Bioherbicide potential of essential oils from plant species used in folk medicine and cuisine in the Amazon region

The potential of essential oils (EOs) has been proven for several solutions in the agricultural sector, among others, which makes the exploration of this matrix an ongoing activity. From this perspective, this work investigated essential oils from medicinal and condimentary species commonly used in the Amazon region for the control of Eragrostis plana Nees, an invasive species with a great impact on forage production. The EOs of Copaifera sp., Bixa orellana L., Piper tuberculatum Jacq., Chenopodium ambrosioides L. and Ocimum gratissimum L. were obtained via hydrodistillation, characterized via GC-MS and used in the preparation of solutions that were applied in vitro tests E. plana. All EOs tested affected the germination and initial growth of E. plana, but that of C. ambrosioides was the most efficient in inhibiting emergence, reaching a reduction greater than 97 % in accumulated germination when applied at a concentration of 0.1 %, followed by the EO of O. gratissimum, with inhibition of almost 75 % at the same concentration. The other oils, although in higher concentrations, also showed an interesting potential for controlling the germination of this invasive species. Similarly, a significant and more pronounced reduction in the initial growth of seedlings was observed in exposure to the EO of C. ambrosioides, which showed a major volatile composition characterized by the identification of ascaridol (5.75 %), glycosylated ascaridol (10.58 %), linalool acetate (11.26 %) and dihydrocitronellol acetate (19.53 %). These results, although initial, validate the efficiency of essential oils as promising biological products for application in the agricultural sector. (c) 2023 SAAB. Published by Elsevier B.V. All rights reserved.