More Information on Kenya's Main Cultivars
Coffee Research Foundation in Kenya currently produces four commercial cultivars (varieties) of Arabica coffee. Different varieties are recommended for various altitudes.
K7 – low altitude coffee areas with serious Coffee Leaf Rust (CLR).
SL 28 – medium to high coffee areas without serious CLR. (The best for high altitude zones)
SL 34 – high coffee zone with good rainfall. (Actually, SL-34 is a medium altitude coffee topping out around 1300 meters)
Ruiru 11 – all coffee growing areas. Resistant to both Coffee Berry Disease (CBD) and CLR.
K7 cultivar was selected at Legetet Estate in Muhoroni from the French Mission Coffee. It is distinguished by its spreading habit on young laterals although older primaries tend to be decumbent or drooping. It has characteristic medium to narrow leaves with young shoot-tips that are intermediate bronze in colour. The cultivar has resistance to some races of CLR as well as partial resistance to CBD. It is suited for lower altitudes where CLR is prevalent. The bean and liquor qualities are good.
The SL 28 cultivar was selected at the former Scott Laboratories (now the National Agricultural Laboratories, NARL situated at Kabete) on a single tree basis from the Tanganyika Drought Resistant variety selected in Northern Tanzania in 1931. The prefix SL in the variety name are acronymous for Scott Laboratories where the variety was selected. The name is completed by a serial number (28) for the selection. The variety is suited for medium to high altitude coffee growing zones.
SL 34 was also selected at the former Scott Laboratories from French Mission Coffee. The cultivar is adapted to high altitude areas with good rainfall. It is majorly characterized by dark bronze shoot tipped plants with a few green-tipped strains. The laterals have semi-erect habit which tend to become decumbent or drooping on older primaries. The cultivar produces high yields of fine quality coffee but is susceptible to CBD, CLR and BBC.
Ruiru 11 variety was released in 1985. The variety name has the prefix “Ruiru” referring to the location of the Kenyan Coffee Research Station where the variety was developed. The name is completed by an additional two code numbers, 11. The first code number denotes the type of variety as a one way cross between two designated parent populations and the second number defines the sequence of release, in this case the first release. The variety is not only resistant to CBD and CLR but is also compact allowing farmers to intensity production per unit land especially in high potential areas where population is high and coffee is in competition with other crops and farm enterprises required for food security and income. Ruiru 11 is planted at a density of 2500/3300 trees/ha compared to 1300 trees/ha for the traditional varieties. This translates into a higher production per unit area of land. The variety comes into production earlier, hence earlier realization of benefits to the farmers. The development of Ruiru 11 also took into consideration the importance of quality as a major marketing parameter. Since the quality of the traditional varieties was already popular among consumers of Kenyan coffee, Ruiru 11 was developed with quality attributes similar to the traditional varieties.
Other coffee varieties
Although the varieties mentioned above are the most commonly grown, some coffee plantations have blue mountain and the original French Mission Coffee in the Arabica range as well as Robusta coffee especially in the low altitude and humid areas such as Western Kenya.