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据有关推测冬季的结冰温度是导致粗穗冰草(Agropyron dasystachyum)采摘后分蘖枝死亡的主要原因。因此,1992和1993年5,6,7,8月每月下旬在萨斯喀彻万省西南部测定了只刈割1次,留茬高度为5cm的粗穗冰草分蘖枝的耐寒力。用未刈割过的粗穗冰草作对照材料。初冬或冬末刈割后立即测定下列条件下粗穗冰草分蘖枝的耐寒力:(1)用-3～-36℃可调控低温处理粗穗冰草分蘖枝;(2)将粗穗冰草分蘖技在-15℃低温处理0～15d。粗穗冰草分蘖枝的LT_(50)(50％的分蘖枝死亡时的温度)在1992～1993年初冬为-29.5～<-36.0℃,1993～1994年平均为-24.0℃;1992～1993年冬末为-18.1～-22.6℃,1993～1994年平均为-22.0℃。将粗穗冰草分蘖枝在-15℃处理0～15d,初冬时分蘖枝的LDur_(50)(50％的分蘖枝死亡时的天数)为8.0～13.1d,而冬末时分蘖枝的LDur_(50)为2.7～4.7d。然而刈割后再生分蘖枝的耐寒力比对照的更强,这是出乎意料的。刈割后分蘖枝的LT_(50)比对照的低1.5～10.0℃。这推翻了采摘会降低粗穗冰草耐寒力的推测。一般而言,在田间试验中冷应激的程度和持续时间不足以降低粗穗冰草分蘖枝的生活力。对粗穗冰草的生活力而言,冬末至初春是关键时期,因为一年的这段时间中粗穗冰草的耐寒力不断下降。如果给粗穗冰草盖一层绝缘材料会起到保?
It is speculated that the freezing temperature in winter is the main reason for the death of tillers after picking of Agropyron dasystachyum. Therefore, in August and June 1993 and June, July and August of each month, the cold hardiness of tillering was observed in southwestern Saskatchewan. Uncultivated Sclerotium glaze as control material. The cold hardiness of Tamarix splendens under the following conditions was determined immediately after mowing at the beginning of winter or at the end of winter: (1) Tillers of Scirpus paniculata were regulated by -3 ~ -36 ℃; (2) Grass tillering technology at -15 ℃ low temperature treatment 0 ~ 15d. The average value of LT_ (50) (50% of the temperature at the time of death of tiller) from the beginning of 1992 ~ 1993 was 29.5 ~ -36.0 ℃, and the average was -24.0 ℃ from 1993-1994. The end of winter is - 18.1 ~ -22.6 ℃, 1993 ~ 1994 average of -22.0 ℃. The LD50 of tillering branches in early winter (the number of days when 50% of tillering branches died) was 8.0-1.3 days after the first tillering of wintergrass was treated at -15 ℃ for 0-15d, whereas the LDur_ (50) is 2.7 ~ 4.7d. However, it was surprising that the cold-tolerance of regenerated tillers after cutting was stronger than that of the control. After cutting, the LT_ (50) of tillers was 1.5 ~ 10.0 ℃ lower than the control. This overturned the speculation that plowing will reduce the cold hardiness of the spike icegrass. In general, the extent and duration of cold stress in field trials are not sufficient to reduce the viability of the spikelet of the spikelet grass. For the vitality of the spike icegrass, the late winter to early spring are the critical periods, since the cold hardiness of the spikegrass declines continuously throughout the year. If the spike ice grass cover a layer of insulation material will play Paul?