Co-treatment with Origanum Oil and Thyme Oil Vapours Synergistically Limits the Growth of Soil-borne Pathogens Causing Strawberry Diseases

Vapours from origanum oil (O) and thyme oil (T) were applied to the four soil-borne strawberry pathogens Fusarium oxysporum f. sp. fragariae, Colletotrichum fructicola, Lasiodiplodia theobromae, and Phytophthora cactorum, causing Fusarium wilt, anthracnose, dieback, and Phytophthora rot, respectively. Increasing T vapour doses in the presence of O vapour strongly inhibited mycelial growths of the four pathogens and vice versa. When mycelia of F. oxysporum f. sp. fragariae and P. cactorum exposed to the combined O + T vapours were transferred to the fresh media, mycelial growth was restored, indicating fungistasis by vapours. However, the mycelial growth of C. fructicola and L. theobromae exposed to the combined O + T vapours have been slightly retarded in the fresh media. Prolonged exposure of strawberry pathogens to O + T vapours in soil environments may be suggested as an alternative method for eco-friendly disease management.