Field and Laboratory Screening of Fine Fescues for Allelopathic Potential.

Fine fescues are a group of cool-season turfgrasses used for their low-input requirements. Previous research has documented weed suppression in field and greenhouse conditions by some fine fescue cultivars. Plant breeders and other turfgrass researchers would benefit from efficient methods by which to identify fine fescues exhibiting allelopathy. Therefore, we conducted field and greenhouse experiments to screen accessions of the fine fescue species hard fescue (Festuca brevipila), Chewings fescue (Festuca rubra ssp. fallax), and strong creeping red fescue (Festuca rubra ssp. rubra) for allelopathic potential. A growth chamber experiment was conducted to measure allelopathy via root inhibition of two weed species (annual bluegrass and white clover) grown in a controlled environment with 20 accessions each for three fine fescue species. Results of the first run of the root inhibition study were used to select accessions demonstrating high or low allelopathic potential to be used in a field screening experiment. Seven accessions from each fine fescue species were planted in fields historically dominated by crabgrass (Digitaria ssp.) in St. Paul, MN and West Lafayette, IN in April 2017. Preliminary results from the growth chamber experiment indicate that root inhibition varies by fine fescue genotype, species, and weed species. In the field screening experiment located in St. Paul, crabgrass seedheads varied by fine fescue genotype and correlated well with root inhibition data in the growth chamber experiment. Results from these experiments will be used to select for fine fescue germplasm demonstrating higher allelopathic potential.