The basic principles of the INGER-Africa mechanism are:

• To provide diversity and variability

• To supply valuable germplasm to target ecosystems and stresses

• To avoid overloading the NARS, since nurseries are constituted on the basis of NARS' specific requests.

The objectives of INGER-Africa nurseries are as follows:

• To provide NARS with improved germplasm from a wide range of sources to broaden the genetic base of their breeding materials and identify varieties for direct introduction.

• To provide NARS scientists with a mechanism to screen their genetic materials for resistance/tolerance to specific stresses at reliable hot-spot locations in the region; each nursery consists of nominations from NARS and WARDA.

• To provide NARS scientists with the means to test the stability and adaptability of their elite varieties in multilocational trials. Promising lines nominated by NARS are used for composing regional yield-stability and adaptability trials. Several countries evaluate the same varieties. These trials provide information on the genotype x environment interactions and wide adaptability of the promising lines.

• To handle segregating populations (from F₃ to more advanced generations) nominated by breeders. These are grown and harvested in bulk for distribution to NARS on request for in situ selection and advancement in national trials.

The approach is more flexible and responsive to the needs of national programs than former approaches. Whereas formally the same nurseries were sent to all participants, nurseries are now tailored to meet the specific needs of each national program. Nurseries are provided at NARS' request, while taking into account the plant characteristics best suited to their particular environmental conditions. The earlier top-down approach has been completely reversed.

History of INGER-Africa

In 1975, the International Rice Research Institute (IRRI) launched the International Rice Testing Program (IRTP) as a systematic global program for the collection, distribution and testing of rice genetic materials. This program was later re-designated the International Network for Genetic Evaluation of Rice (INGER). 

The overall objectives of INGER have been to link national rice-improvement programs and international centers, and to promote genetic diversity for different ecosystems through global exchange, evaluation and utilization of improved breeding materials originating from sources world-wide. 

The African wing of INGER was created in 1985 and located at the International Institute for Tropical Agriculture (IITA). In 1990, the mandate for all rice research in West and Central Africa was given to the West Africa Rice Development Association (WARDA) and in 1991, WARDA and partners in the national agricultural research systems (NARS) established varietal-improvement Task Forces (mini networks) comprising Upland, Lowland, Irrigated and Mangrove Swamp rice breeding activities. 

A review of WARDA in 1993 by the Technical Advisory Committee (TAC) of the Consultative Group on International Agricultural Research (CGIAR) recommended that INGER-Africa be relocated to WARDA, to bring together the effective NARS linkages established by the WARDA Task Forces and the broader coverage of the INGER network. Between 1994 and 1996, the UK Overseas Development Administration funded a project to transfer INGER-Africa activities to WARDA, and to establish a new germplasm exchange mechanism using Task Force approaches. The transfer of INGER-Africa operations to WARDA became effective in April 1997.