Uganda Cereal Postharvest Losses
The smallholder farmers in all four provinces of Uganda cultivate maize, millet, rice, sorghum, and wheat; barley is cultivated in all but Central province. The climate of the Northern, Eastern and Western provinces is tropical savannah (Aw of the Köppen code) while the Central province has an equatorial climate (Af); APHLIS makes little distinction between these two climates types when making loss estimations. In many parts of Uganda there is a bimodal rainfall pattern so that there are two annual cereal harvests but national statistics combine the two harvests as single production estimates. Loss estimates are based on the combined figures which results in some inaccuracy as seasonal data that affect the losses are less specific when seasons are combined.
In 2012, total cereal production was about 3.4 million tonnes of which an estimated 18.3% (or 0.62 million tonnes) was lost in postproduction activities. Most of this loss is contributed by maize both in absolute terms, i.e. because it has by far the largest production, and in relative terms as it suffers a higher proportion of losses (Fig. 1). There may be damp weather at harvest time that prevents good drying and so increases losses. In 2012, this was observed in the millet and rice crops in Central province and in maize and rice in Western province. However, to date farmers have not complained about Larger Grain Borer, an important pest of stored maize which is prevalent in neighbouring Kenya and can increase maize losses substantially if attack occurs on a large scale.
Figure 1: Losses maps for four provinces of Uganda in 2012
The postharvest loss profiles (PLPs), used by the APHLIS calculator to estimate losses, are strongly specific to the situation in Uganda in the case of maize and rice, reasonably specific for millet and sorghum, but much less so for wheat and barley. Specific PLPs give more reliable loss estimates. Wheat and barley cultivation are confined to highland areas and so would not be subject to the majority climate type in all four provinces (Aw/Af), but probably a humid sub-tropical climate (Cwa). As wheat and barley PLP loss estimates used in APHLIS originate mostly from Cwa climate conditions, the fact that the PLPs are not specific to the Aw/Af climate of the project is not a particular concern.