Suppression of Liverwort Growth in Containers by Cinnamic Aldehyde

• Published in: HortScience Vol. 32; no. 3; p. 430
• Main Author: Svenson, Sven E
• Format: Journal Article
• Language: English
• Published: 01.06.1997
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/HORTSCI.32.3.430C

Extensive growth of liverwort (typically Marchantia sp.) on the surface of the growing medium in plant containers is a serious problem in many nursery and greenhouse operations. A spray application of cinnamic aldehyde at 0%, 0.25%, 0.5%, or 1% a.i. was applied to uninfested 4-inch-diameter containers, and to containers infested with Marchantia polymorpha. Application to uninfested containers delayed liverwort establishment for an additional 1, 2, and 4 weeks at the 0.25%, 0.5%, and 1% applications rates, respectively, compared to the 0% control. Ten days after application, 0%, 70%, 95%, and 100% of liverwort thalli covering the growing medium surface of infested containers were killed by the 0%, 0.25%, 0.5%, or 1% application, respectively. However, only the 1% rate also killed the gemmae cups growing on the thalli surface. Regrowth of liverwort began 2, 3, and 5 weeks following application, respectively. Prevention of infestations is desirable, as dead liverworts are less attractive than live growth. No phytotoxicity symptoms were observed on Rhododendron growing in the treated containers.