Groundnut is currently grown on over 22.2 million hectares worldwide with a total production of over 35 million tonnes. India and China are the world's largest producers of groundnuts, accounting for over 41% and over 18% of world production respectively. Millions of small-holder farmers in Sub-Saharan Africa grow groundnut as a food and cash crop, accounting for over 9 million hectares of cultivated farmland. Nigeria, Sudan and Senegal are Sub-Saharan Africa's leading producers, and the crop also does well in southern Mali and adjacent regions of Cote DIvoire, Burkina Faso and Ghana.
Even as India and China are the world's largest producers, they account for only a small part of international trade because most of their production is consumed domestically as peanut oil. Exports from India and China are equivalent to less than 4% of world trade. 90% of India's production is processed into peanut oil. Only a nominal amount of hand-picked select-grade peanuts are exported. The major exporters are the United States, Argentina, Sudan, Senegal, and Brazil. These five countries account for 71% of total world exports, with the United States being the leading exporter. The major peanut importers are the European Union, Canada, and Japan. These three areas account for 78% of the world's imports.
Although Sub-Saharan Africa has 40% of the world total of land under groundnut, its output amounts to only 25% of total world production due to low yield (0.95 tonnes/ha as compared to 1.8 tonnes/ha in Asia). The main constraints hampering higher yields and quality in Africa are intermittent drought due to erratic rainfall patterns and terminal drought during maturation, with drought-related yield losses running to millions of dollars each year.
A drought-related quality issue is pre-harvest contamination with aflatoxin, a carcinogenic mycotoxin produced primarily by the fungus aspergillus flavus, which consequently shuts out SSA groundnuts from export markets which would be more lucrative.
Foliar diseases rust, rosette, early leaf spot (ELS) and late leaf spot (LLS) cause further devastating yield losses. Further compounding the problems of drought, aflatoxin and disease, less productive older varieties and landraces form the dominant cultivars in the absence of much-needed improved varieties.
Groundnuts can be eaten raw, as peanut butter, used in recipes and made into solvents and oils which are in turn used in medicines, textile materials, cosmetics, nitro-glycerine, plastics, dyes, paints, varnishes, lubricating oils, leather dressings, furniture polish, insecticides, and soap. Groundnut shells are used in the manufacture of plastic, wallboard, abrasives, fuel, cellulose and glue. Groundnut also has a high potential for biodiesel.
Processed into butter, groundnut is particularly valuable as a dense, portable food that is high in protein and calories and can be eaten at any time without further preparation. Groundnut oil has a mild flavour, a relatively high smoke point and is resistant to rancidity - making it ideal for cooking, especially given its high content of healthful monounsaturated oils. Groundnut flour is gluten-free, has a high protein content, and is a good flavour enhancer. Groundnut milk is a lactose-free milk-substitute beverage.
Groundnut-based pastes high in protein, calories and other nutrients, have been developed for use by relief organisations as a therapeutic food in emergency situations of extreme drought and famine, particularly targeting malnourished children. Groundnut provides over 30 essential nutrients and phytonutrients, including niacin, folate, fibre, magnesium, vitamin E, manganese and phosphorus. Groundnut rivals the antioxidant content of many fruits. They are a rich source of resveratrol, a chemical thought to reduce the risk of cardiovascular disease and cancer. Groundnut oil has been found to lower LDL (bad) cholesterol without reducing the beneficial HDL cholesterol. Groundnut plant tops are used for hay and the solid residue from groundnut oil processing is used as an animal feed and as a soil fertilizer. Low grade peanuts are also widely sold as a bird feed.