Abstract:
Coffea arabica cv. Ruiru 11 is a composite of sixty six (66) F1 hybrid sibs each derived from a
cross between a specific female and male population. The pedigree of Ruiru 11 consist of CBD
resistance donors, Rume Sudan (R gene), Hibrido De Timor (T or Ck-1 gene), Catimor (T or Ck-
1 gene), K7 (k gene), SL4 and the high yielding, good quality but susceptible cultivars such as
N39, SL28, SL34 and Bourbon. Ruiru 11 sibs reportedly present significant variability in terms
of resistance to CBD, yields and quality. The objective of this study was to select for CBD
resistance, high cherry yields and good quality within Coffea arabica L. cultivar, Ruiru 11.
Thirty four hybrid sibs of Ruiru 11 cultivar grown in three different locations in Kenya were
used for the study. The experiment was conducted between 2009 and 2011. Ripe cherries were
harvested, bulked per replication, weighed and yield data recorded before subjecting them to wet
processing, drying, hulling and grading. Beverage quality was determined following the sensory
evaluation procedure of Specialty Coffee Association of America (SCAA). Evaluation of CBD
resistance was conducted in the laboratory using hypocotyl inoculation method. The study
confirmed earlier reports that Ruiru 11 sibs differ in quality aspects, yields and resistance to
CBD but some sibs that combine all these desirable traits were identified.
