This article presents an overview of the main molecular genetic methods and technologies of remote sensing used in the diagnosis of various diseases of economically valuable plant species and varieties. The introduction shows the main crops cultivated in Russia. The main phytopathogens considered on the example of wheat are also given. These include fungal diseases (various kinds of smut diseases, rust diseases, septiriosis spots, etc.), bacterial diseases, viral diseases and nematode diseases. In the chapter devoted to genetic research methods, both universal primers for fungal and bacterial infections and species-specific primers for phytopathogens for some economically valuable crops are considered. The chapter on remote sensing presents the main stages of identification of phytopathogens using remote sensing of the Earth. The methods used for analyzing remote sensing data of the Earth are also presented. The last chapter describes possible ways to combine genetic methods and remote sensing of the Earth to create libraries for assessing the areas of affected crops. The positive and negative sides of the genetic analysis of phytopathogens are described. The ways of leveling the negative sides using genetic analysis, involving methods of remote sensing of the Earth are proposed.