Determining allelopathic potential for two weed species in the Flint Hills.

Abstract

A plant community is comprised in part of individual plants that are tolerant of their neighbors' competitive strategies. Through the process of succession a plant community changes in composition over time. The competitive strategies used in this community can include allelopathy. Allelochemicals are secondary metabolites which inhibit non-tolerant species. In local disturbed communities in the Flint Hills area, two weed species commonly seen in the early stages of succession are Ambrosia trifida and Helianthus maximilliani. Both species flower late in the growing season and are suspected of allelopathy. As these mature plants decompose, the allelochemicals should be broken down into simpler phenolic acids and released into the environment. This plant residue may affect the germinating seeds of the following growing season. Field research determined the species distribution and plant associations of the communities. Results of the field research showed no relationships with Ambrosia trifida. There was a negative association between Helianthus maximilliani and Solidago canadensis. Germination bioassays were performed in the lab with water extracts from the test species. High performance liquid chromatography methods were used to determine the phenolics present in the plant material