Ethylene regulatory treatment effects on annual bluegrass survival of freezing temperature and ice cover

Abstract

Annual bluegrass (Poa annua L.) is a golf course turfgrass species, often in a mixed stand with creeping bentgrass (Agrostis stolonifera). Annual bluegrass is more susceptible to ice cover damage than creeping bentgrass. The objective was to determine how fall applications of promotive (1-aminocyclopropane-1-carboxylic acid [ACC] or ethephon) or inhibitory (ReTain or aminoethoxyvinylglycine [AVG]) substances to ethylene production influence turfgrass quality, normalized difference vegetation index (NDVI), ethylene production, canopy respiration rates, and recovery from ice encasement under field and/or growth chamber conditions. The field was monitored for fall quality and acclimation parameters, and the growth chamber study was used for ice treatments and recovery of annual bluegrass only, the winter-sensitive species.Under field conditions, ethephon application increased ethylene production and whole plant respiration of both annual bluegrass and creeping bentgrass, and decreased turf quality and NDVI when compared to controls. Ethylene inhibition treatments did not affect turf quality, respiration or NDVI when compared to the untreated controls, but AVG treated annual bluegrass had greater ethylene production than the untreated controls after 35 and 42 d of treatment. In the growth chamber experiment, ethephon decreased annual bluegrass regrowth, while ReTain improved annual bluegrass regrowth after 40 or 80 d of exposure to −4 • C with or without ice cover. Treatments that inhibit turfgrass canopy ethylene production may be viable methods to improve annual bluegrass winter survival of ice encasement conditions, and may have no negative effects on creeping bentgrass. Testing these treatments for ice survival under field conditions is still needed.Abbreviations: ACC, 1-aminocyclopropane-1-carboxylic acid; AVG, aminoethoxyvinylglycine; NDVI, normalized difference vegetation index; TQ, turf quality.

Influence of Ice Encasement and Ethylene Regulation on Cellular-protection Responses in Annual Bluegrass

“…This type of fall plant growth-regulator treatment is being investigated for other purposes, such as reducing unwanted flowering and seed heads in annual bluegrass in the spring, particularly in southern regions of the United States (Askew, 2017). Based on our results and depending on the rate used, fall applications of ethephon to reduce annual bluegrass flowering could be detrimental to annual bluegrass percent regrowth in colder regions (Laskowski and Merewitz, 2020). This current study shows that the percent regrowth reductions could be related to decreased antioxidant activity, increased lipid peroxidation, and higher levels of saturated fatty acids found here in ethephon-treated annual bluegrass.…”

“…Additionally, more research on how ethylene is associated with fatty acid changes, perhaps fatty acid desaturase enzyme activity, in grass species under stress conditions is needed. Ethylene inhibition improved turfgrass recovery from simulated winter conditions (Laskowski and Merewitz, 2020). Ethylene inhibition treatment caused changes in fatty acid content, as some increases in unsaturated fatty acid concentrations and some saturated fatty acids decreases were detected.…”

“…PLANT MATERIAL AND EXPERIMENTAL TREATMENTS. Plant materials used in this study were generated from the same experiment described in Laskowski and Merewitz (2020), which is also where results regarding plant regrowth and other health indicators were presented. All chemical treatments began on 3 Oct. 2016 and on 6 Oct. 2017 and were applied weekly for 6 weeks on the experimental annual bluegrass putting green field at the Hancock Turfgrass Research Center, East Lansing, MI.…”

“…Annual bluegrass and creeping bentgrass are typically found as pure or mixed stands on golf course putting greens and fairways. Previously, we have found that treatments that inhibit ethylene improved annual bluegrass recovery following low temperature and ice conditions; and ethylene-promotive treatments reduced or had no effect on winter recovery, depending on the duration (Laskowski and Merewitz, 2020). As inhibiting ethylene may be a viable management practice that could be used to protect annual bluegrass or other turfgrass species during winter dormancy, it is important to understand the mechanism associated with improved tolerance.…”

Current Outlook on Ice Encasement Stress and Management Strategies in Turfgrasses

“…Ethephon is commonly used on annual bluegrass to control seed head production (Eggens et al, 1989). Conversely, inhibiting ethylene with an aminoethoxyvinylglycine-containing PGR improved annual bluegrass regrowth after 40 or 80 d of exposure to À4 C with or without ice cover by using experimental conditions that involved natural acclimation in the field, fall treatments of PGRs, and ice encasement or no ice at low temperatures in controlled environment chambers (Laskowski and Merewitz, 2020a). Treatments that inhibit turfgrass canopy ethylene production may be a potential management strategy to improve annual bluegrass winter survival of ice encasement conditions without any negative effects on creeping bentgrass, which is an important consideration because many putting greens are a mix of annual bluegrass and creeping bentgrass.…”