Growth cabinet studies into cold-tolerance of Festuca arundinacea populations: II. Responses to pretreatment conditioning and to number and duration of low temperature periods

Abstract

Following three differing pre-stress temperature treatments, potted plants of three populations of Festuca arundinacea, syn. 1 and syn. 2 (North African) and S. 170 (British) were subjected to a cold stress of 20 h at -8 °C in a growth cabinet.In all populations, survival was greatest when the cold stress followed continuous low temperatures for 2 weeks, was intermediate after part-day low temperatures for the same period, and poorest after continuous warmth. The hardening response, especially after the fluctuating regime, was greater in S. 170 than in either syn. 1 or syn. 2, between which little difference was detectable.There was no overall difference in survival between spring-sown and autumn-sown material, nor any apparent relationship between survival and relative growth rate.In a further trial, the same three populations were subjected to differing periods of cold stress at -9 °C-single exposure for 12 or 18 h periods, or one, two or three 6 h periods.The synthetics were progressively weakened by repeated stresses, and were almost completely killed out by 12 or 18 h exposure. Differences in mortality following short and longer periods of exposure were associated with differences in soil temperatures. S. 170 was affected little by the longer stress periods and was stimulated to tiller by repeated, shorter stresses.

Growth cabinet studies into cold-tolerance of Festuca arundinacea populations: III. Cold tolerance of roots and shoots

“…The constancy of scores in excess of 100% following root exposure to temperatures of 19 °F and above, suggested the superiority of S. 170 in this temperature range to have resulted mainly from more rapid tillering in this variety than in either synthetic. Such a suggestion is consistent with evidence previously presented (Thomas & Lazenby, 19686) that exposure to non-lethal low temperatures may stimulate tillering in S. 170. The superior score of S. 170 following root exposure in the '17B' as compared to the '17A' treatment could similarly be explained as resulting from greater tillering amongst surviving material, any such tendency in the synthetics being more than offset by increased mortality.…”

“…Peltier & Tysdal (1932), Kohn & Levitt (1965), and Thomas & Lazenby (19686) Cold-tolerance of Festuca arundinacea. / / / 359 temperature regimes experienced by plants prior to a cold stress greatly influence their survival.…”

Mediterranean and Continental Tall Fescue: II. Effects of Cold, Nonfreezing Temperatures on Leaf Extension, Proline, Fructan, and Abscisic Acid

“…Survival of Mediterranean tall fescue is likely influenced by both managerial practices and climatic conditions, as cutting height and repeated freeze–thaw cycles have a profound influence on the plant's ability to survive (Thomas and Lazenby, 1968a, 1968b). From our observations in field plantings, Mediterranean plants that are not cut in the late autumn had between 30 and 70% winter survival when measured in March, whereas winter survival was 0 to 10% if plants were cut to a 5‐cm height in late autumn (unpublished data).…”

The Independent Assessment of Frost Hardiness of Excised Laminae, Excised Roots and Trimmed Tillers of Tall Fescue (Festuca arundinacea)

“…The use of a bath also has the advantage that uniform exposure is achieved quickly; though the period of exposure and rate of cooling and thawing may affect the results. By contrast, potted plants require prolonged periods of exposure of the above soil parts to obtain uniform exposure of the whole tiller to a particular temperature (Thomas & Lazenby 1968b;Larson 1978;McDonald, unpublished). * Although variation of cooling and thawing rates and of exposure time had effects on the results, there was no case in which variation of these factors altered a damaging temperature treatment into a non-damaging treatment.…”