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

Abstract

AbstractAnnual 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.