Improving quality assurance systems for fresh fruits and vegetables produced by peri-urban resource poor farmers in Zimbabwe
Crop Post Harvest
Central Research Department (now Research and Evidence Division)
Africa, Eastern Africa, Southern Africa
To identify the nature and extent of food safely risks associated with horticultural production and marketing in peri-urban areas, to prioritise the food safety constraints, to develop strategies to minmise food safety risks, and thereby to improve food safety assurance for consumers and develop market opportunities.
Smallholders in peri-urban areas face major problems in resolving pollution and microbiological contamination. They lack the knowledge to fully understand the nature of the constraints, and the technologies and management systems to resolve them.
Increased recognition of the potential hazards arising from consumption of fresh produce, contaminated with micro-organisms and environmental pollutants, has led to extensive research in the field, and the development of improved quality assurance systems for fresh produce. However, this work has focussed mainly on large-scale commercial farms and processing industries in industrialised countries; very little work has been done to address the needs of smallholders in sub-Saharan Africa.
Food safety risks occur throughout the marketing chain. Produce is exposed to contamination during the handling, transportation, storage and retailing process. Consumers are vulnerable to unsafe food, which may not be apparent from the appearance of the food. This applies both to consumers in producer households and to consumers purchasing from market. Food safety is a hidden quality attribute, which is frequently ignored by local consumers, who will only pay a premium for a visible improvement in quality.
However, it is self evident that in ensuring food security, it is not sufficient to simply provide adequate supplies of food of good nutritional quality. If that food has been rendered unsafe by either biological or chemical contaminants, it will represent a threat rather than a benefit to poor consumers, who remain most at risk from foodborne illness.
Some foodborne contaminants cause acute effects, but those such as the heavy metals accumulate over long periods and have chronic effects, retarding the development of young children, and increasing the risk of illness in later life.
In several sub-Saharan countries, production and marketing of fresh fruits and vegetables for domestic and export markets is an increasing and significant source of income generation, and one of the largest labour employers. Rapid urbanisation, increasing wealth associated with the emergence of an urban middle class, and improved international transport and communications, have created increased demands for horticultural produce.
In Zimbabwe, horticulture accounts for 15% of the agricultural gross domestic product, with 46% of production going for export. Production for export is dominated by large-scale commercial farms. Produce for the large urban markets is mainly supplied by resource poor smallholders (communal farmers and resettlement farmers) located in peri-urban areas.
Surveys have estimated that 8,500 small-scale commercial horticulturalists and 950,000 communal farmers operate in peri-urban areas of Zimbabwe. 75% of these farms are run by women. The majority of peri-urban farmers belong to the poorest strata of the community, who grow crops as a survival strategy to provide food and cash income for their families.
Peri-urban horticultural farmers should be well placed to take advantage of these emerging national and international market opportunities. However, they face a key constraint in their ability to provide produce that meets the increasingly demanding quality requirements for these markets and, until recently, smallholders have had a minor role in horticulture export markets.
However, recent internal and external initiatives have produced the impetus for an increasing involvement to smallholders in export horticulture. Hortico Produce is a major exporter of fresh produce, and has already formed links with 1,700 smallholders in peri-urban areas around Harare, providing production inputs and services in return for access to the crop.
Three other companies are also involved in linking smallholders to the horticulture export market. These farmers produce primarily for home consumption and the urban market,
Quality constraints (with implications for safe food delivery facing smallholders in peri-urban locations involved in production and marketing of fresh fruits and vegetables assessed.
Improved quality assurance systems for smallholder production of safer fresh produce, and techniques for imroving the safety of resource poor farmers produce, developed and validated.
Potential for production of safer fruits and vegetables by smallholders in peri-urban areas, and importance of food safety, promoted to agricultural policy makers, rural and urban planners, horticultural exporters, and NGOs that can facilitate uptake of methods for delivery of safer food.
Progress and Impact:
Quality constraints (with implications for safe food delivery) facing smallholders in peri-urban locations involved in production and marketing of fresh fruits and vegetables assessed.
In discussions with individual farmers and in focus group discussions, farmers showed that they have some awareness of food safety issues especially with regard to toxicity of crop protection chemicals. However, they were unaware of any risks associated with unclean water or poorly composted animal manure. Understanding of safe use of crop protection products was limited with most farmers being unaware of the need for pre-harvest withdrawal periods. In fact many farmers used Dithane M45 to give a shine to tomatoes and leafy vegetables just prior to marketing. Farmers felt that contamination at the production stage was likely to be a rare occurrence or non-existent and blamed poor hygiene in Mbare Musika for any outbreaks of foodborne illness associated with their produce. In terms of food safety assurance, problems with irrigation water, poorly composted manure and inappropriate use of crop protection products, and general lack of awareness or training in good agricultural practice were found to be the most important issues for the small-scale sector.
Of the samples analysed for faecal contamination as indicated by the presence and number of E.coli, 92% of samples analysed were found to meet the UK, PHLS definition of satisfactory produce (max 20 CFU/g). Three percent of samples found to be borderline cases and 5% of samples were considered unacceptable under the PHLS standard (>100 - <104 CFU/g). Similar results were obtained in Kenya, where 90% of samples were found to be satisfactory. These results tend to refute the assertion that small-scale growers produce represents a high risk from microbiological contamination, although it is still true that small-scale growers operating practices leave much to be desired and need improving to minimise the risk of an incident occurring.
In general lower income consumers in Harare were found to be aware of foodborne illness, with some 30% reporting illness associated with consumption of fresh produce. Consumers were mainly concerned with visibly unhygienic conditions at vending sites, but were largely unaware of potential hazards associated with inappropriate practices at farm level. Relatively few were aware of chemical contaminants mentioning pesticides and over application of fertiliser as a cause for concern, none of the consumers was aware of heavy metal poisoning as a risk associated with fresh produce. Consumers are guided by considerations of price and availability and as such there was little indication that lower income consumers would be either willing or able to pay a premium for enhanced levels of food safety assurance.
Improved quality assurance systems for smallholder production of fresh produce, and techniques for improving the safety of resource poor farmers produce developed and validated.
The main achievement of this output was the development and validation of food safety management system and guide for small-scale vegetable growers in Kenya. Monitoring and support of farmers over three growing seasons demonstrated a significant reduction in the levels of faecal contamination on produce grown by trained farmers when compared to a control group. Levels of pesticide residue also decreased, but levels of dicofol and endosulphan remained above EU MRLs for French beans thus indicating the need for further training on correct use of chemicals.
Following on from concerns raised by the export industry in Zimbabwe regarding speed and reliability of existing methods for detecting faecal contamination, strategic research was initiated in the UK to address this problem. A review of scientific literature confirmed that the techniques used by laboratories in Zimbabwe and Kenya can give false positive readings for E.coli contamination on fresh produce.
The project was badly affected by the collapse of the economy and continuing political instability in Zimbabwe. However, thanks to the efforts of the team in Zimbabwe, diversification of work into Kenya and development of strategic activities in the UK the following outcomes were still achieved: *An improved understanding of producer practice and risks associated with small-scale vegetable production in Zimbabwe and Kenya, and methods for minimising these risks. *A validated food safety management system for small-scale French bean farmers. *An improved understanding of the viewpoints and motivations of consumers in low income groups in Harare with regard to food safety of vegetables. *An improved understanding of the shortcomings of many laboratories in developing countries, especially with regard to complex chemical analyses. *An experimental system for detection of E.coli in fresh produce within 0.5-5 hours using calorimetry. At the end of the project, the level of impact of outputs on the purpose was necessarily limited due to the project having to focus mainly on strategic and adaptive research issues. This was necessary partly to understand the existing systems through techno-economic surveys and contaminant monitoring, and also to develop appropriate measures for minimising risk. The current project gave emphasis to improving food safety assurance of fresh produce entering domestic markets, using the requirements of export production and tourism as a financial impetus. This concept proved impractical in Zimbabwe, partly due to the collapse of the tourist industry and shift in consumer demand away from quality towards surviving food shortages and economic hardship.
Total Cost to DFID:
VENKATARAGHURAMAN, S., GRAFFHAM, A.J. and BEEZER, A.E. (2001) Development of a rapid method for detection of Escherichia coli in fresh produce. Poster presented at Post-Harvest Postgraduate Conference, Cranfield University at Silsoe, UK. 31 May - 1 June 2001 [Scientific Poster]
COX, J.R. and KING, W.J. (2002) Multi-residue analysis of tomato and kale samples. Laboratory Analytical Report No: 01BR-BS. Natural Resources Institute (NRI), Chatham, UK. 7 pp.
COX, J.R. and KING, W.J. (2002). Multi-residue analysis of tomato and kale samples. Laboratory Analytical Report No: 01BP-BQ. Natural Resources Institute (NRI), Chatham, UK. 17 pp.
COX, J.R. and KING, W.J. (2002) Report of a visit to Kutsaga Research Station to assess pesticide residue analytical quality, 18 January - 3 February 2002. Natural Resources Institute (NRI), Chatham, UK. 15 pp.
GRAFFHAM, A., NENGUWO, N., MANWAYANA, E., CADISCH, G. (2001) National workshop on improving food safety assurance of fresh produce in Zimbabwe. New Ambassador Hotel, Harare, Zimbabwe. 17-18 September 2001. [Two-Day Workshop]
NEW AGRICULTURIST ON-LINE (2003) Exacting standards. New Agriculturist . [On-line magazine]