Antifungal effect of essential oils on control of phytopathogens in stored soybean seeds

Abstract

Soybean is subject to occurrences of pathogens transmitted by seeds, requiring phytosanitary treatment, however, it can be toxic to humans and the environment. The objective of this study was to evaluate the effect of essential oils of rosemary (Rosmarinus officinalis) and eucalyptus (Corymbia citriodora) on the control of phytopathogenic fungi in stored soybean seeds. The experiment was carried out in a completely randomized design, using a 2 × 5 factorial arrangement consisted of seeds with and without fungal inoculation (Aspergillus flavus and Penicillium rubens) and five seed treatments (three essential oils, positive control, and negative control), with four replicates. Rosemary and eucalyptus essential oils and their combination were applied to soybean seeds at the rate of 4 mL kg-1, at a concentration of 700 µL mL-1. Distilled water with 2% Tween® 80 was used as negative control, and the commercial fungicide Vitavax-Thiram® 200SC was used as positive control, according to the manufacturers’ recommendations. The R. officinalis essential oil was efficient in the control of Penicillium sp. in stored soybean seeds and showed a similar effect to the positive control. The C. citriodora essential oil reduced the incidence of Aspergillus sp. Therefore, these essential oils have potential to be used as an alternative control of soybean seed pathogens.