Rubber agroforestry systems-type 1 (RAS1): a strategy towards a productive "jungle rubber"

In Indonesia, most of the rubber area owned by smallholders is exploited under an extensive system called.. "jungle rubber", where rubber is cultivated at minimum cost. The average production under such system is low if compared to rubber estate (500 vs. 1500 kg of dry rubber/ha/year) because of the unselected rubber seedlings used in the system. Jungle rubber has been described as "complex agroforestry system" rich in biodiversity. In 1994 E. Penot proposed an alternative called "Rubber Agroforestry Systems" where many traditional practices are maintained but some technical innovations are introduced in particular the use of budded rubber to increase latex production. In SRAP (Smallholder Rubber Agroforestry Project) an approach called "Rubber Agroforestry System-type 1" (RAS 1) was tested in farmers fields, using a participatory approach, in order to evaluate the effect of various factors and the acceptability of techniques by farmers. Factors studied concerns: weeding intensity on the rubber row, type of planting material and the effect of fertilizers on rubber growth. After 4 years of experimentation, results confirm that budded rubber grows satisfactorily in jungle rubber environment and its girth size is similar to estate conditions. Weeding requirement can be highly reduced where natural vegetation re-growth is fast. Intensive weeding on rubber row was not found to increase significantly rubber growth. Out of 4 rubber clones and seedlings tested the best girth growth was obtained by PB 260 and RRIC 100 clones. The SRAP experiment network confirmed that farmers might adopt easily RAS type-1 strategies as maintenance cost and labor requirement are limited. The Rubber Agroforestry Systems (RAS) approach must be promoted intensively in rubber sector to accelerate the transformation of Indonesian jungle rubber areas into productive rubber agroforests. (Résumé d'auteur