Selectivity of the bioherbicidal potential of Artemisia arborescens L. among model and agronomic crops and implications for pre- and post-emergence applications

Background: The efficacy and selectivity of phytochemicals are required for the development of new botanical bioherbicides for both pre- and post-emergence applications. Questions: How vary the phytotoxic potential of the aqueous extracts of Artemisia arborescens among five plant species? Studied species: Lactuca sativa used as a model species, two monocotyledons (Triticum turgidum, Zea mays) and two dicotyledons (Raphanus sativus, Pisum sativum). Study site and dates: Two Artemisia arborescens genotypes were collected at Bousselem and Kef, North West of Tunisia; March 2021. Results: The aqueous extracts are rich in polyphenols, flavonoids, condensed tannins and terpenoids. The highest in vitroinhibitory potential on germination and seedlings growth was detected against Lactuca sativa. The concentration 8 mg/mL causes total inhibition of lettuce germination and has no significant effect on pea germination. At this concentration, the extracts inhibited the germination of the agronomic crops by 46-58 % (Raphanus sativus), 74 % (Zea mays) and 72-78 % (Triticum turgidum). The inhibition rates of radicles and shoots growth vary according to the applied concentration. The in vivo tests showed higher phytotoxic activity against Lactuca sativa and both monocotyledons. This was confirmed by the variation of the symptomatic and biochemical traits. Conclusions: The obtained results confirm the selective bioherbicidal activity of A. arborescens water extracts which promote its potential as natural resource for the development of new botanical bioherbicides.