Interspecific and Intraspecific Rootstock Suitability for Vegetative Propagation of Petai (Parkia speciosa, Hassak.)

The intraspecific and interspecific suitability of five species as rootstocks for the vegetative propagation of petai (Parkia speciosa, Hassak.) was tested in a two-step study testing budwood and top grafting methods. Stage 1 used rootstock of lamtoro (Leucaena leucocephala), flamboyant (Delonix regia) and petai (as a control). The results showed that the petai-lamtoro and petai-flamboyant graft combinations all died within two weeks of grafting. The petai-petai combination demonstrated 25% survival one month after grafting. Stage 2 again tested lamtoro and petai (as a control), as well as sengon (Paraserianthes falcataria) and kedawung (Parkia timoriana) as rootstocks. Similar to Stage 1 results, the petai-lamtoro and petai-sengon combinations suffered 100% mortality two weeks after grafting. The petai-kedawung and petai-petai combinations demonstrated 40% and 50% survival, respectively, one month after grafting. Based on results it is concluded that kedawung and petai are suitable rootstocks for petai scion with the budwood and top grafting methods, but lamtoro, sengon and flamboyant are incompatible. Examination during the study indicated that grafts of the dead specimen were discoloured and dried. Furthermore, all the species in the study have thin cambiums that are sensitive to high temperature, low humidity and desiccation. Recommendations are provided to reduce the vulnerability of petai grafts to desiccation during scion harvesting, pre-grafting nursery management, grafting operations and post-grafting management. An alternative for multiplying small numbers of high-yielding petai individuals and varieties is suggested.