Prediction of cold hardiness in Douglas fir seedlings by index of injury and conductivity methods

1976 ◽  
Vol 6 (4) ◽  
pp. 511-515 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Cold Hardiness ◽  
Douglas Fir ◽  
Critical Values ◽  
Promising Method ◽  
Controlled Environment ◽  
Electrical Conductivities ◽  
Freezing Temperatures ◽  
Environment Experiment ◽  
Whole Plants ◽  
Stem Segments

Electrical conductivities of diffusate from stem segments of Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) were measured after exposing segments to various freezing temperatures and after heat killing. These data were expressed as conductivity percentage (conductivity after freezing as a percentage of conductivity after heat killing) or as index of injury (It, equivalent to conductivity percentage corrected for conductivity of unfrozen sample). Conductivity percentage, meaned over six test temperatures, predicted the temperature lethal to subsamples of whole plants exposed to different freezing temperatures reasonably well (R2 = 0.77, SEE = ±3.3 °C). However, 'critical' values of It associated with the temperature lethal to 50% of whole plants (T50) could only be determined for the three lowest test temperatures, and they varied from 32 to 40. In a controlled-environment experiment, levels of hardiness predicted by mean conductivity percentage, which seemed the most promising method, did not fully agree with survival results obtained from whole plants after freezing tests.

EFFECT OF PHENOXY HERBICIDES ON COLD HARDINESS OF WINTER WHEAT

1979 ◽  
Vol 59 (1) ◽  
pp. 237-240 ◽  
Author(s):  
S. FREYMAN ◽  
W. M. HAMMAN
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Minor Effect ◽  
Active Growth ◽  
Phenoxy Herbicides ◽  
Freezing Test ◽  
Environment Experiment ◽  
A Minor

In a controlled environment experiment, five phenoxy herbicides were sprayed at two rates on 14-day-old winter wheat (Triticum aestivum L. emend Thell ’Norstar’). After 7 additional days of active growth, the plants were cold-hardened for 14 days and then subjected to a freezing test. Four of the herbicides — MCPA amine, 2,4-D ester, 2,4-DB, 2,4-D amine — significantly reduced the cold hardiness of winter wheat whereas diclofop methyl had a minor effect. The reduction in hardiness was greater at the higher rates of application than at the lower rates.

Trade-offs between growth and cold and drought hardiness in submaritime Douglas-fir

2012 ◽  
Vol 42 (8) ◽  
pp. 1530-1541 ◽  
Author(s):  
N. Darychuk ◽  
B.J. Hawkins ◽  
M. Stoehr
Keyword(s):  
Stress Tolerance ◽  
Water Conservation ◽  
Cold Hardiness ◽  
Seed Orchard ◽  
Tree Breeding ◽  
Douglas Fir ◽  
Controlled Environment ◽  
Abiotic Stress Response ◽  
Trade Off ◽  
Trade Offs

Trade-offs between growth and stress tolerance in plants may limit the possible phenotypes that can evolve or be selected. Such limits would have important implications for tree breeding. We examined evidence for trade-offs between growth and stress tolerance, particularly cold and drought tolerance, in 56 families of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) from wild stand and seed orchard seed with a range of predicted growth rates. Families were assessed in field and controlled-environment experiments for growth and key physiological traits related to abiotic stress response. In the field, family growth was negatively correlated with fall and spring cold hardiness, indicating a trade-off between growth and cold hardiness. Combined results from field and controlled-environment experiments showed lower stomatal conductance and higher water potential in fast-growing families, indicating greater water conservation; thus no evidence existed for a growth – drought hardiness trade-off. Multivariate regression trees of normalized family means of growth and physiological parameters in the field split the families primarily by an index of continentality. Continental families had greater growth, survival, and fall hardiness than coastal families. We conclude that selection pressures in Douglas-fir have resulted in a trade-off between cold hardiness and high vigour, but little evidence exists for a trade-off between growth and drought hardiness.

Genetic variation in fall cold hardiness in coastal Douglas-fir in western Oregon and Washington

2006 ◽  
Vol 84 (7) ◽  
pp. 1110-1121 ◽  
Author(s):  
J. Bradley St. Clair
Keyword(s):  
Genetic Variation ◽  
Cold Hardiness ◽  
Environmental Gradients ◽  
Large Population ◽  
Common Garden ◽  
Cold Season ◽  
Douglas Fir ◽  
Bud Burst ◽  
Population Differences ◽  
Bud Set

Genetic variation in fall cold damage in coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) was measured by exposing excised branches of seedlings from 666 source locations grown in a common garden to freezing temperatures in a programmable freezer. Considerable variation was found among populations in fall cold hardiness of stems, needles, and buds compared with bud burst, bud set, and biomass growth after 2 years. Variation in fall cold hardiness was strongly correlated (r = 0.67) with cold-season temperatures of the source environment. Large population differences corresponding with environmental gradients are evidence that natural selection has been important in determining genetic variation in fall cold hardiness, much more so than in traits of bud burst (a surrogate for spring cold hardiness), bud set, and growth. Seed movement guidelines and breeding zones may be more restrictive when considering genetic variation in fall cold hardiness compared with growth, phenology, or spring cold hardiness. A regional stratification system based on ecoregions with latitudinal and elevational divisions, and roughly corresponding with breeding zones used in Oregon and Washington, appeared to be adequate for minimizing population differences within regions for growth and phenology, but perhaps not fall cold hardiness. Although cold hardiness varied among populations, within-population and within-region variation is sufficiently large that responses to natural or artificial selection may be readily achieved.

Growth, phenology, and cold hardiness of 32 Douglas-fir full-sib families

2009 ◽  
Vol 39 (10) ◽  
pp. 1821-1834 ◽  
Author(s):  
B. J. Hawkins ◽  
M. Stoehr
Keyword(s):  
Cold Hardiness ◽  
Shoot Growth ◽  
Final Height ◽  
Leaf Nitrogen ◽  
Douglas Fir ◽  
Bud Burst ◽  
Freezing Damage ◽  
Family Selection ◽  
Growing Period ◽  
Sib Families

Thirty-two full-sib families of coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) with a range of predicted breeding values were monitored for growth rate, phenology, and cold hardiness over 2 years on two sites to investigate if other traits are being selected when family selection is based on height. Significant differences among families existed in most phenological, growth, and cold-hardiness traits. On average, taller families burst bud later but did not have significantly different growth rates or length of growing period than other families. We found no significant correlations between family date of bud burst and cold hardiness in late spring or between duration of shoot growth or height and autumn freezing damage. Family differences in freezing tolerance were greatest in September and October. In these months, family current-year leaf nitrogen was positively correlated with cold hardiness. Families that were most hardy in the autumn were not the most hardy families in spring. We conclude that, for the studied breeding series, selection based on height does not have a significant impact on cold hardiness. We found no consistent relationships between phenological, growth, or cold-hardiness parameters and final height that could explain family ranking by height. Relationships between grandparent elevation and dates of bud burst and cold hardiness were observed.

Effect of soil temperature, seeding depth and cultivar on wheat tolerance to simulated ethalfluralin carryover

1997 ◽  
Vol 77 (1) ◽  
pp. 181-188
Author(s):  
A. L. Darwent ◽  
L. P. Lefkovitch ◽  
P. F. Mills
Keyword(s):  
Soil Temperature ◽  
Plant Density ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Minor Effect ◽  
Cultivar Selection ◽  
Soil Temperatures ◽  
Environment Experiment ◽  
A Minor

Field and controlled environment experiments were conducted at Beaverlodge, Alberta to determine the effect of soil temperature, seeding depth and cultivar on wheat (Triticum aestivum L.) tolerance to ethalfluralin. In one experiment, ethalfluralin was applied and incorporated, and wheat was seeded at several depths in late April/early May when soil temperatures were lowest or in late May when soil temperatures had increased. Mean 3-yr wheat yields decreased by 45% as the rate of ethalfluralin increased from 0 to 0.75 kg ha−1 and by 21% as the depth of seeding increased from 4 to 12.5 cm but the effect of ethalfluralin on yields was similar regardless of the soil temperature (time of seeding). Mean plant density decreased by 55% as the rate of ethalfluralin increased and by 25% as the depth of seeding increased. Reductions in mean plant density from ethalfluralin were slightly greater when seeded into the warmer soils. In another experiment, the effect of ethalfluralin on the yields of three wheat cultivars, Laura, Conway and Biggar was similar, i.e. the cultivar × rate of ethalfluralin interaction was not significant. However, the mean plant density of Biggar, averaged over rates of ethalfluralin, was less than that of the other cultivars in 1 of 2 yr. In a controlled environment experiment, the oven-dry weight and percent emergence of wheat shoots of the cultivars, Katepwa, Laura and Conway, seeded at 1.5 or 4 cm into soils containing ethalfluralin at concentrations of 0 to 4 ppm and maintained at temperatures of 4.5 or 15 °C, were reduced by decreases in temperature and increases in the rate of herbicide and depth of seeding. However, the interaction of soil temperature × rate of ethalfluralin was not significant for the oven-dry weight of the wheat shoots and the reduction in percent emergence of the wheat shoots as the rate of ethalfluralin increased was only slightly greater at 4.5 °C than at 15 °C. These results indicate that soil temperature and cultivar selection have a minor effect on wheat tolerance to ethalfluralin while herbicide concentration and depth of seeding have a major impact. Key words: Ethalfluralin, wheat, seeding depth, soil temperature, cultivar

Effect of soil nitrate on the growth and nodulation of winter crop legumes

1990 ◽  
Vol 30 (5) ◽  
pp. 651 ◽  
Author(s):  
AL Cowie ◽  
RS Jessop ◽  
DA MacLeod
Keyword(s):  
Pisum Sativum ◽  
Root Growth ◽  
Cicer Arietinum ◽  
Relative Effect ◽  
Controlled Environment ◽  
Soil Nitrate ◽  
Nodule Number ◽  
Winter Crop ◽  
Nitrate Supply ◽  
Environment Experiment

The relative effect of increasing external nitrate supply on the nodulation of 3 winter crop legumes was examined in a controlled environment experiment. Lupin (Lupinus angustifolius cvv. Chittick, Wandoo), chickpea (Cicer arietinum cvv. Tyson, Amethyst) and field pea (Pisum sativum cvv. Maitland, Dundale) were grown at 2 nitrate (NO-3) concentrations of 2 and 8 mmol/L for 40 days.Shoot and root growth were not affected by NO-3 concentration. Increased NO-3 concentration significantly (P<0.05) reduced nodule number and nodule weight in all species. The inhibition of nodulation by increased NO-3 was greatest in peas, followed by chickpeas, and least in lupins.

Short-day treatment alters Douglas-fir seedling dehardening and transplant root proliferation at varying rhizosphere temperatures

2008 ◽  
Vol 38 (6) ◽  
pp. 1526-1535 ◽  
Author(s):  
Douglass F. Jacobs ◽  
Anthony S. Davis ◽  
Barrett C. Wilson ◽  
R. Kasten Dumroese ◽  
Rosa C. Goodman ◽  
...  
Keyword(s):  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
Day Treatment ◽  
Field Performance ◽  
Douglas Fir ◽  
Day Length ◽  
Root Production ◽  
Root Proliferation ◽  
Cold Temperatures ◽  
Short Day

We tested effects of shortened day length during nursery culture on Douglas-fir ( Pseudotsuga menziesii var. menziesii (Mirb.) Franco) seedling development at dormancy release. Seedlings from a 42°N source were grown either under ambient photoperiods (long-day (LD)) or with a 28 day period of 9 h light : 15 h dark photoperiods (short-day (SD)). Seedlings were periodically removed from freezer storage from January to May. Sensitivity of plant tissues to cold temperatures was investigated via electrolyte leakage at nine test temperatures ranging from 2 to –40 °C. New root growth was assessed with rhizosphere temperatures of 10, 15, 20, and 25 °C. From 2 to –13 °C, there was no difference between treatments in cold hardiness. However, at or below –18 °C, LD seedlings exhibited higher indices of damage than SD seedlings. The LT50 (temperature at which 50% cell electrolyte leakage occurred) was consistently lower for SD than LD seedlings. Rhizosphere temperature differentially influenced new root proliferation: LD seedlings had greater new root production than SD seedlings at 20 °C, whereas the opposite response was detected at 10 °C. Our results confirm photoperiod sensitivity of Douglas-fir sources from relatively low (i.e., <45°N) latitudes. Increased spring cold hardiness and greater rooting at lower rhizosphere temperatures may improve field performance potential of SD-treated seedlings.

Impact of climate change on cold hardiness of Douglas-fir (Pseudotsuga menziesii): environmental and genetic considerations

2015 ◽  
Vol 21 (10) ◽  
pp. 3814-3826 ◽  
Author(s):  
Sheel Bansal ◽  
J. Bradley St. Clair ◽  
Constance A. Harrington ◽  
Peter J. Gould
Keyword(s):  
Climate Change ◽  
Pseudotsuga Menziesii ◽  
Cold Hardiness ◽  
Douglas Fir ◽  
Impact Of Climate Change

scholarly journals Time of Pruning Effects on Cold Hardiness of Butterfly Bush

2004 ◽  
Vol 22 (1) ◽  
pp. 1-4
Author(s):  
Jennifer C. Warr ◽  
Gary J. Keever ◽  
Douglas A. Findley ◽  
J. Raymond Kessler
Keyword(s):  
Cold Hardiness ◽  
Treatment Temperature ◽  
Buddleia Davidii ◽  
Freezing Temperatures ◽  
Butterfly Bush

Abstract A study was conducted over a two-year period to determine how time of pruning affects cold hardiness of butterfly bush (Buddleia davidii (Franchet) ‘Royal Red’). Plants were pruned in November, January, or March, and pruned and non-pruned plants were exposed to six freezing temperatures two weeks after pruning treatments were applied. In addition, plants pruned in previous seasons were included in subsequent freezing treatments. Plants were rated for injury 2 or 3 weeks after treatment (WAT), and for mortality at 6 WAT. In fall 2001, at −6C (21.2F), injury ratings were higher in pruned than non-pruned plants. At all other treatment temperatures, injury to pruned and non-pruned plants was similar. In fall 2001, mortality increased with decreasing temperatures and was higher in pruned plants than in non-pruned controls, regardless of treatment temperature. In winter and spring 2002, injury and mortality increased with decreasing temperatures, but were not affected by pruning treatments. In fall 2002, temperature decreased as injury rating and mortality increased, regardless of pruning treatment and pruned plants had a higher injury rating and mortality than non-pruned across all temperatures. In winter 2003, injury rating and mortality increased with decreasing temperatures and pruning did not affect either. Spring 2003 plants, which had deacclimated prior to freeze treatment, were not affected by pruning or freezing treatments.

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