Response of seashore paspalum and bermudagrass to topramezone and triclopyr mixtures

2020 ◽  
pp. 1-8
Author(s):  
Clebson G. Gonçalves ◽  
Austin M. Brown ◽  
Suma Basak ◽  
J. Scott McElroy
Keyword(s):  
Field Conditions ◽  
Single Application ◽  
Seashore Paspalum ◽  
Application Timing ◽  
Application Programs ◽  
Over Time

Abstract Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43.2, 15.6 + 86.3, 15.6 + 172.6, 15.6 + 345.2, or 15.6 g ai ha−1 + 690.4 g ae ha−1). Secondary greenhouse treatments included a single application of topramezone (20.8 g ha−1) or triclopyr (258.9 g ha−1) alone, or in combination at 20.8 + 258.9 or 20.8 + 517.8 g ha−1, respectively. Greenhouse and field results showed that topramezone applications in combination with triclopyr present opposite responses between bermudagrass and seashore paspalum. Topramezone increased bermudagrass injury and decreased seashore paspalum bleaching injury compared to topramezone alone. In field evaluations, topramezone + triclopyr at 15.6 + 690.4 g ha−1 used in sequential applications resulted in >90% injury to bermudagrass, however, injury decreased over time. Furthermore, sequential applications of topramezone + triclopyr at 15.6 + 690.4 g ha−1 resulted in >50% injury to seashore paspalum. Application programs including topramezone plus triclopyr should increase bermudagrass suppression and reduce seashore paspalum injury compared to topramezone alone. However, additional studies are needed because such practices will likely require manipulation of topramezone rate, application timing, application interval, and number of applications in order to maximize bermudagrass control and minimize seashore paspalum injury.

The Common Application and Student Choice

2021 ◽  
Vol 111 ◽  
pp. 460-464
Author(s):  
Brian Knight ◽  
Nathan Schiff
Keyword(s):  
Student Choice ◽  
Single Application ◽  
Individual Level ◽  
Level Data ◽  
First Choice ◽  
The Common ◽  
Common Application ◽  
Over Time

We study the effects of the Common Application (CA) platform, which allows students to submit a single application to multiple institutions, on student choice. Using individual-level data from freshman surveys over the period 1982-2014, we develop two proxies for student choice, one based upon the number of applications submitted and another based upon students attending non-first-choice institutions. Using these proxies, we first document sharp increases in student choice over time. Linking these outcomes to the timing of CA membership, we provide evidence of a link between CA entry and increased student choice.

Microcosm assessment of potential molluscicides for control of the rice snail Isidorella newcombi sens. lat. (Gastropoda: Basommatophora: Planorbidae)

1996 ◽  
Vol 47 (5) ◽  
pp. 673 ◽  
Author(s):  
MM Stevens ◽  
RJ Faulder ◽  
NE Coombes
Keyword(s):  
Field Conditions ◽  
Initial Screening ◽  
Screening Rate ◽  
Irrigated Rice ◽  
Fish Toxicity ◽  
Further Development ◽  
Over Time ◽  
Delayed Exposure

Twenty-seven pesticides were evaluated for their toxicity to mature Isidorella newcombi (Adams & Angas), a serious pest of irrigated rice in NSW, Australia. Evaluations were conducted using microcosms in which typical field conditions were simulated. Only 3 compounds, niclosamide, n-tritylmorpholine, and nicotinanilide, provided >95% mortality at an initial screening rate of 3 mg/L. These compounds were assessed at a range of rates using both immediate and delayed-exposure bioassays to determine LC values and comparative persistence. Niclosamide (as Bayer Bayluscide� 250 g/L EC) and n-tritylmorpholine (as Shell FresconB 165 g/L EC) were the most toxic (LC90, immediate exposure, 0.19 mg/L for both compounds), whilst the corresponding LC90 value for nicotinanilide (laboratory grade in DMSO) was 0.53 mg/L. Persistence (reflected by a slower increase in LC90 values over time in delayed exposure bioassays) was strongest in nicotinanilide and weakest in n-tritylmorpholine. Although niclosamide is the most promising compound for the control of I. newcombi, further development of nicotinanilide is also recommended, as it represents a potentially valuable tool for use in situations where low fish toxicity is required.

scholarly journals Does nitrogen application timing and sources influence barley grain yield?

2020 ◽  
Vol 19 (3) ◽  
pp. 264-269
Author(s):  
Marcos Renan Besen ◽  
Ricardo Henrique Ribeiro ◽  
Felipe Bratti ◽  
Jorge Luiz Locatelli ◽  
Jonatas Thiago Piva
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
N Fertilization ◽  
Barley Grain ◽  
Urease Inhibitor ◽  
Nitrogen Application ◽  
Single Application ◽  
Application Timing ◽  
N Source ◽  
Relevant Factors

The suitable management of nitrogen (N) fertilization can increase barley grain yield, since it is the nutrient required in greater quantity. In this sense, the source and timing of nitrogen application are relevant factors. The objective was to evaluate the effects of N sources and splitting on the performance of barley. The experiment was carried out under a clayey Cambisol (550 g kg-1), in Curitibanos, Santa Catarina. Factorial randomized blocks were used: three mineral sources of N: urea (45% N); urea with urease inhibitor-NBPT (45% of N) and nitrate (30% of N), associated with two nitrogen splitting fertilization: i) split of the rate of N in two seasons: beginning of tillering and full tillering and ii) single application at full tillering. 100 kg ha-1 of N were applied. There was no interaction between the factors and there was no effect of treatments for plant height, ear length, grains per ear, ears per m² and mass of a thousand grains. Yield was influenced by the N source, where nitrate exceeded the yield from amidic sources by 16%. The splitting of N in two times did not present advantages over the single application. Urea with NBPT was not viable in relation to readily soluble forms of N, with the highest yield obtained with a nitric source.

scholarly journals Controlled-release Potassium Fertilizers for Turfgrass

1992 ◽  
Vol 117 (3) ◽  
pp. 411-414 ◽  
Author(s):  
George H. Snyder ◽  
John L. Cisar
Keyword(s):  
Controlled Release ◽  
Direct Measurement ◽  
Cynodon Dactylon ◽  
Laboratory Method ◽  
Hot Water ◽  
The Other ◽  
Field Conditions ◽  
Laboratory Studies ◽  
K Release ◽  
Over Time

Field and laboratory studies were conducted to evaluate the K retention properties of several resin-coated (RC), sulfur-coated (SC), and plastic-coated (PC) K fertilizers. Substantial differences in K release were found among the controlled-release K materials, based both on the K content of `Tifgreen' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burt-Davvy] clippings and on direct measurement of K remaining in fertilizer granules in the field over time. One SC material appeared to release K too rapidly, and one RC material appeared to release K too slowly to be useful for providing extended plant-available K to turfgrass. The other sources appeared to have release characteristics that would be favorable for turfgrass maintenance. Because differences in K release were observed among the sources, a laboratory method for assessing K release would be useful. Toward this-end, models were developed relating K retention of sources in hot water (70C) to K retention under field conditions.

scholarly journals Effect of Timing of Fungicide Applications on Development of Rusts on Daylily, Geranium, and Sunflower

Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 657-661 ◽  
Author(s):  
D. S. Mueller ◽  
S. N. Jeffers ◽  
J. W. Buck
Keyword(s):  
Disease Management ◽  
Effective Means ◽  
Management Program ◽  
Integrated Disease Management ◽  
Lesion Development ◽  
Application Timing ◽  
Fungicide Efficacy ◽  
Ornamental Crops ◽  
Rust Pathogens ◽  
Over Time

Integrated disease management should provide the most effective means of controlling rusts on ornamental crops over time, and fungicides are an important component of an integrated rust management program. Proper timing of fungicide applications is critical for effective disease management; however, information about application timing is lacking for rusts on ornamental crops. The objective of this study was to determine how fungicides affected rust development on daylily, geranium, and sunflower plants when applied several days before or after inoculation. Five fungicides registered for use against rusts on ornamental crops were evaluated: the strobilurin azoxystrobin; three sterol biosynthesis inhibiting fungicides—myclobutanil, propiconazole, and triadimefon; and the broad spectrum protectant chlorothalonil. All five fungicides significantly reduced lesion development by rust pathogens on daylily, geranium, and sunflower plants when these compounds were applied preventatively up to 15 days before inoculation and infection with a few exceptions (e.g., propiconazole on geranium and triadimefon on sunflower). Curative activity, which resulted from fungicide application after inoculation, was observed for the three rusts with some products (azoxystrobin on all three plants and myclobutanil, propiconazole, and triadimefon on geranium) when applied up to 7 days postinoculation. In general, fungicide efficacy with several of the products decreased as the time from application to inoculation (preventative activity) or inoculation to application (curative activity) increased.

Interference Between Soybeans (Glycine max) and Common Cocklebur (Xanthium strumarium) Under Indiana Field Conditions

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 753-760 ◽  
Author(s):  
William T. Henry ◽  
Thomas T. Bauman
Keyword(s):  
Spatial Distribution ◽  
Regression Analysis ◽  
Glycine Max ◽  
Seed Yield ◽  
Soybean Seed ◽  
Growing Season ◽  
Field Conditions ◽  
Xanthium Strumarium ◽  
Soybean Yield ◽  
Over Time

The effects of interference between soybeans and common cocklebur were investigated. Common cocklebur interference reduced soybean growth at each of four sample dates during the growing season. The area of interference surrounding individual common cocklebur plants within the soybean row fluctuated over time with respect to intensity and spatial distribution. Soybean growth was significantly reduced up to 10 cm away from individual cocklebur plants at 6 weeks after planting (WAP), 30 cm at 8 WAP, 20 to 30 cm at 10 WAP, and 40 cm at 12 WAP. The maximum possible distance of cocklebur influence, determined by regression analysis, also varied during the growing season. When areas of interference from adjacent cocklebur plants overlapped, the cumulative influence was found to be additive, especially late in the growing season. Soybean interference caused a 50 to 90% reduction in the size of common cocklebur plants grown within the soybean row compared to plants grown without interference. At harvest, soybean yield was reduced up to 40 to 50 cm within the row from individual cocklebur plants. The maximum distance of interference on one side of individual cocklebur plants was 75 cm. One cocklebur plant reduced soybean yield 16.0% within 1.5 m of soybean row as the result of full-season interference. Interference of common cocklebur plants spaced 60 cm apart within the row overlapped and caused an additive reduction in soybean seed yield. Across all cocklebur treatments, there was a consistent ratio of approximately 1 kg/ha loss in soybean seed yield for each 4 kg/ha of cocklebur herbage produced.

Sulfonylurea Herbicide Safety on Newly Sprigged Bermudagrass and Seashore Paspalum

2010 ◽  
Vol 24 (3) ◽  
pp. 342-348 ◽  
Author(s):  
Aaron J. Patton ◽  
Jon M. Trappe ◽  
Ronald E. Strahan ◽  
Jeffrey S. Beasley
Keyword(s):  
Application Rate ◽  
Sulfonylurea Herbicides ◽  
Sulfonylurea Herbicide ◽  
Herbicide Application ◽  
Seashore Paspalum ◽  
Application Timing

Several sulfonylurea herbicides are labeled for use on established bermudagrass or seashore paspalum, but label recommendations for many of these chemicals vary for sprigged turf. The objective of this study was to determine the safety of various sulfonylurea herbicides on newly planted, ‘Tifway’ bermudagrass and ‘Aloha’ seashore paspalum sprigs in Arkansas and Louisiana. Treatments were arranged as a five by two by two factorial with five herbicides (foramsulfuron at 29 and 59 g ai ha−1, halosulfuron at 35 and 70 g ai ha−1, metsulfuron at 21 and 42 g ai ha−1, sulfosulfuron at 66 and 131 g ai ha−1, and trifloxysulfuron at 28 and 56 g ai ha−1), two herbicide rates (low and high), and two application timings at 2 or 4 wk after sprigging (WAS). There was no discernable herbicide injury to, or reduction in, Tifway bermudagrass coverage in Arkansas, regardless of herbicide, application timing, or application rate. Trifloxysulfuron and metsulfuron were more injurious than other herbicides in Louisiana when applied at 2 WAS to Tifway bermudagrass, but injury levels were acceptable (< 15%), and there was no long-term reduction in establishment. Metsulfuron or halosulfuron applied at 2 or 4 WAS and sulfosulfuron applied at 4 WAS allowed > 90% establishment of Aloha seashore paspalum at both locations. Both trifloxysulfuron and foramsulfuron were injurious to seashore paspalum and reduced its establishment. These results suggest that sulfonylurea herbicides can be safely applied shortly after sprigging to Tifway bermudagrass and that metsulfuron, halosulfuron, and sulfosulfuron could be useful herbicides for establishing Aloha seashore paspalum from sprigs.

Effect of Glyphosate and MSMA Application Timing on Weed Control, Fruiting Patterns, and Yield in Glyphosate-Resistant Cotton

2005 ◽  
Vol 19 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Michael W. Edenfield ◽  
Barry J. Brecke ◽  
Daniel L. Colvin ◽  
Joan A. Dusky ◽  
Donn G. Shilling
Keyword(s):  
Weed Control ◽  
Fruit Development ◽  
Yield Loss ◽  
Window Of Opportunity ◽  
Single Application ◽  
Application Timing ◽  
Leaf Stage ◽  
Pitted Morningglory ◽  
Subsequent Effect ◽  
Over The Top

The limited window of opportunity for glyphosate postemergence (POST) over-the-top applications in glyphosate-resistant cotton poses a problem for growers where a midseason salvage weed control remedy is necessary. The objectives of these experiments were to compare glyphosate and MSMA for midseason weed control and their subsequent effect on cotton fruiting characteristics and yield. Glyphosate at 0.85 kg ai/ha was more effective than MSMA at 1.7 kg ai/ha for POST control of sicklepod, redweed, and pitted morningglory. Single glyphosate treatments applied at the 8-, 10-, or 12-leaf cotton stage resulted in less-effective weed control than when applied at the four-leaf cotton stage. Glyphosate applied at the four-leaf cotton stage followed by a sequential POST-directed application at 6-, 8-, 10-, or 12-leaf cotton stage increased season-long weed control and yield compared with a single application at the four-leaf stage. Both glyphosate and MSMA controlled Florida beggarweed, regardless of POST application timing. Generally, cotton was more tolerant to glyphosate than MSMA when applied over-the-top. Glyphosate applied POST over-the-top to weed-free 12-leaf cotton resulted in a 19 and 14% yield loss compared with the weed-free nontreated cotton in 1997 and 1999. MSMA reduced yield by 58 and 36% in 1997 and 1999, respectively. Glyphosate did not affect weed-free cotton fruit development or yield when applied over-the-top to four-leaf cotton or when a POST-directed application was followed at the 12-leaf stage.

scholarly journals Smooth Crabgrass Control in Perennial Ryegrass and Creeping Bentgrass Tolerance to Quinclorac

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 607-612 ◽  
Author(s):  
Peter H. Dernoeden ◽  
Cale A. Bigelow ◽  
John E. Kaminski ◽  
John M. Krouse
Keyword(s):  
Field Study ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Creeping Bentgrass ◽  
Agrostis Stolonifera ◽  
Single Application ◽  
Cool Season ◽  
Invasive Weed ◽  
Application Timing ◽  
Quinolinecarboxylic Acid

Smooth crabgrass [Digitaria ischaemum (Schreber) Schreber ex Muhlenb.] is an invasive weed of cool-season turfgrasses. Previous research has demonstrated that quinclorac is an effective postemergence herbicide for crabgrass control, but performance has been erratic in some regions. Furthermore, quinclorac may elicit objectionable levels of discoloration in creeping bentgrass (Agrostis stolonifera L.). The objectives of this 3-year field study were to determine optimum rates and timings of quinclorac applications that provide consistent levels of effective crabgrass control and to assess creeping bentgrass quality responses to quinclorac. To evaluate crabgrass control, quinclorac was applied in early-, mid- and late-postemergence timings at various rates to a perennial ryegrass (Lolium perenne L.) turf. Similar treatments were applied to creeping bentgrass to determine if application timing and rate influenced the level and duration of discoloration. Quinclorac was applied alone or was tank-mixed with either urea (N at 6.1 kg·ha-1) or chelated iron (Fe)+nitrogen (N) (FeSO4 at 1.1 kg·ha-1+N at 2.2 kg·ha-1) to determine if they would mask discoloration. Crabgrass control generally was more effective in the early- and midpostemergence application timings. A single application of quinclorac (0.84 kg·ha-1) was effective where crabgrass levels were moderate, but sequential (i.e. multiple) applications were required where crabgrass levels were severe. The most consistent level of crabgrass control where weed pressure was severe occurred with three, sequential quinclorac (0.37 or 0.42 kg·ha-1) applications. Creeping bentgrass exhibited 2 to 11 weeks of unacceptable discoloration in response to sequential quinclorac applications. Chelated Fe+N was more effective than urea in masking discoloration. In general, chelated Fe+N tank-mixed with quinclorac masked discoloration and turf had quality equivalent to untreated bentgrass on most, but not all rating dates. Chemical names used: 3,7,-dichloro-8-quinolinecarboxylic acid (quinclorac).

Sign in / Sign up

Export Citation Format

Share Document