Response of tea cultivars to growing environments in Kenya.

Abstract

In East Africa, tea growing areas fall in several agro-ecological regions differing widely in elevation, climatic factors and soil conditions. However, environmental and climatic factors which control growth vary with geographical locations. We evaluated popular clones that are widely cultivated in Lake Victoria basin for their suitability in the different tea growing regions. Trial was established to compare (a) yield and quality performance of 20 improved cultivars out of which 10 are widely cultivated in Lake Victoria Basin (b) the adaptability and stability level of 20 popular cultivars to different growing regions (c) parameters of genotype stability useful in tea breeding (d) apply the concept of genotype (G) × environment (E) interactions in determining cultivars that are most suitable for Lake Victoria basin. Cuttings from mother bushes were propagated in April 2008 and reared in the nursery. Clones were planted in April 2009 at Sotik and Kericho in Kenya during the long rains in April/May 2009. Yield was recorded in 2010 at Timbilil and Kipkebe while polyphenol contents were assessed in July-August 2011. We found significant differences in yield, ground cover and total polyphenols (P<0.01) while genetic stability varied with clones and traits. Significant interaction effects (P<0.01) between clones and sites was detected for yield, percentage of total polyphenols, active shoot density and fresh shoot weight. We conclude that tea yields and quality vary with geographical area of production. Therefore, regional-specific genotype should be planted in different regions to enhance incomes from tea enterprises.