Effects of a triazole, uniconazol, on shoot elongation and root growth in loblolly pine

1992 ◽  
Vol 22 (1) ◽  
pp. 1-4 ◽  
Author(s):  
A. D. Barnes ◽  
W. D. Kelley
Keyword(s):  
Aqueous Solution ◽  
Root Growth ◽  
Loblolly Pine ◽  
Growing Season ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Height Growth ◽  
Phytotoxic Effects ◽  
Growth Of Seedlings

Uniconazol, applied in an aqueous solution to 3-year-old loblolly pine (Pinustaeda L.) at the soil–stem interface, decreased height growth by up to 55% after one growing season without phytotoxic effects. Results suggest that uniconazol may be useful in controlling height growth of seedlings and seed-orchard trees. The triazoles uniconazol, paclobutrazol, and BAS011106W were tested for effects on loblolly pine root growth. Root-applied uniconazol consistently increased root growth of 1-year-old seedlings. At 100 mg•L−1, uniconazol increased the number of new roots and survival by 47 and 19%, respectively. The increase in survival of uniconazol-treated seedlings was not statistically significant, but the tendency is encouraging.

Vegetation control and site preparation affect patterns of shoot elongation for 3-year-old loblolly pine

1993 ◽  
Vol 23 (10) ◽  
pp. 2110-2115 ◽  
Author(s):  
H. Lee Allen ◽  
Thomas R. Wentworth
Keyword(s):  
Growth Rate ◽  
Weed Control ◽  
Loblolly Pine ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Site Preparation ◽  
Intensive Culture ◽  
Vegetation Control ◽  
Growing Season Length

Effects of vegetation control and site preparation on the magnitude, morphology, and phenology of loblolly pine (Pinustaeda L.) height growth were investigated duing the third growing season following planting in the Piedmont of North Carolina. Biweekly measurements were made of shoot elongation (by flush) throughout the growing season on a subsample of trees within three replicated plots receiving a factorial combination of site preparation (chop versus shear, pile, disk) and weed control (none, partial control with herbicide, and complete control by hand weeding) treatments. Cumulative height growth on the most intensively treated plots was twice that found on the chopped-only plots, with weed control having a more pronounced positive effect than intensive site preparation. Superior height growth resulted principally from greater length per flush but also from an increased number of flushes. Trees on plots where vegetation was controlled averaged between four and five flushes compared with trees on chopped-only plots, which averaged three flushes. As growth rate of one flush slowed, growth rate of the subsequent flush accelerated, resulting in a rather uniform elongation rate for the shoot apex throughout most of the growing season. Treatment effects on the seasonal distribution of growth and on growing season length were minimal. Thus, intensive culture influenced shoot growth rates and morphology, but not phenology. Apparently the effect of intensive culture was to improve the availability of limited environmental resources and, consequently, to increase growth rate throughout the growing season.

The effects of summer shoot production on height growth components of seedlings of California red and white fir

1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Shoot Morphology ◽  
Apical Dome ◽  
White Fir ◽  
Shoot Production ◽  
Terminal Shoot ◽  
Needle Primordia

Morphogenesis of the terminal shoot was studied in 2-year-old seedlings of California red fir (Abiesmagnifica A. Murr.) and two elevational sources of white fir (Abiesconcolor (Gord. & Glend.) Lindl.). Seedlings were either watered or left unwatered during the growing season in order to produce different shoot morphologies and seedlings with and without a summer shoot. Under favorable soil moisture, the frequency of summer shoot production was 32, 53, and 82% for red fir and high- and low-elevation white fir, respectively. Drought from mid-May to mid-September reduced summer shoot production to less than 1% in both species. Spring shoot morphology was not an indicator of capacity to produce a summer shoot. Rate of primordium production was directly related to apical dome diameter. However, when the normal spring increase in apical dome diameter was arrested by summer shoot elongation, the rate of primordium production appeared to be unaffected. Although the apical and subapical meristems were active at the same time, they did not appear to be antagonistic. The major effects of producing a summer shoot were as follows: (i) elongation of 60–120% more intemodes in the current growing season, (ii) production of 15–40% more needle primordia in the overwintering bud, (iii) production of 30–60% more primordia annually, and (iv) increase in the percentage of total primordium production that developed into needles from 60% to 75–80%.

scholarly journals Washing Roots Reduces Vigor of Loblolly Pine Seedlings

2001 ◽  
Vol 25 (1) ◽  
pp. 25-30
Author(s):  
William A. Carey ◽  
David B. South ◽  
M. Williford ◽  
J. Britt
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Fine Roots ◽  
Height Growth ◽  
Initial Height ◽  
Pine Seedlings ◽  
Loam Soil ◽  
Bud Growth ◽  
Pinus Taeda L ◽  
Growth Of Seedlings

Abstract Loblolly pine (Pinus taeda L.) seedlings were lifted from two nurseries in Georgia, and the roots were washed using equipment built for that purpose. Seedlings then received two levels of storage and were outplanted not far from the nursery of origin (one loam soil and one sandy soil). Immediately after washing, root weights and the length of fine roots did not differ among wash treatments from either nursery. Survival was excellent for all treatments on the loam soil, but a single wash reduced survival by 5 to 10% when seedlings were planted in sand. Washing slowed the rate of budbreak and early height growth. Bud growth of seedlings planted in a stress pit (containing sand) was correlated with both root growth 1 month after planting (r = 0.36,P = 0.0003) and survival 2 months after planting (r =0.62,P = 0.01). Among seedlings outplanted on a sandy site, initial height growth also correlated with survival (r = 0.49,P = 0.007). South. J. Appl. For. 25(1):25–30.

Temperature and Other Climatic Influences on Shoot Development and Growth of Eucalyptus regnans

1975 ◽  
Vol 23 (1) ◽  
pp. 27 ◽  
Author(s):  
KW Cremer
Keyword(s):  
Growth And Development ◽  
Shoot Growth ◽  
Climatic Factors ◽  
Growing Season ◽  
Height Growth ◽  
Shoot Development ◽  
Positive Relation ◽  
Eucalyptus Regnans ◽  
Air Temperatures ◽  
Growth Of Seedlings

The growth and development of shoots of Eucalyptus regnans F. Muell. trees up to 8 m tall growing in their natural environment in central Tasmania were studied continuously for 3 years and related to climatic factors. The influences of temperature were further investigated by experiments with seedlings in a phytotron. Height growth was practically nil in winter and greatest in summer. Throughout the year weekly rates of height growth were closely related to weekly mean maximum air temperatures, increasing from nil or slight at 10�C to peak rates at the highest temperatures experienced (25°). Substantial diameter increments were observed in all seasons and their relation to temperature was relatively weak. There was no positive relation between weekly growth in height or diameter and weekly precipitation. Bud and shoot growth were characterized by continuity of development of all organs throughout the growing season. The youngest of the leaves and internodes which had emerged before winter from the bud resumed growth in spring, but did not reach the lengths achieved by those leaves and internodes which emerged from the bud after winter. It was only by this morphological feature that the boundaries of the annual shoot were identifiable. In agreement with the field observations, the growth of seedlings in glasshouses was found to be slow at day/night air temperatures of 10/5°C and to increase steeply with temperatures to 24/19°. Amongst the notable morphogenic influences associated with increasing temperatures in the glasshouses were poorer root development relative to top growth, thinner and smaller but more numerous leaves, and shorter and more numerous internodes. The elongation of individual leaves and internodes was faster but considerably less prolonged as temperatures increased. The E. regnans seedlings tested failed to prove thermoperiodically sensitive. It is concluded that the dormancy in shoot development observed in the field during winter is due to quiescence imposed by low temperatures, and that in the Tasmanian environment the pattern of growth and development of the vegetative shoots of E. regnans is directly and predominantly controlled by air temperatures throughout the year.

Comparison of growth and physiology of layers and naturally established seedlings of black spruce in a boreal cutover in Quebec

1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea
Keyword(s):  
Water Potential ◽  
Picea Mariana ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Height Growth ◽  
Total Height ◽  
Acclimation Period ◽  
Use Efficiency ◽  
Growth Of Seedlings

Growth and physiology of layers versus naturally established seedlings of boreal black spruce (Picea mariana (Mill.) BSP) were compared 15 years after a cutover in Quebec. During the first 8 years, height growth of seedlings was greater than that of layers, averaging 10.4 and 7.0 cm/year, respectively. For the last 5 years, annual height growth of layers and seedlings did not differ (25 cm/year; p > 0.05). Over the entire 15-year period, total height growth of seedlings (251 cm) was greater than that of layers (220 cm), although total height did not differ (p > 0.05) over the last 6 years. During the 15th growing season, there were no differences (p > 0.05) for predawn shoot water potential, stomatal conductance, net photosynthesis, intercellular to ambient CO2 ratio, water use efficiency, and hydraulic conductance between layers and seedlings. For diurnal shoot water potential, seedlings showed slightly less stress than layers on two of the four sampling dates. Thus, in the first few years following the cutover, the slower growth observed for layers indicated that they had a longer acclimation period following the cutover. Afterwards, similar height growth, total height, and physiological characteristics of the two regeneration types indicated that layers can perform as well as naturally established seedlings.

Changes in loblolly pine root growth potential from September to April

1987 ◽  
Vol 17 (7) ◽  
pp. 635-643 ◽  
Author(s):  
Laura E. DeWald ◽  
Peter P. Feret
Keyword(s):  
Root Growth ◽  
Loblolly Pine ◽  
Environmental Changes ◽  
Lateral Roots ◽  
Root Systems ◽  
Shoot Elongation ◽  
Growth Potential ◽  
Late Winter ◽  
Root Growth Potential ◽  
Shoot Phenology

Loblolly pine (Pinustaeda L.) 1 + 0 seedlings were periodically hand lifted from a Virginia nursery to determine how root growth potential (RGP) varied between September and April. Several seedling characteristics, RGP, and shoot phenology were recorded for each lift date in 1983–1984 and 1984–1985. An attempt was made to relate RGP variation to changes in the nursery environment and to shoot phenology. Root growth potential variation was consistent between years and was more closely related to shoot phenological changes than to short-term environmental changes. During the development of dormancy, RGP was low, RGP increased when shoot activity resumed during the RGP tests (late winter, early spring), and declined as active shoot elongation began in the nursery. When RGP was low, elongation of existing lateral roots primarily contributed to the new root systems, but as seedling metabolism increased in the late winter, new root initiation also contributed to new root systems. Absolute differences in RGP between years may be related to the fibrosity of seedling root systems.

Black Alder Seedlings Demonstrate Tolerance to Preemergence Herbicides in Preliminary Trials1

1986 ◽  
Vol 3 (2) ◽  
pp. 76-79
Author(s):  
Kip E. Hall ◽  
Larry H. McCormick ◽  
Larry J. Kuhns
Keyword(s):  
Growth Inhibition ◽  
Seedling Survival ◽  
Growing Season ◽  
Height Growth ◽  
Seedling Height ◽  
Black Alder ◽  
Emulsifiable Concentrate ◽  
Phytotoxic Effects ◽  
Preemergence Herbicides ◽  
Significant Mortality

Abstract Seven preemergence herbicides, atrazine, metolachlor, napropamide, oryzalin, oxadiazon, oxyfiuorfen, and simazine, were screened for phytotoxic effects on newly planted black alder seedlings. All treatments containing atrazine significantly reduced seedling survival, as did simazine treatments greater than 3.4 kg/ha. The simazine rate of 3.4 kg/ha, the napropamide rate of 26.9 kg/ha, and metolachlor rates greater than 3.4 kg/ha temporarily stunted seedling height growth early in the first growing season. Temporary stunting was also observed for the highest rates of the granular and emulsifiable concentrate formulations of oxyfluorfen, 9.0 and 4.5 kg/ha respectively. However, those treatments that temporarily stunted height growth had no significant effect on seedling survival. Excluding atrazine, all of the preemergence herbicides evaluated in this study could be safely applied to newly planted black alder seedlings with no significant mortality or growth inhibition, providing the rate guidelines previously mentioned are observed. North. J. Appl. For. 3:76-79, June 1986.

Flowering in a jack pine seedling seed orchard increased by spraying with gibberellin A4/7

1983 ◽  
Vol 13 (6) ◽  
pp. 1056-1062 ◽  
Author(s):  
Robert A. Cecich
Keyword(s):  
Growing Season ◽  
Seed Orchard ◽  
Shoot Elongation ◽  
Jack Pine ◽  
Ethanol Solution ◽  
Bud Development ◽  
Seedling Seed Orchard ◽  
Female Flowering ◽  
Accelerated Growth ◽  
Control Tree

Jack pine (Pinusbanksiana Lamb.), in a 3-year-old orchard established with accelerated-growth seedlings, were sprayed with gibberellin A4/7 (GA4/7) in an Aromox–ethanol solution during the 1981 growing season. Seven treatment periods were evaluated: the entire growing season, shoot elongation, bud development, early (first half) and late (second half) shoot elongation, and early and late bud development. Three concentrations of GA4/7 (200, 400, and 600 mg•L−1) were applied in all combinations with treatment periods. Three treatments increased female flowering: 400 and 600 mg•L−1 GA4/7 sprayed the entire growing season and 600 mg•L−1 sprayed during bud development. The number of pollen clusters was increased by spraying 400 and 600 mg•L−1 GA4/7 during any treatment period except early shoot elongation and late bud development or during shoot elongation (400 mg•L−1 only). The 200 mg•L−1 GA4/7 increased pollen clusters only if sprayed during early bud development or the entire growing season. The percentage of trees bearing pollen increased with all concentrations of GA4/7. The 1982 shoot growth of trees sprayed in 1981 during shoot elongation or the entire growing season (all GA4/7 levels pooled) was significantly less than control-tree growth or that of trees in the other treatment periods. The best treatment for increasing both male and female strobili was 600 mg•L−1 GA4/7 sprayed during bud development.

Fertilization and Irrigation Stimulate Flowering and Cone Production In a Loblolly Pine Seed Orchard

1982 ◽  
Vol 6 (1) ◽  
pp. 44-48
Author(s):  
J. D. Gregory ◽  
W. M. Guinness ◽  
C. B. Davey
Keyword(s):  
Organic Matter ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Soil Acidity ◽  
Female Flower ◽  
Growing Season ◽  
Seed Orchard ◽  
Cone Production ◽  
Flower Production ◽  
Pinus Taeda L

Abstract Fertilizer and water were applied in a loblolly pine (Pinus taeda L.) seed orchard to evaluate the effects on female flower and cone production. Treatments were (1) control; (2) fertilized with approximately 300 kg/ha N, 25 kg/ha P, and 47 kg/ha K; (3) irrigated through the growing season; (4) fertilized and irrigated. Treatments have been imposed annually since orchard establishment in 1963. Average female flower production per tree for 1968-1970 and number of cones per tree for 1968-1975 were increased by fertilization, by irrigation, and by the combination of fertilization plus irrigation. Flower and cone production as well as responses to the treatments varied widely among clones. The treatments caused changes in soil acidity, organic matter, and available P, K, Ca, and Mg.

Effects of salinity stress on seed germination and root growth of seedlings in island cotton

2019 ◽  
Vol 45 (1) ◽  
pp. 100
Author(s):  
Qing-Qing YAN ◽  
Ju-Song ZHANG ◽  
Xing-Xing LI ◽  
Yan-Ti WANG
Keyword(s):  
Seed Germination ◽  
Root Growth ◽  
Salinity Stress ◽  
Growth Of Seedlings
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