Impacts of Herbaceous Weeds in Young Loblolly Pine Plantations

1981 ◽  
Vol 5 (3) ◽  
pp. 153-158 ◽  
Author(s):  
Larry R. Nelson ◽  
Richard C. Pedersen ◽  
Lanny L. Autry ◽  
Stuart Dudley ◽  
John D. Walstad
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Loblolly Pine ◽  
Ground Cover ◽  
Biomass Accumulation ◽  
First Year ◽  
Seedling Height ◽  
Weed Infestation ◽  
Plant Moisture ◽  
Pinus Taeda L

Abstract The effects of herbaceous weed competition on loblolly pine (Pinus taeda L.) development during the first year of plantation growth were investigated on five sites across the South. Seedling height-growth response to weed control in relation to soil type, soil moisture, soil nutrients, and weed-infestation levels was examined. Seedling height response to weed control was significantly related to percent ground cover of weeds 7 weeks after herbicide applications and to weed biomass accumulation at the end of the growing season. Plant moisture measurements and analysis of precipitation occurrence indicated that weeds depleted the soil moisture necessary for maximum pine height development. Twelve-and four-fold increases in pine biomass due to weed control occurred on sites in Arkansas and Oklahoma, respectively. Results demonstrate the benefits of total weed control to loblolly pine seedlings during the first three years on two sites.

scholarly journals Seedling Evaluation of Atlantic Coastal and Piedmont Sources of Loblolly Pine and Their Hybrids for Height Growth

2004 ◽  
Vol 28 (2) ◽  
pp. 83-90
Author(s):  
Steven E. McKeand ◽  
Angelia J. Kegley ◽  
Bailian Li
Keyword(s):  
Loblolly Pine ◽  
Cold Hardiness ◽  
Female Parent ◽  
Height Growth ◽  
First Year ◽  
Seedling Height ◽  
Bud Set ◽  
Early Seedling ◽  
Pinus Taeda L ◽  
Atlantic Coastal

Abstract Seedlings of 60 loblolly pine (Pinus taeda L.) polycross families representing four populations, Atlantic Coastal (CxC), Piedmont (PxP), Coastal × Piedmont (CxP), and Piedmont × Coastal (PxC) were evaluated for first-year seedling height growth in an outdoor site in Raleigh, North Carolina. The CxP hybrids grew as well as the pure Coastal loblolly source, and the PxC hybrids were not significantly taller than the pure Piedmont population. The hybrid populations were intermediate between the parental populations and did not exhibit heterosis for height. However, the hybrids were 4–10% taller than the PxP population, which is the population currently used for forestation in the Piedmont region. There was an advantage for early seedling height growth in having the female parent from the Coastal plain, which appeared to be related to length of the growing season as measured by bud set time. There were strong family differences for seedling height within populations, indicating the potential for selecting the best families within the best populations. The implication is that the hybrid populations of CxP and PxC with improved growth may be better planting stock for the Piedmont than the pure Piedmont populations on some sites. Before implementing such a plan, cold-hardiness and long-term growth and adaptability should be evaluated. South. J. Appl. For. 28(2):83–90.

Comparison of duration and method of herbaceous weed control on loblolly pine response through midrotation

1993 ◽  
Vol 23 (10) ◽  
pp. 2116-2125 ◽  
Author(s):  
Dwight K. Lauer ◽  
Glenn R. Glover ◽  
Dean H. Gjerstad
Keyword(s):  
Weed Control ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Tree Height ◽  
Control Treatment ◽  
Control Individual ◽  
First Year ◽  
Individual Tree ◽  
Stem Infection ◽  
Herbaceous Weed Control

Herbaceous weed control studies installed by the Auburn University Silvicultural Herbicide Cooperative to examine response to methods and duration of herbaceous weed control in eight loblolly pine (Pinustaeda L.) plantations were analyzed to determine stand response through age 9. Studies were designed to compare weed control treatments with an untreated check, weed control methods (band vs. broadcast), and weed control duration (first year vs. first 2 years). Pine growth was increased by weed control on all sites. Growth was increased by an additional year of weed control (duration) on about one-half of the sites, but did not differ between band and broadcast treatments (method). Age 9 volume response above the check averaged 27.3 m3/ha for first-year weed control and 42.9 m3/ha for the first 2 years of weed control. Individual-tree height growth between ages 7 and 9 did not differ by treatment at most sites, but stand volume growth was higher with weed control at six of the eight sites. Uniformity of individual tree size, as represented by the standard deviation of DBH adjusted for dominant height, was more dependent on survival, hardwood encroachment, and level of fusiform rust stem infection, which varied by treatment and site, than on the result of herbaceous weed control per se. Growth projections made with the least intensive weed control treatment at each site indicated that on average, merchantable volume at age 22 with weed control will equal that of an age 25 stand without weed control. Largest gains were on sites where weed control increased survival.

scholarly journals Effect of the Growth Regulator Uniconazole on Biomass Allocation of Bareroot Loblolly Pine Seedlings

2004 ◽  
Vol 28 (1) ◽  
pp. 41-47
Author(s):  
Andrew D. Barnes ◽  
David B. South
Keyword(s):  
South Carolina ◽  
Loblolly Pine ◽  
Growth Regulator ◽  
Foliar Spray ◽  
Seedling Height ◽  
Root Shoot Ratio ◽  
Pine Seedlings ◽  
Nursery Management ◽  
Pinus Taeda L ◽  
Root Collar

Abstract Improving seedling performance by reducing seedling height can be an important aspect of nursery management. The plant growth regulator uniconazole was applied to regulate height growth of nursery-grown loblolly pine (Pinus taeda L.) seedlings. Tests involving a foliar spray (0,0.125, 0.25, 0.5 and 1.0 kg ai/ha) or a wick application (0, 125, 250, 500, and 1000 ppm) were conducted in Alabama, Georgia, and South Carolina. The wick applicator consisted of a perforated plastic pipe covered with a sponge cylinder supplied by a reservoir. With both application methods, as the rate of uniconazole increased, seedling height, root-collar diameter, and biomass decreased. Compared to the controls, uniconazole decreased the percentage of seedlings with root-collar diameters greater than 4.7 mm. At lifting there was no difference among rates for root/shoot ratio, but root/shoot ratios of uniconazole treated seedlings increased significantly after outplanting. Eighteen months after outplanting, there were no treatment effects on seedling height or survival. Wick applications of uniconazole merit further research because of soil persistence and costs associated with spray applications. South. J. Appl. For. 28(1):41–47.

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.

An Economic Evaluation of the Use of Oust for Herbaceous Weed Control in Loblolly Pine Plantations

1992 ◽  
Vol 16 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Rodney L. Busby
Keyword(s):  
Pinus Taeda ◽  
Weed Control ◽  
Loblolly Pine ◽  
Economic Returns ◽  
Stand Growth ◽  
Growth Increments ◽  
Long Term Effect ◽  
Herbaceous Weed Control ◽  
Pinus Taeda L

Abstract Herbaceous weed control using Oust (sulfometuron methyl²) is economically efficient in loblolly pine (Pinus taeda L.) plantations given reasonable expectations about the long-term effect of the treatment on stand growth. Increases in the sizes of the growth increments following treatment that have been reported in the literature, and the economic returns this analysis shows are possible, indicate that investment in herbaceous weed control can be a prudent silvicultural option. South. J. Appl. For. 16(1):40-47.

Tenth-Year Results of Herbaceous Weed Control in a Loblolly Pine Plantation

1994 ◽  
Vol 18 (3) ◽  
pp. 105-109 ◽  
Author(s):  
James D. Haywood
Keyword(s):  
Pinus Taeda ◽  
Weed Control ◽  
Loblolly Pine ◽  
Untreated Control ◽  
Pine Plantation ◽  
Herbaceous Vegetation ◽  
Growing Seasons ◽  
Volume Production ◽  
Herbaceous Weed Control ◽  
Pinus Taeda L

Abstract Herbaceous weed control influenced the growth of planted loblolly pine (Pinus taeda L.) over a 10-yr-period. Five treatments were examined: (1) Untreated control: seedlings were planted in the established herbaceous vegetation; (2) Glyphosate: glyphosate was broadcast in September 1981 before planting; (3) Disked: plots were cross-disked in September 1981 before planting; (4) Glyphosate-PPWC: glyphosate was broadcast before planting as in Treatment 2, and postplant weed control (PPWC) herbicides were broadcast yearly for 4 yr (1982, atrazine plus simazine ; 1983, atrazine plus oxyfluorfen; 1984 and 1985, hexazinone ); and (5) Disked-PPWC: plots were disked before planting as in Treatment 3, and the PPWC herbicides were broadcast as in Treatment 4. Four years of PPWC did not affect survival and resulted in greater height, dbh, and volume per loblolly pine through 10 growing seasons. The disked-PPWC plots were the most productive through 8 growing seasons, but higher than average mortality after 8 yr on the disked-PPWC treatment resulted in the glyphosate-PPWC plots producing more volume per acre after 10 growing seasons. Total volume production was 253 inside bark ft³/ac greater on the two PPWC treatments than on the untreated controls. South. J. Appl. For. 18(3): 105-109.

Effect of Irrigation and Weed Control Treatment on Yield and Net Return from Soybean (Glycine max)

1994 ◽  
Vol 8 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Larry G. Heatherly ◽  
C. Dennis Elmore ◽  
Stan R. Spurlock
Keyword(s):  
Weed Control ◽  
Ground Cover ◽  
Field Studies ◽  
Control Treatment ◽  
First Year ◽  
Net Return ◽  
Yield Increase ◽  
Net Returns ◽  
Broadleaf Species ◽  
Determine Effect

Field studies were conducted from 1987 through 1990 on Sharkey clay to determine effect of weed control treatment (WTRT) on yield and net return from soybean grown with no irrigation (NI) or irrigation (I) during reproductive development. Weed control treatments were: 1) PRE glyphosate plus metribuzin plus metolachlor or pendimethalin, followed by POST bentazon plus acifluorfen or 2,4-DB plus linuron (high WTRT); 2) PRE glyphosate at a rate to kill existing weeds at planting (medium WTRT); or 3) PRE paraquat at a rate to desiccate but not necessarily kill existing weeds at planting (low WTRT). POST cultivation was used in all treatments. Weed ground cover in the high, medium, and low WTRT's was composed of annual grass and moderately competitive broadleaf species, and averaged 7, 25, and 49%, respectively, at harvest in 1990. Yield declined with decreasing weed control in the I treatment after the first year, but average net returns from the high and medium WTRT's were not different, and both exceeded average returns from the low WTRT. Yields from the high and medium WTRT's in the NI treatment were not different, and both exceeded yield from the low WTRT. Average net returns from the medium WTRT were greater than those from the high and low WTRT's in all years. Yield increase from irrigation and difference in average net returns between I and NI declined with decreasing weed control.

Effects of Herbaceous Weeds on Fourth Year Water Relations and Gas Exchange of Loblolly Pine

1991 ◽  
Vol 5 (4) ◽  
pp. 753-758 ◽  
Author(s):  
Thomas H. Green ◽  
Robert J. Mitchell ◽  
Kailash C. Paliwal ◽  
Uday V. Pathre ◽  
Bruce R. Zutter ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Loblolly Pine ◽  
Water Status ◽  
Stand Development ◽  
Plant Water ◽  
Direct Benefit ◽  
Available Soil Moisture ◽  
Plant Water Potential ◽  
Loblolly Pines

Stands of four-year-old loblolly pines grown with and without herbaceous competition were compared to determine whether early increases in soil moisture and plant water status had been maintained throughout the first four years. Non-weeded stands tended to have greater soil moisture than weeded stands, although these differences were never statistically significant (P > 0.05). Plant water potential was remarkably similar between treatments, as were photosynthesis and stomatal conductance. The increase due to weed control in foliage production early in stand development apparently caused a depletion in available soil moisture to levels similar to non-weeded stands. Therefore, the direct benefit of increased soil resources with weed control is short lived.

scholarly journals A Southwide Rate Test of Azinphosmethyl (Guthion®) for Cone and Seed Insect Control in Loblolly Pine Seed Orchards

1998 ◽  
Vol 22 (2) ◽  
pp. 106-110
Author(s):  
A.C. Mangini ◽  
L.R. Barber ◽  
R.S. Cameron ◽  
G.L. DeBarr ◽  
G.R. Hodge ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Insect Control ◽  
First Year ◽  
Seed Orchards ◽  
Control Programs ◽  
Rate Test ◽  
Second Year ◽  
Pinus Taeda L

Abstract A southwide efficacy test of reduced rates of azinphosmethyl (Guthion®) for control of seed and cone insects in loblolly pine seed orchards was conducted in 1992. In each of nine loblolly pine (Pinus taeda L.) seed orchards, an untreated (no protection) check and two of five possible rates of Guthion® (1.0, 1.5, 2.0, 2.5, or 3.0 lb ai/ac/application) were randomly assigned to three test plots. Insecticide treatments improved first-year conelet survival, second-year cone survival, sound seeds per cone, and sound seeds per conelet at nearly every rate. There was no trend of better protection with increasing rates of Guthion®. The 1.0 lb ai/ac rate was as efficacious as the EPA-registered maximum aerial rate of 3.0 lb ai/ac. Based on these results, orchard managers should consider reduced rates of Guthion® for operational cone and seed insect control programs. South. J. Appl. For. 22(2):106-110.

Herbaceous Weed Control with Hexazinone in Loblolly Pine (Pinus taeda) Plantations

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 583-588 ◽  
Author(s):  
C. H. Fitzgerald ◽  
J. C. Fortson
Keyword(s):  
Field Study ◽  
Pinus Taeda ◽  
Weed Control ◽  
Loblolly Pine ◽  
Activated Charcoal ◽  
Sandy Loam ◽  
Seedling Height ◽  
Clay Loam ◽  
Pine Seedlings ◽  
Herbaceous Weed Control

Hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4 (1H, 3H)-dione] effectively controlled herbaceous weeds in a loblolly pine (Pinus taeda L.) plantation in 1975. Pine seedling height increased as a result of weed control following 1 to 3 kg/ha applications but phytotoxic symptoms were evident. A 1976 field study indicated activated charcoal root coatings may reduce phytotoxic action. Hexazinone at 3 and 4 kg/ha applied to either the foliage or the soil was toxic to potted pine seedlings in 1976. The addition of surfactant to hexazinone treatments at 2, 3, and 4 kg/ha increased pine phytotoxicity to unacceptable levels. When hexazinone was applied to soil at 2, 3, and 4 kg/ha, activated charcoal root coatings reduced pine mortality to acceptable levels on Norfolk sandy loam. Charcoal was less effective on Madison clay loam. Pine tolerance on both soils was acceptable at 2 kg/ha.

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