Source Year: 2000

Rubber(Hevea brasiliensis) plants derived from 7 clones bud grafted onto rootstock were evaluated on 5 contrasting sites in the plateau region of Sao Paulo state, Brazil. Analysis of variance of girth at 6 years indicated a highly significant clone x site interaction. The clones GT 1 and PB 235 showed the greatest stability in relation to girth increment, with predictable responses to changes to the sites. The clones PB 235 and IAN 873 showed significant differences in relation to the regression coefficient, identifying them as clones with adaptability to favourable and unfavourable sites, respectively. The clone GT1 was the most promising in terms of stability and adaptability. Expected genetic gains at these sites, together with estimates of clonal variance and repeatability of clonal means, were generally greatest when selection was done at the same site.