THE WORLD OF POTATO R ESEARCH From potato yield to supply chain In the early nineties I was involved in a study for the international potato center (CIP) that identified the yielding possibilities of potatoes worldwide. We calculated the potential yield and yield under water limited conditions. (Stol et al., 1991). The actual production was compared with the potential production and a yield gap was calculated. The causes of the yield gap were established and a way to improve potato yields was planned. Based on this study many projects have been initiated to improve potato production worldwide. Often the solution was found in a combination of fertilizer, crop protection, and high quality healthy seed. In another case farmers succeeded to raise their yields by the use of external input of clean seed, fertilizer or crop protection. But the growers depended on a few traders who were not able to absorb the extra amount of tubers produced by the farmers. The result was that prices declined and the extra investment in these inputs was not earned back. The next season no new inputs could be bought an yields dropped again to the old levels. When starting a new potato improvement project in a region the focus on raising potato yields and production has to be broadened to the whole supply chain. Starting at the farmers level there should be no constraints for lasting improvement. Farms should have a minimum size and be enabled to do investments in lasting potato production. This production should have a market, when there is no market yet a new market should be developed together with the logistics to transport the products in market in time. This means also that this process should be accompanied for a longer time until a supply chain can function on its own. When all these factors are taken into account a healthy potato supply chain can be established and sustainable potato farming can have a shining future. A conclusion could be that in general, the reason for low production is not technical but of another nature. Dr. Ir. Peter Kooman Professor Potato supply chain and sector innovation CAH Vilentum University of Applied Sciences p.kooman@cahvilentum.nl The last few years I had students working in countries where potato production was still at basic levels. In a demonstration field they showed that with good seed, ample water and nutrients and basic crop protection, crop yield could triple compared to the average of the area. From these examples we can conclude that raising yield in a technical way is relatively easy. Still, in many developing countries yields remain low. Improving production at farmers level in a durable way seems to be a lot tougher. A conclusion could be that in general, the reason for low production is not technical but of another nature. For example in some areas potatoes are the only cash crop for smallholder farmers, with less than a hectare of ground. They need the cash for their living and are not able to invest in healthy seed, fertilizer or crop protection. Because of their small plots they grow crop after crop without any rotation, resulting in unhealthy crops low yields. I have seen projects where NGO’s provide quality seed to these smallholder farmers, but without a proper production conditions and too narrow crop rotations, seed degraded and yields returned to the old levels. Source: Stol, W., De Koning, G., Kooman, P., Haverkort, A., Van Keulen, H., & de Vries, F. P. (1991). Agro-ecological characterization for potato production. A simulation study at the request of the International Potato Center (CIP), Lima, Peru. CABO-DLO, Report, 155. Potato World 2017 • number 3 45 Pagina 48
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