Seasonal and Environment Variations of Yields and Yield Components of Tea (Camellia sinensis) Cultivars in Kenya

Abstract

In Kenya, tea is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300
m to 2700 m above mean sea level. These areas vary widely in seasonal and locational environmental
factors leading to differences in responses in growth, productivity and quality of tea genotypes.
Despite these differences, tea husbandry practices are uniform across tea growing regions in the
country. Understanding modes of variations in tea growth parameters and yields to varying
environments is crucial for optimization of husbandry practices for tea productivity
improvements. Responses in clonal tea growth and yield parameters to season and locations of
production effects and their contribution to yields were evaluated, using 20 cultivars in a genotype
× environment trial conducted in three locations (Kipkebe, Timbilil and Kangaita). There were
yield variations (pd”0.05) between clones, locations and seasons. Tea yield components responses
to weather parameters varied with location and season. Shoot growth rates in Kangaita and shoot
density in Timbilil linearly correlated (pd”0.05) with yields but varied with season. Yield
components and weather parameters contribution to the yield also varied with location and
seasons causing significant (pd”0.05) interactions effects. Drought reduced yields while rainfall
distribution influenced seasonal yield distribution. Seasonal yield variations were due to shoot
growth rate, and shoot dry weight changes but not shoot density. The variations were due to
seasonal environmental factors that limited yields rather than factors that increased yields.