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Brown rot is one of the most important diseases of stone fruits and is caused by the fungus <i>Monilinia fructicola</i> in the southeastern United States. Populations of this pathogen have evolved resistance to several fungicides since the early 1970’s starting with benomyl. More recently, DMI fungicide resistance and reduced sensitivity to QoI fungicides have been reported in several eastern U.S. peach orchards. Synthetic analogues of the marine natural product oroidin, called 2-aminoimidazole (2-AI) derivatives, were recently shown to inhibit and disperse fungal (eg. <i>Candida</i>) and bacterial biofilms and suppress antibiotic resistance in human pathogenic bacteria. Thus our objective was to evaluate the potential antifungal activity of 2-AI compounds on plant pathogenic fungi using <i>M. fructicola</i>. <i>In vitro</i> screens were utilized to assess the impact on spore germination and to calculate the concentration required to suppress mycelial growth by 50%. Additionally, analogues with differing chemical structures were investigated and results indicated the importance of a positively charged compound for inhibition of conidial germination. A 2-AI compound also similarly inhibited growth of <i>M. fructicola</i> isolates with decreased sensitivity to benomyl, DMI, and QoI fungicides, and fungicide sensitive isolates <i>in vitro</i>. A study utilizing electron microscopy was conducted to examine the effect of a 2-AI analogue on the ultrastructure and gross morphology of<i> M. fructicola</i> conidia.<p><p>Keywords: Fungus, Fruits-Nuts