A participatory breeding initiative for resilient rubber cultivation systems for smallholders in a context of global change. 

Context

Hevea brasiliensis is a major source of NR and timber. Smallholders are responsible for 85% of NR production. Monospecific plantations are the main rubber-based cropping system worldwide, except in Indonesia where rubber-based agroforestry systems (RAS) still account for 20-30% of the surface of rubber plantations. The improvement of the productivity of rubber plantations is related to several factors including the quality of planting material (high-yielding budded clones), optimization of the production potential (harvesting system, ethephon stimulation, latex diagnosis), and more recently reducing the production cost using low tapping intensity systems.

Nowadays, rubber cultivation is facing socio-economics and environmental issues. Smallholders’ low income due to the fluctuation and low rubber price leads many farmers abandoning rubber cultivation. Low adoption of recommended practices by research organizations remains a main factor of the low efficiency of rubber smallholdings. Although rubber plantations are considered as forest system, the loss of biodiversity in this monospecific cropping system and in the short-term impact of climate change question our research practices and directions.

Objectives

The project aims to develop rubber-based agroforestry systems associated with food crops that seem more resilient to these global changes in a participatory selection process in order to have a greater impact of our work.

The project targets a three-level paradigm shift:

• The first shift is associated with the target of breeding program. Usually, conventional breeding programs are devoted to monospecific cropping system and the design of rubber clones for estate plantations and intensive production. Our target will be the smallholders.
• The second shift is related to the multidisciplinary approach integrating modern technology for the analysis and adaptation of complex cropping system to accelerating climate change.
• The third shift is associated with the participatory approach. In this respect, we expect that the co-construction of solutions for smallholders through a participatory approach with stakeholders will facilitate the future support of national and local authorities by funding replanting program with “climate-smart packages” defined in the RUBIS Project.

Methodology

Socio-economic, agronomic and genetic studies will be conducted in parallel and integrated throughout the project.

• An international workshop will bring together the main scientific actors in order to deliver a complete inventory of all rubber-based agroforestry system (RAS) studies and to establish both a typology of these systems and new directions to make RAS more efficient and resilient to global changes.
• Farmer survey and Focus Group Discussion will determine the current typology of stakeholders and rubber cropping systems on the one hand, and will identify the stakeholders’ demand and need, and local knowledge.
• Biotic and abiotic constraints will be analyzed to characterize the performances of rubber agroforestry systems through literature and field surveys.
• The rubber double row agroforestry system separated by wide-spacing and associated with rice intercrop will be monitored and modeled.
• Ecophysiological and ecosystem services will be analysized in monocropping and rubber-based agroforestry systems.
• Traits related to latex production, rubber properties, tolerance to Tapping Panel Dryness and leaf diseases as well as tree architecture will be characterized in rubber clones recommended in Indonesia and in a biparental population.
• Genetic and genomic tools will be developed for further deployment of marker-assisted selection and genomic selection.
• Multilateral workshops will be organized between scientists and stakeholders in order to design both planting packages, experimental network and tools for further establishment and monitoring of on-farm trials.

Expected results

• Creation of a stakeholders’ network
• Concept note on agronomic, socio-economic and environmental issues in rubber-based agroforestry systems
• Typology of Hevea germplasm for agronomic, physiological and technological traits 
• Hevea Genome Hub
• Scientific papers
• Training on crop modelling, NIRS, multivariate analyses, QTLs and genes identification 
• Position paper on the resilience of rubber-based agroforestry system
• Design of replanting packages for smallholders