Background and purpose: Response of cacao plants to fertilizer is influenced by plant condition and homogeneity, which requires optimal dose to obtain the best vegetative and product. Cacao plants will experience deficiency if they receive below-optimal dose of fertilizer, and they will experience toxicity when they receive above-optimal dose of fertilizer. The purpose of this study was to determine the best dose of balanced N.P.K.Ca.Mg fertilization on productive and non-productive yield of TSH 858 clone cacao. Determine a dose that is more suitable for flush, cherelle, and fruit development to increase cocoa yield. Methodology: This research consisted of 2 parallel experiments, on productive and non-productive plants in one same area. It used randomized non factorial design, with treatments consisting of 4 levels of dose N.P.K.Ca.Mg 12.9 : 11.4 : 16.8 : 10.6 : 4.8 stages, namely: 896; 1,120; 1,344; and 1,568 (g tree-1). Observations were made for 24 weeks on the parameters such as number of flush, flower, cherelle, fruit stock, water shoot, size of leaf flush, fruit volume, fruit weight, and seed weight. Results: Dose of fertilizer insignificantly affected all observation parameters; dose of 1,344 g tree-1 produced best yield with 39.7 cherelles and 25.0 fruits stock. Higher dose 1,568 g tree-1, tended to reduce the number of flush, flower, cherelle, fruit stock, fruit volume, fruit weight, and seed weight. Conclusion: Productive plants had better response to fertilization compared to non-productive plants, so that individual productive plant needs preliminary inventory before intensive fertilization. The research recommends maximum dose of fertilizer at 1,344 g tree-1.

Key words: Balanced fertilizer, dose, productive cacao