Storage Losses in Traditional Maize Granaries in Togo

Abstract

During the two years research 1983–1985 on traditional maize granaries in Togo, we studied three methods for loss assessment which are discussed by the FAO: the count and weigh method, the standard volume/weight method and the thousand-grain mass method. In general, between 80 and 90% of the overall losses were caused by insect feedings. Besides Prostephanus truncatus (Horn), the most important storage pests were Sitophilus zeamais (Motsch.), Tribolium spp. and Cathartus quadricollis (Guer.). Best results were given by the count and weigh method. The significantly highest losses of dry weight (12–13%) were found after 6 months in stored hybrids. At the same time, local varieties appeared much more adapted to traditional storage methods, exhibiting losses of only 3% under the same conditions. Lowest level of losses (< 1%) were observed in regularly smoked granaries in the mountain regions. The mean losses of dry weight during primary season were found to be 6.4% after 6 months, while after a storage period of 4 months during the secondary season, losses were as high as 8%. In Togo, P. truncatus was observed for the first time in spring 1984. Because of the different damage P. truncatus causes on corn, a newly developed sample weight method was examined in an additional test. After 6 months of observation, this dangerous pest caused serious losses up to 30.2%.