Growth of stump by girth stock and gifth phosphate effect. The objective of the research was to study the effect of girth stock and phosphate for the growth of Hevea brasilliensis Muell Arg. The research was conducted at experimental field of Agriclture Faculty, North Sumatera University, Medan with attitude 25 metres above on the sea level, from Juni to October 2009. The research was used the Randomized Group Design with 2 factors. Girth stock level (L) as main factor with 3 level e.g. 3,6 – 4,6 cm ( L1), 4,7 – 5,7 cm (L2), 5,8 – 6,8 cm (L3) and phosphate as second factor with 4 level e.g. 0 g (F1), 15 g (F2), 30 g (F3), 45 g (F4) with 3 replications. The parameters which is noticed were speed of eye stump out, percentage stump of shoot, length’s shoot, girth’s shoot, leaf’s number, percentage of stump one umbrella leaf’s. The result show that girth stock L3 give the best result at the parameters length’s shoot, turn’s shoot, leaf’s number. The girth stock is not significant to eye of out time, percentage stump of shoot, and percentage of stump umbrella leaf’s. The best of the phosphate treatment at the research is F3 to indicate best result by length shoot parametres. The interaction both factor is significant to length’s shoot. The combination of treatments that result high length’s shoot is L3F1 (girth stock 5,8-6,8 cm and phosphate 15 g) already significant to increase growth stump of rubber.
