SUMMARY
The common gain storage structures existing in Nigeria sudan savannah zone are the mud rhombus, thatched rhombus, underground pit, earthen pot and warehouse storage. The gains which are usually stored in unthreshed forms include millet, sorghum, maize and cowpea. The most popular of these structures is the thatched rhombus, probably due to the availability of the availability of the materials and low cost of construction. Preliminary survey was carried out on the structure to evaluate the defects of this popular storage structure with the view to provide possible solution to on –farm storage of grains. Results show that the construction of the structure is completed within three to four days. The defects are observed in virtually all parts of the structure that is the roof, walls, foundation and the supports. This is basically due to the poor strength of the construction materials which invariably leads to huge losses of stored products. The structure is not moisture proof, rodent proof, alright, not resistant to insect/pest infestation and it is highly flammable. Therefore the use of this type of indigenous structure should be modified and other structures such as the use of small metal storage bins are suggested.