Hevea brasiliensis: results from the Cambodian large scale clone trials in 2011

In order to update the clonal recommendations in Cambodia, a set of 14 Large Scale Clonal Trials (LSCT) was analysed globally for 36 clones, based on linear adjustments of the data from each trial. Although this method was statistically not very powerful, it made possible to compare all the clones between each other, whatever the trials in which they were set. Among the 36 clones, the adjusted mean girth at opening varied from 41 cm (RRIC102) to 52 cm (PB235), with a medium group of 20 clones (including GT1) varying from 46 cm to 48 cm. The cumulated yield over the first 7 years of tapping (Cum1?7) varied from 5279 kg/ha (K2) to 14935 kg/ha (IRCA130). The ranking of the clones by decreasing girth at opening was as following : PB235, PB330, IRCA130, IRCA209, PB280, IRCA111, KV4, IRCA230, TJIR1, PR261, IRCA209, PB310, PB254, GT1, AVROS208, PB255, PB260, RRIC121, IRCA18, RRIM600, RRIC101, RRIM712, PB314, PB217, KHA9, PR306, BPM24, PR303, PR255, K2, IRCA41, PR300, PR107, PB324, PB86, and RRIC102. The ranking of the clones by decreasing cumulated yield over 7 years of tapping (Cum1?7) was as following : IRCA130, PB235, KV4, RRIC101, IRCA109, PB314, RRIM712, PB280, PB260, IRCA230, RRIM600, PB330, PB310, PR303, IRCA111, RRIC121, PB255, IRCA41, PB254, PB217, PR300, PR255, BPM24, IRCA18, PR306, IRCA209, PB324, GT1, PB86, KHA9, PR261, PR107, RRIC102, AVROS308, TJIR1, and K2. The relationships between girth at opening and yields were examined, and a method was carried out for making cumulated yields independent from girth at opening (Cum1?7reg). However this correction had important effects only for the two extreme clones PB235 (highest vigour) and RRIC102 (lowest vigour). There was a good correlation between the initial yield of the first four years (Cum1?4) and the later yield from year 5 to year 7 (Cum5?7) with R² = 0.40. Girth at opening partly explained the initial yield (R² = 0.37), but its correlation with the later yield was non significant (R² = 0.09). Initial yield was generally higher than later yield for high?yielding clones, and the opposite was found for low?yielding clones. By decreasing order of Cum1?7, the clones with initial yield higher than later yield were IRCA130, PB235, RRIC101, PB314, PB280, PB260, IRCA230, IRCA111, PB255, IRCA18, and IRCA209 (group A, quick?starters). The clones with initial yield equivalent to later yield were KV4, IRCA109, RRIM712, RRIM600, PB330, PB310, IRCA41, PB254, PB217, PR300, PR255, BPM24, GT1, PB86, and PR261 (group B). The clones with later yield higher than initial yield were PR303, RRIC121, PR306, PB324, KHA9, PR107, RRIC102, AVROS308, TJIR1, and K2 (group C). These results were submitted to a critical discussion for application to clonal recommendations.

Bibliographic Details

Main Authors:	Phearun, Phen, Chetha, Phean, Clément-Demange, André
Format:	conference_item biblioteca
Language:	eng
Published:	s.n.
Subjects:	F30 - Génétique et amélioration des plantes, Hevea brasiliensis, clone, http://aims.fao.org/aos/agrovoc/c_3589, http://aims.fao.org/aos/agrovoc/c_1678, http://aims.fao.org/aos/agrovoc/c_4073,
Online Access:	http://agritrop.cirad.fr/563767/ http://agritrop.cirad.fr/563767/1/document_563767.pdf
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