Effects of chilling and photoperiod on dormancy release of container-grown loblolly pine seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1265-1270 ◽  
Author(s):  
Melvin P. Garber
Keyword(s):  
Loblolly Pine ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Height Growth ◽  
Broad Temperature Range ◽  
Dormancy Release ◽  
Chilling Requirement ◽  
Seedling Mortality ◽  
Pine Seedlings ◽  
Chilling Temperatures

Loblolly pine (Pinustaeda L.) seedlings, which set bud in fall, required exposure to chilling temperatures before growth could resume under a 10- or 12-h photoperiod; whereas a 14-h photoperiod partially substituted for the chilling requirement. A 10- to 14-h photoperiod, however, did not affect the rate of budbreak once the chilling requirement was satisfied. A broad temperature range (0 – 12 °C) was equally effective in satisfying the chilling requirement. In situations where subfreezing temperatures were sufficient to decrease the extent of shoot growth or result in seedling mortality, the rate of budbreak for surviving seedlings was not affected. Exposure to low but above freezing temperatures beyond that necessary to satisfy the chilling requirement for budbreak resulted in increased height growth. Chilling temperatures apparently were involved both in ameliorating bud dormancy and promoting vegetative growth.

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.

Foliar Nitrogen Content at Lifting Correlates with Early Growth of Loblolly Pine Seedlings from 20 Nurseries

1988 ◽  
Vol 12 (3) ◽  
pp. 181-185 ◽  
Author(s):  
Harry S. Larsen ◽  
David B. South ◽  
James N. Boyer
Keyword(s):  
Nitrogen Content ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Field Performance ◽  
Height Growth ◽  
Growth Potential ◽  
Root Weight ◽  
Root Growth Potential ◽  
Foliar Nitrogen ◽  
Pine Seedlings

Abstract Height growth of outplanted loblolly pine seedlings was monitored over a 3-year period. Growth of seedlings from 20 nurseries was correlated with initial seedling characteristics from paired samples. Height growth during the first 6 months after planting was negatively correlated with the initial seedling height and shoot/root ratio and was positively correlated with root growth potential (RGP) and root weight. However, these variables were not significantly correlated with later growth. Foliar nitrogen content (mg of foliar nitrogen per seedling) was positively correlated with both initial and subsequent field growth. Foliar nitrogen content was the only variable that was significantly correlated with diameter growth and volume growth during the third year after planting. This variable accounted for 36% of the variation among sample means for 3-year height growth. These data support a previous report that field performance of loblolly pine seedlings during the first 3 years in the field can be influenced by the foliar nitrogen content at lifting. South. J. Appl. For. 12(3):181-185.

Benomyl Root Dips Adversely Affect First-Year Performance of Stored Loblolly Pine Seedlings

1991 ◽  
Vol 15 (3) ◽  
pp. 133-137 ◽  
Author(s):  
Nancy J. Stumpff ◽  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Active Ingredient ◽  
Height Growth ◽  
Prolonged Storage ◽  
First Year ◽  
Pine Seedlings ◽  
Beneficial Response ◽  
Clay Slurry ◽  
Survival Of Seedlings

Abstract Dipping loblolly pine roots into a clay slurry containing benomyl (1.25% active ingredient) at the time of packing did not improve survival of seedlings stored (near 3°C) for 1 to 4 weeks. In some situations, benomyl decreased out-planting survival. Regardless of lifting date or storage length, benomyl slightly decreased first-year height growth (by 12 to 17%). Although previous research has demonstrated that a benomyl treatment can improve the ability of March-lifted seedlings to withstand prolonged storage, a beneficial response is not yet predictable for loblolly pine seedlings lifted between October and February. South. J. Appl. For. 15(3):133-137.

Recovery of 1-year-old loblolly pine seedlings from simulated browse damage

2002 ◽  
Vol 32 (2) ◽  
pp. 373-377 ◽  
Author(s):  
Michael G Shelton ◽  
Michael D Cain
Keyword(s):  
Loblolly Pine ◽  
Ground Level ◽  
Recovery Process ◽  
Quantitative Information ◽  
First Year ◽  
Seedling Mortality ◽  
Factors Affecting ◽  
Pine Seedlings ◽  
Pinus Taeda L ◽  
Multiple Stems

Loblolly pine (Pinus taeda L.) seedlings are frequently browsed by a wide variety of animals during the first few years of their development. Although anecdotal observations indicate that the potential for seedling recovery is good, there is little quantitative information on the factors affecting the recovery process. Thus, we conducted a study to evaluate the effects of the extent and season of simulated browse damage on the recovery of 1-year-old loblolly pine seedlings under controlled conditions. Seedlings were clipped at five positions: at the midpoint between the root collar and cotyledons and so that 25, 50, 75, and 100% of the height between the cotyledons and the terminal remained after clipping. Clipping treatments were applied in two seasons: winter and spring. All seedlings clipped below the cotyledons died, confirming that dormant buds or lateral shoots are required for recovery. Survival of seedlings clipped above the cotyledons was 97% for winter clipping and 96% for spring clipping. Most of the seedling mortality (73%) was for seedlings with only 25% of their height remaining. Regression analysis revealed that second-year seedling size was positively affected by first-year size and percentage of remaining height after clipping and that seedlings clipped in winter were larger at 2 years than those clipped during spring. Logistic regression indicated a higher probability of multiple stems resulting from the more severe clipping treatments. Clipping season and severity also significantly affected the probability for tip moth (Rhyacionia spp.) damage, which occurred more frequently in the larger seedlings. Results suggest that planting seedlings deep, with the cotyledons just below ground level, may be an advantage in areas where browse damage is common.

Influence of Fertilization and Ectomycorrhizae on Loblolly Pine Growth and Susceptibility to Fusiform Rust

1983 ◽  
Vol 7 (2) ◽  
pp. 101-103 ◽  
Author(s):  
H. R. Powers ◽  
S. J. Rowan
Keyword(s):  
Loblolly Pine ◽  
Cultural Practices ◽  
Mycorrhizal Fungus ◽  
Height Growth ◽  
Pisolithus Tinctorius ◽  
Fusiform Rust ◽  
Infected Tree ◽  
Pine Seedlings ◽  
Susceptible Control ◽  
Rust Severity

Abstract The application of fertilizer and the mycorrhizal fungus, Pisolithus tinctorius, did not increase the height growth of loblolly pine seedlings during their first four years of growth. Fertilization, however, did increase the overall number of fusiform rust galls per infected tree. This increase was highly significant on the susceptible control seedlings, but was not significant on resistant Livingston Parish seedlings. This indicates that cultural practices such as fertilization can be applied to rust-resistant seedlings, such as the Livingston Parish seed source, without significantly increasing rust severity.

scholarly journals Evaluation of Selective Postemergence Herbicides for Yellow Nutsedge Control and Loblolly and Slash Pine Seedling Tolerance

2011 ◽  
Vol 29 (3) ◽  
pp. 125-131
Author(s):  
D. Paul Jackson ◽  
Charles H. Gilliam ◽  
David B. South
Keyword(s):  
Loblolly Pine ◽  
Pinus Elliottii ◽  
Height Growth ◽  
Slash Pine ◽  
Cyperus Esculentus ◽  
Yellow Nutsedge ◽  
Pine Seedlings ◽  
Pinus Taeda L ◽  
Postemergence Herbicides ◽  
Over The Top

Abstract Yellow nutsedge (Cyperus esculentus) is a difficult weed to control in conifer nurseries. Soil fumigation with methyl bromide has been used to control yellow nutsedge for years but may not be available in the future. For this reason, the objective of this research was to identify herbicides that can control yellow nutsedge but do not injure loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) when used over-the-top of seedlings. Yellow nutsedge tubers and loblolly and slash pine seedlings were potted separately, and treated with three rates of the herbicides mesotrione (Callisto®), imazosulfuron (Valent-V10142), and halosulfuron (Sedgehammer®). Imazosulfuron and halosulfuron provided the best suppression of nutsedge, but imazosulfuron injured loblolly and slash pine. Slash pine diameter and height growth were reduced by imazosulfuron. Halosulfuron did not affect loblolly pine but it reduced slash pine height growth and the number of new leaders (spring flush growth) the following spring. Mesotrione injured slash pine but provided intermediate control of yellow nutsedge. Halosulfuron applied at 35 to 140 g ai·ha−1 (active ingredient per hectare) over the top of loblolly pine (≥ 60 cm height and ≥ 8 mm diameter) can control yellow nutsedge without injuring pine seedlings.

Cold-Hardiness of Containerized Loblolly Pine Seedlings: Its Effect on Field Survival and Growth

1979 ◽  
Vol 3 (1) ◽  
pp. 15-19 ◽  
Author(s):  
John G. Mexal ◽  
Roger Timmis ◽  
William G. Morris
Keyword(s):  
Loblolly Pine ◽  
Cold Hardiness ◽  
Height Growth ◽  
Cold Hardening ◽  
Short Photoperiod ◽  
Cold Temperatures ◽  
Containerized Seedlings ◽  
Pine Seedlings ◽  
Natural Photoperiod ◽  
Survival And Growth

Abstract Loblolly pine seedlings grown in the greenhouse for 92 days in 64 ml Leach cells were hardened outdoors for 0, 14, 28, or 42 days. Those seedlings outplanted in November after cold-hardening for 14 days did not survive temperatures below -4°C (25°F). Seedlings cold-hardened for 42 days were hardier and their survival and height growth better the following season than trees hardened for 14 days or less. Seedlings kept in the greenhouse under an 8-hour photoperiod survived as well as seedlings hardened outdoors during a 42-days period. But seedlings held in the greenhouse under the natural photoperiod (∼11.5 hours) were unable to survive temperatures below -6°C (21°F). Results suggest that a short photoperiod may be substituted for cold temperatures to induce hardiness. For a successful fall planting of containerized seedlings, seedlings must be cold-hardened for at least 42 days, either outdoors or under shortened photoperiod.

Inoculation of loblolly pine seedlings with Fomes annosus in the greenhouse

1969 ◽  
Vol 47 (12) ◽  
pp. 2079-2082 ◽  
Author(s):  
E. G. Kuhlman
Keyword(s):  
Soil Temperature ◽  
Loblolly Pine ◽  
Reliable Method ◽  
Disease Index ◽  
Seedling Mortality ◽  
Pine Seedlings ◽  
Soil Temperatures

A reliable method of inoculating loblolly pine seedlings with Fomes annosus under greenhouse conditions is described. Type of wound, wounding vs. nonwounding, and soil temperature influenced the number of pine seedlings killed. Inoculum weight and orientation of the inoculum block had less effect on mortality. No variation in virulence of eight isolates of the fungus was demonstrated. Seedling mortality occurred at soil temperatures from 10 to 30 °C, but the disease index was highest at 15–25 °C.

Gibberellins and sorghum development

1988 ◽  
Vol 66 (6) ◽  
pp. 1101-1106 ◽  
Author(s):  
Stewart B. Rood ◽  
Darla M. Bruns ◽  
Susan J. Smienk
Keyword(s):  
Vegetative Growth ◽  
High Performance ◽  
Shoot Growth ◽  
Developmental Stages ◽  
Shoot Elongation ◽  
Field Trials ◽  
Reversed Phase ◽  
Height Growth ◽  
Forage Production ◽  
Sorghum Bicolor L

Sorghum (Sorghum bicolor (L.) Moench) hybrids adapted for grain (cv. Northrup King X8102) or forage production (cv. Pride PF70) were grown in field trials at Lethbridge, Alta., Canada, and shoot cylinders containing the apical meristems were harvested at various developmental stages for analyses of endogenous gibberellin-like (GA-like) substances. Extracts were purified and chromatographed on sequential SiO2 partition columns and C18 reversed-phase high-performance liquid chromatography, and GA-like substances were detected and quantified by the cv. Tan-ginbozu dwarf rice microdroop assay. Concentrations of GA-like substances in the shoots were higher during vegetative growth than during shoot elongation or panicle elongation and the pattern of declining concentration of GA-like substances was observed for both hybrids over both field seasons. The qualitative distribution of GA-like substances was generally similar across hybrids and developmental stages, with a GA19-like substance accounting for about 60% of the total GA-like activity (GA19 is a native GA of sorghum). The exogenous application of GA3 promoted height growth and inhibited tillering, with maximal effects occurring when application was early, during rapid vegetative growth. Applications of GA3 subsequent to panicle initiation promoted panicle elongation but did not alter the time of anthesis. These results on endogenous GA concentration and response to exogenous GA3 application suggest a role for endogenous GAs in the control of shoot growth and development in sorghum.

Effects of overstory and understory competition and simulated herbivory on growth and survival of white pine seedlings

1999 ◽  
Vol 29 (5) ◽  
pp. 536-546 ◽  
Author(s):  
Mike R Saunders ◽  
Klaus J Puettmann
Keyword(s):  
Growth Stimulation ◽  
Height Growth ◽  
First Year ◽  
Canopy Closure ◽  
Resource Reallocation ◽  
Seedling Mortality ◽  
White Pine ◽  
Growth And Survival ◽  
Pine Seedlings ◽  
Brush Control

The interactive impact of overstory canopy closure, understory brush control, and simulated white-tailed deer (Odocoileus virginianus Zimmermann) herbivory (i.e., clipping) on growth and survival of underplanted white pine (Pinus strobus L.) seedlings was examined. Clipping was conducted in April 1996 and 1997 at three intensities (control, 0% previous year's growth removed; lightly clipped, terminal and 50% previous year's growth removed, and heavily clipped: 100% of previous-year's growth removed) and three frequencies (never clipped, clipped once, clipped 2 years in a row). Decreasing overstory canopy closure and brush competition generally increased growth of seedlings under all clipping regimes, with heavily clipped seedlings showing the least benefit of reduced competition. Although first-year height growth was stimulated after light-intensity clipping, this effect did not persist the following year, and these trees still were significantly shorter than controls at the end of the experiment. Diameter growth was reduced at any clipping intensity or frequency, and remained below controls throughout the experiment. Seedling mortality was higher without brush control and after clipping. Results suggest that increased overstory and understory competition reduced seedling growth and survival. In regards to clipping, initial height growth stimulation may result from (i) resource reallocation away from diameter and root growth and (or) (ii) hormonal redistributions from loss of apical control in the seedling. Since both high competition levels and increased herbivory reduced seedling vigor, we suggest that understory brush control and deer protection (e.g., budcapping) go hand in hand to regenerate white pine.

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