RESPONSES OF TEA TO ENVIRONMENT IN KENYA. 2. DRY MATTER PRODUCTION AND PARTITIONING

Abstract

In a genotype × environment experiment at four sites with four tea (Camellia sinensis) clones in Kericho, Kenya, differences in ground cover and total dry matter production and partitioning were found between clones and between sites. The major contributor to these differences was the daily intercepted solar radiation that differed by as much as 30% between sites. Differences in radiation use efficiency (RUE) between the sites were small, but varied from 0.3 to 0.45 g MJ⁻¹ between the clones. The rate of dry matter production was affected by the prevailing weather conditions. During the dry seasons the rate of dry matter production differed between the sites and clones by a maximum of 2 g m⁻² d⁻¹. Harvest indices were found to vary between the sites and increased with time. Partitioning to harvested shoots ranged from 10% for clone TN14-3 to a maximum of 19% in clone S15/10 at site 4. Partitioning to roots showed distinct differences between clones, being least in clone S15/10 (10–20%) compared with 15–32% in other clones. Rooting depths were greatly influenced by the prevailing temperatures.