Changes in drought resistance and root growth capacity of container seedlings in response to nursery drought, nitrogen, and potassium treatments

1992 ◽  
Vol 22 (5) ◽  
pp. 740-749 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Drought Stress ◽  
Root Growth ◽  
Drought Resistance ◽  
Lodgepole Pine ◽  
Dry Weight ◽  
White Spruce ◽  
Douglas Fir ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
N Treatment

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) seedlings, each represented by two seed lots, were grown in Styroblock containers in a greenhouse and plastic shelter house from February 1989 to January 1990. The seedlings were exposed to two nitrogen (N) treatments and three potassium (K) treatments arranged factorially within three drought treatments. After winter storage, seedlings from a complete set of treatments were planted into hygric, mesic, and xeric sand beds during 12–14 March. Increasing nursery drought stress increased survival of Douglas-fir and lodgepole pine after planting, and high N treatment level increased survival of lodgepole pine and white spruce. Under xeric conditions, combined nursery drought and high N treatments increased survival of lodgepole pine by 33%, indicating the importance of nursery cultural regime for stock quality. Increase in nursery drought decreased seedling size relatively little, but increase in N increased seedling size one season after planting. A positive relationship between shoot/root ratio and survival in lodgepole pine and white spruce indicated that increase in N increased both shoot growth and drought resistance over the N range investigated. Only Douglas-fir showed an interaction between drought and N treatment and a small response in both survival and dry weight to K. Root growth capacity, measured at the time of planting, showed an approximate doubling in all species due to high N treatment, and was also increased in white spruce by drought stress. Survival and root growth capacity were poorly correlated, but dry-weight growth in sand beds was well correlated with root growth capacity. Shoot dry weight and percent N in shoots measured after nursery growth were correlated with root growth capacity. Manipulation of root growth capacity by changing nursery treatment was apparently possible without altering resistance to drought stress after planting.

Frost hardiness, root growth capacity, and field performance relationships in interior spruce, lodgepole pine, Douglas-fir, and western hemlock seedlings

1990 ◽  
Vol 20 (5) ◽  
pp. 566-572 ◽  
Author(s):  
David G. Simpson
Keyword(s):  
Root Growth ◽  
Lodgepole Pine ◽  
Field Performance ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Western Hemlock ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Forest Sites ◽  
Interior Spruce

Interior spruce (Piceaglaucaengelmannii complex), lodgepole pine (Pinuscontorta Dougl.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), and western hemlock (Tsugaheterophylla (Raf.) Sarg.) were grown from seed for 20 weeks in containers, with 18-h photoperiods. Fortnightly, over a 12-week acclimation period (September 7 – December 1) outdoors at Vernon, B.C., samples were taken for (i) foliage frost hardiness measurement, (ii) poststorage root growth capacity, and (iii) outplanting on forest sites. In all species, frost hardiness and root growth capacity increased with weeks of acclimation. Frost hardiness and root growth capacity were correlated with each other in western hemlock, lodgepole pine, and Douglas-fir, and with field performance (survival or growth) in interior spruce, lodgepole pine, and Douglas-fir.

Influence of container nursery regimes on drought resistance of seedlings following planting. I. Survival and growth

1991 ◽  
Vol 21 (5) ◽  
pp. 555-565 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Drought Stress ◽  
Lodgepole Pine ◽  
Weight Ratio ◽  
Dry Weight ◽  
White Spruce ◽  
Douglas Fir ◽  
Reduced Height ◽  
Growth Increase ◽  
Sand Beds ◽  
Container Nursery

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) seedlings were grown in Styroblock containers in a container nursery from February to July 1988 and then exposed to three temperatures and three levels of drought stress applied factorially during 18 July to 29 September 1988. Mean temperatures of 13, 16, and 20 °C were imposed in growth chambers, in a cooled plastic house, and in an ambient plastic house, respectively. Control, medium, and severe levels of drought stress were imposed in a series of eight cycles, resulting in mean xylem pressure potentials of −0.32, −0.50, and −0.99 MPa, respectively. Seedlings were kept in the ambient plastic house until January, when they were lifted and cold-stored until planting. Between 11 and 18 April 1989, seedlings were planted in 0.5 m deep sand beds, which provided hygric, mesic, and xeric conditions for testing all species and treatments. At the end of nursery growth, increase in nursery temperature increased height and height:diameter ratio in all species and shoot:root dry weight ratio in Douglas-fir and lodgepole pine. Increase in temperature also increased the number of seedlings with large well-formed buds in white spruce, but reduced the number in Douglas-fir. Drought stress reduced height and dry weight in all species and bud length in lodgepole pine. After 9 weeks in sand beds, low nursery temperature increased survival (19% for lodgepole pine and white spruce grown in the xeric bed), except for Douglas-fir grown in the xeric bed. Nursery drought stress also increased survival (16% for Douglas-fir and lodgepole pine in the xeric bed), but had little effect on white spruce. Low temperature and drought stress treatments that increased survival also reduced height and dry weight of lodgepole pine and white spruce after one growing season in sand beds. Survival showed significant negative correlations with height, dry weight, and height:diameter and shoot:root weight ratios. Low nursery temperature continued to affect growth after planting, increasing relative growth rate and allometric ratio (K) of Douglas-fir and decreasing K of white spruce.

Influence of container nursery regimes on drought resistance of seedlings following planting. II. Stomatal conductance, specific leaf area, and root growth capacity

1991 ◽  
Vol 21 (5) ◽  
pp. 566-572 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Stomatal Conductance ◽  
Root Growth ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Temperature Treatment ◽  
Drought Treatment ◽  
Growth Capacity ◽  
Root Growth Capacity

Seedlings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), lodgepole pine (Pinuscontorta Dougl.), and white spruce (Piceaglauca (Moench) Voss) were grown in a container nursery from February to July 1988 and then exposed to three temperatures and three levels of drought stress applied factorially during mid-July to October 1988. Seedlings were retained in a shelter house until January 1989, when they were cold-stored until early May. Measurements of stomatal conductance (gs), transpiration (E), and specific leaf area (SLA) were made at the end of the treatment period in September 1988 and again after growth the following year at the end of June. Root growth capacity (RGC) was tested in early May 1989. Results were considered in conjunction with performance of other samples of the same plants that had been planted in sand beds in April 1989, where irrigation was regulated to provide three levels of moisture stress. Low temperature (13 °C) generally reduced gs and E, which were adjusted for xylem pressure potential, and SLA in all species by the time nursery treatment was completed at the end of September. No effect of nursery temperature treatment on gs and E could be detected when new needles were measured in June and July (after 9 to 12 weeks of growth), but SLA of lodgepole pine increased with nursery temperature treatment, and SLA of white spruce decreased with nursery temperature treatment. RGC was higher for the 13 °C treatment than for the 16 and 20 °C treatments. Survival of outplanted seedlings was mainly inversely related to nursery temperature. Low nursery temperature reduced gs, E, and SLA and increased RGC. SLA of planted lodgepole pine increased with level of nursery drought treatment, and severe nursery drought increased gs under stress, when measured in June. No other effects of drought were detected, although drought treatment was effective in increasing survival of planted seedlings.

scholarly journals Filmforming Antitranspirants: Their Effects on Root Growth Capacity, Storability, Moisture Stress Avoidance, and Field Performance of Containerized Conifer Seedlings

1984 ◽  
Vol 60 (6) ◽  
pp. 335-339 ◽  
Author(s):  
David G. Simpson
Keyword(s):  
Root Growth ◽  
Field Performance ◽  
White Spruce ◽  
Moisture Stress ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Stress Avoidance ◽  
Vapor Gard

The antitranspirants, XEF-4-3561-A. Wilt Pruf, Plantgard, Folicote, Clear Spray, and Vapor Gard, were sprayed on container-grown lodgepole pine, white spruce, western hemlock, and Douglas-fir seedlings before or after a 12-week cold (+ 2 °C) storage period. The effects of the six antitranspirants on root growth capacity, storability, and field performance varied between species. XEF-4-3561-A. Wilt Pruf, Folicote, and Vapor Gard increased moisture stress avoidance of all species, while Plantgard and Clear Spray had no effect. None of the six antitranspirants are recommended for use on white spruce, western hemlock, or Douglas-fir planting stock because of the risk of reducing field performance. Further trials of XEF-4-3561-A and Wilt Pruf on lodgepolo pine seedlings seem War-ranted.

Early growth of planted spruce

1984 ◽  
Vol 14 (5) ◽  
pp. 644-651 ◽  
Author(s):  
A. N. Burdett ◽  
L. J. Herring ◽  
C. F. Thompson
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Slow Release ◽  
Unit Length ◽  
White Spruce ◽  
Early Growth ◽  
Height Growth ◽  
Needle Length ◽  
Growth Capacity ◽  
Root Growth Capacity

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.

Carbohydrate reserves and root growth potential in Douglas-fir seedlings before and after cold storage

1982 ◽  
Vol 12 (4) ◽  
pp. 905-912 ◽  
Author(s):  
Gary A. Ritchie
Keyword(s):  
Root Growth ◽  
Cold Storage ◽  
Drought Resistance ◽  
Dry Weight ◽  
Douglas Fir ◽  
Growth Potential ◽  
Frost Hardiness ◽  
Root Growth Potential ◽  
Carbohydrate Reserves ◽  
Before And After

Carbohydrate reserves and root growth potential (RGP) of 2 + 0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were monitored through a lifting season and during dark, cold storage. Concentrations of total nonstructural carbohydrate and extractable sugars in root and stem tissues remained relatively constant through winter, while foliar sugars showed a sharp midwinter peak at about 195 mg•g−1 dry weight. RGP was lowest in November and March and peaked in January. During storage at +2 and −1 °C, carbohydrates were depleted in all tissues through respiratory consumption. In contrast, RGP increased during the first 6 months in storage and then fell rapidly. The results do not support the view that changes in RGP are driven by changes in carbohydrate concentrations. Storage may affect frost hardiness and drought resistance through its effect on sugar concentrations.

Assessment of photosynthetic activity of nursery-grown Piceaglauca seedlings using an integrating fluorometer to monitor variable chlorophyll fluorescence

1989 ◽  
Vol 19 (11) ◽  
pp. 1478-1482 ◽  
Author(s):  
William Vidaver ◽  
Wolfgang Binder ◽  
R. C. Brooke ◽  
G. R. Lister ◽  
P. M. A. Toivonen
Keyword(s):  
Chlorophyll Fluorescence ◽  
Root Growth ◽  
Photosynthetic Activity ◽  
Fluorescence Emission ◽  
White Spruce ◽  
Physiological Status ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
C Storage ◽  
Variable Chlorophyll Fluorescence

Photosynthetic activity of intact nursery-grown white spruce (Piceaglauca (Moench) Voss) seedlings was assessed by measuring CO2 exchange (apparent photosynthesis) and normalized, integrated variable chlorophyll fluorescence emission. Agreement between fluorescence and apparent photosynthesis indicated that photosynthetic inactivation of seedlings from selected seedlots began in mid-August and approached completion in late October. Inactivation occurred somewhat earlier in northern seedlot seedlings than in those from a more southerly provenance. Seedlings tested in late October showed significant photosynthetic inactivation, as indicated by both fluorescence and apparent photosynthesis. These seedlings also had passed the −18 °C frost hardiness test currently used in British Columbia as an indicator for safe lifting. On removal from −2 °C storage, seedlings lifted and stored according to nursery practises showed fluorescence emission indicative of photosynthetic reactivation and also had high root growth capacity scores. Low root growth capacity scores were associated with delayed or incomplete photosynthetic reactivation. These results show that fluorescence assessment provides information about the physiological status of white spruce seedlings. Variable fluorescence assays are nondestructive and can be made and interpreted within minutes. As an indicator of shoot metabolic activity, fluorescence assessment provides information useful in selecting lifting dates and in evaluating the effects of dark cold storage on white spruce seedlings.

Root growth and root growth capacity of white spruce (Piceaglauca (Moench) Voss) seedlings

1985 ◽  
Vol 15 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Anne M. Johnson-Flanagan ◽  
John N. Owens
Keyword(s):  
Root Growth ◽  
Root Elongation ◽  
Shoot Growth ◽  
Lateral Roots ◽  
White Spruce ◽  
Shoot Elongation ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
Root And Shoot Growth

Root growth in the root systems of Styroplug-grown white spruce (Piceaglauca (Moench) Voss) seedlings increases in the spring before shoot elongation and again in the fall after bud development is complete. This is followed by root dormancy and quiescence, which are distinguished on the basis of ability to elongate under root growth capacity (RGC) conditions. The number of white long lateral roots produced during RGC tests correlated significantly with the number of white long lateral roots under lathhouse conditions. Increased mitotic activity is required for root elongation. However, mitotic frequencies could not be used to assess RGC because of the confounding effects of independent growth cycles in individual roots. Cell expansion and transformation of insoluble carbohydrates are important controls of root elongation. The relationship between root and shoot growth under RGC conditions may not support the role of shoot elongation in decreasing root elongation. Conversely, this may indicate that RGC tests alter the endogenous controls of root and shoot growth.

New methods for measuring root growth capacity: their value in assessing lodgepole pine stock quality

1979 ◽  
Vol 9 (1) ◽  
pp. 63-67 ◽  
Author(s):  
A. N. Burdett
Keyword(s):  
Root Growth ◽  
Constant Temperature ◽  
Lodgepole Pine ◽  
The Other ◽  
Night Temperature ◽  
Root Volume ◽  
Growth Capacity ◽  
Root Growth Capacity ◽  
New Methods ◽  
Stock Quality

The survival of lodgepole pine (Pinusconforta Dougl.) planted in the spring under a variety of conditions was found to be closely related to its root growth capacity as measured by two newly developed methods. One method employed a displacement technique to measure the root volume of test seedlings, nondestructively, both at the beginning and end of a period of growth under standard conditions. The change in root volume that occurred during the test was taken as a measure of root growth capacity. The other method for measuring root growth capacity was to record, by means of a semiquantitative scale, the number of newly elongated roots possessed by test seedlings after a 1-week period of growth under standard conditions. For comparative purposes, it was found that very similar results were obtained in root growth capacity tests of this type run at two widely differing temperatures (30 °C day – 25 °C night temperature, and a constant temperature of 15 °C).

Growth, survival, and physiology of Douglas-fir seedlings following root wrenching and fertilization

1983 ◽  
Vol 13 (2) ◽  
pp. 270-278 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Root Growth ◽  
Cold Hardiness ◽  
Shoot Growth ◽  
Late Summer ◽  
Early Summer ◽  
Douglas Fir ◽  
Nutrient Concentrations ◽  
High Survival ◽  
Growth Capacity ◽  
Root Growth Capacity

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were subjected to wrenching treatments during their 2nd year of growth in two experiments at different nurseries on Vancouver Island. Seedlings were wrenched with a fixed blade at 20–25 cm below the bed surface. In experiment 1 wrenching reduced water potential of trees on unirrigated loam soil by an average of 300 kPa during August and September. Wrenched trees lifted in October, which were stored at 2 °C until May, showed 25% higher survival than unwrenched trees 1 year after planting. Trees lifted in December had uniformly high survival (98%) and showed no effect of wrenching. Wrenched trees from irrigated plots had lower shoot length relative growth rates (RGR) than unwrenched trees during the year after planting. In experiment 2 wrenching treatments were applied to seedlings, growing in a loamy sand, for different periods between 15 May and 11 September as follows: (i) unwrenched, (ii) early summer, (iii) midsummer, (iv) late summer, (v) all summer. Three different levels of fertilization were applied to each wrenching treatment, and seedlings were lifted for storage at 2 °C in October and December. Stored trees and freshly lifted trees were planted at 700 m elevation on 3 March. Wrenching increased root dry weight, particularly when additional fertilizer was applied, but had no measurable effect on cold hardiness or root growth capacity. Nevertheless, late summer wrenching increased survival 5 and 7% above control 1 and 2 years after planting, when average survival was 47% after 1 year. Wrenching had little subsequent effect on new shoot growth of planted trees during 2 years after planting. However, late summer wrenched trees showed significantly more new shoot growth than all summer wrenched trees. Increasing fertilization reduced cold hardiness and survival of cold-stored trees, but increased root growth capacity. Cold hardiness, measured by electrical impedance, was correlated with survival of cold-stored trees after planting (r2 = 0.82). Root growth capacity, averaged over all fertilizer levels, was closely correlated with survival of stored and freshly lifted trees (r2 = 0.93). Foliar nutrient concentrations were reduced by wrenching, but fertilization increased nutrient reserves within the seedling.

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