Effects of essential oils on mycoflora and winter wheat seed germination

The mycoflora of winter wheat seed consists of various fungi that differ as to the parasitism rate. Their harmfulness is connected with their phytotoxic action and ability to produce mycotoxins. Assuming that essential oils have an effective antifungal impact, we studied the effectiveness of 13 essential oils which were produced by LLC "Aromatyka", Ukraine (cinnamon, orange, peppermint, rosemary, vervain, ylang-ylang, sandal, fennel, lavender, eucalypt, bergamot, frankincense, and geranium) on securing of a group of fungi from winter wheat seeds. The seed mycoflora of Bogdana variety harvested in 2017-2020, which was grown in the North- Eastern Forest-Steppe zone of Ukraine (Sumy oblast), was analyzed. A fungi complex analysis was made on the media PGA. The impact of essential oils on seed germinating ability and the length of wheat sprouts on the 7th day has been determined. A longterm studying of seed treatment by essential oils showed their effects on mycoflora formation. These plants affected not only the fungi amount but also changed their secure spectrum. The studies admit a negative impact of fungi on seed germination and plant development. The highest seed germination equaled 95% under its treatment with rosemary and orange oils. However, under seed treatment with rosemary oil, there appeared Fusarium sp. and Bipolaris sorokiniana (Sacc.) Shoem., which harms seed germination. Orange oil has increased the number of fungi of Penicillium sp. The best results (based on three indices) had sandal oil, under which the fungus colony has increased half, and seed germination equaled 61%, the sprout length was maximal when applying other oils (58.8 mm). The essential oils which fully inhibited seed and fungi development (cinnamon, fennel, vervain, geranium) were determined. The study of two of them as fungicides for treatments at the beginning of wheat flowering proved a similar effect to falcon on the change of the internal seed mycoflora.