Farmers urged to adopt a business approach to sweet potato

For many African small-holder farmers the sweet potato is a reliable food security crop. Easy to cultivate, naturally sweet and filling, it constitutes an important part of the diet of many families.
Sweet potato (Ipomea spp. ) can be grown as a perennial crop in many regions and has the addded advantage of tolerating drought well.

As with so many humble, well-adapted-to-Africa crops, it has often not been taken seriously as a commercial crop. The "modernization" of food preferences amongst Africans over the last century or so has also caused nutritious but humble foods to lose out to modern convenience foods such as bread. They may not be as nutritious but are relatively inexpensive to buy, are perceived to be easier and quicker to prepare into a snack or meal and benefit from slick, attractive packaging and marketing compared to "lowly" foods like cassava, sweet potato and others.

Growing health awareness, a rethinking of what exactly "modernization" entails, means and costs; the expence and difficulties of importing or growing wheat : all these and more reasons are causing a reawakening of the importance of crops that in recent decades had begun to be thought of as "unsophisticated" to grow or consume. Calls are increasingly heard for a shift or return to foods that had been sidelined as Africans adopted a more western-style diet.

Along with the realization of how well adapted to African conditions many traditional crops have always been compared to more recently introduced ones and their nutritional benefits, is a nascent awareness of the commercial potential of many of these crops. Farmers are therefore being urged to cultivate them not just as a household food security measure as in olden days, but to look at doing so from a commercial perspective as well. New and innovative ways of cooking, preserving and packaging these crops are also adding impetus to their gradual revival.

As an example of the renewed seriousness with which crops like sweet potato are viewed, a senior agronomist in Zambia's ministry of agriculture recently urged the country's farmers to venture into sweet potato growing with the same level of preparation and seriousness as they would their usual cash crops. The sweet potato is easy to grow under a variety of conditions. For that reason and because it is generally considered by farmers to be of secondary economic and nutritional importance to grains and vegetables, it is often cultivated with little attention to techniques that might substantially increase yields.

Mr. Alick Daka pointed out that the sweet potato was not only a delicacy in Zambia, but in Botswana and Zimbabwe as well. It was a good crop to grow for crop diversification purposes, for nutritional supplementation as well as for sale locally and potentially beyond the country's borders. He urged farmers to adopt new sweet potato cultivation techniques to improve their yields. For instance, he pointed out that traditionally little attention is paid to soil fertility or supplementation in the cultivation of sweet potato, perhaps because of its ability to still deliver a yield, albeit low, when neglected this way. It is not unusual to see the crop grown in whatever pieces of land are left over after the maize and vegetabe crops have been planted.

Among management practices he urged farmers to adopt in sweet potato cultivation were to create ridges in passes for the tuber crop, rather than mounds as is customary. In addition to incorporating organic matter in the soil, Mr. Daka advised farmers to take advantage of what is now known about preventive practices against sweet potato weevil and sweet potato virus. Ensuring weevil-free planting material, earthing up the growing tubers to prevent cracks, the use of resistant varieties and disinfecting cutting tools are examples of preventitive measures generally well within the capabilities of small scale-scale farmers he gave.

Of the most common sweet potato varieties in Zambia, good management practices can result in yields of from 15 to 20 tonnes per hectare depending on the variety.