Robusta Coffee (Coffea robusta L.) seed germination response in various plant natural growth regulators with soaking duration

One of causes coffee germination process takes a long period time, because the caffeine contained in beans can inhibit activity amylase enzyme plays role process. Therefore, study was conducted on provision Natural Growth Regulatory Substances (Natural PGR). This research at Green House, Faculty Agriculture, Univeritas Sumatera Utara, Medan from October 2019 to January 2020 using Randomized Block Design (RBD) with two treatment factors : Factor 1 PGR: A0 (water), A1 (bamboo shoot extract), A2 (shallot and A3 extract + shallot extract). 2 soaking duration L1 (6 hours), L2 (12 L3 (18 hours). The results showed that application natural growth regulators or extract) significantly increase rate seed vigor index. Soaking durationof 18 hours presentation but not different for 12 hours, there no interaction between factors.
 
 Keywords: Germination, Robusta coffee, PGR,