Call Prefix : PR-T

Call Suffix : 1991

Call Cutter : D - Agri 2

Location : SEARCA Library

Format : TD

Publisher : Universiti Pertanian Malaysia,

Publication Date : March 1991

Publication Place : Malaysia :

Summary : Studies to reduce the uneven early growth of Hevea buddings were done to overcome the problem of low percentage of tappable trees during the early years of tapping. These included experiments on Hevea seed germination: bud activation of budded stumps to induce early bud-break by using growth regulators, other techniques, and other growth regulating materials; and the manipulation of early growth of Hevea budshoot under various bud activation treatments was also carried out. Research on seed on the germination revealed that Hevea seeds (RRIM 600) gathered during the early seedfall had very low percentage of germination compared with seeds gathered during the peak seedfall. However, partial cracking of the seed coat improved the percentage of germination in both groups of seeds. Moreover, the heavier seeds (4-5 g) germinated earlier (before 14 days from sowing) and their seedlings were more vigorous than those from the lighter seeds. Seedlings from the early germinated seeds reached buddable girth size for young budding after two months from planting. Studies on bud activation using benzyladenine at 3,500 - 4,000 ppm revealed that 40-60 percent early bud-break could be obtained in green and young buddings. This was significantly higher than the result from the untreated control. A similar response was obtained when different clonal materials were used in green buddings. Early bud-break was also induced by dipping the budded stumps in melted paraffin wax with temperature between 60 degree C and 85 degree C. This technique resulted in 40-50 percent bud-break three weeks after treatment. The early shoot growth of Hevea buddings was not affected by any of the growth regulators applied onto the dormant buds. However, after bud emergence, brushing gibberellin preparation on the shoot at bud stage stimulated rapid growth of the shoot. Significant rapid growth of shoot in height, particularly the first internode, was very evident between 15 to 30 days after the application of the regulator.