Pre and Postharvest Management of Aflatoxin Contamination in Groundnut

1. F Waliyar, B R Natre, A Traoré, B Diarra, O Kodio and P Lava Kumar International Crops Research Institute for the Semi-Arid Tropics Institut d'Economie Rurale (IER), Mali ICRISAT ICRISAT Pre and Postharvest Management of Aflatoxin Contamination in Groundnut www.aflatoxin.info

2. Groundnut / Peanut (Arachis hypogea) Groundnut • Major oilseed crop in the tropical and semi-tropical parts of the world -Major producers are India, China and the USA -Nigeria, Senegal, Sudan and Argentina • Developing countries account for 95% global production -70% in Asia, 23% in Sub-Saharan Africa (SSA) -West Central Africa (WCA) accounts for 78% of total SSA production • About 95% of the groundnut produced serves subsistence needs and domestic markets

3. Importance of Groundnut • Important in small-holder agriculture, grown mostly under subsistence conditions • A major source of income especially for women • Increasing shift towards edible groundnut (food purpose) (209% increase in West Africa during the past 3 decades) • Source of: • Digestible protein (24-34%) • Fat (44-56%) • Carbohydrate (11-27%) • Vitamins • Meal and Fodder • Nitrogen fixation (60 kg/ha)

4. Aflatoxins in Groundnut • Aflatoxins are produced by A. flavus / A. parasiticus • Grows over a wide range of temperature (between 10-40°C) • Thrives at high relative humidity and kernel moisture content (10 to 30%)

5. Liver cancer & other diseases Aflatoxin contamination Trade restriction Malnutrition Enhances HIV/AIDS Aflatoxins in Groundnut • Can occur at all stages: pre-harvest, harvest, and storage • Accumulates in seeds • Deteriorate quality • Barrier to international trade • Cause serious health risks of various kinds, accounting for several deaths in Africa

6. Status in Africa • Endemic problem especially in Sub-Saharan Africa (SSA), • - Due to frequent droughts and cultivation under subsistence conditions • Pre-harvest contamination is the major source: • -End-of-season drought; mechanical damage to pods; poor harvesting and storage methods • High contamination in seeds • -Reduction in exports by 19% during past 2-decades • Lack of awareness and monitoring facilities • -For most countries specific aflatoxin regulations • do not exist • -Regulations will have limited effect on health • protection, as groundnut produced is mainly • consumed by the producers themselves FAO, 2004 No regulations Regulations in place No information available

7. Predisposing Factors • Drought stress • Weather conditions during pod maturation and during drying • Time of harvest • Method of harvest/drying • Time of pod removal • Insects damage • Storage conditions

8. Aflatoxin Management Strategies Resistance Conventional , Transgenics Agronomic and Cultural practices Soil amendments (lime, farmyard manure, crop residues, etc) Pre and Posharvest Aflatoxin management Bio-control agents Trichoderma Pseudomonades Harvesting and Postharvest Drying, Threshers, Storages

9. Strategy for Aflatoxin Management in SSA • Reduce aflatoxin contamination to improve health and incomes of groundnut farmers and consumers • Promote pre and post-harvest technologies that minimize aflatoxin contamination of groundnuts • Information dissemination • Awareness campaigns • Participatory varietal selection of tolerant varieties • Participatory evaluation of cultural practices to reduce aflatoxin contamination • Demonstration of best-bet harvest and drying techniques • Training for technology dissemination

10. (i) Resistance Conventional resistance • Source of resistance available • Low level of resistance • Breeding lines developed • Some have been tested in Asia and Africa • High yielding lines identified • Difficulties • Screening • Variability (field) • Transgenic resistance • Incorporation of anti-fungal genes (Chitinase) in elite varieties (cv. JL24) • T1 generation plants being evaluated for resistance.

11. (ii) Agronomic and Cultural Practices The main objective is to reduce effect of drought at the end of cropping season • Farmyard manure • Calcium (as lime/gypsum applications) • Cereal Crop Residues • Density • Planting date etc.,

12. (iii) Soil Amendments to Mitigate Aflatoxin Contamination • On station experiments conducted at Sadore, Niger and Samanko, Mali, during 1999-2001 • Soil amendments with lime (2.5 t hat-1), farmyard manure (10 t ha-1) and cereal crop residues (5 t ha-1) applied at sowing or 50 days after sowing, either individually or combinations of these three (12 treatments). • Three cultivars used: Two resistant cultivars, J11 and 55-437; and a susceptible cultivar Fleur 11

13. Aflatoxin Concentration (ppb) in Groundnut Seeds from Various Treatments *Three year average Resistant cvs. 55-437 and J11 Susceptible cv. Fleur 11 F = Farmyard manure R = crop residues L = Lime 1 = Application at sowing 2 = Application at 50 days after sowing

14. Aflatoxin Concentration (ppb) in Groundnut Seeds from Various Treatment Combinations F = Farmyard manure R = crop residues L = Lime 1 = Application at sowing 2 = Application at 50 days after sowing *Three year average Resistant cvs. 55-437 and J11 Susceptible cv. Fleur 11

15. Samanko, Mali Sadore, Niger 300 200 Aflatoxins (ppb)* 100 0 Control L1 F1 R1 L1 R1 L1 F1 L1 F1 R1 L2 F1 R2 L1 F1 R2 L2 Promising Soil Amendments for Reducing Aflatoxin Contamination in Groundnut 25 *Three year average F = Farmyard manure R = Cereal crop residues L = Lime 1 = Application at sowing 2 = Application at 50 days after sowing Average from 3 years on-station trials (1999-2001) Groundnut cv. Fleur 11 (Highly susceptible to aflatoxin)

16. Effect of Lime, Crop Residues and Farmyard Manure in Farmers Fields • A resistant (55-437) and a susceptible (JL 24) cvs used in the study • Demonstrations in farmers in Kolokani and Kayes; on-station • 400 kg ha-1 lime applied at 50 days after sowing • 2.5 t of Crop residues and farmyard manure at planting and 50 days after sowing

17. Aflatoxin Content Under Various Agronomic Practices in Kayes (Mali) F = Farmyard manure R = Crop residues

18. Aflatoxin Content Under Various Agronomic Practices in Kolokani FYM = Farmyard manure CR = Crop residues

19. Method of Harvesting and Drying • Demonstration in farmers in Kolokani and Keyes, Mali • Drying pods facing the sun Traditional Field Drying Improved Batch Drying (Pods facing the sun)

20. Effect of Method of Drying on Aflatoxin Content - Kolokani *parts per billion

21. Effect of Method of Drying on Aflatoxin Content - Kayes *parts per billion

22. Effect of Time of Pod Removal on Aflatoxin Content • Lifting at maturity • Remove pods immediately • After 1 week • After 2 weeks • Usual farmers practice (when ready)

23. Time of Pod Removal After Uprooting

24. Increase in Aflatoxin Concentration During Storages in the Farmers Fields

25. Imparting Awareness • Increased awareness among farmers of the value of modern varieties and have responded by being directly involved in variety selection and seed production • Farmers awareness of the needs of processors and consumers who in turn recognize the value of improved quality

26. Information Dissemination Pathways • Use of farmer trial and demonstration plots through farmer-to farmer visits • End of season meetings • Brochures and flyers (Fr and local languages) • Television and radio debates

27. Future Outlook • Risk assessment of mycotoxins in other crops in addition to groundnut • Assess the impact of mycotoxins on human health and socio-economic conditions of people in marginal farming systems • Increase public awareness on the risks of mycotoxins • Develop and implement quality control methods and safety standards • Develop and/or promote technologies to produce mycotoxin free products • Study the impact of aflatoxin contaminated food on HIV/AIDS patients

28. ICRISAT Thank you www.aflatoxin.info