Horticulture Research Institute, Box 810

Marondera, Zimbabwe

An Overview Of Our Solution

Zimbabwe like many southern African countries depends on rain fed agricultural systems that have been threatened by climate change. In a bid to promote biodiversity, nutrition and food security, the project is promoting the sustainable production of virus free sweet potato varieties. Twenty varieties of sweet potatoes have been maintained. Planting material have been made readily available to farmers through the decentralization of nurseries. The practice has seen minimum use of agrochemicals, promotion of crop rotations, increased organic matter and enhanced water holding capacity of the soils. Yield increase from about 5t/ha – 40t/ha has been recorded and cultivation of the crop in marginalized areas hence widely commercializing the crop. Information dissemination and awareness has been through production pamphlets, fact sheets, field days and farmer training.

Who is this solution impacting?

Community Type

Rural

Organization type

Government

Ecosystem (select all that apply)

Grasslands

Population impacted

300 000 people

Size of agricultural area

15 000 hectares

Production quantity

30000-40000 kg/ha

People employed

15 people

Describe your solution

We identified that farmers were getting low yields on sweet potatoes as a result of poor planting material. It was found out that farmers were discarding some varieties due to poor performance. The crop was also considered a minor crop which farmers put little effort. Sweet potato cultivars were collected across the country, characterized and cleaned for viruses through tissue culture techniques. We have promoted the commercialsation of sweet potatoes using clean materials. Production manuals and fact sheets were prepared to avail information to farmers. The Institute took it for its mandate to preserve the sweet potato germplasm, provide clean planting material and improve the yield potential through tissue culture techniques. Mother plants of the cultivars are being maintained yearly at the Institute. Plants are maintained in greenhouses over winter followed by rapid multiplication and sale to farmers at subsidized prices. Farmers have access to extension services, training, and platforms to share experiences.

Describe your implementation

* Main activities included base line survey to access the status of sweet potato production within Zimbabwe. Findings showed a general loss of germplasm due to poor performance which initiated the collection of germplasm from farmers. Germplasm was characterized and improved through tissue culture techniques. The germplasm is currently being maintained/preserved at the Institute. Cleaned planting material is bulked through rapid multiplication for sale to farmers at subsidized prices. Awareness programs have been raised through demonstration plots, exhibitions at field days and green shows and national agricultural shows. Farmers have been trained on sustainable production. Information dissemination is being done through pamphlets, fact sheets, and live broadcasts. * We ensured that our solution was adopted through engaging the communities at project conception and through regular monitoring and evaluation. The communities own the project and are eager to see its success. * Conditions have been enabling because the planting material prices were subsidized by the government. Favorable policies on starch and other carbohydrates in staple diet have promoted the production and consumption of tuber crops e.g. sweet potato, irish potato and taro to complement maize meal, which is in short supply. * Our success benefits from the condition that sweet potato is adaptable to a wide range of environmental conditions. We have seen about 70% from 15% of the farmers venturing in the commercialsation of sweet potato also realizing significant yields from as low as 5t/ha to 30-40t/ha. The decentralization of nurseries has made planting material within reach. * The lack of a formal market for sweet potatoes is challenging making farmers skeptical about commercializing the crop. Some farmers do not readily accept the use of Biotechnology techniques in agriculture. This was overcome by intensive training programs on demystifying science of biotech and sweet potato value chains.

External connections

We are working with local NGOs such as the Biotechnology Trust of Zimbabwe and World Vision, National Biotechnology Authority of Zimbabwe, Tobacco Research Board, Food and Agricultural Organization, Extension division and local Universities. Our efforts connects closely with the health sector especially when we promote the orange fleshed varieties which are high in beta carotene. The livestock sector is also deriving direct benefits of livestock feed from sweet potato leaves and by products. The efforts are a direct contribution to the country as it promotes the food and nutrition cluster as outlined in the national document, ZIMASSET blueprint. The sweet potato also features in the country’s food and nutrition policy set in 2013. The increased yields in sweet potatoes also improves the farmer’s livelihoods through increased incomes.

What is the environmental or ecological challenge you are targeting with your solution?

The solution aims at promoting the production/ commercialization of improved sweet potato cultivars under a well-managed crop rotation where the crop will benefit from residual nutrients from previous crops such as maize and beans. Improved planting material is less susceptible to pests and diseases resulting in a reduction on use of chemicals. Sweet potato is an important crop to consider towards the diversification of food especially with issues of climate change. Sweet potato is a low input crop which can thrive on sandy soils and with little water.

Describe the context in which you are operating

In southern Africa, rainfall variability has a major effect on the population's vulnerability to food insecurity (Milgroom and Giller, 2013). Although the climate records for Zimbabwe do not show specific trends in rainfall patterns, intensities and distribution (Unganai, 2009), an increase in the occurrence of extreme weather events, cyclones and droughts has been documented across the country (Mutasa 2008). This has had a negative impact on agriculture which dominates almost 90% of Zimbabwean communities. Poor yields have also been compounded by poor farming practices such as mono-croping our staple maize which affects the soil structure and texture rendering it susceptible to soil erosion and poor nutrient holding capacity. Mono-cropping also promotes the proliferation of pests and diseases eventually affecting both quantity and quality of expected crop yields. The diversification of crops within farming systems and good agricultural practices becomes key to increase food security and environmental management.

How did you impact natural resource use and greenhouse gas emissions?

The baseline survey gave us a general overview of the status of sweet potato production within Zimbabwe. We managed to reduce the sweet potato viral load in sweet potato planting materials collected from farmers and enhance their management practices through training. The Institute managed to establish a sweet potato gene bank with twenty cultivars. We are seeing improvements in soil organic matter from crop rotations and green manure which has improved soil texture and structure improving water holding capacity of the soils. Notable increases in sweet potato yields. Farmers are now using minimal nutrients due to utilization of residual nutrients

Water

Water samples showed minimum pollution in water bodies due to a reduction in the use of chemicals by farmers

Food Security/Nutrition

Farmers are now yielding more sweet potatoes per hectare meaning they have surplus to sell for increased incomes.

Economic/Sustainable Development

Increased sweet potato yields from 5t/ha to 30-40t/ha saw famers being able to sell their produce at a profit. The orange fleshed cultivars must have improved the communities’ nutrient status.

Climate

The project promotes diversified farming towards a diversified diet in the face of climate change. Good farming practices improves the soils fertility and water holding capacity.

Sustainability

The solution is sustainable and does not rely fully on government subsidies. Government subsidies were important at the start of the project as the initial injection for running a tissue culture laboratory are high. The Institute and farmers generate income from their proceeds which is channeled back to the project. Sweet potatoes have a high return per dollar invested guaranteeing profits when properly done. When farmers use first generation sweet potato planting material they can produce their own cutting materials for at least three more seasons.

Return on investment

The initial production of tissue cultured sweet potatoes was not our direct cost but a donation from one of our collaborators. Other overheads such as our salaries are taken care by the Government since we will be carrying out our national mandate. The Institute incurred costs during cultivar collections around the country around US$6000. Training programs were facilitated by collaborators such as FAO and World vision. Sweet potato production has a high return on a dollar investment to the farmer. Total variable costs to produce a hectare are US$850. Subsidized planting material for a hectare costs US$350. Expected yields 30t/ha. At a selling price of US$0.10/kg a farmer expects a total revenue of US$3000. A gross margin of US$2150.

How could we successfully replicate this solution elsewhere?

The solution can be replicated successfully elsewhere because the crop itself if highly adaptable to a wide range of environmental conditions. This has been done locally by some local NGO, Biotechnology Trust of Zimbabwe but project was on a smaller scale approximating 2000 hectares as the crop then was perceived a poor man’s crop. Sweet potatoes were a minor crop with production on small pieces of land with not much attention given to yields and quality. To further expand the project and for monitoring and evaluation the project requires additional funding. Specific needs will be for farmer training and further decentralization of sweet potato nurseries.

Overview