scholarly journals Glyphosate tolerance of eastern white cedar: Third year results

2017 ◽  
Vol 93 (02) ◽  
pp. 190-193
Author(s):  
Thomas L. Noland ◽  
Rongzhou Man ◽  
Michael Irvine
Keyword(s):  
Seedling Survival ◽  
Herbicide Tolerance ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Application Timing ◽  
White Cedar ◽  
Eastern White Cedar ◽  
Survival Pattern ◽  
Manual Weeding ◽  
And Control

Little is known about the herbicide tolerance of eastern white cedar (Thuja occidentalis L.). To determine the sensitivity of cedar seedlings to timing and concentration of herbicide applications, glyphosate was applied to 2-year-old seedlings at three concentrations (1.04, 2.07, and 4.14 acid equivalent (ae) kg ha-1) at three times (July 28, August 10 and 31), at a research site in north central Ontario. Seedling survival, growth, and biomass three years after spraying were compared with those of seedlings in manual weeding (competition/weed free via manual weeding) and control (no weeding and therefore always competition/weeds) treatments. Only glyphosate applied at 4.14 ae kg ha-1 significantly reduced, by 27%, third year seedling survival. Pattern of sensitivity of cedar seedling growth to glyphosate was diameter>height. Seedlings treated with 2.07 and 4.14 ae kg ha-1 glyphosate had significantly less root biomass than those in the control plots, whereas only cedar treated with 4.14 ae kg ha-1 glyphosate had lower shoot biomass. Application timing made no difference in survival, growth, or final biomass. All glyphosate and the no weeding control treatments reduced root, shoot, and total biomass of cedar relative to the manually weeded seedlings.

Determining the glyphosate tolerance of eastern white cedar: First year post-treatment results

2015 ◽  
Vol 91 (02) ◽  
pp. 182-186 ◽  
Author(s):  
Thomas L. Noland ◽  
Rongzhou Man ◽  
Michael Irvine
Keyword(s):  
Volume Growth ◽  
First Year ◽  
Treatment Results ◽  
Thuja Occidentalis ◽  
Application Timing ◽  
White Cedar ◽  
Eastern White Cedar ◽  
Snow Damage ◽  
Survival And Growth ◽  
Growth Of Seedlings

Little is known about the silvicultural traits of eastern white cedar (Thuja occidentalis L.), and especially the tolerance of seedlings to herbicides. A study was established to determine the sensitivity of cedar seedlings to timing and concentration of glyphosate applications. Glyphosate was applied to seedlings at three concentrations (1.04, 2.07, and 4.14 acid equivalent (ae) kg ha-1) at three times (July 28, August 10 and August 31) and their survival and growth was compared with that of seedlings in three control treatments (competition free, always competition, and competition free after an August 10 application of 2.07 kg ha-1 glyphosate) for a total of 12 treatments. Damage to foliage increased (r2 = 0.99) and first-year volume growth decreased (r2 = 0.91) with increasing glyphosate concentration. Glyphosate applied at 4.14 kg ha-1 killed 9% of the seedlings; even the lowest concentration of glyphosate (1.04 kg ha-1) reduced first-year volume growth more than continuous herbaceous competition. Application timing did not affect the amount of foliar damage or the growth of seedlings. However, in the winter following the treatments, snow damage was greater in the weed-free control seedlings than in all other treatments.

Rice safety and control of penoxsulam resistant and susceptible barnyardgrass (Echinochloa crus-galli) populations with soil-applied herbicides

2021 ◽  
pp. 1-26
Author(s):  
Tingting Liu ◽  
Jialin Yu ◽  
Jiapeng Fang ◽  
Liyao Dong
Keyword(s):  
Rice Fields ◽  
Shoot Biomass ◽  
Rice Varieties ◽  
And Control

Abstract Resistance to penoxsulam among barnyardgrass populations is prevalent in rice fields in China. Seeds of penoxsulam-resistant (AXXZ-2) and -susceptible (JLGY-3) barnyardgrass populations, as well as the seeds of two rice varieties including Wuyungeng32 (WY) and Liangyou669 (LY) were planted in plastic pots and then treated with a rate titration of acetochlor, anilofos, butachlor, clomazone, oxadiazon, pendimethalin, pretilachlor, pyraclonil, or thiobencarb. The two barnyardgrass populations exhibited similar susceptibility to acetochlor, anilofos, butachlor, oxadiazon, pretilachlor, or pyraclonil. However, the susceptibility differed between the barnyardgrass populations in response to clomazone, pendimethalin, and thiobencarb. For AXXZ-2, herbicide rates that caused 50% reduction in shoot biomass from the nontreated control (GR50) were 179, >800, and 1798 g ha-1 for clomazone, pendimethalin, and thiobencarb, respectively; while JLGY-3 GR50 values were 61, 166, and 552 g ha-1, respectively. Both rice varieties demonstrated excellent tolerance to acetochlor, butachlor, oxadiazon, pretilachlor, and thiobencarb. However, substantial rice damage was observed with anilofos and clomazone. Anilofos at 352 g ha-1 and clomazone at 448 g ha-1 reduced rice shoot biomass by 41 and 50% from the nontreated, respectively. Averaged across herbicide rates, clomazone reduced rice shoot biomass from the nontreated control by 52 and 34% for WY and LY, respectively; and pendimethalin reduced rice shoot biomass from the nontreated control by 25 and 9% for WY and LY, respectively.

FACTORS AFFECTING THE MORTALITY OF LEAFMINERS ARGYRESTHIA THUIELLA AND PULICALVARIA THUJAELLA (LEPIDOPTERA: YPONOMEUTIDAE AND GELECHIIDAE) ON EASTERN WHITE CEDAR, IN ONTARIO

1979 ◽  
Vol 111 (11) ◽  
pp. 1299-1306 ◽  
Author(s):  
N. L. Bazinet ◽  
M. K. Sears
Keyword(s):  
Host Species ◽  
Life Tables ◽  
Mortality Factors ◽  
Factors Affecting ◽  
White Cedar ◽  
Eastern White Cedar ◽  
Overwintering Mortality

AbstractMortality factors affecting populations of the leafminers Argyresthia thuiella (Pack.) and Pulicalvaria thujaella (Kft.), on eastern white cedar in the area of Guelph, Ontario were identified and summarized in life tables. During the two annual generations studied from 1975 to 1977, overwintering mortality varied widely. Winterkill increased from 6.8% to 62.9% for A. thuiella and from 8.1% to 54.6% for P. thujaella, from 1976 to 1977. Several parasitoids produced substantial mortality of each host species, but their effect may have been superseded by winterkill in 1977. Data indicate that both populations of leafminers increased from 1975 to 1976 but decreased substantially from 1976 to 1977.

Biomass allocation in tomato (Lycopersicon esculentum) plants grown under partial rootzone drying: enhancement of root growth

2004 ◽  
Vol 31 (10) ◽  
pp. 971 ◽  
Author(s):  
Darren M. Mingo ◽  
Julian C. Theobald ◽  
Mark A. Bacon ◽  
William J. Davies ◽  
Ian C. Dodd
Keyword(s):  
Lycopersicon Esculentum ◽  
Root System ◽  
Biomass Allocation ◽  
Root Biomass ◽  
Leaf Water ◽  
Total Biomass ◽  
Split Root ◽  
Split Root System ◽  
Partial Rootzone Drying ◽  
And Control

Tomato (Lycopersicon esculentum Mill.) plants were grown in either a glasshouse (GH) or a controlled environment cabinet (CEC) to assess the effects of partial rootzone drying (PRD) on biomass allocation. Control and PRD plants received the same amounts of water. In control plants, water was equally distributed between two compartments of a split-root system. In PRD plants, only one compartment was watered while the other was allowed to dry. At the end of each drying cycle, wet and dry compartments were alternated. In the GH, total biomass did not differ between PRD and control plants after four cycles of PRD, but PRD increased root biomass by 55% as resources were partitioned away from shoot organs. In the CEC, leaf water potential did not differ between treatments at the end of either of two cycles of PRD, but stomatal conductance of PRD plants was 20% less at the end of the first cycle than at the beginning. After two cycles of PRD in the CEC, biomass did not differ between PRD and control plants, but PRD increased root biomass by 19% over the control plants. The promotion of root biomass in PRD plants was associated with the alternation of wet and dry compartments, with increased root biomass occurring in the re-watered compartment after previous exposure to soil drying. Promotion of root biomass in field-grown PRD plants may allow the root system to access resources (water and nutrients) that would otherwise be unavailable to control plants. This may contribute to the ability of PRD plants to maintain similar leaf water potentials to conventionally irrigated plants, even when smaller irrigation volumes are supplied.

Rare forest types in northeastern Ontario: a classification and analysis of representation in protected areas

2010 ◽  
Vol 40 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Charles R. Drever ◽  
James Snider ◽  
Mark C. Drever
Keyword(s):  
Protected Areas ◽  
Local Population ◽  
Red Oak ◽  
Betula Alleghaniensis ◽  
White Pine ◽  
Yellow Birch ◽  
Eastern White Pine ◽  
Habitat Specificity ◽  
White Cedar ◽  
Eastern White Cedar

Our objective was to assess the relative rarity and representation within protected areas of Standard Forest Units (SFUs) in northeastern Ontario by applying the concepts of geographic range, habitat specificity, and local population size. SFUs are stand type classifications, routinely employed by forest managers, based on tree composition, disturbance history, and prescribed silvicultural system. We identified several SFUs as rare because of a narrow distribution, association with only one landform type, or lack of at least one stand larger than an ecoregion-specific threshold. In the Boreal forest, rare SFUs comprised stands dominated by eastern hemlock ( Tsuga canadensis (L.) Carrière), red oak ( Quercus rubra L.), yellow birch ( Betula alleghaniensis Britt.), or eastern white-cedar ( Thuja occidentalis L.). Rare SFUs also included eastern white pine ( Pinus strobus L.) and (or) red pine ( Pinus resinosa Ait.) leading stands managed by shelterwood or seed tree silviculture as well as low-lying deciduous stands and selection-managed stands of shade-tolerant species. In the Great Lakes – St. Lawrence forest, rare SFUs were yellow birch stands, stands dominated by conifer species abundant in the Boreal, and shelterwood-managed hardwood stands. Several rare SFUs had <12% of their total area in protection, i.e., stands dominated by eastern white pine, yellow birch, eastern white pine – red oak, or eastern white-cedar. These rare stand types require increased protection in reserves and tailored silvicultural practices to maintain their probability of persistence.

scholarly journals Direct Biotic Plant–soil Feedback Promotes Dodonaea Viscosa Growth in a Dry-hot Valley, China

2021 ◽  
Author(s):  
Xuemei Wang ◽  
Bangguo Yan ◽  
Liangtao Shi ◽  
Gangcai Liu
Keyword(s):  
Nutrient Cycling ◽  
Soil Biota ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Conditioning Phase ◽  
Dodonaea Viscosa ◽  
Soil Sterilization ◽  
Plant Soil ◽  
Soil Feedback ◽  
Feedback Phase

Abstract Biotic plant-soil feedback has been widely studied, and may be particularly important in resource-poor areas. However, the roles of soil nutrient cycling in affecting plant growth in this process still remained unclear. The aim of this study was to explore the roles of soil biota in regulating nutrient cycling by conducting a two-phase feedback experiment in a dry-hot valley, with a conditioning phase during which there were Dodonaea viscosa or no D. viscosa growing in the soil, and a feedback phase in which the effect of the conditioned soil biota on D. viscosa performance was measured. The growth of D. viscosa significantly reduced soil N after the conditioning phase. However, D. viscosa showed a positive plant-soil feedback. In the feedback phase, the D. viscosa conditioned soil promoted the stem diameter, leaf area, and leaf dry mass content of D. viscosa. Total biomass was also significantly higher in D. viscosa conditioned soil than that in not conditioned soil. In contrast, soil sterilization had a negative effect on the growth of D. viscosa, with a significant reduction in plant biomass, especially in D. viscosa conditioned soil, and soil sterilization significantly increased the root: shoot biomass ratio and litter mass. Furthermore, we showed that although the biota-driven changes in enzyme activities correlated with the leaf N and P amount especially P amount, the enzyme activity was not the main reason to promote D. viscosa growth in the conditioned soil.

Evidence of high self-fertilization in natural populations of eastern white cedar (Thuja occidentalis)

1990 ◽  
Vol 68 (3) ◽  
pp. 663-668 ◽  
Author(s):  
Daniel J. Perry ◽  
Peggy Knowles
Keyword(s):  
Natural Populations ◽  
Outcrossing Rate ◽  
Significant Heterogeneity ◽  
Embryo Survival ◽  
Thuja Occidentalis ◽  
White Cedar ◽  
Northwestern Ontario ◽  
Outcrossing Rates ◽  
Self Fertilization ◽  
Eastern White Cedar

Arrays of open-pollinated seeds were assayed for allozyme polymorphisms at four loci (Mdh-1, Me, 6Pg-2, and Pgm) to obtain estimates of outcrossing rates for three eastern white cedar populations in northwestern Ontario, Canada. Multilocus population outcrossing rate estimates were low, ranging from 0.507 to 0.745, with significant heterogeneity among populations. Low stand densities and relatively high selfed embryo survival may have contributed to the low effective outcrossing rates observed. Single-tree multilocus outcrossing rate estimates were obtained for nine trees from one population. When estimated jointly with outcross pollen pool allele frequencies, these outcrossing rate estimates ranged from 0.253 to 1.023 with significant heterogeneity among trees. Key words: mating system, outcrossing rate, Thuja occidentalis L.

scholarly journals Effects of High Potassium and Low Temperature on the Growth and Magnesium Nutrition of Different Tomato Cultivars

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 710-714 ◽  
Author(s):  
Huixia Li ◽  
Zhujun Chen ◽  
Ting Zhou ◽  
Yan Liu ◽  
Sajjad Raza ◽  
...  
Keyword(s):  
Low Temperature ◽  
Shoot Biomass ◽  
Total Biomass ◽  
High Potassium ◽  
Hydroponic Experiment ◽  
Root Shoot Ratio ◽  
High K ◽  
Significant Difference ◽  
Tomato Cultivars ◽  
K Concentration

The interaction between potassium (K) and magnesium (Mg) in plants has been intensively studied. However, the responses of different tomato (Solanum lycopersicum L.) cultivars to high K levels at low temperatures remained unclear. Herein, a complete randomized hydroponic experiment was conducted to evaluate the effects of temperature (25 °C day/18 °C night vs. 15 °C day/8 °C night) and K concentrations (156 mg·L−1 vs. 468 mg·L−1) on the growth and Mg nutrition of tomato cultivars Gailiangmaofen (MF) and Jinpeng No. 1 (JP). Compared with the control temperature (25 °C day/18 °C night), the low temperature decreased total biomass, shoot biomass, and Mg uptake in shoot by 17.3%, 24.1%, and 11.8%, respectively; however, the root/shoot ratio was increased. High K had no significant effect on plant growth or biomass compared with the control K concentration (156 mg·L−1); however, Mg concentrations and uptake in shoot were significantly lower under high-K treatment. Significant difference was observed for K uptake, but not for Mg uptake, between the two cultivars. There was no significant interaction between temperature and high K on Mg uptake of tomato, so a combined stress of low temperature and high K further inhibited Mg uptake and transport. Low temperature and high K increased the risk of Mg deficiency in tomato.

Patterns of Architectural Variation in Thuja occidentalis L. (Eastern White Cedar) from Upland and Lowland Sites

1991 ◽  
Vol 152 (4) ◽  
pp. 494-499 ◽  
Author(s):  
Christopher H. Briand ◽  
Usher Posluszny ◽  
Douglas W. Larson ◽  
Uta Matthes-Sears
Keyword(s):  
Thuja Occidentalis ◽  
White Cedar ◽  
Eastern White Cedar
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