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

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.

2021 ◽  
Author(s):  
David K Schnake ◽  
Scott D Roberts ◽  
John L Willis ◽  
John D Kushla ◽  
Ian A Munn

Abstract This study was established to evaluate underplanting as a method of reestablishing a shortleaf pine (Pinus echinata Mill.) component to a dry upland hardwood stand in the Piedmont region of the southeastern United States. Replicated treatment plots were harvested to retain four levels (approximately 0, 3, 7, and 10 m2 of basal area per hectare) of residual overstory density. One-year-old containerized seedlings with both smaller (93.4 cm3) and larger (113.1 cm3) plugs and bareroot seedlings were underplanted beneath the residual overstory treatments. After five growing seasons, seedling survival averaged 61% and was not meaningfully affected by residual overstory density. Seedling height growth ranged from 1.42 m to 2.61 m and was inversely related to residual overstory density. Containerized seedlings with larger plugs had the highest survival (77.4%) and best height growth (2.11 m), followed by containerized seedlings with smaller plugs (64.3%, 1.76 m) and bareroot seedlings (40.2%, 1.85 m). The results of this study indicated that underplanting containerized seedlings, particularly those with higher plug volume and greater plug depth, was a suitable option for reestablishing shortleaf pine on drier, hardwood dominated upland sites in the Piedmont. However, even low levels of overstory retention suppressed seedling height growth after a few years. Study Implications The study was conducted on a dry upland site typical of the North Carolina Piedmont. Retaining up to 10 m2 ha–1 of oak and hickory overstory basal area did not strongly affect survival among underplanted shortleaf pine seedlings after five growing seasons. However, overstory cover as low as 3 m2 ha–1 had negative effects on height growth of underplanted seedlings over the same time period. Height growth declined as overstory density increased. Containerized seedlings had better survival than bareroot seedlings. Further improvements in survival and height growth were realized by planting containerized seedlings with higher plug volume and greater plug depth.


1988 ◽  
Vol 18 (7) ◽  
pp. 867-871 ◽  
Author(s):  
C. L. Tuttle ◽  
D. B. South ◽  
M. S. Golden ◽  
R. S. Meldahl

Initial planting height of loblolly pine (Pinustaeda L.) seedlings from several nurseries and seed sources was related to survival and height growth on "good" and "poor" planting chances in Alabama. A planting chance was classified as poor if 2-year survival was less than 75% and total 2-year height growth was less than 75 cm. Seedling height (measured immediately following planting) was negatively related to survival, and the slope of the regression was four times greater when the planting chance was classified as poor than when it was classified as good. Initial height was also negatively related to 2-year height growth on poor planting chances, with shorter seedlings at planting reaching the same total height as taller ones after two seasons. As a result, initial field height on poor planting chances had little impact on total seedling height after two growing seasons. Therefore, there was no height growth advantage gained by planting seedlings taller than 20 cm when survival was less than 75%. Planting seedlings with heights of 20–34 cm was less of a problem when the planting chance was good. The use of shorter seedlings on planting chances where low survival may be expected may significantly increase loblolly pine seedling survival in the southern United States.


1983 ◽  
Vol 7 (1) ◽  
pp. 16-20 ◽  
Author(s):  
Harold E. Grelen

Abstract After seven annual May burns, grass-stage longleaf pine (Pinus palustris Mill.) seedling survival averaged 71 percent, significantly higher than survival on a biennial May burn, an annual or biennial March burn, or an unburned control. Seedling height growth on the annual May burn was no better than that on the biennial May burn, but both May burns significantly exceeded the other treatments in height growth. The annual May burn also provided greatest survival and growth for longleaf seedlings that had begun height growth before the study began.


1986 ◽  
Vol 1 (4) ◽  
pp. 108-111 ◽  
Author(s):  
Chao-Hsiung Tung ◽  
Jim Batdorff ◽  
David R. DeYoe

Abstract Two vegetation management methods, paper mulching and spot-spraying with glyphosate, were combined with a root-dipping treatment, Terra Sorb®, to test effects on seedling survival and height growth on a harsh site in Oregon. Survival of Douglas-fir (Pseudotsuga menziesii) seedlings was significantly higher after the third growing season when competing vegetation had been controlled with mulch or glyphosate during the first two growing seasons. Seedlings retreated with paper mulch and glyphosate before the second growing season had 36 and 25% higher survival than those that were not retreated. None of the seedlings was retreated before the third season; after this season, survival of seedlings treated twice with glyphosate was 26, 23, and 21% higher than seedlings receiving one glyphosate treatment and one or two mulch applications, respectively. There were no differences in seedling height growth among treatments. Rootdipping with Terra Sorb® did not influence survival or growth. West. J. Appl. For. 1:108-111 Oct. 86.


1992 ◽  
Vol 22 (1) ◽  
pp. 1-4 ◽  
Author(s):  
A. D. Barnes ◽  
W. D. Kelley

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.


2019 ◽  
Vol 33 (03) ◽  
pp. 393-399 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Pavle Pavlovic ◽  
O. Adewale Osipitan ◽  
Ethann R. Barnes ◽  
Clint Beiermann ◽  
...  

AbstractWidespread and repeated use of glyphosate resulted in an increase in glyphosate-resistant (GR) weeds. This led to an urgent need for diversification of weed control programs and use of PRE herbicides with alternative sites of action. Field experiments were conducted over a 4-yr period (2015 to 2018) across three locations in Nebraska to evaluate the effects of PRE-applied herbicides on critical time for weed removal (CTWR) in GR soybean. The studies were laid out in a split-plot arrangement with herbicide regime as the main plot and weed removal timing as the subplot. The herbicide regimes used were either no PRE or premix of either sulfentrazone plus imazethapyr (350 + 70 g ai ha−1) or saflufenacil plus imazethapyr plus pyroxasulfone (26 + 70 + 120 g ai ha−1). The weed removal timings were at V1, V3, V6, R2, and R5 soybean stages, with weed-free and weedy season-long checks. Weeds were removed by application of glyphosate (1,400 g ae ha−1) or by hoeing. The results across all years and locations suggested that the use of PRE herbicides delayed CTWR in soybean. In particular, the CTWR without PRE herbicides was determined to be around the V1 to V2 (14 to 21 d after emergence [DAE]) growth stage, depending on the location and weed pressure. The use of PRE-applied herbicides delayed CTWR from about the V4 (28 DAE) stage up to the R5 (66 DAE) stage. These results suggest that the use of PRE herbicides in GR soybean could delay the need for POST application of glyphosate by 2 to 5 wk, thereby reducing the need for multiple applications of glyphosate during the growing season. Additionally, the use of PRE herbicides could provide additional modes of action needed to manage GR weeds in GR soybean.


1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms

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%.


1988 ◽  
Vol 18 (4) ◽  
pp. 421-426 ◽  
Author(s):  
T. C. Hennessey ◽  
E. M. Lorenzi ◽  
R. W. McNew

An experiment to quantify the response of unnodulated, fertilized European black alder (Alnusglutinosa (L.) Gaertn.) seedlings to progressive water stress showed contrasting drought tolerance among five clones, using stomatal conductance, leaf area, and height as indices of drought sensitivity. In particular, one rapidly growing clone (AG 8022-14) showed the ability to moderate changes in water stress more efficiently than the more slowly growing clones. After 30 days of moderate levels of water stress, clones that had higher stomatal conductance also had greater leaf area and height growth. Leaf area and height were both sensitive to plant water status, although no threshold of stress associated with a cessation of leaf area or height expansion was found even though stomatal conductance decreased to 0.05 cm s−1 under severe water stress.


Weed Science ◽  
1982 ◽  
Vol 30 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Victor Raboy ◽  
Herbert J. Hopen

The persistence and effectiveness in pumpkin [Cucurbita moschata(Puch.) Poir.] weed control of several starch xanthide (SX) and commercial formulations of the ammonium (NH3) salt and methyl (CH3) ester of chloramben (3-amino-2,5-dichlorobenzoic acid) were studied in the laboratory and field. The soluble concentrate (SC) of chloramben NH3salt and the emulsifiable concentrate (EC) of chloramben CH3ester controlled weeds throughout the growing season on a silt loam soil. SC chloramben NH3salt was not effective, and EC chloramben CH3ester was inconsistent in weed control on sandy soil. Manipulation of the SX formulation produced products with slow, uniform release rates. The release rates (crosslinking reagent in parenthesis) rank as follows, from fastest to slowest: SX(Ca2+) CH3ester = SX(H2O2) acid > SX(H2O2) CH3ester > SX(Fe3+) acid > SX(Fe3+) CH3ester. In trials on silt loam and sand, SX formulations did not control weeds better than EC chloramben CH3ester.


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