The most significant losses frequently occur towards the end of the storage season (when small scale farmers, at least, will be short of food) and tend to arise at the farm level when the traditional capability to conserve grain is disturbed with the introduction of new improved varieties or multiple cropping. The traditional handling, drying and storage systems may be inadequate to cope with the increased yield. Furthermore, the characteristics of the crop may be changed so that the grain is more susceptible to insect or fungal attack, or the timing of harvest may be changed from the usual dry season to the less favourable wet season.