Goal. To study possibility of biological preparations and their compositions with microelements against fusarium-fomos rot.
 Methods. Laboratory (pathogens identification) and field (analysis, tubers materials treating) techniques of researches. The biological preparations researches efficiency conducted separately and in complex with microelements conducted on the base of Ukrainian science-research plant quarantine station Institute of Plant Protection NAAS on natural infectious background during 2021—2022. The tubers put into the biological preparations suspension: Biospectre BT (1.5 l/t); Glocladyn BT (2 l/t); Trychopsyn (2.5 l/t) and then joined them with microelements complexes — microfertillizer Urozhay TK (2 l/t) before planting. Two rootless feeding conducted by the same preparations during the growing period.
 Results. The researches results showed that the potato treating of variety Sante by biopreparations and in combination with microelements before planting and during growing favored the plant increase on 4.4—13.7%, stems quantity increase in bush on 5.3—13.2, yield increase on 9.5—15.5% and ill tubers quantity decrease in 2.5—3.7 times in comparison with control variant. The biological preparations efficiency in combination with complex of microelements consisted of for variety Sante 72.0—73.2% to the most spread disease fusarium-phomos rot. The analogeous resulys received for variety Virineya. The potatoes biological preparations treating before planting and during growing favored the plants’ growth on 7.8—16.3%. The quantity of ill tubers decreased in 2.0—3.1 times. The composition biological preparations with microelements efficiency against fusarium-phomos rot consisted of 49.5—68.0%.
 Conclusions. The following biological preparations usage Biospectre BT (1.5 l/t); Gliocladyn BT (2 l/t); Trychopsin (2.5 l/t) before tubers planting and during growing separately and in complex with microfertillizer Urozhay TK allowed to decrease tubers defeating in 2.0—3.7 times and to receive additional 9.5—16.3% of potato yield.