Roles Of Growth Regulator To Shorten The Immaturity Period In Some Rubber Clones

Abstrak The objective of the research was to find out the influence of IAA hormone kinetin and paclobutrazol which were applied to the clones and which treatment that most likely indicated the response for expediting the girth increment and bark thickness so that the trees can be quickly tapped. The experiment was conducted at Kebun Karang Inong East Aceh . The research was organized based on Nested Design of three factors namely a clone factor with 5 levels hormonal factor of IAA Kinetin with 7 levels and paclobutrazol factor with 3 levels. The results showed that the growth regulators applied could accelerate the girth increment and other parameters. Hormone applications significantly influenced the parameters of the girth increment and number of chlorophyll. Athough for other parameters the hormone applications did not have a significant effect. The paclobutrazol application treatment through soil P1 was the best treatment for all the parameters observed. Clone treatment also had a significant effect on the girth increment leaf area and number of chlorophyll. The best clone to girth increment was clone PB 330 K2. Combination of application treatments with paclobutrazol and hormone only significantly affected the girth increment and the best treatment was P1H2. The combination of all three treatments between clones with paclobutrazol and hormones only significantly affected the number of latex vessels. The largest number of latex vessels was in K2H3P1 treatment.