Response of growth and production of potato plants to application of NPK fertilizer

Fertilizer is one of the determining factors for the success of potato cultivation. Various types of fertilizers have been produced, but those that are suitable for regional conditions in North Sulawesi do not yet exist. The decreasing of potato production in North Sulawesi is due to the limited use of quality and certified seeds, as well as inappropriate fertilizer dosages. This research objective was to see the effect of NPK fertilization on the production of Medians potato plants. The research was conducted from August to December 2020, in Rurukan Village, East Tomohon District, Tomohon City, North Sulawesi. The experimental design used was randomized complete block design (RCBD) with seven treatments, namely the NPK fertilizer dosage of 0 kg ha-1 (P0), 150 kg ha-1 (P1), 300 kg ha-1 (P2), 450 kg ha-1 (P3), 600 kg ha-1 (P4), 750 kg ha-1 (P5) and 900 kg ha-1 (P6). Each treatment was repeated three times and resulting in 21 treatment plots. The results showed that application of NPK fertilizer of 450 kg ha-1 resulted the highest yields on the components of weight of fresh plant, tuber diameter, and potato productivity