The Effect of Pruning at Different Heights on Yields, Dry Matter Production and Partitioning in Clonal Tea (Camellia Sinensis) in Kenya

Abstract

SUMMARYDry matter production and partitioning in old clonal tea bushes pruned and maintained at different heights were investigated. New tissues (leaves, new branches and small roots) consti- tuted a small fraction of the total dry matter in all bushes pruned and initially maintained at 70, 40, 25 and 10 cm high, 36 months after pruning. Leaf/frame dry matter ratio was larger and the shoot/root and frame/root ratios were smaller in the bushes initially maintained at 10 cm than in the bushes maintained at other heights. Yields per unit area of the plucking surface were greatest in the smallest bushes initially maintained at 10 cm in 42 months of recording but on the basis of the available space they were greatest in the large bushes initially maintained at 70 cm.

PHYSIOLOGICAL BASIS OF YIELD VARIATION OF TEA (CAMELLIA SINENSIS) DURING DIFFERENT YEARS OF THE PRUNING CYCLE IN THE CENTRAL HIGHLANDS OF SRI LANKA

“…Reduction of the number of shoots initiated, which was one of the causal factors of the observed yield reduction during the fourth year of the pruning cycle, could be the result of this overall down-regulation of the physiology of the tea bush. The observation of Magambo (1983, as cited in Magambo andWaithaka, 1985) that older clonal tea had a lower HI than younger clonal tea is an agreement with this explanation.…”

“…At elevations above 2000 m, the pruning cycle can be extended to 5–6 years (Kulasegaram, 1986). In Kenya, where the conventional pruning method is a straight cut-across at a height of 40–45 cm, the pruning cycle varies from three to four years (Magambo and Waithaka, 1985). Pruning cycles in machine-harvested tea in Southern Tanzania extend up to seven years or longer (Burgess et al ., 2006).…”

“…This is followed by a significant, and sometimes drastic, yield reduction during the fourth year of the pruning cycle in many plantations in Sri Lanka (Jayakody, 1995). Similar yield reductions in the fourth year of the pruning cycle have been observed in Kenya (Bore et al ., 2003; Magambo and Waithaka, 1985) and Tanzania (Burgess et al ., 2006). Although seasonal variation of tea yields depending on temperature and rainfall have been reported from Malawi (Fordham and Palmer-Jones, 1977), Tanzania (Burgess and Carr, 1996a) and Kenya (Ng'Etich et al ., 2001), there have been hardly any detailed investigation of tea yield variation during different stages of the pruning cycle.…”

“…However, there is scant information about how this possible shift in biomass partitioning proceeds during the rest of the pruning cycle. Magambo and Waithaka (1985) observed that post-pruning biomass partitioning varied with the pruning height, with shoot:root ratio being smaller at lower pruning heights even 36 months after pruning. They further argued that the increased proportion of root biomass following pruning meant that biomass partitioning to the root system could increase because of the greater sink strength of large roots.…”

“…They further argued that the increased proportion of root biomass following pruning meant that biomass partitioning to the root system could increase because of the greater sink strength of large roots. Several authors (Burgess and Carr, 1996b; Magambo and Cannell, 1981; Magambo and Waithaka, 1985; Ng'Etich and Stephens, 2001) have reported on biomass partitioning of the tea bush to roots, stems and leaves. However, apart from the work of Magambo and Waithaka (1985), which is on 15-year-old tea, the rest were on young tea during the first 1–3 years after planting.…”