1. A method of protecting a plant from a bacterial pathogen, pathogenic fungus or viral pathogen, comprising the steps of: bringing a plant into contact with an effective amount of a bismuth-thiol (BT) composition under conditions and for a time sufficient for one or more of :( i) preventing infection of the plant with a bacterial pathogen, pathogenic fungus or viral pathogen, (ii) inhibiting cell viability or cell growth of almost all plankton cells of a bacterial pathogen, pathogenic fungus or virus a pathogen, (iii) inhibiting the formation of biofilms by a bacterial pathogen, pathogenic fungus or viral pathogen, and (iv) inhibiting the viability of biofilms or the growth of biofilms of almost all bacterial pathogen, pathogenic fungus or viral pathogen-forming biofilms, where the BT composition contains an almost monodisperse suspension of microparticles which contain a BT compound, said microparticles having a volumetric average diameter of from about 0.4 microns to about 10 microns. 2. The method of claim 1, wherein the bacterial pathogen comprises Erwinia amylovora cells. 3. The method of claim 1, wherein the bacterial pathogen is selected from the group consisting of Erwinia amylovora, Xanthomonas campestris pv dieffenbachiae, Pseudomonas syringae, Xylella fastidiosa； Xylophylus ampelinus； Monilinia fructicola, Pantoea stewartii subsp. Stewartii, Ralstonia solanacearum and Clavibacter michiganensis subsp. sepedonicus. 4. The method of claim 1, wherein the bacterial pathogen exhibits antibiotic resistance. The method of claim 1, wherein the bacterial pathogen is resistant to streptomycin. The method of claim 1, wherein the plant is a food crop plant. Cn1. Способ защиты растения от бактериального патогена, патогенного гриба или вирусного патогена, включающий этапы, на которых:приводят в контакт растение с эффективным количеством висмут-тиольной (ВТ) композиции при условиях и в течение времени, достаточного для одного или более из:(i) предупреждения инфицировани
