Abstract
Twenty-two potential wild Hevea accessions along with three modern clones viz. RRII 105, RRIM 600 and RRII 208 were evaluated in the seventh to eleventh years of growth in the traditional rubber growing region of Kerala, India. Highly significant clonal differences were observed for yield and growth traits, except bole height. RO 2629 had the highest yield of 29.4 g t~(-1)t~(-1) followed by AC 716 (24.9 g t~(-1) t~(-1)) and AC 4149 (23.6 g t~(-1) t~(-1)), respectively. RO 2629 also had the highest girth, girth increment per year over four years and bole volume. The girth in the seventh year ranged from 26.9 cm (RO 287) to 47.8 cm (RO 2629); girth increment from 3.6 cm (RO 3804) to 6.7 cm (RO 2629); branching height from 2.2 m (RO 3804) to 3.1 m (MT 2233); wood quantity from 0.03 m~3 (RO 3804) to 0.10 m~3 (RO 2629). PCV was higher than the GCV for all the characters and the highest PCV was recorded for mean yield over two years. Heritability was also high for mean yield. Girth was significantly correlated with girth increment and wood quantity. RO 2629, MT 2233, AC 4149 and AC 626 ranked top with the maximum number of desirable traits. Having a different genetic background from the traditional Wickham clones, these accessions will serve to broaden the genetic base of present-day cultivated Hevea by introgression into the elite cultivars.
NSTL