Shoot population density and shoot weight of clonal tea (Camellia sinensis) at different altitudes in Sri Lanka

The production of shoots and mean dry weight of a harvested shoot of two tea clones, TRI 2023 and TRI 2025, were examined during a period of 27 weeks at five sites across an altitudinal range of 30 to 1859 m. An increase in mean air temperature with decrease in altitude lowered the shoot population density (SPD) but increased the mean dry weight of the harvested shoot in both clones. Clone TRI 2023 had the largest SPD (3854-5115 shoots m(-2)) while clone TRI 2025 had the heaviest shoot (0.2-0.32 g) across the test altitudinal range. The increase in altitude significantly decreased (p<0.001) the number of harvested shoots per square metre in the centre of the plucking surface of done TRI 2023 but increased the same in clone TRI 2025. However, the number of shoots harvested per square metre from the entire plot remained unchanged in clone TRI 2023 while this in TRI 2025 increased by 53% (p<0.001) when altitude rose from 30 to 1859 m. Both clones showed the occurrence of 'low yielding edges' in the plucking surface of a bush, though in clone TRI 2023 this was greatly reduced with the increase in altitude. The shoot population density, density of harvested shoots and mean shoot dry weight are discussed in relation to yield at the five test altitudes. (C) 1999 Elsevier Science B.V. All rights reserved.