Fertilizer Response and Environment Interactions of Yield and Yield Components of Clonal Tea (Camellia Sinensis) in Kenya

Abstract

Tea is an important cash crop, providing income and employment to rural populations in many countries. In Kenya, tea is the leading export commodity crop and is grown in highlands east and west of the Rift Valley at altitudes ranging from 1300 to 2700 m above mean sea level. This has significant effects on growth, productivity, tea quality and response to fertilizer and has been particularly noted for the popular, widely planted, quality clone TRFK 6/8. In East Africa, tea husbandry practices are uniform despite the variations in responses to agronomic inputs. Fertilizer is the most expensive input in tea production after plucking. In tea, nitrogen availability is the most limiting crop growth factor. However, responses of tea yields to fertilizer application vary with the region of production even with the same cultivar. The utilization of nitrogen, therefore, varies with location. The responses in growth and yield parameters of clonal tea TRFK 6/8 and their contribution to yields were investigated across different environments, in a trial setup in three locations in the east of the Rift Valley in Kenya, using clone TRFK 6/8, a popular commercial cultivar. Yield and yield components response to nitrogen rates varied with location. The highest yields were not always attained at the highest nitrogen levels and the best response to fertilizer did not translate to the highest yields. Tea crop response to fertilizer is the site-specific and universal application of fertilizer may only apply as a general guideline but will not optimize production.