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The objective of this study was to evaluate the girth and yield performance of new Hevea genotypes obtained from the 1998 hand pollination (HP) program. Sixty-five new genotypes were assessed along with the control clones viz. RRIC 121, RRIC 130 and RRISL 205. Dry rubber yield for six years, annual girth at the 14th year and girth increment, percentage of tappable trees, survival trees and tapping panel dryness affected trees and latex properties of selected genotypes were evaluated. Considering the results, 63% of the genotypes were recorded as significantly higher or similar average yield compared to control clones. The genotypes, 98-80 and 98-219 were the top-rankers with average yields of 53.7 g and 52.0 g per tree per tapping, respectively. Moreover, the progeny generated from 1998 hand pollination consisted of good yielders similar to the yield of the clone RRIC 121 and could be considered as potential candidates for future clonal selection programmes to develop elite clones. Eighty-two percent of the genotypes showed significantly higher or similar mean girth compared to controls. Genotypes, 98-276 and 98-68 were ranked at number one and two, which have obtained respective girth values of 80.6 cm and 76.5 cm. Eighteen percent of genotypes recorded more than 70 cm of mean girth, which was an indicator of the development of vigorous timber clones in the future. Moreover, these genotypes possess high yield potential. Almost all the genotypes had significantly high girth increment during the immature phase than the post tapping phase. Genotypes 98-80 and 98-219 had performed well based on the dry rubber content (DRC), sucrose and inorganic phosphorus values. In conclusion, the 1998 HP programmes has generated a valuable pool of genotypes that have paved the path to producing outstanding Hevea clones. |
