One type of timber plants that had rapid growth potential was white teak (Gmelina arborea). The metodh of nurseries very influential on germination and grewth, one of these nursery techniques giving GA3 concentration and the long immersion.
This research was conducted in the Bandungan village, Kajen district, Pekalongan at ± 70 meterson above sea level (m asl). The experiment had been implemented for 3 months, from July until September 2012. The design of used in this experiment of research was RAK (rancanganacakkelompok) with a 4 x 3 factorial treatment. The first factor concentration Giberellin GA¬3, which consists of four levels, namely 0 ppm.50 ppm.100 ppm and 150 ppm. The second factor consists of soaking time on 3 levels that are, 1 hour, 2 hours and 3 hours. The combination treatmentas much as 12 kinds of, each combination was repeated three times so that there are 36 units of experiment
The observed of variables including : the speed of germination, percentage of grewth, plant of height grewth, stem diameter, broad leaf, number of leaves per plant, number of roots, the longest root length, wet weight per plant, and dry weight per plant. The results showed that the concentration Giberellin (GA¬3) influence on all variables except speed off is germinating and grewth of percentage with positive linear effect pattern, giving Giberellin (GA¬3) up to 150 ppm can still improve germination and growth of teak white. The long immersion gived effect on all observed variables, except percentage and plant height grewth, germination and grewthon best long immersion white teak soaking 3 hours. There was interaction between the concentration of GA¬3with long soaking in all the observed variables, the best interaction on a combination of concentration Giberellin (GA¬3) 150 ppm with a long soaking 3 hours. There is interaction between GA3 concentration with immersion time at all observed variables, the best interactions in combination treatments giberellin concentration (GA3) 150 ppm with a 3 hour long immersion in the variable percentage of growth, plant height and number of leaves per plant with variable values 93,33 %, 67,83 cm, and 18,30 strands.

Keywords: White teak, Gmelinaarborea, GA¬3 concentrations and longer immerse

• PENGARUH KOSENTRASI GA3 DAN LAMA PERENDAMAN TERHADAP PERKECAMBAHAN DANPERTUMBUHAN BIJI JATI PUTIH (Gmelina arborea)