Effect of Timing on Chemical Control of Dalmatian Toadflax (Linaria dalmatica) in California

2013 ◽  
Vol 6 (3) ◽  
pp. 362-370 ◽  
Author(s):  
Guy B. Kyser ◽  
Joseph M. DiTomaso
Keyword(s):  
Residual Activity ◽  
Early Spring ◽  
High Rate ◽  
Effective Control ◽  
Grass Species ◽  
Optimal Timing ◽  
Linaria Dalmatica ◽  
Time Of Application ◽  
Dalmatian Toadflax ◽  
Second Year

AbstractDalmatian toadflax is listed as a noxious weed in most of the western United States, but control of this species has not been extensively studied in California. Studies in other states show effective control of Dalmatian toadflax with picloram, but this herbicide is not registered for use in California. In addition, reports vary as to the optimal timing for herbicide applications. In this study we evaluated several herbicides with combined foliar and soil-residual activity at two times of application: postsenescence (fall) and rosette (winter to early spring). We applied two series of treatments (2008 and 2009 to 2010) on adjacent sites in high desert scrub of southern California. In the year of treatment and the following year, we evaluated Dalmatian toadflax cover and presence/absence of associated dominant species (≥ 5% cover). Although time of application, treatment, and timing by treatment interaction all produced significant differences in Dalmatian toadflax cover in the 2008 trial, only the high rate of aminocyclopyrachlor (280 g ae ha−1) applied to dormant plants in fall consistently reduced cover through the second year. No treatments at the rosette stage consistently produced 2 yr of control. In 2009 to 2010, treatments were more effective, probably owing to higher precipitation in spring. In both dormant and rosette applications made in 2009 to 2010, aminocyclopyrachlor (140 and 280 g ae ha−1) and aminocyclopyrachlor + chlorsulfuron (140 g ae ha−1+ 53 g ai ha−1) gave second year control; chlorsulfuron at the dormant stage (105 and 158 g ai ha−1) and aminopyralid at the rosette stage (245 g ae ha−1) also gave 2 yr of control. The treatments had only minor effects on grass species. The response of broadleaf species varied among treatments, with aminocyclopyrachlor at the high rate increasingEriogonumspp., but greatly reducing Asteraceae species. These results provide options for the management of Dalmatian toadflax in California and other western states.

Carbohydrate Reserves in Roots of Dalmatian Toadflax

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 212-214 ◽  
Author(s):  
W. C. Robocker ◽  
Roland Schirman ◽  
B. A. Zamora
Keyword(s):  
Reducing Sugars ◽  
Growing Season ◽  
First Year ◽  
Linaria Dalmatica ◽  
Dalmatian Toadflax ◽  
Carbohydrate Depletion ◽  
Beginning Of Flowering ◽  
Second Year ◽  
Reserve Carbohydrate ◽  
Eastern Washington

Reserve carbohydrates of Dalmatian toadflax (Linaria dalmatica(L.) Mill.) in eastern Washington were at their highest levels in autumn at the end of the growing season, and the lowest point occurred at the beginning of flowering about June 15. A one-time removal of first-year floral stems (June 11, 1964) did not significantly lower reserve carbohydrates when measured in September, but similar clipping of floral stems the second year (June 16, 1965) did cause a significant reduction. Reserves were reduced by 2-(2,4,5-trichlorophenoxy)propionic acid (silvex) at 1.12 or 1.68 kg/ha but were not reduced by 4-amino-3,5,6-trichloropicolinic acid (picloram) at the same rates. Combinations of equal weights of the two herbicides to total 1.12 or 1.68 kg/ha caused a significant reduction in reserve carbohydrates. The combinations of silvex and picloram appeared to have an additive toxic effect, but the reduction of reserve carbohydrates was no greater than that caused by silvex alone at 1.12 or 1.68 kg/ha. Lethal action of the herbicides did not appear to be caused by reserve carbohydrate depletion. Glucose and fructose were the major reducing sugars detected in chromatographic analysis.

scholarly journals Control of glyphosate-resistant giant ragweed (Ambrosia trifida L.) with premix of iodosulfuron/thiencarbazone applied alone or in tank mixtures in no-till corn (Zea mays L.)

2018 ◽  
Vol 98 (4) ◽  
pp. 908-917 ◽  
Author(s):  
Simranpreet Kaur ◽  
Amit J. Jhala
Keyword(s):  
Field Experiments ◽  
Zea Mays L ◽  
Residual Activity ◽  
Early Spring ◽  
Effective Control ◽  
Corn Yield ◽  
Ambrosia Trifida ◽  
No Till ◽  
Giant Ragweed

The objectives of this study were to evaluate the efficacy of a new premix of iodosulfuron (6%)/thiencarbazone (45%) applied alone or tank-mixed with 2,4-D, dicamba, glyphosate, or metribuzin in the fall and (or) early spring followed by preemergence (PRE) and postemergence (POST) herbicide applications for control of glyphosate-resistant giant ragweed and their effect on corn yield. Field experiments were conducted in no-till corn fields infested with glyphosate-resistant giant ragweed (20–30 plants m−2) near Clay Center and McCool Junction, NE, in 2013 and 2014, respectively. A premix of iodosulfuron/thiencarbazone applied alone or in split applications in the fall and early spring controlled glyphosate-resistant giant ragweed <60% and resulted in a density of 14 giant ragweed plants m−2, which was comparable to the untreated control at 28 d after early spring treatment (DAEST). Metribuzin or 2,4-D applied alone resulted in <75% giant ragweed control at 28 DAEST; however, 2,4-D or dicamba tank-mixed with iodosulfuron/thiencarbazone provided ≥92% control. Treatments including 2,4-D or dicamba led to 85%–98% reduction in giant ragweed biomass at 28 DAEST. A follow-up application of a premix of isoxaflutole/thiencarbazone tank-mixed with atrazine applied PRE was not effective, although a POST application of tembotrione + atrazine resulted in >91% control at 28 d after postemergence treatment. The premix applied alone did not provide effective control of giant ragweed in corn primarily because lack of residual activity.

TIME OF APPLICATION AND SOURCE OF NITROGEN FERTILIZER ON YIELD, QUALITY, NITROGEN RECOVERY, AND NET RETURNS FOR DRYLAND FORAGE GRASSES

1986 ◽  
Vol 66 (4) ◽  
pp. 915-931 ◽  
Author(s):  
C. A. CAMPBELL ◽  
A. J. LEYSHON ◽  
R. P. ZENTNER ◽  
H. UKRAINETZ
Keyword(s):  
Ammonium Nitrate ◽  
Early Spring ◽  
N Fertilizer ◽  
Grass Species ◽  
N Recovery ◽  
Brown Soil ◽  
Time Of Application ◽  
Net Returns ◽  
Soil Zone ◽  
Forage Yields

Studies were conducted in Saskatchewan for 4 yr at Swift Current (Brown soil zone) and 3 yr at Scott (Dark Brown soil zone) to assess the effect of time of application and source of N fertilizer on grass forage yields and N and P content, fertilizer N recovery and net returns. A single rate of N, 50 kg ha−1 was applied to established forage stands at three dates during the late fall to early winter period and one or two dates during the early spring period. Six grass species were grown at Swift Current and one at Scott. At Swift Current there were significant differences in dry matter yields between grass species but no species × fertilizer interactions. Fertilizer applied in April generally gave the highest forage yields and N concentration, N recovery, and net returns, but sometimes October and/or November applications provided as good or better results. At Swift Current relative yields (averaged over grass species and source of N) for the different application dates were: April, 158; late October, 154; late November, 145; and late December, 137; with the unfertilized control given a value of 100. At Scott, a similar rating of yields gave: mid-April, 225; mid-October, 219; mid-November, 216; mid-December, 213; and mid-March, 192. Nitrogen concentration in forages averaged 2.06% at Swift Current and 1.53% at Scott, and was mainly affected (increased) by the April fertilizer application date. Yields were 11–13% greater when ammonium nitrate was used compared to when urea was used. Because the N was broadcast and yields were small, recoveries of N by the crop were low, variable due to weather, and averaged 21% at both sites. In most years N fertilizer increased yields, but net returns varied depending on the occurrence of early spring precipitation and on whether the forage was sold for hay or fed on the farm. Fertilization was profitable in the wetter years, but in dry years money was lost irrespective of the N source or site. Net returns favored the ammonium nitrate source of N.Key words: Grass species, grass yield, urea, ammonium nitrate, net returns

scholarly journals Do applications of systemic herbicides when green fruit are present prevent seed production or viability of Alliaria petiolata (garlic mustard)?

2021 ◽  
pp. 1-17
Author(s):  
Leo Roth ◽  
José Luiz C. S. Dias ◽  
Christopher Evans ◽  
Kevin Rohling ◽  
Mark Renz
Keyword(s):  
Seed Production ◽  
Seed Viability ◽  
Early Spring ◽  
Alliaria Petiolata ◽  
Late Spring ◽  
Garlic Mustard ◽  
Viable Seed ◽  
Application Timing ◽  
Control Seed ◽  
Second Year

Garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande] is a biennial invasive plant commonly found in the northeastern and midwestern United States. Although it is not recommended to apply herbicides after flowering, land managers frequently desire to conduct management during this timing. We applied glyphosate and triclopyr (3% v/v and 1% v/v using 31.8% and 39.8% acid equivalent formulations, respectively) postemergence to established, second-year A. petiolata populations at three locations when petals were dehiscing, and evaluated control, seed production and seed viability. Postemergence glyphosate applications at this timing provided 100% control of A. petiolata by 4 weeks after treatment at all locations whereas triclopyr efficacy was variable, providing 38-62% control. Seed production was only reduced at one location, with similar results regardless of treatment. Percent seed viability was also reduced, and when combined with reductions in seed production, we found a 71-99% reduction in number of viable seed produced plant-1 regardless of treatment. While applications did not eliminate viable seed production, our findings indicate that glyphosate and triclopyr applied while petals were dehiscing is a viable alternative to cutting or hand-pulling at this timing as it substantially decreased viable A. petiolata seed production. Management Implications Postemergence glyphosate and triclopyr applications in the early spring to rosettes are standard treatments used to manage A. petiolata. However, weather and other priorities limit the window for management, forcing field practitioners to utilize more labor-intensive methods such as hand-pulling. It is not known how late in the development of A. petiolata these herbicides can be applied to prevent viable seed production. Since prevention of soil seedbank replenishment is a key management factor for effective long-term control of biennial invasive species, we hypothesized late spring foliar herbicide applications to second year A. petiolata plants when flower petals were dehiscing could be an effective management tool if seed production or viability is eliminated. Our study indicated that glyphosate applications at this timing provided 100% control of A. petiolata plants by 4 weeks after treatment at all locations, whereas triclopyr efficacy was inconsistent. Although both glyphosate and triclopyr decreased viable seed production to nearly zero at one of our three study locations, the same treatments produced significant amounts of viable seed at the other two locations. Our findings suggest late spring glyphosate and triclopyr applications should not be recommended over early spring applications to rosettes for A. petiolata management, as our late spring application timing did not prevent viable seed production, and may require multiple years of implementation to eradicate populations. Nonetheless, this application timing holds value in areas devoid of desirable understory vegetation compared to no management practices or mechanical management options including hand-pulling when fruit are present, as overall viable seed production was reduced to similar levels as these treatments.

Effect of method and time of application of nitrogen fertiliser on yield and quality of seed of creeping red fescue

2000 ◽  
Vol 80 (4) ◽  
pp. 809-811 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Quality ◽  
Early Spring ◽  
Festuca Rubra ◽  
Grass Seed ◽  
Red Fescue ◽  
Time Of Application ◽  
Vigorous Plant ◽  
Tiller Density

Six trials were conducted on commercial seed fields of creeping red fescue (Festuca rubra L. var. rubra) in the Peace region to evaluate the sensitivity of seed production to the method and time of application of N fertiliser. In each trial, 68 kg ha−1 N was applied using three methods (surface-broadcast, granular, ammonium nitrate 34-0-0; foliar/soil spray of 28-0-0 solution N; soil-injected 28-0-0 solution N) at each of three times (fall, early spring, late spring). No statistically significant (P = 0.05) interaction, or main effect, of method and time of N were revealed for seed yield, fertile tiller density or for several seed quality characteristics. Seed yield varied greatly among trials (142 to 1240 kg ha−1) and averaged 566 kg ha−1. The results indicate that there is considerable flexibility in the method and time of application of N fertiliser for seed production of creeping red fescue in the Peace region, provided it is applied before the commencement of vigorous plant growth in the spring. Key words: Creeping red fescue, Festuca rubra L., nitrogen fertility, grass seed production, grass seed quality

scholarly journals Emergence of Unusual Rotavirus G9p[4] and G8p[8] Strains During Post Vaccination Surveillance in Argentina, 2017-2018 

2020 ◽  
Author(s):  
Juan I Degiuseppe ◽  
Juan A Stupka
Keyword(s):  
Early Spring ◽  
High Rate ◽  
Phylogenetic Study ◽  
Genotype Distribution ◽  
Post Vaccination ◽  
Rotavirus Vaccination ◽  
Immunization Strategies ◽  
Monovalent Vaccine ◽  
The Impact ◽  
Children Under 5

Abstract Background. In 2015, Argentina included RotarixTM monovalent vaccine for universal administration and it showed a sharp decline in all-cause and rotavirus-confirmed cases as well as an immediate predominance of the G2P[4] genotype. The aim of this study was to analyze the impact of rotavirus vaccination on disease burden and genotype distribution in our country following its introduction. Methods. Prevalence and seasonality of laboratory-confirmed rotavirus cases data were assessed. Analyses of circulating genotypes were performed by conventional binary characterization (G and P typing). Phylogenetic study of VP7 gene was performed from emergent unusual strains. Results. During 2017-2018, 1183 rotavirus cases (13.2%) were detected and prevalence was uniform among different age subgroups. Weekly distribution showed a raise of confirmed cases around late July and early August. In 2017 the most frequently detected genotypes were G2P[4] and G3P[8]. However, in 2018 G12P[8] genotype increased and it was detected at a high rate. Noteworthy, the detection of uncommon G9P[4] and G8P[8] strains (bearing DS-1-like genetic backbones) was observed at moderate rates. Conclusions. Following four years of this strategy, the prevalence of rotavirus remained low in children under 5 years of age with a shift of the seasonal peak in early spring. The emergence of uncommon genotypes was due to introduction of new strains rather than to reassortment of local strains. Continuous monitoring of rotavirus burden of disease and genotype distribution provides useful evidence to evaluate existing immunization strategies and to contribute in the development of new vaccines as well.

Bioactivity of oxymatrine and azadirachtin against Tetranychus evansi (Acari: Tetranychidae) and their compatibility with the predator Phytoseiulus longipes (Acari: Phytoseiidae) on tomato

2021 ◽  
Author(s):  
Patrice Jacob Savi ◽  
Marcio Barbosa Martins ◽  
Gilberto José De Moraes ◽  
Fabien Charles Cossi Hountondji ◽  
Daniel Júnior Andrade
Keyword(s):  
Residual Activity ◽  
Residual Effect ◽  
Development Stage ◽  
Effective Control ◽  
Tetranychus Evansi ◽  
Tomato Plants ◽  
Laboratory Conditions ◽  
Low Toxicity ◽  
Phytoseiulus Longipes ◽  
Screen House

Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) is one of the main tomato pests in several countries, mainly in Africa, and applications of synthetic acaricides are the main strategy for its control. Efficient biopesticides to suppress pest populations, with low toxicity against natural enemies, is highly desirable for integrated pest management. Here, we evaluated under laboratory conditions the effect of azadirachtin- and oxymatrine-based formulations on each development stage of T. evansi and on the adult stage of the predatory mite Phytoseiulus longipes, the single promising predator of this pest. We also assessed the residual effect of these biopesticides on T. evansi under laboratory conditions on leaflets excised from treated tomato plants maintained in a screen-house 1, 5, and 10 days after application. Azadirachtin-based formulations were effective in controlling T. evansi immature stages. Oxymatrine-based treatments controlled T. evansi immatures and adult females faster than azadirachtin-based treatments. Both biopesticides had no effect on T. evansi eggs, but oxymatrine-based treatments were highly efficient on newly hatched T. evansi larvae. Oxymatrine displayed residual activity that controlled T. evansi up to 10 days after application. Azadirachtin formulations caused lower mortality of P. longipes adults (8–28%) and slightly reduced fecundity (24.8–56.1%). In contrast, oxymatrine treatments caused higher mortality (60–88%) of the predator and reduced substantiality its fecundity (73.1–90.7%). Our findings suggest that Azadirachtin and oxymatrine provide effective control of T. evansi. Azadirachtin may be relatively safer to the predatory mites whereas oxymatrine should be used with caution, to avoid suppression of P. longipes.

Annual weed management in isoxaflutole-resistant soybean using a two-pass weed control strategy

2019 ◽  
Vol 33 (03) ◽  
pp. 411-425
Author(s):  
Andrea Smith ◽  
Nader Soltani ◽  
Allan J. Kaastra ◽  
David C. Hooker ◽  
Darren E. Robinson ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
High Rate ◽  
Grass Species ◽  
Annual Grass ◽  
Common Lambsquarters ◽  
Control Programs ◽  
The One ◽  
Herbicide Programs

AbstractTransgenic crops are being developed with herbicide resistance traits to expand innovative weed management solutions for crop producers. Soybean with traits that confer resistance to the hydroxyphenylpyruvate dioxygenase herbicide isoxaflutole is under development and will provide a novel herbicide mode of action for weed management in soybean. Ten field experiments were conducted over 2 years (2017 and 2018) on five soil textures with isoxaflutole-resistant soybean to evaluate annual weed control using one- and two-pass herbicide programs. The one-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, at a low rate (52.5 + 210 g ai ha−1), medium rate (79 + 316 g ai ha−1), and high rate (105 + 420 g ai ha−1); and glyphosate applied early postemergence (EPOST) or late postemergence (LPOST). The two-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, followed by glyphosate applied LPOST, and glyphosate applied EPOST followed by LPOST. At 4 weeks after the LPOST application, control of common lambsquarters, pigweed species, common ragweed, and velvetleaf was variable at 25% to 69%, 49% to 86%, and 71% to 95% at the low, medium, and high rates of isoxaflutole plus metribuzin, respectively. Isoxaflutole plus metribuzin at the low, medium, and high rates controlled grass species evaluated (i.e., barnyardgrass, foxtail, crabgrass, and witchgrass) 85% to 97%, 75% to 99%, and 86% to 100%, respectively. All two-pass weed management programs provided 98% to 100% control of all species. Weed control improved as the rate of isoxaflutole plus metribuzin increased. Two-pass programs provided excellent, full-season annual grass and broadleaf weed control in isoxaflutole-resistant soybean.

Dalmatian Toadflax (Linaria dalmatica): New Host for Cucumber Mosaic Virus

2007 ◽  
Vol 21 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Courtney L. Pariera Dinkins ◽  
Sue K. Brumfield ◽  
Robert K. D. Peterson ◽  
William E. Grey ◽  
Sharlene E. Sing
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Aphid Transmission ◽  
Negative Control ◽  
Enzyme Linked Immunosorbent Assay ◽  
New Host ◽  
Tobacco Plants ◽  
Linaria Dalmatica ◽  
Mechanical Methods ◽  
Dalmatian Toadflax

To date, there have been no reports of Dalmatian toadflax serving as a host for cucumber mosaic virus (CMV). Infestations of Dalmatian toadflax may serve as a reservoir of CMV, thereby facilitating aphid transmission of CMV to both agricultural crops and native plants. The goal of this study was to determine whether Dalmatian toadflax is a host for CMV. Dalmatian toadflax seedlings were randomly assigned to two treatments (18 replicates/treatment): no inoculation (control) and inoculation with CMV (Fast New York strain). The Dalmatian toadflax seedlings were inoculated by standard mechanical methods and tested for the presence of CMV using enzyme-linked immunosorbent assay (ELISA). Ten of the 18 CMV-inoculated toadflax plants tested positive for the virus; 6 of the 18 displayed systemic mosaic chlorosis and leaf curling. All control plants tested negative. Transmission electron microscopy obtained from CMV-positive plants confirmed the presence of CMV based on physical properties. To verify CMV infestation, tobacco plants were assigned to the following treatments (six replicates/treatment): no inoculation (control), CMV-negative (control) inoculation, and a CMV-positive inoculation. Plants were inoculated by standard methods. Five of the 6 tobacco plants treated with the CMV-positive inoculum tested positive for CMV using ELISA. All control plants tested negative for the virus.

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