In the Krasnodar Territory, on the Renet Simirenko apple variety, symptoms corresponding to the manifestation of viral diseases were found: chlorotic leaf spot, dark green depressed spots on the fruit, which manifest themselves at the end of ripening before harvesting and during storage. Identification of pathogens was performed by Enzyme Immunoassay (ELISA). Samples were tested for the presence of apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), and apple mosaic virus (ApMV). As a result of the analysis, viruses of chlorotic leaf spot of the apple tree (ACLSV) and pitted of apple tree wood (ASPV) were detected. To protect the apple tree from viruses, the drug Farmaiod, GS, whose active ingredient is iodine, was tested. The first treatment was carried out during the 2014 leaf fall period with a consumption rate of 1.0 l/ha and continued in the following 2015 in the phenophase "green cap" and "fruit diameter 10-20 mm" in two versions with consumption rates of 0.5 and 1,0 l/ha. With the onset of leaf fall in the same areas, the treatment cycle was repeated according to the same scheme. Accounting was carried out by the method of visual diagnostics, in addition, at the end of the first and second seasons, virological analyzes were performed by ELISA. As a result of research, it was noted that 3-fold use of the drug Farmaiod, GS in apple trees of the variety Renet Simirenko restrained the development of the apple tree acle virus (ASPV) and completely suppressed the apple leaf chlorophyll virus (ACLSV). The weather conditions of 2016 test triggered a strong manifestation of scab on leaves and fruits. In the experimental variants, it was noted that the drug at 78.3-83.1 % inhibits the development of apple scab. Treatment with Farmaiod, GS also fostered harvest increase and premium output. The maximum results regarding restraints of infectious processes as well as harvest increase were received when applying the preparation with consumption rate of 1,0 l/ha.