Rubber Agroforestry Experiments in Jambi at the end of a 25-Year Cycle

Abstract

The rubber agroforestry experiments in Jambi started with the theory of change that productive clonal rubber could be economically used in low-labour intensity rubber agroforests, allowing selective retention of forest species or planted fruit trees in interrows. At the end of what was expected to be a 25-year production cycle we revisited the farmers (or their next generation), recorded what had happened to the plot and registered farmer plans for a way forward. Qualitatively, the results showed a wide range of directions of actual change. The envisaged plots, with full-grown tapped rubber in a secondary forest setting did occur – but as exception rather than rule. Some plots had early on been converted to oil palm when white root rot disease killed many of the rubber trees. Others were in a gradual transition to oil palm, already interplanted, or depended on natural regeneration of rubber within the plot for the trees currently being tapped. Some plots had been completely destroyed as the land was sold to a local coal-mine developer. Overall tapping frequency was low, as farmgate rubber prices have in recent years been low and farmers had other options (including participating in small-scale gold mining). Farmer experience with the various clones tested led to mixed opinions on which (if any) of the clones introduced were superior to what farmers used in the past (and what still regenerates in the landscape). GT1, a robust clone, was seen as hardly more productive as local germplasm, the PB260 and BPM1 clone were productive, but especially PB260 clone sensitive to white root rot disease. The quality of rubber wood was a concern for some farmers. The most successful intervention, from farmers’ as well as environmental perspective, has probably been the interplanting of meranti (Shorea leprosula) or tembesu (Fagraea fragrans) trees in young rubber stands, with good prospects for generating substantial income.