What is it?Potatoes will sustain losses during their post-harvest life as they are living organisms with an active metabolism. Depending on storage conditions potato tubers will -to a lesser or greater extent -respire and transpire and thus lose fresh weight. Maintenance and metabolic processes require energy, and potato tubers use part of their dry matter (mainly starch) for necessary energy supply resulting in dry matter loss. Tubers therefore always show a weight loss due to transpiration (water loss) and respiration (dry matter loss). Moreover, potato tubers show changes in their chemical position during the period of storage. Finally, total weight losses can be increased substantially by storage diseases and pests. Nevertheless potato is a commodity that can be stored successfully for up to 10 months provided the right initial product is loaded, the right storage conditions are created and the right treatments are applied.Two types of storage losses can be distinguished: weight losses and losses in quality. The major factors causing weight and quality losses are:

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ObjectiveTo determine, by means of official tests, the resistance to foliage blight under field conditions of advanced clones and new potato cultivars which may be included on a National List or The Common Catalogue of Varieties of Agricultural Plant Species. Experimental conditions Seed productionWhere possible, all seed tubers used in the trials should be produced at the same location and should receive the same post-harvest and storage treatments. Selection and number of cultivarsWhere the trial site is uniform and individual clones or cultivars are compared only with the control cultivars, the total number of cultivars per trial is not critical. Seed treatmentsWhere a pre-planting treatment is deemed necessary, all cultivars should receive the same treatment. Number of sitesMultiple trial sites are the most desirable, but it will usually not be practical to have more than one site, Number of trial yearsIrrespective of the number of trial sites used the cultivars should be tested over a minimum of two years.

Genotype by environment interaction was investigated for yield data from the official Dutch Variety List trials for potato . The data set included 64 genotypes by 26 environments, where environments consisted of year by soil type combinations . Factorial regression models incorporating genotypic and environmental covariates in the interaction were used to analyse the data . The merits of factorial regression models were compared with those of biadditive models . Factorial regression models and biadditive models described comparable amounts of interaction, but factorial regression models provided a better basis for biological interpretation of the interaction .

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Potato processing at the industrial level is relatively insignificant in the tropical highlands of Africa in Ethiopia, Kenya, Uganda and Rwanda. No large international companies are present in this area whereas they have successfully established themselves in North Africa (Egypt) and South Africa. The reason for the presence of large French fries (chips) and crisps factories in northern and southern Africa is the availability of growers who have relatively large areas of irrigated land assuring a year-round flow of raw material with the required specification and consistency for the finished product. The objectives of recently carried out investigations in Rwanda and Ethiopia funded by The Netherlands government were to investigate the challenges and opportunities for the establishment of (private) industrial processing facilities. Such factories and installations would create added value through employment in the whole supply chain from breeding new varieties, creating a supply chain of seed and ware (raw material) potatoes, postharvest handling, processing and trade. The study in Rwanda and Ethiopia consisted of the following elements: (i) a quick scan of potato production related to the potential supply of raw material to the industry; (ii) an inventory of current processing at household and restaurant level such as boiling, mashing, and the preparation of French fries and crisps; and (iii) an inventory of processed potato products such as frozen French fries, crisps and mashed potato powder and packed fresh tubers in markets and supermarkets. An estimate was then made of the current and future market for these products. The type of small- and medium-sized equipment needed and their costs was assessed. Historical meteorological data and a crop growth model that calculated attainable yields and water use in the two countries were used for yield gap analyses. From this and from farm surveys the costs and competitiveness of the raw material were derived and from it conclusions regarding the costs of locally produced versus imported finished products. We concluded that the farm-gate potato price, which is related to the cost of production, is quite competitive - in Ethiopia it is about half that of northern Europe and in Rwanda it is about equal to north-western Europe - which is most important in order to be competitive with imports in the future. An investor planned a frozen French fry (chips) factory in Ethiopia to open in 2014. In Rwanda a similar action is planned with government involvement.

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Since 2013 the Netherlands Ministries of Economic and Foreign Affairs has been involved in private companies in research and development (R&D) in developing countries. This in a policy going “from aid to trade”. Especially in upcoming markets, R&D is carried out through Public Private Partnerships. Such partnerships not only include R&D organizations in the two countries but specifically also include businesses in both countries. This was to assure a logical flow of material and knowledge by all parties involved. Half of an R&D project is funded by the ministry and the rest is covered by a consortium of companies that contribute in kind and in cash. The policy is aimed at stimulating business development in developing countries and the Netherlands through cooperation and joint R&D. The paper explains how eleven consortia around potato business opportunities were formed, their R&D need was elicited and R&D projects formulated in the Asian countries China, India, Indonesia, Vietnam, Bangladesh and Myanmar, and Ethiopia and Kenya in Africa. In common are fact finding and descriptions of cropping systems, yield gap analysis and value chains in each country. Emphases differ with China looking for an integrated system of field operations, India for optimization of storage and processing, Indonesia to reduce pesticide and nutrient inputs, Vietnam for widening the varietal base, Bangladesh for combating late blight, Myanmar for cultural practices that lead to increased yield, Ethiopia where a potato processing unit is being established and Kenya importing seed potato from the Netherlands. Some content information is given as examples to illustrate the approach and some preliminary conclusion are discussed.