Downy Brome (Bromus tectorum) Competition and Control in No-Till Spring Wheat

2013 ◽  
Vol 27 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Michael H. Ostlie ◽  
Kirk A. Howatt
Keyword(s):  
Spring Wheat ◽  
Yield Loss ◽  
Total Yield ◽  
Wheat Yield ◽  
Control Measures ◽  
Downy Brome ◽  
Herbicide Application ◽  
Application Timing ◽  
No Till ◽  
And Control

Downy brome is one of the leading plant pests in winter wheat and no-till spring wheat in many areas of the country. It has recently been studied in North Dakota where it is emerging as a serious crop competitor. Downy brome plants produced up to 60 tillers and more than 7,500 seeds when no control measures were used and densities were less than 2 plants m−2. Experiments focusing on herbicide-application timing identified differences in downy brome control and the grain yield of spring wheat. Regardless of fall or spring application timing, glyphosate applied PRE to wheat completely controlled downy brome in 2007. In 2008, control was not achieved with the earliest glyphosate-application timings because of late-emerging plants. When comparing fall and spring application timings of other herbicides, imazapic provided at least 79% control at each timing and location, resulting in the highest imazamox-resistant spring wheat yield. In general, herbicides performed better when applied in fall than they did when applied in spring. When herbicides were applied POST, imazamox provided the greatest downy brome control and usually caused the largest numerical reduction in downy brome biomass, seed, and stem number. If downy brome was left untreated, regression analysis predicted approximately 2,000 stems m−2could result in total yield loss of spring wheat.

Weed Control in a Conservation Tillage Rotation in the Texas Blacklands

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 695-699 ◽  
Author(s):  
Steven M. Brown ◽  
James M. Chandler ◽  
John E. Morrison
Keyword(s):  
Control Systems ◽  
Weed Control ◽  
Conservation Tillage ◽  
Grain Sorghum ◽  
Control Measures ◽  
Sorghum Halepense ◽  
Low Intensity ◽  
No Till ◽  
Primary Tillage ◽  
And Control

A field experiment was conducted to evaluate weed control systems in a conservation tillage rotation of grain sorghum [Sorghum bicolor(L.) Moench.] – cotton (Gossypium hirsutumL.) – wheat (Triticum aestivumL.). Herbicide systems included fall and spring/summer inputs of high and low intensity. Tillage regimes were no-till (NT) and reduced-till (RT) systems; the latter included fall primary tillage followed by spring stale seedbed planting. Both tillage systems utilized controlled traffic lanes and wide, raised beds. Effective johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control required intense herbicide inputs at one or both application periods, i.e., in the fall and/or spring/summer. Grain sorghum and cotton yields for the most intense weed control system, which included high inputs in both the fall and spring/summer, were not superior to systems that included high inputs in only one of the two application periods. Seedling johnsongrass emergence occurred before spring planting in RT (but not in NT) in 2 of 3 yr, and control measures were ineffective. After 3 yr, the predominant weeds were johnsongrass and browntop panicum (Panicum fasciculatumSw. # PANFA).

Downy Brome (Bromus tectorum) Interference and Economic Thresholds in Winter Wheat (Triticum aestivum)

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Phillip W. Stahlman ◽  
Stephen D. Miller
Keyword(s):  
Winter Wheat ◽  
Bromus Tectorum ◽  
Yield Loss ◽  
Wheat Yield ◽  
Dry Weight ◽  
Quadratic Equation ◽  
Downy Brome ◽  
Economic Threshold ◽  
Weed Density ◽  
Economic Thresholds

Densities up to 100 downy brome m2were established in winter wheat in southeastern Wyoming and west-central Kansas to quantify wheat yield loss from downy brome interference and to approximate economic threshold levels. A quadratic equation best described wheat yield loss as a function of weed density when downy brome emerged within 14 days after wheat emergence. Densities of 24, 40, and 65 downy brome m2reduced wheat yield by 10, 15, and 20%, respectively. Wheat yield was not reduced when downy brome emerged 21 or more days later than wheat. Economic thresholds varied with changes in downy brome density, cost of control, wheat price, and potential wheat yield. In a greenhouse experiment, dry weight of 72-day-old wheat plants grown in association with downy brome was not affected by the distance between the weeds and wheat, whereas downy brome plant dry weight increased with increasing distance between the weeds and wheat.

Foxtail (Setariaspp.) seedling dynamics in spring wheat (Triticum aestivum) are influenced by seeding date and tillage regime

Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Eric Spandl ◽  
Beverly R. Durgan ◽  
Frank Forcella
Keyword(s):  
Spring Wheat ◽  
Wheat Yield ◽  
Seedling Density ◽  
Emergence Period ◽  
No Till ◽  
Seeding Date ◽  
Emergence Patterns ◽  
Seedling Dynamics ◽  
Chisel Plow ◽  
Moldboard Plow

Emergence patterns of foxtail in spring wheat following soybean were evaluated for three seeding dates and three tillage regimes. Cumulative foxtail emergence, as a percentage of total plants emerged in the growing season, was generally not influenced by tillage regime throughout most of the emergence period, but when differences occurred, emergence was lower with no-till than with moldboard plow. Foxtail seedling densities were greater in no-till and chisel plow than in moldboard plow. Weed biomass and wheat yields were not affected by tillage regime. Delaying wheat seeding reduced foxtail percent emergence and emerged seedling density. Differences in emergence patterns of foxtail were attributable to thermal accumulation after seeding. Wheat yield was not influenced by seeding date in 2 of 3 yr.

Effects of summer and winter annual scentless chamomile (Matricaria perforata Mérat) interference on spring wheat yield

1991 ◽  
Vol 71 (3) ◽  
pp. 841-850 ◽  
Author(s):  
D. W. Douglas ◽  
A. G. Thomas ◽  
D. P. Peschken ◽  
G. G. Bowes ◽  
D. A. Derksen
Keyword(s):  
Spring Wheat ◽  
Yield Loss ◽  
Wheat Yield ◽  
Weather Conditions ◽  
Yield Reduction ◽  
Hyperbolic Model ◽  
Loss Parameter ◽  
Winter Annuals ◽  
Winter Annual ◽  
Experimental Plots

The influence of summer and winter annual scentless chamomile (Matricaria perforata Mérat) on the yield of spring wheat in Saskatchewan was determined. In experimental plots, spring wheat was seeded into barley stubble where summer and winter annual scentless chamomile had been established. A rectangular hyperbolic model was used to describe the relationship between wheat yield and the density of flowering scentless chamomile plants. Winter annuals caused more yield reduction than did summer annuals. Weather conditions appeared to have an influence on the effect of scentless chamomile on spring wheat yield. The same model was fitted to sample data from farmers' fields and showed yield losses similar to those on the experimental plots. The rectangular hyperbolic model fitted the data best when high weed densities occurred. At densities more typical of those found in farm fields, the asymptotic yield loss parameter of the model was poorly estimated. Key words: Scentless chamomile, Matricaria perforata, yield loss, weed competition, rectangular hyperbola, spring wheat

Control of Italian Ryegrass (Lolium multiflorum) in Winter Wheat

2005 ◽  
Vol 19 (2) ◽  
pp. 261-265 ◽  
Author(s):  
Aaron J. Hoskins ◽  
Bryan G. Young ◽  
Ronald F. Krausz ◽  
John S. Russin
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Lolium Multiflorum ◽  
Wheat Yield ◽  
Acetolactate Synthase ◽  
Field Studies ◽  
Italian Ryegrass ◽  
Acetyl Coa Carboxylase ◽  
Application Timing ◽  
Foliar Symptoms

Field studies were established in 1999 and 2000 to evaluate Italian ryegrass, wheat, and double-crop soybean response to fall and spring postemergence applications of flucarbazone, sulfosulfuron, clodinafop, diclofop, and tralkoxydim applied alone and in combination with thifensulfuron + tribenuron to winter wheat. Fall-applied herbicides caused 5% or less wheat injury. Spring-applied herbicides caused 3 to 45% wheat injury, and the greatest injury occurred with the combination of flucarbazone with thifensulfuron + tribenuron in the spring of 2001. Spring-applied sulfosulfuron, tralkoxydim, diclofop, and clodinafop caused 3 to 6% and 16 to 26% wheat injury in 2000 and 2001, respectively. Herbicide injury to wheat did not reduce wheat grain yield compared with the hand-weeded treatment. Italian ryegrass competition in the nontreated plots reduced wheat yield by as much as 33% compared with herbicide-treated plots. Italian ryegrass control was 89 to 99% from clodinafop and diclofop and 78 to 97% from flucarbazone, with no differences because of application timing in either year of the study. Italian ryegrass control from sulfosulfuron and tralkoxydim was greater from the spring of 2000 applications (94 to 99%) compared with the fall of 1999 applications (65 to 88%). However, in 2001, application timing (fall vs. spring) for sulfosulfuron and tralkoxydim did not affect Italian ryegrass control. Thifensulfuron + tribenuron combined with tralkoxydim reduced control of Italian ryegrass control compared with tralkoxydim alone in both years of the study. Italian ryegrass control was not reduced when thifensulfuron + tribenuron was combined with sulfosulfuron, flucarbazone, diclofop, or clodinafop. Italian ryegrass was controlled effectively by the acetyl-CoA carboxylase–inhibiting herbicides diclofop, clodinafop, and tralkoxydim. However, control of Italian ryegrass with the acetolactate synthase–inhibiting herbicides flucarbazone and sulfosulfuron was inconsistent. Double-crop soybean after wheat did not have foliar symptoms or yield loss from fall- or spring-applied herbicides.

Yield Loss Assessment for Spring Wheat (Triticum aestivum) Infested with Canada Thistle (Cirsium arvense)

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 590-598 ◽  
Author(s):  
William W. Donald ◽  
Mohammad Khan
Keyword(s):  
Linear Regression ◽  
Spring Wheat ◽  
Yield Loss ◽  
Wheat Yield ◽  
Growing Season ◽  
Shoot Density ◽  
Regression Equations ◽  
Loss Assessment ◽  
Canada Thistle ◽  
Yield Loss Assessment

In eight of nine trials spanning 5 yr, relative yield of semidwarf hard red spring wheat (yield expressed as a percent of estimated weed-free yield) decreased linearly as Canada thistle shoot density increased when measured in late July to early August in the northern Great Plains. Differences between yield loss assessment (YLA) equations could not be distinguished statistically between no-tillage and chisel-plowed production systems. Multiple linear regression equations of relative wheat yield versus wheat density plus Canada thistle shoot density accounted for more variability in YLA equations than simple linear regression equations of wheat yield versus Canada thistle shoot density alone. Estimated weed-free wheat yield and negative slope (b) for yield loss assessment equations increased as cumulative growing-season (April to August) rainfall increased. Thus, relative wheat yield was decreased more by increasing Canada thistle density (slope b became more negative) in years of greater growing-season rainfall.

scholarly journals Models for Predicting Potential Yield Loss of Wheat Caused by Stripe Rust in the U.S. Pacific Northwest

2011 ◽  
Vol 101 (5) ◽  
pp. 544-554 ◽  
Author(s):  
D. Sharma-Poudyal ◽  
X. M. Chen
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Stripe Rust ◽  
Spring Wheat ◽  
Yield Loss ◽  
Wheat Yield ◽  
The Other ◽  
Potential Yield ◽  
Highly Correlated ◽  
The U.S

Climatic variation in the U.S. Pacific Northwest (PNW) affects epidemics of wheat stripe rust caused by Puccinia striiformis f. sp. tritici. Previous models only estimated disease severity at the flowering stage, which may not predict the actual yield loss. To identify weather factors correlated to stripe rust epidemics and develop models for predicting potential yield loss, correlation and regression analyses were conducted using weather parameters and historical yield loss data from 1993 to 2007 for winter wheat and 1995 to 2007 for spring wheat. Among 1,376 weather variables, 54 were correlated to yield loss of winter wheat and 18 to yield loss of spring wheat. Among the seasons, winter temperature variables were more highly correlated to wheat yield loss than the other seasons. The sum of daily temperatures and accumulated negative degree days of February were more highly correlated to winter wheat yield loss than the other monthly winter variables. In addition, the number of winter rainfall days was found correlated with yield loss. Six yield loss models were selected for each of winter and spring wheats based on their better correlation coefficients, time of weather data availability during the crop season, and better performance in validation tests. Compared with previous models, the new system of using a series of the selected models has advantages that should make it more suitable for forecasting and managing stripe rust in the major wheat growing areas in the U.S. PNW, where the weather conditions have become more favorable to stripe rust.

Volunteer Barley Interference in Spring Wheat Grown in a Zero-Tillage System

Weed Science ◽  
2007 ◽  
Vol 55 (1) ◽  
pp. 70-74 ◽  
Author(s):  
John T. O'Donovan ◽  
K. Neil Harker ◽  
George W. Clayton ◽  
Linda M. Hall ◽  
Jason Cathcart ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Field Experiments ◽  
Yield Loss ◽  
Wheat Yield ◽  
High Rate ◽  
Initial Slope ◽  
Threshold Values ◽  
Economic Threshold ◽  
Economic Thresholds ◽  
The Impact

There is no published information on the impact of volunteer barley on wheat yield loss or on the economics of controlling barley with a herbicide. With the registration of imazamox-resistant wheat, it is now possible to control volunteer barley in wheat. Thus, the likelihood of growing wheat in rotation with barley may increase. Field experiments were conducted in 2003 and 2004 at Beaverlodge, Lacombe, and Edmonton, AB, Canada, and Saskatoon, SK, Canada, to determine the impact of volunteer barley on yield of imazamox-resistant spring wheat seeded at relatively low (100 kg ha−1) and high (175 kg ha−1) rates. Barley was seeded at different densities to simulate volunteer barley infestations. Regression analysis indicated that wheat-plant density influenced the effects of volunteer barley interference on wheat yield loss, economic threshold values, and volunteer barley fecundity among locations and years. Economic thresholds varied from as few volunteer barley plants as 3 m−2at Beaverlodge in 2003 and 2004 to 48 m−2at Lacombe in 2003. In most cases, wheat yield loss and volunteer barley fecundity were lower and economic thresholds were higher when wheat was seeded at the higher rate. For example, averaged over both years at Beaverlodge initial slope values (percentage of wheat yield loss at low barley density) were 4.5 and 1.7%, and economic threshold values of volunteer barley plants were 3 m−2and 8 m−2at low and high wheat seeding rates, respectively. Results indicate that volunteer barley can be highly competitive in wheat, but yield losses and wheat seed contamination due to volunteer barley can be alleviated by seeding wheat at a relatively high rate.

Timing of Chlorimuron and Imazaquin Application for Weed Control in No-Till Soybeans (Glycine max)

Weed Science ◽  
1991 ◽  
Vol 39 (2) ◽  
pp. 232-237 ◽  
Author(s):  
J. Boyd Carey ◽  
Michael S. Defelice
Keyword(s):  
Weed Control ◽  
Field Studies ◽  
Row Spacing ◽  
Herbicide Application ◽  
Poor Control ◽  
Application Timing ◽  
Common Lambsquarters ◽  
No Till ◽  
Giant Foxtail ◽  
Herbicide Treatments

Field studies were conducted to evaluate the influence of herbicide application timing on weed control in no-till soybean production. Row spacing generally had no effect on weed control. Herbicide treatments containing chlorimuron plus metribuzin applied as many as 45 days prior to planting in 1988 and 1989 controlled broadleaf weeds throughout the growing season. Imazaquin applied 45 and 30 days prior to planting provided poor control of common cocklebur in 1989. Giant foxtail control was inconsistent with all herbicide treatments. Soybean yields subsequent to early preplant herbicide applications were greater than or equal to those in which applications were made at planting when late-season weed control was adequate. Herbicides applied preemergence did not control high densities of common lambsquarters in 1989.

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