Dehardening of Annual Bluegrass and Creeping Bentgrass during Late Winter and Early Spring

Abstract

Changes in cold hardiness levels of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds.) were monitored under field conditions during the dehardening period of late winter and early spring. During the course of two spring periods the cold hardiness levels of the two species were monitored in conjunction with the following hydration treatments: snow cover maintained to prolong dormancy, snow removal in March, and hydration of crown tissues in combination with snow removal. Cold hardiness levels, percent crown moisture, and soil temperatures were monitored throughout this period. Cold hardiness levels were significantly influenced by year, species, hydration treatment, and a number of interactions of these factors. Generally, plants dehardened 2 wk earlier in 1997 than in 1996. On 1 April, creeping bentgrass had cold hardiness levels averaging −20°C compared to −13°C for annual bluegrass. By 15 April, creeping bentgrass plants had lost their cold hardiness advantage. Increased soil temperature was the greatest contributor to the loss of hardiness in the spring. An increase in crown moisture of 4% for annual bluegrass and 6% for creeping bentgrass occurred during the period from 25 March to 22 April. Maintaining a snow cover on plots delayed the loss of cold hardiness by 6 to 9 d in 1996 but had no effect in 1997. Maintaining a snow cover also delayed the increase in crown hydration by a week. Plants were able to partially regain cold hardiness when soil temperatures dropped.

Comparative assessment of metabolic responses to cold acclimation and deacclimation in annual bluegrass and creeping bentgrass

“…of AB has been documented and could be a significant source of recurrent winter injury in swards invaded by unsown AB (Dionne et al, 1999;Tompkins et al, 2000Tompkins et al, , 2004. Winter injury can result from a combination of factors including high crown hydration, extensive cell desiccation, infections by low temperature pathogens, anoxia, and insufficient tolerance to freezing temperatures.…”

Various Turf Covers for Kentucky bluegrass Growth and Spring Green-up

“…Turf covers may help protect the crowns from direct low temperatures and desiccation. Tompkins et al (2000) reported that it is important to keep turfgrass covered with snow in order to maintain dormancy for as long as possible. Snow can be a constant source of moisture and insulator for higher temperature than air temperature (Happ, 2004).…”

Optimal Regulation of the Balance between Productivity and Overwintering of Perennial Grasses in a Warmer Climate

“…There are several reports describing deacclimation and re-acclimation responses in perennial grass species [99][100][101][102][103][104][105], and some of them also report a negative association between freezing resistance and leaf growth during the de-acclimation period. In cereals, it has been shown that both freezing resistance and expression of cold-induced genes are down-regulated in shoot base tissue when the vernalization requirement is saturated, but before any development of the apex is visible in the microscope [106][107][108].…”