Abstract
The needs of fertilizer for immature rubber plant (IRP) is influenced by many factors, including the type of soil, clones, plant age and cultivation technique. Information on fertilizers needs of IRP on various types of soils is still limited. Therefore, this study was conducted to evaluate the response of the IRP toward organic and inorganic fertilizers in latosol soil in Sukabumi, West Java. The research was conducted at Pakuwon Experimental Station, Indonesian Industrial and Beverage Crop Research Institute (IIBCRI) Sukabumi from June 2014 until June 2016. The research used split plot design with three replications. The main plot was organic fertilizer doses (0, 2, and 4 kg/plant), whereas the subplot was anorganic fertilizers doses (50%, 75%, 100%, and 125% from recommended dose). Variable observed were stem girth and length, leaf number, and leaf density of the apical branch, length of petiole, length and width of leaflet. The results showed that there was no significant interaction between dose treatment of organic fertilizer and inorganic fertilizer on all parameters of IRP grown on latosol soil in Sukabumi. Organic fertilizer significantly affect the character of stem girth, length and width of the leaflet. The more organic fertilizer given, the bigger stem girth of IRP, but the smaller length and width of the leaflet.