisture.2 Test seeds were carbonized by heating on an asbestos pad for ten minutes. This is thought to be a rough equivalent to grains accidentally dropped into an open fire by site occupants. It was apparent that the lower moisture percentage resulted in carbonized grains more representative of unaltered grain. Table I shows that in every case the length of the grain was shortened, but at 11 per cent moisture the grains were wider following carbonization whereas at 15 per cent they were narrowed. Although more tests with other moisture percentages and other methods of carbonization could