Under conditions in vitro the effect of PRP SOL fertilizer on linear growth of the investigated phytopathogenic fungi colony in the first place depended on the fungus species and concentration of the fertilizer applied in the culture medium. Independently of the applied concentration, the strongest fungistatic effect of PRP SOL was observed on Fusarium sporotrichoides, for which a significant inhibition of surface growth was registered on the level of 25.38% and on Sclerotinia sclerotiorum (32.68%). A weaker inhibitory influence of the tested fertilizer was noted on Phoma exiqua. Applied field doses (2.0 and 1.0mg/cm3) of PRP SOL fertilizer markedly inhibited linear growth of Trichoderma harzianum saprophytic fungus by 19% and 10.11% respectively. Among the tested phytopathogenic fungi F. solani var. coeruleum revealed the best resistance. Surface development of this species colony on the media with the participation of the tested fertilizer was stimulated within the range from 33.99 to 35.88%. F. sulphureum and F. poae fungi revealed a similar but much weaker response. On the other hand a variable response was registered for F. culmorum. Higher concentration of PRP SOL contributed to a limited growth of its mycelium of 10.1% whereas the lower one significantly enhanced surface hyphae growth.