THE STUDY OF CHITOSAN, Morganella morganii, AND THEIR SYNERGISTIC EFFECT

ABSTRACT

The oil palm Elaeis guineesis Jacq is native to West Africa. Oil palm diseases are one of the major challenges affecting the growth of oil palm industry globally. Ceratocystis paradoxa is the causal agent of black seed-rot in oil palm seeds and dry basal rot in adult oil palm. This research was carried out to evaluate the effect of chitosan, Morganella morganii and their synergistic effects on the mycelia growth of oil palm seed-rot disease pathogen. Ceratocystis paradoxa and Morganella morganii were isolated from oil palm seeds and ogi respectively. The commercial biopolymer chitosan was obtained from Green Stone Swiss Company Limited, Japan. The antimicrobial test for the effects of chitosan, M. morganii and their synergistic effect on the mycelial growth of Ceratocystis Paradoxa were carried out by Poisoned Food Technique. The bacterium concentration was standardized (0.5 McFarland standard). The mean values of the samples were analyzed statistically using one way ANOVA with statistical package SPSS version 16. The results showed that chitosan at a concentration range of 1% - 5% exhibited no antagonistic effects on the mycelia growth of C. paradoxa throughout the experimental period. The effects of M. morganii, at MF 0.5 (10-2 – 10-5 cfµ/ml) exhibited no inhibition on the mycelia of C. paradoxa throughout the experiment. In contrast, at standardized MF 0.5 (10-1 cfµ/ml) there was growth inhibition on the mycelia of C. paradoxa throughout the experiment in comparison with the control. The synergistic effect of chitosan and M. morganii (0.5 McFarland standard 10-1 - 10-5 cfµ/ml) at 1:1 ratio against the growth of mycelia of C. paradoxa showed antagonistic effect throughout the experiment. The synergistic results implicated chitosan as a biostimulant of M. morganii which alone could not induce growth inhibition on the mycelia of C. paradoxa at a lower concentration. The application of chitosan and Morganella morganii for the management of oil palm black seed-rot disease at the right formulation can reduce the chemical burden of synthetic fungicides on the environment as well as cut cost.