Abstract
Effectivity of Morinda citrifolia extract on in-vitro growth inhibition of Ralstonia sp. Morinda citrifolia has been known as one of plants having numerous medicinal properties. Extract of the fruits shows antibacterial activity against several bacteria including Pseudomonas aeruginosa. The purpose of this study was to observe inhibitor effect of M. citrifolia fruit extract, and to investigate the effect of different concentrations of M. citrifolia fruit extract on in-vitro growth of Ralstonia (Pseudomonas) sp., the causal agent of banana bacterial wilt disease in Lampung. Inhibition effect of M. citrifolia was determined by the presence of inhibition zone, and concentration effect was determined by the diameter of inhibition zone . The study consisted of two experiments. The treatments of the first experiment were three different kinds of fruit extract, namely the whole fruit, the seeds, and the fleshy parts, and the second one consisted of six different levels of extract concentrations. The results showed that the whole fruit extract was the most effective as an in-vitro growth inhibitor, and the higher the concentration level the higher the growth inhibition zone formed.