Growth of Cut-Grafting Robusta Coffee Seeds Utilizing Orthotropic and Plagiotropic Rootstocks with Application Bacillus and Pseudomonas Mixture

Vegetative propagation by cut-grafting has the advantage of being able to obtain seeds that inherit two superior traits from two scion clones in a relatively short time. The purpose of this research is to determine the effect of using orthotropic and plagiotropic rootstocks applied by Bacillus and Pseudomonas on the early growth of robusta coffee seedlings from cut grafting. The method used was by using a completely randomized factorial design with 2 factors and was   repeated 3 times. The first factor was the use of rootstock cuttings which consisted of 2 levels, which were S1 (orthotropic stem) and S2 (plagiotropic stem). The second factor was the concentration of Bacillus and Pseudomonas which consisted of 5 levels, which were B0 (0 ml/L), B1 (20 ml/L), B2 (40 ml/L), B3 (60 ml/L) and B4 (80 ml/L). The results showed that (1) there was no interaction between the use of variatic rootstock and the application of the biological agent (2) The use of orthotropic rootstock increased plant growth, that is the number of primary roots and the number of leaves and (3) Application of the biological agent of Bacillus and Pseudomonas with concentrations of B4 increased seedling growth on all observed parameters except the number of shoots. Based on the results of this research, the benefit for coffee planters is to obtain alternative planting materials, namely from orthotropic branches. For further research, the use of orthotropic branch planting material as a scion plant can be investigated.