scholarly journals Herbicide Release of 3-Year-Old Loblolly Pine from Competing Hardwoods in Arkansas

1996 ◽  
Vol 20 (3) ◽  
pp. 121-126 ◽  
Author(s):  
Harold E. Quicke ◽  
Glenn R. Glover ◽  
Dwight K. Lauer

Abstract Objectives were to identify effective late-summer and spring herbicide treatments for the release of 3-yr-old loblolly pine (Pinus taeda L.) from competing hardwoods and to quantify longer term pine growth response to varying levels of hardwood control. Effective late-summer treatments included imazapyr at 1.0 and 0.5 lb ae/ac, imazapyr at 0.5 lb ae/ac in combination with glyphosate at 1.125 lb ae/ac, and imazapyr at 0.25 lb ae/ac with surfactant. The best spring treatment was hexazinone at 2.0 lb ai/ac. Although spring imazapyr treatments stunted pine height growth 2 growing seasons after treatment, height growth had recovered by age 10. Late-summer imazapyr treatments provided better hardwood control than spring treatments. Although check plot hardwood basal area averaged 9 ft2/ac, and winged elm (a species known to be tolerant to imazapyr) was the predominant hardwood species at treatment, pine basal area response to treatment ranged from 6 to 27 ft2/ac at age 10. Pine response increased with imazapyr rate for late-summer treatments. Adding hexazinone to imazapyr did not improve hardwood control, and no benefits were observed from adding metsulfuron to either glyphosate or hexazinone. South. J. Appl. For. 20(3): 121-126.

1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop

Abstract Four variations of the fell-and-burn technique, a system developed to produce mixed pine-hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing of felling residual stems, as prescribed by the fell-and-burn technique, may be flexible because winter and spring felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of the first growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods within four growing seasons in burned plots and within six growing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122.


1988 ◽  
Vol 12 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Donald H. Marx ◽  
Charles E. Cordell ◽  
Alexander Clark

Abstract Loblolly pine (Pinus taeda L) seedlings with different initial amounts of Pisolithus tinctorius (Pt) ectomycorrhizae (Pt index 0, 27, 46, 68, or 88) were planted on a good-quality site (site index 90 ft at age 50) in southwest Georgia. After 8 years and crown closure, trees with Pt indices of 88 and 68 had significantly better survival and greater heights, diameters, volumes, and green weights per tree and per ac than nursery-run, control seedlings (Pt index 0). Volume and weight yields per ac were over 50% greater and volume and weight yields per tree were over 20% greater for trees in the Pt index 88 treatment than they were for control trees. A special statistical analysis indicated that average per ac volume was positively correlated with initial Pt index values larger than 58. Tree-ring analyses showed that trees with a Pt index of 88 had significantly greater annual basal area growth than controls during growing seasons with water deficits of 8 to 13 in. Annual growth did not differ when water deficits were greater or less than these amounts. After 8 years, Pt basidiocarps were present throughout the study site. Mycorrhizal treatment integrity may have been lost after 3 or 4 years. South. J. Appl. For. 12(4):275-280


1988 ◽  
Vol 12 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Bruce R. Zutter ◽  
Patrick J. Minogue ◽  
Dean H. Gjerstad

Abstract Four growing seasons after aerial applications of glyphosate at 1.0, 1.5 or 2.0 lb ai/ac in a three-year-old loblolly pine (Pinus taeda L.) plantation in late summer, diameter at breast height (dbh) and total height of pines were greater on treated compared to untreated areas. Pines on treated plots averaged 2.5 in. dbh and 15.2 ft in height while pines on untreated plots averaged 1.9 in. dbh and 13.5 ft in height. Height growth curves of treated pines through four growing seasons following treatment. In general, reduction in hardwood density and pine response each increased with increasing glyphosate rate. Relative composition of red maple in the stand increased two years after treatment for all rates of glyphosate, but did not change in the plots without treatment. South. J. Appl. For. 12(1):54-58.


1994 ◽  
Vol 18 (1) ◽  
pp. 35-39 ◽  
Author(s):  
James D. Haywood

Abstract Twenty-two-year-old loblolly (Pinus taeda L.) and slash pine (P. elliottii Engelm. var. elliottii) research plantations were clearcut-harvested and replanted with the same species. The objective was to compare tree growth between the two rotations. Seven growing seasons into the second rotation, loblolly and slash pines averaged an 8- and 3-ft reduction in total height, respectively. Height growth of loblolly pine was especially reduced on replanted plots that had been harrowed or harrowed and bedded 22 yr earlier, but the reduction in growth occurred on the burn-only (check)plots as well. The reasons for these growth declines were not identified, but it was unlikely that differences between rotations in rainfall patterns, logging damage, or competition were responsible. South. J. Appl. For. 18(1):35-39.


1982 ◽  
Vol 6 (2) ◽  
pp. 108-112 ◽  
Author(s):  
E. L. Stone ◽  
C. A. Hollis ◽  
E. L. Barnard

Abstract Boron deficiency in seedling loblolly (Pinus taeda L.) and slash pine (Pinus elliotti Engelm.) in a northern Florida nursery was diagnosed by: (1) characteristic damage to shoot tips and buds, including necrosis of only part of the terminal; and (2) boron concentrations as low as only 1.9 ppm (dry weight) in affected tissues. Soil and soil-management features associated with deficiency include extremely low silt and clay contents, organic matter levels of 1 percent or less, lack of boron addition, and high calcium irrigation water leading to soil reactions above pH 6 by late summer. Consequences of deficiency were not limited to the nursery. Damaged seedlings that survived outplanting developed into bushy plants incapable of normal height growth in the first year or two.


1991 ◽  
Vol 15 (1) ◽  
pp. 22-27
Author(s):  
Terry R. Clason

Abstract A hardwood suppression treatment applied to a 7-year-old, loblolly pine (Pinus taeda L.) plantation enhanced projected productivity through a 35-year rotation that included three commercial thinnings. By age 22, growth data showed that hardwood removal treatments had larger pines and smaller hardwoods than check treatments. Fifteen-year pine basal area and merchantable volume growth on hardwood removal plots exceeded the check plots by 25 and 27%. Projected growth between ages 22 and 35 indicated that 28 years after early hardwood removal thinned plantation merchantable volume yields improved by 840 ft³ per acre. South. J. Appl. For. 15(1):22-27.


2001 ◽  
Vol 25 (1) ◽  
pp. 25-30
Author(s):  
William A. Carey ◽  
David B. South ◽  
M. Williford ◽  
J. Britt

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.


1998 ◽  
Vol 28 (9) ◽  
pp. 1344-1351 ◽  
Author(s):  
Hubert Sterba ◽  
Ralph L Amateis

Crown efficiency was first defined by Assmann (1961. Waldertragskunde. BLV, München) as individual tree volume increment per unit of crown projection area. He hypothesized that within a given crown class, smaller crowns are more efficient because their ratio between crown surface and horizontal crown projection is higher. Data from a loblolly pine (Pinus taeda L.) spacing experiment were used to test if this hypothesis also holds in young loblolly pine stands and, if so, to determine if it explains the increment differences between spacings in the spacing experiment. Using individual tree height relative to plot dominant height to describe crown class, within-plot regression showed that crown efficiency decreased with crown size for trees below dominant height. This relationship was much less pronounced than indicated from Assmann's examples, although the crown surface to crown projection ratio behaved in the same way as Assmann had hypothesized. Crown efficiency as well as the crown surface to crown projection area ratio decreased with increasing density. Basal area increment per hectare increased until total crown closure approached 130% and then stayed constant. This major impact of total crown coverage brings into question the usefullness of crown efficiency as an indicator for unit area growth.


1988 ◽  
Vol 12 (4) ◽  
pp. 270-273 ◽  
Author(s):  
Charles R. Blinn ◽  
Al Lyons ◽  
Edward R. Buckner

Abstract Color aerial photography was used to assess crown color classes in loblolly pine (Pinus taeda L.) plantations. Three distinct Munsell color classes were delineated on the resulting photographs. Foliar N levels and, to a lesser degree, foliar K levels were directly related to color. Significant relationships between color and site index and color and basal area were shown. Application of color aerial photography, combined with Munsell color coding, could expedite land classification and also make possible more efficient use of fertilizers. South J. Appl. For. 12(4):270-273.


1992 ◽  
Vol 16 (2) ◽  
pp. 93-98 ◽  
Author(s):  
Steven A. Knowe

Abstract Prediction equations were developed for basal area and percentiles of diameter distributions to account for the hardwood component in site-prepared, Piedmont and Upper Coastal Plain loblolly pine (Pinus taeda L.) plantations. Unlike existing stand-level simulation models that incorporate hardwood competition, the new equations resulted in constant total basal area regardless of the amount of hardwood competition and permitted the variance of the diameter distribution to increase with increasing proportion of hardwoods. The equations presented can be used with existing dominant height, survival, and volume equations as a tool for assessing the impact of hardwoods on loblolly pine yield. South. J. Appl. For. 16(2):93-98.


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