Clonal test had been conducted at Udon Thani and Khon Kaen provinces to determine difference of tree performances among clones at different sites and to produce improved genetic materials of teak for planting in the Northeast region. The experiment was undertaken with randomized completely block design (RCBD) with four replications. One replication contained three ramets of each clone planted in row. Fifty clones were selected based on previous field trail studies and shooting ability of the seedlings. Total seedlings of 600 seedlings/sites (50 clones x 3 tree plot x 4 replications) were planted.
The preliminary results on survival rate, height (H) and diameter at root collar (D0) had been conducted when the seedlings reached three months, one year and two years. At two years, survival rate of the seedlings in Udon Thani and Khon Kaen was 68% and 70% respectively. In general, it was likely that the growth rate in terms of H (1.17 m) and D0 (2.99 cm) was relatively poor at both sites.
However, H & D0 in Udon Thani (1.30 m, 3.05 cm) was slightly higher than those in Khon Kaen (1.02 m, 2.93 cm). In terms of clone performances, statistical analysis showed that there was no significant difference in H & D0 of seedlings among clones on the two sites. There was no interaction effect between site and clone on H & D0.