The Study of Planting space on Wood Volume and Latex Yield of Recommended Rubber Clones in the Upper South of Thailand

Abstract

The study effect of the planting space and clones on wood volume for biomass and latex yield was carried out to evaluate the performance of rubber clones and to identify suitable planting density for wood production and latex yield during 9 years after planting. Split plot design in RCB was performed with 3 replications. Main plot was planting density (D) consisting of 3 spacing patterns i.e. D1 178 plants/rai (3x3 m), D2 133 plants/rai (3x4 m) and D3 100 plants/rai (3x3 m). Subplot was rubber clone consisting of 5 newly clones i.e. RRIT 402, 403, 404, 408 and 412. A trial unit (plot) was 45 experimental units and 180 trees plant/unit test. The rubber has been planted in July 2007 in the Fang Daeng soil series with an area of 110 rai in Surat Thani Agricultural Research and Development Center, Thachana District, Surat Thani Province. After 9 years, the planting density and clone affected the trunk girth and height. The lower density (D3, 55.60 cm and D2, 53.33 cm) gave greater trunk girth than the highest density (D1, 49.88 cm) while D1 (3.83 m) had a trunk height taller than D3 (3.53 m) and D2 (3.47 m). Clone RRIT 404 showed the highest trunk girth (55.36 cm) and trunk height (3.59 m) comparing to other clones. The highest planting density (D1) and clone RRIT 404 gave the highest of wood volume per area (13.62 and 13.92 m3/rai, respectively). Moreover, there was no interactions between planting space and clones in this experiment. The first two years of tapping, clone RRIT 408 and 404 gave the maximum mean latex yield (298 and 289 kg/rai/year, respectively) but planting density did not influence on the latex yield. Results indicate that the density D2 (3x4 m) and clone RRIT 404 can be recommended for maximum income and latex yield under the upper south of
Thailand in the period of early tapping.