Dry Matter Production of Hevea Clone Pb 260

Abstract

The study on the dry matter production of PB 260 was made on one-year-old to five- and three quarter-year- old trees during the immature phase and on eight-and-a-half-year-old to nineteen-and-a-half-year-old trees during the mature phase. All trees were located within the same vicinity on similar soil type, terrain and provided with similar management practices. Tree dry weight of four-year-old PB 260 at 109 kg was much higher than the dry weight reported for clones of older vintage, GTI, PB 86 and LCB 1320, of similar age. At maturity, comparison of tree dry weight of PB 260 with other clones reported elsewhere was confounded by the high variability of the latter, attributed mainly to site differences. Using the CurveExpert version 1.36 (Hyams, 1995), total dry matter produced by PB 260 inclusive of cumulative branch litter, seed-fall and latex production was estimated at 205 tonnes per hectare at eleven years and 300 tonnes per hectare at twenty years after planting. Overall, the dry matter production reported by other researchers for other clones has mainly not been computed on the same basis, differing in the inclusion and exclusion of certain tree components. Keywords: Dry matter production, tree components, branch litter, seed-fall, latex production.