Palweed:Wheat: A Bioeconomic Decision Model for Postemergence Weed Management in Winter Wheat (Triticum aestivum)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 595-603 ◽  
Author(s):  
Tae-Jin Kwon ◽  
Douglas L. Young ◽  
Frank L. Young ◽  
Chris M. Boerboom
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Decision Model ◽  
Damage Function ◽  
Yield Response ◽  
Density Functions ◽  
Yield Model ◽  
Weed Density ◽  
Annual Grasses ◽  
Winter Annual

Based on six years of data from a field experiment near Pullman, WA, a bioeconomic decision model was developed to annually estimate the optimal post-emergence herbicide types and rates to control multiple weed species in winter wheat under various tillage systems and crop rotations. The model name, PALWEED:WHEAT, signifies a Washington-Idaho Palouse region weed management model for winter wheat The model consists of linear preharvest weed density functions, a nonlinear yield response function, and a profit function. Preharvest weed density functions were estimated for four weed groups: summer annual grasses, winter annual grasses, summer annual broadleaves, and winter annual broadleaves. A single aggregated weed competition index was developed from the four density functions for use functions for use in the yield model. A yield model containing a logistic damage function performed better than a model containing a rectangular hyperbolic damage function. Herbicides were grouped into three categories: preplant nonselective, postemergence broadleaf, and postemergence grass. PALWEED:WHEAT was applied to average conditions of the 6-yr experiment to predict herbicide treatments that maximized profit. In comparison to average treatment rates in the 6-yr experiment, the bioeconomic decision model recommended less postemergence herbicide. The weed management recommendations of PALWEED:WHEAT behaved as expected by agronomic and economic theory in response to changes in assumed weed populations, herbicide costs, crop prices, and possible restrictions on herbicide application rates.

Validation of HERB for Use in Peanut (Arachis hypogaea)

1997 ◽  
Vol 11 (3) ◽  
pp. 573-579 ◽  
Author(s):  
Anthony D. White ◽  
Harold D. Coble
Keyword(s):  
Environmental Impact ◽  
Arachis Hypogaea ◽  
Weed Management ◽  
Decision Model ◽  
Yield Loss ◽  
Field Validation ◽  
The Public ◽  
Weed Density ◽  
Competitive Index ◽  
Peanut Production

Researchers are currently developing predictive weed management models to aid producers in maintaining or improving economic profitability of peanut production while minimizing herbicide inputs and reducing environmental impact. HERB (Version 2.1.P), a computer decision model, has recently been developed for peanut and is now awaiting validation of weed control decisions before being released to the public. Field validation trials in 1994 and 1995 indicate that the current competitive index parameters in the HERB model are invalid, and statistically estimated competitive indices were generated. Estimating new parameters improvedR2values from 0.37 to 0.61. New competitive index parameters allow the HERB model to more accurately predict the level of yield loss at a given weed density.

Cropping Systems to Control Winter Annual Grasses in Winter Wheat (Triticum aestivum)

1999 ◽  
Vol 13 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Oleg Daugovish ◽  
Drew J. Lyon ◽  
David D. Baltensperger
Keyword(s):  
Winter Wheat ◽  
Cropping Systems ◽  
Field Studies ◽  
Downy Brome ◽  
Jointed Goatgrass ◽  
Long Term Effect ◽  
Annual Grasses ◽  
Winter Annual ◽  
Feral Rye

Field studies were conducted from 1990 through 1997 to evaluate the long-term effect of 2- and 3-yr rotations on the control of downy brome, jointed goatgrass, and feral rye in winter wheat. At the completion of the study, jointed goatgrass and feral rye densities averaged 8 plants/m2and < 0.1 plant/m2for the 2- and 3-yr rotations, respectively. Downy brome densities averaged < 0.5 plant/m2for both the 2- and 3-yr rotations, with no treatment differences observed. Winter annual grasses were not eradicated after two cycles of the 3-yr rotations, but weed densities were reduced 10-fold compared to densities after one cycle and more than 100-fold compared with the 2-yr rotations. Wheat grain contamination with dockage and foreign material followed a similar trend. The 3-yr rotations were economically competitive with 2-yr rotations and provided superior control of the winter annual grass weeds.

Cover Crop and Postemergence Herbicide Integration for Palmer amaranth Control in Cotton

2017 ◽  
Vol 31 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Matthew S. Wiggins ◽  
Robert M. Hayes ◽  
Robert L. Nichols ◽  
Lawrence E. Steckel
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Field Experiments ◽  
Palmer Amaranth ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Annual Grasses ◽  
Winter Annual ◽  
Hand Weeding

Field experiments were conducted to evaluate the integration of cover crops and POST herbicides to control glyphosate-resistant Palmer amaranth in cotton. The winter-annual grasses accumulated the greatest amount of biomass and provided the most Palmer amaranth control. The estimates for the logistic regression would indicate that 1540 kg ha−1would delay Palmer amaranth emerging and growing to 10 cm by an estimated 16.5 days. The Palmer amaranth that emerged in the cereal rye and wheat cover crop treatments took a longer time to reach 10 cm compared to the hairy vetch and crimson clover treatments. POST herbicides were needed for adequate control of Palmer amaranth. The glufosinate-based weed control system provided greater control (75% vs 31%) of Palmer amaranth than did the glyphosate system. These results indicate that a POST only herbicide weed management system did not provide sufficient control of Palmer amaranth, even when used in conjunction with cover crops that produced a moderate level of biomass. Therefore, future recommendations for GR Palmer amaranth control will include integrating cover crops with PRE herbicides, overlaying residual herbicides in-season, timely POST herbicide applications, and hand weeding in order to achieve season-long control of this pest.

Ecological Characteristics of Three Winter Annual Grasses

1998 ◽  
Vol 12 (3) ◽  
pp. 478-483 ◽  
Author(s):  
R. L. Anderson
Keyword(s):  
Winter Wheat ◽  
Seed Production ◽  
Cultural Practices ◽  
Seedling Emergence ◽  
Cultural Control ◽  
Downy Brome ◽  
Jointed Goatgrass ◽  
Annual Grasses ◽  
Winter Annual ◽  
Feral Rye

Producers rely on cultural practices to manage downy brome, jointed goatgrass, and feral rye in winter wheat because there are no effective herbicides for in-crop control. This study characterized seedling emergence, growth, and development of these winter annual grasses, with the goal of suggesting or improving cultural control strategies. Feral rye seedlings emerged within 4 wk, whereas downy brome and jointed goatgrass seedlings emerged over a 10-wk period. Emergence patterns of these grasses suggest that delay of winter wheat planting may be effective in reducing feral rye densities, but this strategy most likely will be ineffective with downy brome or jointed goatgrass. Downy brome began anthesis 1 to 2 wk earlier than the other two grasses and winter wheat. Both downy brome and jointed goatgrass were shorter than winter wheat during the growing season, whereas feral rye was at least as tall as wheat. Producers mow infested wheat to prevent weed seed production, but this practice may not be effective with jointed goatgrass and downy brome because of their short stature and downy brome's earlier development. Conversely, mowing has potential in preventing feral rye seed production. The grasses produced between 340 and 770 seeds/ plant.

PALWEED: WHEAT II: revision of a weed management decision model in response to field testing

Weed Science ◽  
1998 ◽  
Vol 46 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Tae-Jin Kwon ◽  
Douglas L. Young ◽  
Frank L. Young ◽  
Chris M. Boerboom
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Decision Model ◽  
Wheat Yield ◽  
Field Tests ◽  
Field Testing ◽  
Original Model ◽  
Linear Functions ◽  
Management Decision ◽  
Data Set

PALWEED:WHEAT is a bioeconomic decision model for determining profit-maximizing postemergence herbicide treatments for winter wheat in the Washington–Idaho Palouse region. PALWEED:WHEAT performed relatively well economically in 2 yr of on-farm field tests. However, the model was less sensitive than desired in prescribing postemergence broadleaved herbicides in the presence of high densities of broadleaved weed seedlings. Therefore, PALWEED:WHEAT was revised in response to the field testing. This paper compares the revised model's agronomic and economic performance to the original model in computer simulations. The revised model, PALWEED:WHEAT II, differs from the original model in several respects: (1) exponential functions replace linear functions in predicting weed survival, (2) preplant application of a nonselective herbicide is entered as an exogenous binary variable, (3) separate indices of broadleaved and grass competition are substituted for an aggregate weed competition index in the wheat yield function, (4) hyperbolic replaces logistic functional representation of weed damage to wheat yield, and (5) separate models are estimated for winter wheat after spring dry pea and for winter wheat in all examined crop rotation positions. In simulations including a variety of agronomic and economic conditions, PALWEED:WHEAT II recommended postemergence herbicide types and rates that consistently complied with agronomic and economic theory. Furthermore, the revised model, especially when estimated from the relevant wheat after pea data set, was markedly more balanced in recommending both broadleaved and grass herbicides in response to observed densities of both weed groups. The substantial change in herbicide recommendations in response to changes in model functional specifications following field testing confirms the importance of field testing and revision of bioeconomic decision models.

Nitrogen Fertility and Weed Management Critical for Continuous No-Till Wheat in the Pacific Northwest

2006 ◽  
Vol 20 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Frank L. Young ◽  
Mark E. Thorne ◽  
Douglas L. Young
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Crop Yield ◽  
Spring Wheat ◽  
Weed Management ◽  
Weed Density ◽  
N Level ◽  
No Till ◽  
The Pacific ◽  
Density And Biomass

No-till cropping is an option for growers needing to reduce soil erosion in the Palouse annual-cropped region of the Pacific Northwest, which is well suited for wheat production. A 6-yr field study was conducted to determine optimum levels of fertilizer and herbicide inputs in a no-till continuous wheat crop production system. Three levels of nitrogen (N) and two weed management levels (WML) were compared in a spring wheat (SW)–winter wheat (WW)–WW rotation through two rotation cycles. The high WML reduced weed densities about 50% compared with the low WML. In general, herbicide treatments were more effective on broadleaf weeds and may have facilitated a shift toward grass weeds. The high WML reduced grass weed biomass only at the reduced N levels, whereas the high WML reduced broadleaf weed density at all N levels. Variable environmental conditions affected wheat yield; however, yield tended to be highest where winter wheat immediately followed spring wheat. Nitrogen had little effect on weed density but increased crop yield about 13% with each increased N level. Crop yield was greater at the high versus low WML at each N level, even though weed density and biomass were reduced least between WMLs at the highest N level. The highest crop yield and net returns were obtained with the highest N and WML; however, none of the N and WML combinations were profitable.

Buckwheat Residue Effects on Emergence and Growth of Weeds in Winter-Wheat (Triticum aestivum) Cropping Systems

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 567-573 ◽  
Author(s):  
Virender Kumar ◽  
Daniel C. Brainard ◽  
Robin R. Bellinder ◽  
Russell R. Hahn
Keyword(s):  
New York ◽  
Winter Wheat ◽  
Weed Management ◽  
Cropping Systems ◽  
Soil Surface ◽  
Bare Soil ◽  
Weed Species ◽  
Winter Annual ◽  
Winter Annual Weeds ◽  
Annual Weeds

Field and pot studies were conducted in Central New York to determine the potential weed-management benefits of a buckwheat cover crop grown before winter wheat. Specific objectives were to determine buckwheat residue effects on (1) emergence and growth of winter annual weeds; (2) wheat establishment and yield; and (3) emergence of summer annual weeds in the spring following overwinter seed burial. In a field study, buckwheat was sown at two timings (July or August), mowed, and either incorporated or left on the soil surface. Winter wheat was drilled into buckwheat residue in September and weed and crop growth were monitored. In a complementary pot study, four winter annual weeds were sown in soil removed from buckwheat and bare-soil plots at 0 or 15 d after incorporation and monitored for emergence and early growth. To assess buckwheat residue effects on spring emergence from overwintering seeds, seeds of three weed species were buried in buckwheat residue and bare-soil plots in the fall, exhumed in April, and evaluated for emergence. To investigate the mechanism for possible effects of buckwheat residue on overwintering seeds, two levels each of seed treatment (none or fungicide) and fertilization (none or 170 kg ha−1) were applied before burial. Buckwheat residue had no negative effect on wheat yields but suppressed emergence (22 to 72%) and growth (0 to 95%) of winter annual weeds, although effects were often small and inconsistent. Buckwheat residue had no effect on the emergence of buried weed seeds in spring. However, fungicide treatment enhanced the emergence of Powell amaranth seeds by 12.5 to 25.5% and of barnyardgrass seeds by 0 to 12%. Our results suggest that buckwheat residue can contribute to weed management in wheat cropping systems, but that further studies investigating the mechanistic basis for the inconsistent selective effects of buckwheat residue on weeds are needed before buckwheat use can be optimized.

Winter Wheat Cultivar Characteristics Affect Annual Weed Suppression

2004 ◽  
Vol 18 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Gail A. Wicks ◽  
Paul T. Nordquist ◽  
P. Stephen Baenziger ◽  
Robert N. Klein ◽  
Roger H. Hammons ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Production Systems ◽  
Weed Suppression ◽  
Maturity Stage ◽  
Weed Density ◽  
Boot Stage ◽  
Seeding Date ◽  
Annual Grasses ◽  
Winter Wheat Cultivars ◽  
Annual Weeds

Thirteen hard red winter wheat cultivars were evaluated for their ability to suppress summer annual weeds in grain production systems near North Platte, NE, from 1993 through 1997. ‘Turkey’, a 125-yr-old landrace selection, suppressed both broadleaf and grass weeds more than other cultivars. Some relatively new cultivars, such as ‘Arapahoe’, ‘Jules’, ‘Pronghorn’, and ‘Vista’ suppressed summer annual grasses almost as well as Turkey. Total weed density was negatively correlated with number of winter wheat stems/m2, mature winter wheat height, and lodging. Weed density after wheat harvest was positively correlated with delay in winter wheat seeding date and was negatively correlated with precipitation 0 to 30 d after winter wheat seeding, during tillering, tillering to boot stage, and heading to maturity stage. Mean air temperature 0 to 30 d after wheat seeding was positively correlated with weed density. In the spring, weed density was positively correlated with temperatures during the tillering stage, tillering to boot stage, and heading to maturity stage. Stinkgrass and witchgrass densities were positively correlated with severity of wheat leaf rust. The highest grain-producing cultivars included three medium height cultivars ‘Alliance’, Arapahoe, and ‘Niobrara’. Alliance wheat produced 53% more grain than Turkey, and the other two produced 43% more grain.

Dose-Responses of Weeds and Winter Wheat (Triticum aestivum) to MON 37500

1996 ◽  
Vol 10 (4) ◽  
pp. 870-875 ◽  
Author(s):  
Patrick W. Geier ◽  
Phillip W. Stahlman
Keyword(s):  
Winter Wheat ◽  
Residual Effects ◽  
Downy Brome ◽  
Annual Grass ◽  
Jointed Goatgrass ◽  
Weed Growth ◽  
Annual Grasses ◽  
Winter Annual ◽  
Dose Responses ◽  
Weed Emergence

Greenhouse studies determined the dose-responses of cheat, downy brome, Japanese brome, jointed goatgrass, and winter wheat to preplant-incorporated MON 37500 and its residual effects on kochia. Concentrations of MON 37500 up to 60 ppbw did not affect winter wheat. MON 37500 did not prevent weed emergence, but increasingly inhibited weed growth as the dose was increased up to about 20 ppbw. GR50values were 16, 16, 11, and 31 ppbw for cheat, downy brome, Japanese brome, and jointed goatgrass, respectively. Japanese brome was more susceptible than cheat or downy brome, and jointed goatgrass tolerated two to three times more MON 37500 than theBromusspecies. Plant dry weights of kochia seeded after removal of the winter annual grasses decreased with increasing initial MON 37500 concentrations up to 20 ppbw. Kochia density was influenced by which winter annual grass was grown previously.

Herbicide safener increases weed-management tools for control of annual grasses in wheat

2020 ◽  
pp. 1-10
Author(s):  
Damilola A. Raiyemo ◽  
William J. Price ◽  
Traci A. Rauch ◽  
Joan M. Campbell ◽  
Fangming Xiao ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Weed Management ◽  
Wheat Varieties ◽  
Fatty Acid Elongase ◽  
Wheat Seedlings ◽  
Annual Grasses ◽  
The Impact ◽  
Gst Activity ◽  
Winter Wheat Varieties

Abstract Annual grass weeds reduce profits of wheat farmers in the Pacific Northwest. The very-long-chain fatty acid elongase (VLCFA)-inhibiting herbicides S-metolachlor and dimethenamid-P could expand options for control of annual grasses but are not registered in wheat, because of crop injury. We evaluated a safener, fluxofenim, applied to wheat seed for protection of 19 soft white winter wheat varieties from S-metolachlor, dimethenamid-P, and pyroxasulfone herbicides; investigated the response of six varieties (UI Sparrow, LWW 15-72223, UI Magic CL+, Brundage 96, UI Castle CL+, and UI Palouse CL+) to incremental doses of fluxofenim; established the fluxofenim dose required to optimally protect the varieties from VLCFA-inhibiting herbicides; and assessed the impact of fluxofenim dose on glutathione S-transferase (GST) activity in three wheat varieties (UI Sparrow, Brundage 96, and UI Castle CL+). Fluxofenim increased the biomass of four varieties treated with S-metolachlor or dimethenamid-P herbicides and one variety treated with pyroxasulfone. Three varieties showed tolerance to the herbicides regardless of the fluxofenim treatment. Estimated fluxofenim doses resulting in 10% biomass reduction of wheat ranged from 0.55 to 1.23 g ai kg−1 seed. Fluxofenim doses resulting in 90% increased biomass after treatment with S-metolachlor, dimethenamid-P, and pyroxasulfone ranged from 0.07 to 0.55, 0.09 to 0.73, and 0.30 to 1.03 g ai kg−1 seed, respectively. Fluxofenim at 0.36 g ai kg−1 seed increased GST activity in UI Castle CL+, UI Sparrow, and Brundage 96 by 58%, 30%, and 38%, respectively. These results suggest fluxofenim would not damage wheat seedlings up to three times the rate labeled for sorghum, and fluxofenim protects soft white winter wheat varieties from S-metolachlor, dimethenamid-P, or pyroxasulfone injury at the herbicide rates evaluated.

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