Assessment of fertilizing technology for vegetative growth of Borneo Prima oranges in Bulungan District, North Kalimantan

Abstract

Fiana Y, Purwantiningdyah DN, Rizal M. 2015. Assessment of fertilizing technology for vegetative growth of Borneo Prima oranges in Bulungan District, North Kalimantan. Pros Sem Nas Masy Biodiv Indon 1 (2): 319-323. The purpose of this study was to assess cultivation technology, especially fertilization, of Borneo Prima oranges, a superior local orange variety in Bulungan, Kalimantan. The study was conducted for two years since 2012 in Tanjung Buyu village, Tanjung Palas Subdistrict, Bulungan District of North Kalimantan Province (formerly East Kalimantan Province). The experiment was started by planting the orange plants in 40x40x40cm3 planting holes at 5x5 m2 individual distance. Fertilization was done during the vegetative stage of the plants using, (i) 20- 40kg of bio-organic fertilizer per tree, and (ii) anorganic fertilizers (Urea, TSP, and ZA) with appropriate dosages to the plant age. Data was tabulated and analyzed using Analysis of Variance. The result showed stem height and diameter growth of fertilized plants ranged 45-61 cm and 7.2-7.5 cm respectively, at 1 year old, while non-fertilized plants showed only 38 cm of height growth and 5.9 cm of diameter growth, at both 1 and 2-year-old. Appropriate fertilization on Borneo Prima oranges can enhance the plant’s productivity, added value, and competitiveness, supporting orange horticulture in East Kalimantan Province.