CropBasedApproachTeam.pngContact: Dr. Sunette Laurie, +27 (0)12 808 8000

A food diversification program focusing on nutrition, education and production of pro-vitamin A rich vegetables.

Many children and adults all over the world suffer from inadequate intake of vitamins and minerals. Vitamin A is no exception and it is a public health problem in many developing countries. The consequences of vitamin A deficiency are higher risks of maternal death, increased risk of death from measles and diarrhea in children, reduced resistance to infections, delayed recovery from illness, and eye damage. In South Africa, 49.3% of 1-9 year old children have vitamin A deficiency (serum retinol <20 µg/dl). This is a severe prevalence of vitamin A deficiency and can be considered a public health problem.

To address this chronic problem, ARC-Roodeplaat applies a crop-based approach. This approach is based on the establishment of food gardens to increase the production, availability, access to, and consumption of provitamin A rich foods together with education in nutrition.

This model was developed by the Medical Research Council and ARC-Roodeplaat, and has proved to be successful in decreasing vitamin A deficiency in a pilot project in the Ndunakazi community in Kwazulu-Natal.

The crops with high provitamin A content which are promoted are swiss chard, orange butternut/pumpkin, and dark orange-fleshed sweet potato. Orange-fleshed sweet potato is one of the few crops which are both an excellent source of energy and contains high quantities of provitamin A. Some cultivars have such high levels of beta-carotene that children only need to consume 100 g to obtain 100% of the recommended daily allowance (RDA). The ARC-Roodeplaat sweet potato breeding program focuses on the development of orange-fleshed cultivars that are better adapted to local conditions than the imported ones.

​Research Team

  1. Dr S. Laurie (Senior Researcher)
    Project leader

  2. S Tjale (Senior Research Technician)

  3. M. Mtileni (Senior Research Technician)

    In collaboration with Dr Mieke Faber, Medical Research Council

Research  Focus Areas

Crop-based model
- Activities:

  • Community meeting to form a partnership between the project team and the community

  • Analyzing the situation in the community, i.e. existing dietary practices and garden activities, infrastructure and resources and stakeholders

  • Community project-planning meeting to discuss the proposed gardening project, formulate objectives and set goals. This is done in a participatory fashion

  • Recruiting and training of fieldworkers establishing home/community gardens with provitamin A rich crops and nutrition education aspects

  • Establishing demonstration gardens with provitamin A rich vegetables to serve as community training centres

  • Establish a community-based nursery for supply of cuttings of orange-fleshed sweet potato and seeds

  • Provide the community with the necessary knowledge through nutrition education and promotion to enable behavior change:

      • Cook provitamin A-rich vegetables and introduce these to small children

      • Teaching caregivers how to prepare vitamin A-rich vegetables

      • Nutrition education focusing on vitamin A

      • Monitor growth of pre-school children (optional)

      • Providing training in planting of vitamin A-rich vegetables

  • Monitoring and evaluation: i) monitoring of project execution; and ii) project progress.

Implementation of crop-based projects:
The project team provides training in production of crops with high provitamin A content such as dark orange-fleshed sweet potato, swiss chard, carrot and orange butternut/pumpkin, in addition to training in the nutritional value of the crops, the importance of vitamin A and provides cuttings of orange-fleshed sweet potato to start production. Broadly ARC-VOP can assist organizations in implementing the crop-based projects through training and demonstration.

Previous projects were implemented with Department of Basic Education implementing growing of orange-fleshed sweet potato in school gardens in various provinces.


Schools in Western Cape growing and serving orange-fleshed sweet potato.

A larger scale project was implemented in collaboration with Department of Social Development in Eastern Cape where half hectare plots of orange-fleshed sweet potato was established and the project members was trained in preparation of processed products from orange-fleshed sweet potato e.g. doughnuts, chips, and chutney.

Orange-fleshed sweet potato field of
Ilitha Project near King Williamstown

ARC exibition of orange-fleshed
at a sweet potato promotion event

In a recent project, the ARC-VOP joined efforts of the University of Pretoria, Faculty of Family Medicine in the Zama Zama informal settlement near Daspoort, training some community members in growing orange-fleshed sweet potato and other vegetables. The principles of the crop-based approach to address vitamin A deficiency is included in modules of the ARC-VOP vegetable training course.

Cover 2013 Cropbased manual.pngThe ARC and MRC published a manual titled: "A crop-based approach to address vitamin A deficiency in South Africa" to assist organizations in the implementation of this approach. The manual is available from ARC-Roodeplaat.

Publications and Presentations

Department of Basic Education, 2011. Horticulture Manual for Schools: A guide to establish and sustain food gardens. National School Nutrition Programme, Department of Basic Education, Pretoria. South Africa. (Authors: LAURIE, S., van den Heever, E., du Plooy, I. & Mkula, L., Agricultural Research Council – Roodeplaat Vegetable and Ornamental Plant Institute)

FABER M, LAUBSCHER R & LAURIE S, 2011. Availability of, access to, and consumption of fruits and vegetables and it's relation to LSM in a peri-urban area in KwaZulu-Natal, South Africa. Maternal and Child Nutrition doi: 10.1111/j.1740-8709.2011.00372.x.

FABER  M & LAURIE SM, 2010. A home-gardening approach developed in South Africa to address vitamin A deficiency. In: Thompson B, Amoroso L (eds). Food Based Approaches (FBAs) for Combating Micronutrient Deficiencies. Food and Agricultural Organization (FAO) and CABI bookshop. Pg. 163-182. ISBN-13: 978 92 5 106546 4.

Faber M, Laurie S, Ball A & Andrade M, 2013. A crop-based approach to address vitamin A deficiency in South Africa. Medical Research Council, Cape Town / ARC-Roodeplaat, Pretoria, South Africa

Faber M, Laurie S, Maduna M, Magudulela T & Muehlhoff E, 2013. Is the school food environment conducive to healthy eating in poorly resourced South African schools? Public Health Nutrition doi:10.1017/S1368980013002279 (ISI 2.25)

Faber M, LauriE SM, van Jaarsveld PJ, 2013. Total β-carotene content of orange sweetpotato cultivated under optimal conditions and at a rural village. African Journal of Biotechnology Vol. 12(25): 3947-3951 DOI:  10.5897/AJB2013.12380

Faber M, Laurie SM, Van Jaarsveld PJ, 2014. Critical issues to consider in the selection of crops in a food-based approach to improve vitamin A status – based on a South African experience. In: Thompson B, Amoroso L (eds). Improving diets and nutrition. Food-based approaches. CABI and FAO, pp 45 – 57, 2014.

Faber M, Wenhold FAM, Laurie SM. 2017. Dietary diversity and vegetable and fruit consumption of households in a resource-poor peri-urban South African community differ by food security status. Ecology of Food and Nutrition. Ecology of Food and Nutrition 56(1):62-82.

Laurie SM, Faber M, Maduna M.  2017. The potential, gaps and constraints of school food gardens in a nutrition-sensitive time: the case of primary schools in South Africa. South African Journal of Clinical Nutrition. Accepted in December 2017 SAJCN issue

Laurie SM, Faber M, Malebana ME & van den Heever E, 2013. Results from a survey on school food gardens in South Africa: Perceptions of teachers, learners and parents. Acta Hort. (ISHS) 1007:681-687.

RAUTENBACH F, FABER M, LAURIE S & LAURIE R, 2010. Antioxidant capacity and antioxidant content in roots of 4 sweetpotato varieties. Journal of Food Science 75(5): 400-405.

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