Lolium arundinaceum leaf and root developmental temperatures influence its allelopathic potency on Poa annua

Abstract

Allelopathy is a commonly recognized but not fully understood method that could be utilized for weed management. Controlled environment studies in a growth chamber were conducted at Virginia Tech's Glade Road Research Facility in Blacksburg, VA, to determine whether aqueous leaf or root extracts from two Lolium arundinaceum (Schreb) Darbysh (tall fescue) cultivars grown under different growing temperature conditions affected the seed germination and growth of Poa annua L. (annual bluegrass). Two cultivars ('Falcon III' and 'Kentucky 31') of L. arundinaceum were maintained at cold (day/night 4.4:-1.1˚C) or warm (day/night 32.2:26.7˚C) conditions for 20 d. Leaf and root extracts were collected via destructive methods and applied to P. annua seed placed in petri dishes. The results indicated that aqueous leaf extracts of L. arundinaceum could inhibit P. annua seed germination, though there was no significant germination reduction with the root extract of L. arundinaceum. The results suggest that temperature may interact with other factors, such as L. arundinaceum cultivar, to influence its allelopathic potency on P. annua seed germination. These results further demonstrate that different cultivars of L. arundinaceum might have different allelopathic effects on P. annua germination. INTRODUCTIONPoa annua L. (annual bluegrass) is considered the most troublesome weed in managed turfgrass systems throughout the United States, as indicated by a nationwide survey conducted by the Weed Science Society of America (Van Wychen, 2020). Turfgrass managers have historically relied on herbicides for annual bluegrass control, and the weed now ranks third among all herbicide-resistant weed species globally, with resistance to at least nine different herbicide sites of action (Heap, 2021). The growing threat of herbicide resistance has increased the need for alternative management practices for P. annua control. Turfgrass cultural practices, such as cultivar selection, fertility programs, mowing heights Abbreviations: DAT, days after treatment.

Allelopathic Effect of Aqueous Extracts of Grass Genotypes on Eruca Sativa L.

“…Lipinska et al (2019) investigated the allelopathic potential of six cultivars of Festuca arundinacea, Festuca ovina, and reported that Festuca rubra had different inhibitory effects on the growth of grass weeds, and their allelopathic potential depended on the content of flavonoids and phenolic acids in their leaves [46]. In the study of Koo et al (2022), the aqueous extract of the leaves of different cultivars of Lolium arundinaceum showed an inhibitory effect on the germination and growth of Poa annua L. in a petri dish, and there was a difference between different cultivars of L. arundinaceum in terms of allelopathic effects [47].…”