THE PERFORMANCE OF IRR SERIES RUBBER CLONES ON TRIAL SCALE AND IN COMMERCIAL PLANTATIONS

Abstract

Increase of rubber productivity is the main factor for rubber commodities to remain competitive and profitable under fluctuating rubber prices. The use of Superior rubber clones is one of the most important technological components that contribute significantly to increase productivity. The superiority of a clone is determined by the genotype and environment of plant growth factors. The physical and biological environment conditions affect the growth and production of plants. The exposure to various agro-ecosystem conditions is required to select of superior clones with good stability or adaptation to specific environments, to ensure optimum productivity. Rubber breeding and selection activities in Indonesia had been covered four generations and produced several potential clones. The fourth-generation rubber clones have great genetic progress in terms of potential for rubber production and fast growth. The fourth-generation rubber clones are of IRR series 100, 200, 300 and 400. The performance of superior rubber clones is evaluated based on data from Small Scale Clone Trials (SSCT), Promotion Plots Trials, and Large Scale Clone Trials (LSCT)/Adaptation Trials. Some clones of IRR series 100 and 200 such as IRR 112, IRR 118, IRR 220 and IRR 230 can be recommended for planting. The clones IRR 112 and IRR 220 have a good stabilized of growth and production on normal to high rainfall environments, while, IRR 118 and IRR 230 have good growth and production in low rainfall (dry) conditions. IRR 118 and IRR 230 are moderately susceptible to Corynespora leaf fall disease. Some of the IRR 300 and 400 series clones have vigourus growth and high production on SSCT, Promotion Plot Trials and LSCT. These are IRR 302, IRR 309, IRR 406, IRR 420, IRR 425, and IRR 429. The development of these clones on the commercial scale could be done gradually by considering the suitability for different plant growth environments. Keywords: Hevea brasiliensis , breeding and selection, growth and productivity, IRR series clones