Vegetation Control and Soil Moisture Depletion Related to Herbicide Treatments on Forest Plantations in Northeastern Oregon

2018 ◽  
Vol 32 (4) ◽  
pp. 461-474 ◽  
Author(s):  
Elizabeth Cole ◽  
Amanda Lindsay ◽  
Michael Newton ◽  
John D. Bailey
Keyword(s):  
Soil Moisture ◽  
First Year ◽  
Forest Plantations ◽  
Vegetative Cover ◽  
Tree Seedling ◽  
Vegetation Control ◽  
Herbicide Treatments ◽  
Inland Northwest ◽  
Comparable Control ◽  
Second Year

AbstractReforestation in the Inland Northwest, including northeastern Oregon, USA, is often limited by a dry climate and soil moisture availability during the summer months. Reduction of competing vegetative cover in forest plantations is a common method for retaining available soil moisture. Several spring and summer site preparation (applied prior to planting) herbicide treatments were evaluated to determine their efficacy in reducing competing cover, thus retaining soil moisture, on three sites in northeastern Oregon. Results varied by site, year, and season of application. In general, sulfometuron (0.14 kg ai ha–1 alone and in various mixtures), imazapyr (0.42 ae kg ha–1), and hexazinone (1.68 kg ai ha–1) resulted in 3 to 17% cover of forbs and grasses in the first-year when applied in spring. Sulfometuron+glyphosate (2.2 kg ha–1) consistently reduced grasses and forbs for the first year when applied in summer, but forbs recovered in the second year on two of three sites. Aminopyralid (0.12 kg ae ha–1)+sulfometuron applied in summer also led to comparable control of forb cover. In the second year after treatment, forb cover in treated plots was similar to levels in nontreated plots, and some species of forbs had increased relative to nontreated plots. Imazapyr (0.21 and 0.42 kg ha–1) at either rate, spring or summer 2007, or at lower rate (0.14 kg ha–1) with glyphosate in summer, provided the best control of shrubs, of which snowberry was the dominant species. Total vegetative cover was similar across all treatments seven and eight years after application, and differences in vegetation were related to site rather than treatment. In the first year after treatment, rates of soil moisture depletion in the 0- to 23-cm depth were correlated with vegetative cover, particularly late season soil moisture, suggesting increased water availability for tree seedling growth.

scholarly journals Vegetation Cover Response and Second-Year Loblolly and Slash Pine Response Following Bedding and Pre- and Post-Plant Herbicide Applications in Florida

2001 ◽  
Vol 25 (2) ◽  
pp. 75-83 ◽  
Author(s):  
Dwight K. Lauer ◽  
Bruce R. Zutter
Keyword(s):  
Loblolly Pine ◽  
Site Preparation ◽  
Slash Pine ◽  
First Year ◽  
Double Pass ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Herbicide Treatments ◽  
Woody Shrubs ◽  
Second Year

Abstract Site preparation treatments of early single bed (EB), late single bed (LB), double bed (DB), EB + banded pre-plant herbicide (PP), and EB + broadcast pre-plant herbicide (BPP) were applied to four locations in Florida. Three of the four locations included these treatments crossed with a first-year post-plant herbicide application to control herbaceous vegetation(HC). Second-year pine heights evaluated at two slash pine (P. elliottii Engelm.) locations and one loblolly pine (P. taeda L.) location averaged taller (4.6 vs. 3.5 ft) following double-pass (DB, PP, BPP) than single-pass (EB, LB) treatments, taller (4.9 vs. 4.0 ft) for pre-plant herbicide (PP, BPP) than DB, but did not differ between PP and BPP. There were no significant interactions between site preparation and HC with HC, increasing second-year pine height by 0.5 ft. Pine height was greater for pre-plant herbicide treatments than for DB treatments because pre-plant herbicide treatments provided better control of competing vegetation. Vegetation control differed among treatments. DB improved control of woody shrubs over single bedding alone, but increased herbaceous cover in the first growing season. The increase in herbaceous cover following DB accounts for the relatively small gain in second-year pine height (0.2 ft) for DB compared to LB. Pre-plant herbicide treatments following early bedding improved control of both woody shrubs and first-year herbaceous vegetation. Pre-plant herbicide treatments also shifted the composition of herbaceous vegetation towards less competitive species. HC improved control of herbaceous plants, and lowest first-year herbaceous cover was achieved with the combination of HC with pre-plant herbicide treatments. South. J. Appl. For. 25(2):75–83.

Studies on the Reproductive Biology of Leafy Spurge (Euphoriba esula)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 106-109 ◽  
Author(s):  
L. A. Morrow
Keyword(s):  
Soil Moisture ◽  
Dry Matter ◽  
Perennial Grass ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
First Year ◽  
Growth Room ◽  
Available Soil Moisture ◽  
Second Year ◽  
Field Plots

Studies on the development of leafy spurge (Euphorbia esula L.) were conducted in the field and growth room. Sixteen months after planting in field plots, leafy spurge plants arising from underground bud-producing root segments, transplanted seedlings, or seeds averaged 96, 83, and 136 shoots per plant, respectively, when grown free of interference from other vegetation. A number of plants arising from each source flowered the first year, and all plants flowered and produced seed the second year after planting. When grown in a perennial grass sod consisting of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] and smooth brome (Bromus inermis Leyss.), no plant flowered or produced additional shoots. Soil moisture was less where a dense sod was present. In the growth room, total dry matter of tops and roots was greatest at a soil temperature of 18.3 C or higher, and plant height was greatest at 33.3 C. An early emerging crop might suppress leafy spurge by utilizing the available soil moisture early in the growing season.

Summer Fallow and After-Planting Bermudagrass (Cynodon dactylon) Control Programs for Sugarcane (Saccharumspp. hybrids)

1999 ◽  
Vol 13 (1) ◽  
pp. 127-131 ◽  
Author(s):  
Donnie K. Miller ◽  
James L. Griffin ◽  
Edward P. Richard
Keyword(s):  
Cynodon Dactylon ◽  
Ground Cover ◽  
First Year ◽  
Single Application ◽  
Fallow Period ◽  
Control Programs ◽  
Sugarcane Stalk ◽  
Herbicide Treatments ◽  
Second Year ◽  
Summer Fallow

Based on bermudagrass ground cover 2 wk prior to sugarcane planting, tillage plus glyphosate applied postemergence sequentially at 3.4 followed by 2.2 kg ai/ha or a single application at 3.4 kg/ha during the summer fallow period was more effective than tillage alone. Effectiveness of tillage was enhanced when less rainfall was received during the summer fallow period the first year. Rainfall of less than 1 cm 20 d after preemergence application of sulfometuron at 0.2 kg ai/ha in June resulted in 100% bermudagrass ground cover the first year compared with 37% the second year with 15 cm of rainfall during the same period. Terbacil applied after sugarcane planting and metribuzin applied in February resulted in bermudagrass ground cover in May or June of 62% (experiment 1) and 2% (experiment 2) when sulfometuron was used during the fallow period, but no more than 5% when terbacil and metribuzin followed glyphosate plus tillage or tillage alone. In most cases, bermudagrass ground cover at that time was greater when the same glyphosate/tillage treatments were followed by atrazine after planting and pendimethalin plus atrazine in February compared with terbacil after planting and metribuzin in February. When after-planting and February herbicide treatments were applied, sugarcane stalk population, height, and yield each was equivalent regardless of the previous fallow treatment.

Integrated weed management using row arrangements and herbicides in pigeonpea (Cajanus cajan) in Australia

2019 ◽  
Vol 70 (8) ◽  
pp. 676
Author(s):  
Gulshan Mahajan ◽  
Rao C. N. Rachaputi ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Cajanus Cajan ◽  
Untreated Control ◽  
First Year ◽  
Row Spacing ◽  
Single Application ◽  
Herbicide Treatments ◽  
Weed Flora ◽  
Second Year

In Australia, efforts are under way to revive the pigeonpea (Cajanus cajan (L.) Millsp.) industry, which has high export potential because of an increased demand in the international market. However, weeds are a major constraint to achieve high yield in pigeonpea. This study was designed to assess the effect of row arrangement and herbicide treatment on weed suppression and pigeonpea grain yield. Row arrangements included row spacing (narrow, 25 cm; wide, 50 cm) and paired rows (rows 25 cm apart within a pair, each pair separated from the next by 75 cm). Herbicide treatments were: untreated control; pre-emergent pendimethalin at 910 g a.i. ha–1; post-emergent imazapic at 84 g a.i. ha–1; and pre-emergent pendimethalin followed by post-emergent imazapic (rates as above). In the first year, Trianthema portulacastrum was the dominant weed, and infestation was 100% in the non-treated control plots. In the second year, other weeds (Setaria viridis, Eragrostis cilianensis and Chloris virgata) comprised 30% of the weed population. Averaged over row arrangements, grain yield varied from 2088 to 2689 kg ha–1 in 2017 and from 835 to 2145 kg ha–1 in 2018, and was lowest in the untreated control and highest in the plots treated with the sequential application of pendimethalin and imazapic. Averaged over years and herbicide treatments, yield was lower in paired rows (1850 kg ha–1) than in narrow (2225 kg ha–1) and wide (2165 kg ha–1) row spacings. In the first year, all herbicide treatments provided >50% control of T. portulacastrum in the narrow and wide row spacings and increased yield by >22% over the untreated control. In the second year, the single application of imazapic proved inferior for controlling weeds, resulting in a 21% reduction in grain yield compared with sequential application of pendimethalin and imazapic. In both years, grain yield was similar for the single application of pendimethalin and sequential application of pendimethalin and imazapic. Despite the complex weed flora in 2018, the single application of imazapic provided acceptable weed control only when the crop was planted at 25 cm row spacing. Our results suggest that the single application of pendimethalin was effective on T. portulacastrum. However, in a complex weed flora situation, the sequential application of pendimethalin and imazapic provided effective weed control and resulted in improved yield.

Perennial sowthistle control with sequential herbicide treatments applied under minimum and zero tillage systems

1998 ◽  
Vol 78 (3) ◽  
pp. 505-511 ◽  
Author(s):  
A. L. Darwent ◽  
K. N. Harker ◽  
G. W. Clayton
Keyword(s):  
Field Experiments ◽  
Initial Density ◽  
First Year ◽  
Zero Tillage ◽  
Hordeum Vulgare L ◽  
Tillage Systems ◽  
Minimum Tillage ◽  
Herbicide Treatments ◽  
Second Year ◽  
Sonchus Arvensis

Perennial sowthistle (Sonchus arvensis L.) control under minimum and zero tillage systems, and following several sequential in-crop herbicide treatments applied in a crop rotation of canola (Brassica rapa L.) followed by 3 yr of barley (Hordeum vulgare L.), was evaluated in two field experiments near Grande Prairie, Alberta. Under zero tillage, in-crop applications of clopyralid at 0.1 to 0.3 kg active ingredient (a.i.) ha−1 to canola, followed by annual in-crop applications of clopyralid at 0.15 kg a.i. ha−1 plus MCPA at 0.42 kg a.i ha−1 to barley in the next 2 yr, reduced perennial sowthistle from a mean initial density of 3.9 shoots m−2 to ≤0.5 shoots m−2 in the fourth year. Glyphosate at 0.45 kg acid equivalent (a.e.) ha−1 plus dicamba at 0.14 kg a.i. ha−1 was applied annually before seeding barley in these plots. In the second experiment, the same herbicide treatments, except for an additional preseeding application of glyphosate at 0.9 kg a.e. ha−1 in the first year, reduced perennial sowthistle density from 9.2 shoots m−2 to ≤0.1 shoots m−2 Increasing the rate of clopyralid in the first year resulted in decreases in perennial sowthistle density in the second and third years following application but not in the fourth year. In unweeded zero tillage check plots of the two experiments, perennial sowthistle increased to 41.8 and 36.0 shoots m–2, respectively, over the same period. Applying metsulfuron at 0.0045 kg a.i. ha–1 in the second year and dicamba plus the potassium salt of MCPA (1:4) at 0.54 kg a.i. ha−1 in the third year, in place of clopyralid plus MCPA, produced similar reductions in perennial sowthistle density. Under minimum tillage, where tillage was limited to a single preseeding discing before seeding and a single mid-to-late October deep tillage cultivation, reductions in perennial sowthistle density following in-crop applications of clopyralid in the first year and clopyralid plus MCPA in the next 2 yr were similar to those following application of the same in-crop herbicides under zero tillage. However, in minimum tillage plots where metsulfuron and dicamba plus MCPA were applied in the second and third years, perennial sowthistle density was not reduced or declined at a slower rate than in other sprayed plots. Canola and barley yields increased as a result of reductions in perennial sowthistle density. Key words: Perennial sowthistle, Sonchus arvensis L., tillage, clopyralid, metsulfuron, dicamba

Soil moisture and salinity under bladder saltbush (Atriplex vesicaria) pastures in the New SouthWales Riverine plain

1969 ◽  
Vol 9 (41) ◽  
pp. 603 ◽  
Author(s):  
RM Jones
Keyword(s):  
Soil Moisture ◽  
Soil Salinity ◽  
New South ◽  
First Year ◽  
Chloride Level ◽  
South Wales ◽  
Reproductive Response ◽  
Second Year ◽  
Soil Wetting ◽  
Previous Summer

Soil moisture, soil salinity, and phenological measurements were made over two years on adjacent pastures with and without bladder saltbush (Atriplex vesicaria) in the Riverina district of New South Wales. Soil moisture percentages beneath pastures with and without saltbush were similar in the first year. In the second year moisture percentages were slightly higher under pastures without saltbush. The soil profile was at matric tensions higher than 15 atmospheres for 48 per cent of the first year and 64 per cent of the second. Phenological observations related soil moisture levels to vegetative and reproductive response of the pastures. The maximum depth of soil wetting was 30 inches in the exceptionally wet autumn-winter of and 10 inches in the slightly drier than average winter of 1964. Salt was leached during the first winter of sampling, the chloride level at four inches falling from 0.107 per cent in the previous summer to 0.008 per cent. The level was partly restored during the following summer (0.055 per cent) and this was maintained during the drier second winter.

scholarly journals No evidence of a demographic response to experimental herbicide treatments by the White-crowned Sparrow, an early successional forest songbird

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
James W Rivers ◽  
Jake Verschuyl ◽  
Carl J Schwarz ◽  
Andrew J Kroll ◽  
Matthew G Betts
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Nest Survival ◽  
Control Measures ◽  
Vital Rates ◽  
Population Declines ◽  
Vegetative Cover ◽  
Vegetation Control ◽  
Herbicide Treatments ◽  
Demographic Response

Abstract Early-successional forest birds, which depend on disturbance events within forested landscapes, have received increased conservation concern because of long-term population declines. Herbicides are often used to control vegetation within early-successional forests, with unknown effects on avian vital rates. We used a large-scale experiment to test how nest and post-fledging survival were influenced by herbicide intensity within managed conifer plantations across 2 breeding seasons. We created a gradient of 4 stand-scale herbicide treatments (light, moderate, and intensive, and no-spray control) and evaluated the reproductive response of the White-crowned Sparrow (Zonotrichia leucophrys), a declining songbird in managed forest landscapes of the Pacific Northwest. Against initial predictions, we found no evidence that either daily nest survival (n > 760 nests across all treatments) or post-fledging survival (n = 70 individuals reared in control and moderate treatments) were influenced by herbicide application intensity. Increased herbicide intensity resulted in an extensive reduction in vegetation cover at both stand and nest-patch scales; in contrast, vegetative cover at nest sites did not differ across herbicide treatments, nor was nest survival related to vegetation concealment measures. As the largest experimental investigation to assess forest herbicide effects on songbird demography, our study indicates that components of sparrow reproductive success were not influenced by experimental vegetation control measures, although additional work on other early-successional species will be useful to evaluate the generalities of our findings.

Natural regeneration of jack pine following harvesting and site preparation in the Clay Belt of northwestern Quebec

1999 ◽  
Vol 75 (5) ◽  
pp. 821-831 ◽  
Author(s):  
Martin Béland ◽  
Yves Bergeron ◽  
Richard Zarnovican
Keyword(s):  
Natural Regeneration ◽  
Jack Pine ◽  
First Year ◽  
Seedling Density ◽  
Vegetation Control ◽  
Pine Regeneration ◽  
Soil Scarification ◽  
Second Year ◽  
Abundance And Distribution ◽  
Positive Effect

A 36-ha experiment was carried out to assess the possibility of naturally regenerating jack pine stands following harvesting on clay soils of northwestern Quebec. Although differences between treatments were not statistically significant, there was a trend toward a positive effect of one treatment combining on-site delimbing and scarification with the Silva Wadell™ cone scarifier on jack pine seedling density (up to 10 000/ha) and distribution (50% of 1 m2 plots with at least one seedling, corresponding to 94% with 4 m2 plots), two years after harvest. However, scarified microsites contained fewer seedlings than expected and undisturbed humus contained more seedlings than expected. This result, contrary to what is generally reported in the literature may be explained either by the fairly humid conditions, favourable to germination and seedling establishment, occurring on clay sites or by the scarifier spreading the cone-bearing slash outward. Seedling abundance and distribution improved substantially from the first year to the second year following treatment. Although the irregular branch distribution over the cutover area appears to have limited regeneration success, combining on-site delimbing with soil scarification could lead to relatively good stocking of jack pine regeneration that could be enhanced by some fill-planting. This regeneration method could constitute an alternative to planting jack pine on clay. However, vegetation control to remove aspen competition might be necessary. Key words: jackpine, silviculture, natural regeneration, boreal mixed wood

An inevitable crisis? From first to second year in counsellor training

2020 ◽  
Vol 5 (1) ◽  
pp. 74-89
Author(s):  
Hugh Crago
Keyword(s):  
Right Hemisphere ◽  
Training Programme ◽  
First Year ◽  
Training Experience ◽  
Counsellor Training ◽  
Student Dropout ◽  
Second Year ◽  
Neurological Research ◽  
First Year Of Life ◽  
And Control

In a seminal 1973 paper, Robert Clark described the very different “cultures” of the first and second year students in a four year clinical psychology PhD programme. The author applies Clark’s template to his own experiences as trainee or trainer in five different counsellor education programmes, one in the US and four in Australia. Each of the programmes, to varying degrees, demonstrates key features of the pattern identified by Clark, where the first year is “therapeutic” and other-oriented, the second is “professional” and self-focused. The author concludes that all the surveyed programmes exhibited some level of “second year crisis”, in which a significant number of students felt abandoned, dissatisfied, or rebellious. The author extends and refines Clark’s developmental analogy (first year = childhood; second year = adolescence) to reflect recent neurological research, in particular, the shift from a right hemisphere-dominant first year of life, prioritising affiliative needs, to a left hemisphere-dominant second year, prioritising autonomy and control. This shift is paralleled later by a more gradual move from a protective, supportive childhood to necessary, but sometimes conflictual, individuation in adolescence. The first two years of a counsellor training programme broadly echo this process, a process exacerbated by the second year internship/placement, in which students must “leave home” and adjust to unfamiliar, potentially less nurturing, authority figures. Finally, the author suggests introducing more rigorous “academic holding” into the first year, and greater attention to “therapeutic holding” of dissident students in the second, hopefully decreasing student dropout, and achieving a better balanced training experience.

Implementation of the Second-year course in an Engineering Professional Spine

2018 ◽  
Author(s):  
Umar Iqbal ◽  
Deena Salem ◽  
David Strong
Keyword(s):  
Learning Outcomes ◽  
Research University ◽  
Engineering Students ◽  
Employability Skills ◽  
First Year ◽  
Computer Engineering ◽  
Core Courses ◽  
Second Year ◽  
First Time ◽  
Academic Year

The objective of this paper is to document the experience of developing and implementing a second-year course in an engineering professional spine that was developed in a first-tier research university and relies on project-based core courses. The main objective of this spine is to develop the students’ cognitive and employability skills that will allow them to stand out from the crowd of other engineering graduates.The spine was developed and delivered for the first time in the academic year 2010-2011 for first-year general engineering students. In the year 2011-2012, those students joined different programs, and accordingly the second-year course was tailored to align with the different programs’ learning outcomes. This paper discusses the development and implementation of the course in the Electrical and Computer Engineering (ECE) department.

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