MODELING THE ENDOPHYTIC FUNGUS EPICOCCUM NIGRUM ACTION TO FIGHT THE “OLIVE KNOT” DISEASE CAUSED BY PSEUDOMONAS SAVASTANOI PV. SAVASTANOI (PSV) BACTERIA IN OLEA EUROPAEA L. TREES.

n this paper a four populations nonlinear mathematical model is introduced toanalyze the interactions between two different microorganisms and the olive treeon which they reside. One such microorganism infects and ultimately kills thebranches while the other one has a beneficial effect on the plant. We aim at devis-ing a control strategy of the action of the pathogenic microorganism on the plant.To this end, the equilibrium points of the ecosystem are investigated. Feasibilityand stability conditions of the equilibria are derived analytically. The numericalsimulations show that the infection transmission rate and the disease-related mor-tality can deeply affect the spread of the disease. Some conditions for the diseaseeradication are investigated and suggestions are given for the implementation ofsuitable biological controls, such as pruning of the infected leaves.