Agroecological approach to seed protection using basil essential oil

Abstract Essential oils have been widely studied for the protection of crops and their products against pests and diseases, as an alternative to the use of synthetic pesticides, mainly because they are less harmful to the environment and human health. Basil essential oil (Ocimum basilicum L.) is known for its antimicrobial properties. In this study, basil aromatic oil was obtained by hydrodistillation for different times (20, 40, 60, 90 and 120 min), to estimate and evaluate variations in chemical composition. Basil essential oil and linalool, the major substance in the essential oil, were submitted to toxicity tests against three common storage fungi (Fusarium oxysporum, Penicillium spp. and Colletotrichum gloeosporioides) and for their effect on the germination of commercial seeds (lettuce and tomatoes). Considering the estimates based on the extraction kinetics, hydrodistillation times longer than 60 min proved to be disadvantageous, considering the variations observed in the quantity and quality of essential oil, which did not constitute a considerable gain in essential oil mass, as well as, a different chemical profile. The basil essential oil and linalool showed toxicity against the fungi F. oxysporum (median inhibitory concentration (IC50) = 13.18 and 12.60 μg/mL), Penicillium spp. (IC50 = 17.5 and 8.77 μg/mL) and C. gloeosporioides (IC50 = 12.91 and 9.15 μg/mL), respectively. The tomato and lettuce seeds’ germination were not significantly affected by the essential oils. The results indicate the potential use of basil essential oil for the protection of tomato and lettuce seeds.