Biotechnology, Breeding and Seed Systems

After a long time since the last release of improved bean varieties, five new bean lines were recommended for pre-release by the bean national variety release technical committee in a meeting held at the Kenya Plant Health Inspectorate (KEPHIS) headquarters in Nairobi on 26 March 2006. KEPHIS has the national mandate of testing bean varieties submitted by breeding programs in Kenya. The GLP (Grain Legume Project) beans widely cultivated and traded in Kenya were released in 1984 by the National Horticultural Research Centre, presently KARI-Thika. The next set of four varieties (Kat B1, Kat B9, Kat X56 and Kat 69) was released by the National Dryland Farming Research Center (NDFRC), presently KARI-Katumani, between 1987 and 1998. Release of improved bean varieties to Kenyan farmers has been hindered by lack of a clear and transparent variety testing and release procedure, and often by conflict of interests. The formation of KEPHIS through an act of parliament in 1996, variety development on one hand, and testing (also known as national performance trials), registration and release, on the other, were separated.

National performance trials (NPT). The trials for beans were restarted in 2005. Two trials were conducted. The first trial had 16 bush bean entries and three checks. These entries were contributed by KARI-Kakamega (3), Egerton University (3), University of Nairobi (8), Kenya Seed Company (1) and Western Seed Company (1). The second trial had five climbing bean lines and two checks – all jointly contributed by KARI-Embu and the University of Nairobi. Except for entries from Kenya Seed Company and Western Seed Company, all others either had their origins, or were derived from International Centre for Tropical Agriculture (CIAT) germplasm and distributed through the collaborative regional bean breeding program based at the University of Nairobi. The entries were tested during the long rain season (March- June) of 2005 and short rain season (October- January 2006). Three climbing bean lines (MAC 13, MAC 34 and MAC 64) and two bush bean lines (AFR 708 and KK 8) were recommended for pre-release. Due to failure of rains at most of the testing sites in the short rains cropping season (October- January 2006), the variety release committee recommended a repeat of the national performance trials for other bush bean entries.

This is the first time climbing beans, which have 3:1 yield advantage over bush bean varieties, are formally pre-released in Kenya. The lines will be fully released when the distinctiveness, uniformity and stability (DUS) tests are completed. Although Kenya is the leading producer of beans in Africa, with an estimated 800,000 ha under the crop each year, yields are low. The demand for beans in the country exceeds local production levels. Kenya is presently a net importer of beans from the neighbouring countries of Uganda and Tanzania. The release and dissemination of the new bean varieties with high yield potential and resistance to major biotic and abiotic stresses is expected to reduce the current production deficit.