Innovative practices in potato production for food and nutrition security
Ngo Tien Dung, Udaya Sekhar Nagothu, Alma Linda MoralesAbubakar, Jan Willem Ketelaar and Mehreteab Tesfai
Potato (Solanum spp.) is the third most important root and tuber crop in the world, domesticated more than 7000 years ago in Peru and Bolivia (Maranzani, 2013; Devaux et al., 2014). The Andes is the main source of origin for more than 4,000 types of potatoes showing the wide range of genetic diversity and the nutritional value of the crop. Potato is grown in more than 125 countries with annual production of about 300 million tons and consumed almost daily by more than a billion people. Millions of people in developing countries depend on potatoes for their survival. Developing countries are now the world’s biggest producers as well as importers of potatoes and potato products (FAO, 2009; CIP, 2017). At the global level, production and trade in potatoes has increased dramatically, as consumers realize the nutritional benefits of the crop. Devaux et al. (2014) in their study show the untapped potential of potato to help improve food security and livelihoods in developing countries.
Potato is an important source of carbohydrates. One medium-sized potato provides about half of the daily adult requirement of vitamin C, whereas other staples, such as rice and wheat, have none. However, potato is very low in fat compared with just about 5 percent of the fat content of wheat. It has about one-fourth of the calories of bread.
When boiled, potato provides more protein than maize and about twice as much calcium (The Crop Trust, 2017). Potato has the dual role of contributing to subsistence farming and reducing hunger on one hand and as a high value crop providing income and employment to farmers on the other (Thiele et al., 2010). Potato production in Africa has started to increase in recent years and will further increase significantly (Okello et al., 2017). With the fluctuating – but in general trends rising – prices of rice and other staples in the world, potatoes have the potential to deliver an alternative source of carbohydrates (Independent, 2016).
Potato production has become an input-intensive economic activity with excessive use of fertilizer and pesticides in regions of South and Southeast Asia which has led to environmental problems. To reduce environmental pollution in agricultural soils and water bodies, use is made of organic residues for, e.g. rice straw as soil fertilizers and for promoting soil health. There are several challenges related to the production and post- harvest management of potatoes that need to be addressed to realize the untapped potential of the crop, particularly in Africa, South America and Asia. More specifically, this is relevant for countries such as Peru, Columbia, Vietnam, India, Pakistan, Kenya, Uganda, Malawi and South Africa among others where potato consumption – particularly in processed format – is rapidly increasing in the urban areas and among
Smallholder challenges in potato production
The main challenges of smallholders involved in potato production are related to procurement of and access to healthy seed material, soil fertility, disease and pest control, unorganized post-harvest handling operations, including cold storage, and low market prices of tubers at harvesting (Finckh et al., 2006; Uddin et al., 2010; Karanja et al., 2014; Gebru et al., 2017a). Some of these are well studied and known challenges to potato scientists and development workers. However, the research and development sector is still far from providing effective, efficient and sustainable solutions to smallholder farmers involved in potato production due to the following factors:
Seed material: Potato yield is largely influenced by the health status of seed tubers, including the physiological age of the tuber at the time of planting (FAO, 2008). The biological and physical quality of the tubers influence the yield and quality of the produce. A majority of smallholders does not have access to certified seed potato material and hence use part of their produce for seed purpose and at the same time supply to fellow farmers (Gebru et al., 2017a, 2017b). Thus, in developing countries, farmers obtain seed mostly through informal systems or non-regulated channels (Lutaladio et al., 2009). This may be a risk in case the seed material is infected by crop pests and disease pathogens, especially viruses but also late blight, nematodes or insect pests. Lack of clean seed material was found to be one of the major challenges facing potato production in the Oljoro–Orok Division of Kenya (Karanja et al., 2014).There is a large scope for improvement in the seed potato value chain given the market potential for potato that is replacing the traditional diets in Africa and other regions. Recent studies show that potato yields continue to remain very low in parts of Africa and Asia mainly due to use of poor quality seed material (FAO, 2008; Okello et al., 2017; Uddin et al., 2010; Karanja et al., 2014). By mere supply of healthy seed material, the potato productivity is expected to increase significantly.
Soil fertility management: Soil fertility management is important to maintain optimum tuber quality and yield since potato has a shallow root system (Rosen, 2016). Problems such as soil compaction, poor drainage and low soil pH can adversely affect potato production (McKenzie, 2013). Farmers do not pay much attention to the soil management due to lack of knowledge and resources. In the absence of systematic soil testing and analyses of the various nutrients, need based and efficient use of fertilizer is rarely seen on smallholder farms. If the fertilizer application is not done at the right time and with the right dosage, yield responses can be poor. Split applications of Nitrogen fertilizer is recommended at pre-planting, emergence and hilling phase of the plant for best results. The other major nutrients such as Phosphorus and Potassium applications should be done prior to planting. A need-based soil nutrient management is necessary to address the smallholder problems and enable sustainable intensification of potato production.