The National Institute for Agronomic Study of the Belgian Congo (French: Institut national pour l'étude agronomique du Congo belge, or INÉAC) was a research facility established in Yangambi in the Belgian Congo, operating from the 1930s until the country gained independence in 1962.
INEAC was established as a successor to the Régie des Plantations de la Colonie (REPCO). The INEAC experimental fields and laboratories were built along a road parallel to the north bank of the Congo river, and along a road stretching northward from the river for about 25 kilometres (16 mi). In the 1930s researchers at INEAC found the relationship between the tenera, dura and pisifera oil palms. Oil palms have relatively low yield around Yangambi compared to coastal regions. This appears to be due to the lower night temperatures in the continental interior, which have a mean minimum at Yangambi of around 20 °C (68 °F). The scientific research undertaken by INEAC played an essential role in improving the supply of rubber and palm oil during World War II.
Later the institute studied a broader range of agricultural topics, gaining an international reputation, with centers throughout the Belgian Congo and Rwanda-Urundi. The center developed a number of varieties of soy beans for use in different parts of the country. Early-maturing varieties yielded over 1,200 kg/ha of soybeans. Field trials showed that inoculation could increase yields by 80% to 300%. In the 1950s INEAC researchers discovered the 'Yangambi km 5' (AAA) dessert banana. This variety yields large numbers of small fruit with an excellent taste, is productive even on poor soils and is resistant to black leaf streak disease. There is some evidence that this cultivar may have originated in southern Thailand, introduced to the Kilo-Moto region in northeastern Congo and then brought to Yangambi before World War II.
After independence, INEAC was closed on 31 December 1962. The institute has been criticized for concentrating on large-scale agriculture for export markets.