The present invention is directed to utilization of antimicrobial agents derived from plants of the alliaceae family for the prevention and control of crop diseases, post-harvest rotting and as environmental disinfection products. The agents include propyl propylthiosulfinate and propyl propylthiosulfonate compounds for pre- and post-harvest treatments, control of rotting in fruits and vegetables; disinfection of agricultural soils, control of microorganisms, environmental disinfection in agricultural processing industries, facilities and equipment, disinfection of food containers and boxes. The agents can be used as pure active principles or in mixtures, in aqueous solutions or in any formulation, either liquid or supported in a solid agent or formulation; as single active principles or in formulation, together with other synthetic or natural antifungal agents, biocontrol agents, fertilizers, antioxidants, growth regulators or regulators of any other type; by means of immersion, fogging, wetting, spraying, atomization, injection in the soil, in irrigation systems, by means of drenchers or in general any other treatment or application system.