AUTHOR=Zhou Shixing , Han Caixia , Zhang Chenpeng , Kuchkarova Nigora , Wei Caixia , Zhang Chi , Shao Hua 

TITLE=Allelopathic, Phytotoxic, and Insecticidal Effects of Thymus proximus Serg. Essential Oil and Its Major Constituents

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.689875

DOI=10.3389/fpls.2021.689875

ISSN=1664-462X

ABSTRACT=<p>The chemical profile of <italic>Thymus proximus</italic> essential oil (EO) and its allelopathic, phytotoxic, and insecticidal activity was evaluated. Carvacrol, p-cymene, and γ-terpinene were detected as the major components of the EO, representing 85.9% of the total oil. About 50 g fresh plant material of <italic>T. proximus</italic> in a 1.5-L air tight container completely inhibited the seed germination of <italic>Amaranthus retroflexus</italic> and <italic>Poa anuua</italic>. Meanwhile, the EO exhibited potent phytotoxic activity, which resulted in 100% germination failure of both the test species when 2 mg/ml (for <italic>A. retroflexus</italic>) and 5 mg/ml (for <italic>Poa annua</italic>) oil was applied. The EO also triggered a significant insecticidal activity on <italic>Aphis gossypii</italic> with a LC<sub>50</sub> value of 6.34 ppm. Carvacrol was identified as the main active compound responsible for both the plant suppressing effect and the insecticidal activity of the EO. Our study is the first on the allelopathic, phytotoxic, and insecticidal activity of <italic>T. proximus</italic> EO, and the determination of the responsible compound, which indicated their potential of being further explored as environment friendly biopesticides.</p>