Groundnuts are prone to infestation by two closely related fungal species, Aspergillus flavus and A. parasiticus. Both species produce highly toxic mycotoxins known as aflatoxins. A. flavus is the most common species found in groundnut and groundnut by-products worldwide.

• Secondary metabolites of fungi
• Present in many foods and feeds
• Small molecules that are difficult to estimate

Aflatoxins are:

• Carcinogens that can cause liver cancer
• Immunosuppressive in nature
• Synergistic with hepatitis B and C viruses
• Hazardous to the health of human beings, cattle, sheep, poultry, and ducks

Aflatoxin contamination affects regional and international trade and farmers' incomes, as:

• The quality of the contaminated groundnuts deteriorates
• Contaminated groundnut cannot meet international standards

Cultural Practices

Preharvest

As the end-of-season drought favors aflatoxin contamination, several management practices have been developed to improve water retention at the end of the rainy season. Aflatoxin contamination can be reduced by varying degrees with treatment as follows:

• Lime application can reduce aflatoxin contamination by 72%
• Farm Yard Manure (FYM) by 47%
• Cereal crop residue by 28%
• Combination of FYM and lime by 84%
• Combination of lime and residue by 82%
• Combination FYM, and residue by 53% and
• Combination of FYM, residue, and lime by 85%

Postharvest

Postharvest practices advised are:

• Avoid damage to pods during harvest
• Avoid end-of-season drought with irrigation (if possible)
• Harvest the crop at maturity
• Eliminate damaged pods 
• Dry the pods to 8% moisture level
• Avoid rehumidification of pods during storage
• Store pods under insect-free and low humidity conditions

Aflatoxin contamination can occur in the field, during postharvest drying and storage, and shipment. Crop husbandry practices, climatic conditions, and soil factors, in addition to host-plant susceptibility, significantly influence aflatoxin contamination.

Management of Aflatoxin Contamination

Many Practices have been developed to reduce aflatoxin contamination, the most important ones being:

Host Plant Resistance

Several sources of resistance have been identified, particularly under the Common Fund for Commodities (CFC)-funded Groundnut Germplasm Project (See Table).

• Resistant sources have been used in breeding programs
• High-yielding resistant varieties hae been developed
• Some of the lines showed high performance in on-farm trials

New sources of resistance to aflatoxin contamination identified from the germplasm collection available in Western and Central Africa (WCA), through CFC funding.

Genotypes	Genotypes
ICG 6101	ICG 10609
ICG 7	ICG 51
ICG 6222	ICG 4440
ICG 11682	ICG 27
ICG 2051	ICG 1323

Diagnostic Tools

• Chemical methods are expensive and time consuming
• ELISA-based diagnostic aids developed by ICRISAT are quick,cost effective, and easily adaptable by developing countries
• Training courses have been carried out for NARS in both Asia and Africa