Incidence of Resin-Soaked Roots in Subsoiled Loblolly Pine Seed Orchards on Sandy Soils

1982 ◽  
Vol 6 (2) ◽  
pp. 104-107
Author(s):  
R. S. Webb ◽  
S. A. Alexander

Abstract The root systems of 70 loblolly pines (Pinus taeda L.) from three subsoiled seed orchards were excavated to determine the association of subsoiling with the incidence of resin-soaked lateral roots. The number of lateral roots and the proportion of resin-soaked and healthy root tissue were recorded. Chips from the resin-soaked margin of lateral roots were incubated for 10 days at 24°C on two general media and two media selective for Heterobasidion annosum (Fr.) Bref. Verticicladiella procera Kend. was isolated from 30 percent of the declining/subsoiled trees at one seed orchard. Monilia spp. were also isolated. Of the lateral roots severed by subsoiling, 60 percent were resin-soaked from 10 to 45 cm in length.

1991 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
N. C. Wheeler ◽  
D. L. Bramlett

Abstract Flowering in conifer seed orchards may be sporadic and insufficient to meet reforestation needs at early ages. Consequently, considerable effort has been made to develop cultural treatments to enhance flowering in operational seed orchards. For a number of species, flower-promoting technology is well-defined. This study evaluated two known technologies, currently in use for other species, for flower-promoting effects in loblolly pine (Pinus taeda L.). A replicated experiment was installed in a 10-year-old, second-generation loblolly pine seed orchard at Lyons, GA. Overlapping, saw-cut girdles and stem-injected GA4/7 were applied alone, and in combination, to main boles of ramets of four clones. Timing of treatments was evaluated using four treatment dates. All treatments significantly enhanced female flower production, relative to controls, although girdling was clearly the most effective single treatment. There was no treatment effect on pollen production. Timing of treatment is important but may require evaluation on a site-by-site basis. Tree health 1 year after treatment was excellent, although clonal sensitivity to some treatments was noted. Use of flower stimulation techniques is recommended, particularly for younger loblolly pine orchards. South J. Appl. For. 15(1):44-50.


2002 ◽  
Vol 26 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Donald M. Grosman ◽  
William W. Upton ◽  
Frank A. McCook ◽  
Ronald F. Billings

Abstract Three systemic insecticide treatments, emamectin benzoate alone, imidacloprid alone, and a combination of emamectin benzoate and thiamethoxam, were injected one or two times into loblolly pine,Pinus taeda L., during a 2 yr period in a seed orchard in east Texas. Single injections of treatments containing emamectin benzoate reduced coneworm (Dioryctria spp.) damage by 94–97% during the study period. A second injection after 1 yr did not improve protection. Imidacloprid also significantly reduced coneworm damage in 1999, but not in 2000. Significant reductions in damage from pine seed bugs (Tetyra bipunctata Say andLeptoglossus corculus Herrich-Schaffer) and an increase in the number of full seeds per cone resulted from imidacloprid and thiamethoxam treatments and to a lesser extent from emamectin benzoate. Yearly injections of imidacloprid or thiamethoxam were required to maintain protection against seed bugs. The best overall treatment, two injections of emamectin benzoate plus thiamethoxam, reduced cone and seed losses from insects by 86%. South. J. Appl. For. 26(3):146–152.


1988 ◽  
Vol 12 (1) ◽  
pp. 33-36 ◽  
Author(s):  
William H. McKee ◽  
Larry P. Wilhite

Abstract In three separate studies on the Lower Atlantic Coastal Plain, sites were sheared, root-raked, and bedded, and phosphorus was applied. Loblolly pine (Pinus taeda L.) seedlings were planted, and nitrogen fertilizer and preemergence herbicide were applied at several different times. In all three studies, loblolly pine responded positively in height, diameter, and aboveground biomass to herbicide applied in the spring following planting. Responses to nitrogen application were inconsistent. A pronounced increase in growth was found in only one study. There, a nitrogen and a herbicide treatment interacted to give a three-fold increase in aboveground seedling biomass after one growing season. The lack of response to nitrogen in the other two studies may be attributable to low rainfall in the spring after planting and mineralization of native nitrogen from soil organic matter. South. J. Appl. For. 12(1):33-36.


1981 ◽  
Vol 5 (2) ◽  
pp. 62-65
Author(s):  
John F. Kraus ◽  
Earl R. Sluder

Abstract Control-pollinated polymix progenies of 9 slash pine (P. elliottii Engelm.) and 10 loblolly (Pinus taeda L.) pine from some of the best clones in a South African tree improvement program were tested in Georgia. Overall, the progenies of the South African selections in both species have done well after five years in the field. One of the slash pine and three of the loblolly pine families were better than open-pollinated progeny from established seed orchards.


1980 ◽  
Vol 4 (3) ◽  
pp. 153-156
Author(s):  
John Talbert ◽  
Gordon White ◽  
Charles Webb

Abstract In a comparison of three diverse seed sources of improved Virginia pine (Pinus virginiana Mill.) planted at two locations in north Alabama and south-central Tennessee, only stem straightness differences were statistically significant at six years of age. Families and seed sources tended to maintain the same ranking relative to each other at both locations. A majority of families performed significantly better than a Virginia pine commercial check lot, indicating substantial improvement in growth and straightness characteristics in one generation of selection. Two improved loblolly pine (Pinus taeda L.) seed orchard mixes from the South Carolina Piedmont showed a 27-percent height advantage over the Virginia pine at age 6.


1998 ◽  
Vol 28 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Boris Zeide

A new method for estimating fractal characteristics (fractal dimension and foliage density) of a single crown or its portions is developed. The proposed method operates with volume and mass of natural units of the crown, such as shoots and branches, rather than with numbers of regular cubes. Fractal dimension alone is not sufficient to describe foliage distribution in the crown because it says nothing about the density of foliage at a given point. The density is defined as the ratio of foliage mass to fractal volume it occupies. Fortunately, the intercept of the regression, which contains fractal dimension as the slope, provides a measure of foliage density. Thus the method makes it possible to separate purely spatial factors represented by fractal dimension from ecophysiological effects characterized by foliage density. Application of the method showed that neither fractal dimension nor foliage density of the studied loblolly pines (Pinus taeda L.) correlates with current diameter increment. At the same time, there is a pronounced negative correlation between fractal dimension and crown size. These results suggest that as crowns become larger, the amount of foliage located at the crown periphery increases in proportion to the foliage amount inside the crown. As a spin-off of this analysis, a method for estimating relative foliage density (defined as the ratio of actual to maximal foliage mass for a given branch) is developed.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 607e-607
Author(s):  
Farrell C. Wise ◽  
Laura L. Greenwood ◽  
D. Bradley Rowe

Clonal propagation of recalcitrant conifers like loblolly pine depends on producing juvenile cuttings on hedges sheared several times annually. Although dormant cuttings root well, it will be economically important to also root softwood shoots produced between shearings. Several variables were therefore evaluated in a factorial experiment to enhance rooting and handling of summer cuttings. Rooting percentages were equivalent for 3 media after a 5-week hardening period (56% overall), but open flats of 1 perlite:1 vermiculite induced larger root systems at the end of rooting and hardening phases. Extending the rooting period from 10 to 14 weeks increased rooting from about 45% to 58% by the end of hardening. Primary root length per cutting increased 12-63% during hardening, depending on medium. After transplanting, overwintering survival was 98%. Foam rooting wedges produced smallest root systems, and resulting plants were consistently shortest through the following growing season. Weekly applications of soluble fertilizer during the last 6 weeks of rooting did not improve rooting or subsequent growth


1998 ◽  
Vol 74 (2) ◽  
pp. 185-189 ◽  
Author(s):  
F. E. Bridgwater ◽  
D. L. Bramlett ◽  
T. D. Byram ◽  
W. J. Lowe

Controlled mass pollination (CMP) is one way to increase genetic gains from traditional wind-pollinated seed orchards. Methodology is under development by several forestry companies in the southern USA. Costs of CMP depend on the efficient installation, pollination, and removal of inexpensive paper bags. Even in pilot-scale studies these costs seem reasonable. Net present values from CMP in a sample of sixty-seven loblolly pine (Pinus taeda L.) seed orchards in the Western Gulf Forest Tree Improvement Program are conservatively expected to average $108 per acre of plantation established with seedlings from CMP among the best six parents in each of five breeding regions and $154 per acre for CMP among the best pair of parents in each breeding region. Key words: supplemental mass pollination, expected genetic gains, pollen contamination


2002 ◽  
Vol 26 (4) ◽  
pp. 173-180 ◽  
Author(s):  
Michael D. Cain ◽  
James P. Barnett

Abstract Genetically improved, container loblolly pine (Pinus taeda L.) seedlings were compared to naturally established loblolly seedlings on a cutover pine site. Crop pines on 6 of 12 plots were released from woody and herbaceous competition within a 2 ft radius of each stem. On release plots, woody competition was controlled by hand-cutting for 5 consecutive yr and herbaceous competition was controlled with herbicides for 4 consecutive yr after pine establishment. Competition control increased 12 yr survival by 68 percentage points for natural pines and by 47 percentage points for planted pines. Twelve years after field establishment, mean-tree volume of planted pines was no different than that of naturally established pines. Nevertheless, volume gains of 150% to 200% were achieved within regeneration techniques as a result of release. South. J. Appl. For. 26(4):173–180.


1993 ◽  
Vol 3 (3) ◽  
pp. 169 ◽  
Author(s):  
DD Wade

The relationship between fire-caused stem girdling and groundline diameter (GLD) in loblolly pine (Pinus taeda L.) was determined. Results of 10 experimental prescribed bums conducted across a wide range of ambient temperature conditions during both the dormant and growing season demonstrate that low-intensity backing fires (< 346 KW/m) are an effective tool to eliminate loblolly pines less than 3.8 cm (1.5 in.) GLD. Wide differences in ambient temperature at time of burning did not affect stem kill of unscorched trees in this study. Virtually all fire-caused mortality took place within four months postburn. A predictive model that explained 92% of the variation in mortality was developed to facilitate the use of fire to thin young, overcrowded loblolly pine stands in the southeastern United States. Use of this model in conjunction with a preburn stand survey allows estimation of the number and distribution of survivors prior to ignition.


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