The basic correlation is defined which characterizes an influence of electromagnetic radiation on a system of individual particles of ellipsoidal geometry dispersed into some volume (chaotic arrangement) of another medium. The field intensity inside one isolated particle is determined depending on the parameters of the external (relative to the volume) electromagnetic field. Energy loss in an isolated particle is calculated. The shielding effect of a field in an isolated particle by other surrounding particles is taken into account. The relative dielectric permittivity and the relative loss tangent as a function of grain moisture content are measured. Drying and disinfestation of wheat grain by electromagnetic methods are observed.