Annual bluegrass (Poa annua) is a cool-season, managed turfgrass species that is susceptible to winter injury, particularly ice encasement. Development of winter preparatory practices in the fall is important for turfgrass managers to decrease the incidence and costs associated with ice encasement damage. In the first experiment, a two-year growth chamber study evaluated the effect of fall soil water content (SWC) at three different levels (8%, 12%, and 20%) on ice encasement survival. Plants were analyzed for relative water content, percent recovery, total nonstructural carbohydrates, and lipid peroxidation. Low SWC during cold acclimation improved recovery could be associated with higher root TNC content. In the second experiment, plant growth regulator (PGR) treatments in the fall season were used to evaluate their ice encasement recovery in controlled conditions and field spring recovery. Field plots were treated with mineral oil, aminoethoxyvinylglycine (AVG), ethephon [(2-chloroethyl)phosphonic acid)], and a control (water). Refraining from high levels of ethephon or reducing water inputs during the fall acclimation period may reduce annual bluegrass stand loss due to ice encasement. A third growth chamber experiment was conducted to observe the differences in gas accumulation between creeping bentgrass (Agrostis stolonifera; ice encasement tolerant) and annual bluegrass (ice encasement sensitive) during ice encasement and after melt. Annual bluegrass had reduced regrowth after ice encasement when compared to creeping bentgrass, which could be associated with higher amounts of ethylene and CO2 in annual bluegrass plants and a decrease in glucose and fructose after 20 d of ice encasement. This research improves our understanding of the effects of ice encasement on turfgrass growth, winterkill preventative management practices, and mechanisms that may correlate to ice encasement resilience.
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