Management of Italian Ryegrass (Lolium perennessp.multiflorum) in Western Oregon with Preemergence Applications of Pyroxasulfone in Winter Wheat

Management of Italian ryegrass in cereal-based cropping systems continues to be a major production constraint in areas of the United States, including the soft white winter wheat producing regions of the Pacific Northwest. Pyroxasulfone is a soil-applied herbicide with the potential to control broadleaf and grass weed species, including grass weed biotypes resistant to group 1, 2, and 7 herbicides, in several crops for which registration has been completed or is pending, including wheat, corn, sunflower, dry bean, and soybean. Field experiments were conducted from 2006 through 2009 near Corvallis, OR, to evaluate the potential for Italian ryegrass control in winter wheat with applications of pyroxasulfone. Application rates of PRE treatments ranged from 0.05 to 0.15 kg ai ha−1. All treatments were compared to standard Italian ryegrass soil-applied herbicides used in winter wheat, including diuron, flufenacet, and flufenacet + metribuzin. Visual evaluations of Italian ryegrass and ivyleaf speedwell control and winter wheat injury were made at regular intervals following applications. Winter wheat yields were quantified at grain maturity. Ivyleaf speedwell control was variable, and Italian ryegrass control following pyroxasulfone applications ranged from 65 to 100% and was equal to control achieved with flufenacet and flufenacet + metribuzin treatments and greater than that achieved with diuron applications. Winter wheat injury from pyroxasulfone ranged from 0 to 8% and was most associated with the 0.15–kg ha−1application rate. However, this early-season injury did not negatively impact winter wheat yield. Pyroxasulfone applied at the application rates and timings in these studies resulted in high levels of activity on Italian ryegrass and excellent winter wheat safety. Based on the results, pyroxasulfone has the potential to be used as a soil-applied herbicide in winter wheat for Italian ryegrass management and its utility for management of other important grass and broadleaf weeds of cereal-based cropping systems should be evaluated.

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Scouringrush (Equisetum spp.) control in dryland winter wheat

Weed Technology ◽

10.1017/wet.2019.45 ◽

2019 ◽

Vol 33 (6) ◽

pp. 808-814

Author(s):

Blake D. Kerbs ◽

Andrew G. Hulting ◽

Drew J. Lyon

Keyword(s):

Species Composition ◽

Winter Wheat ◽

Pacific Northwest ◽

Field Experiments ◽

Cropping Systems ◽

Yield Response ◽

Herbicide Application ◽

Weed Species ◽

Herbicide Treatments ◽

Chemical Fallow

AbstractThe adoption of chemical fallow rotations in Pacific Northwest dryland winter wheat production has caused a weed species composition shift in which scouringrush has established in production fields. Thus, there has been interest in identifying herbicides that effectively control scouringrush in winter wheat–chemical fallow cropping systems. Field experiments were established in growers’ fields near Reardan, WA, in 2014, and The Dalles, OR, in 2015. Ten herbicide treatments were applied to mowed and nonmowed plots during chemical fallow rotations. Scouringrush stem densities were quantified the following spring and after wheat harvest at both locations. Chlorsulfuron plus MCPA-ester resulted in nearly 100% control of scouringrush through wheat harvest. Before herbicide application, mowing had no effect on herbicide efficacy. We conclude chlorsulfuron plus MCPA-ester is a commercially acceptable treatment for smooth and intermediate scouringrush control in winter wheat–chemical fallow cropping systems; however, the lack of a positive yield response when scouringrushes were controlled should factor into management decisions.

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Halauxifen-methyl controls glyphosate-resistant horseweed (Conyza canadensis) but not giant ragweed (Ambrosia trifida) in winter wheat

Weed Technology ◽

10.1017/wet.2020.21 ◽

2020 ◽

Vol 34 (4) ◽

pp. 607-612 ◽

Cited By ~ 1

Author(s):

Jessica Quinn ◽

Nader Soltani ◽

Jamshid Ashigh ◽

David C. Hooker ◽

Darren E. Robinson ◽

...

Keyword(s):

Winter Wheat ◽

Weed Management ◽

Field Experiments ◽

The United States ◽

Integrated Weed Management ◽

Conyza Canadensis ◽

Limited Information ◽

Weed Species ◽

Ambrosia Trifida ◽

Giant Ragweed

AbstractHorseweed is a competitive summer or winter annual weed that produces up to 230,000 small seeds per plant that are capable of traveling more than 500 km via wind. Giant ragweed is a tall, highly competitive summer annual weed. Glyphosate-resistant (GR) horseweed and GR giant ragweed pose significant challenges for producers in the United States and Ontario, Canada. It is thought that an integrated weed management (IWM) system involving herbicide rotation is required to control GR biotypes. Halauxifen-methyl is a new selective broadleaf POST herbicide registered for use in cereal crops; there is limited information on its efficacy on horseweed and giant ragweed. The purpose of this research was to determine the efficacy of halauxifen-methyl applied POST, alone and in a tank mix, for the control of GR horseweed and GR giant ragweed in wheat across southwestern Ontario. For each weed species, an efficacy study consisting of six field experiments was conducted over a 2-yr period (2018, 2019). At 8 wk after application (WAA), halauxifen-methyl, fluroxypyr/halauxifen-methyl, fluroxypyr/halauxifen-methyl + MCPA EHE, fluroxypyr + MCPA ester, 2,4-D ester, clopyralid, and pyrasulfotole/bromoxynil + ammonium sulfate controlled GR horseweed >95%. Fluroxypyr and MCPA provided only 86% and 37% control of GR horseweed, respectively. At 8 WAA, fluroxypyr, fluroxypyr/halauxifen-methyl, fluroxypyr/halauxifen-methyl + MCPA EHE, fluroxypyr + MCPA ester, fluroxypyr/halauxifen-methyl + MCPA EHE + pyroxsulam, 2,4-D ester, clopyralid, and thifensulfuron/tribenuron + fluroxypyr + MCPA ester controlled GR giant ragweed 87%, 88%, 90%, 94%, 96%, 96%, 98%, and 93%, respectively. Halauxifen-methyl and pyroxsulam provided only 45% and 28% control of GR giant ragweed, respectively. Halauxifen-methyl applied alone POST in the spring controlled GR horseweed but not GR giant ragweed in winter wheat.

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Cropping systems for the Southern Great Plains of the United States as influenced by federal policy

Renewable Agriculture and Food Systems ◽

10.1079/raf2005119 ◽

2006 ◽

Vol 21 (2) ◽

pp. 77-83 ◽

Cited By ~ 3

Author(s):

Jon T. Biermacher ◽

Francis M. Epplin ◽

Kent R. Keim

Keyword(s):

Winter Wheat ◽

Federal Policy ◽

Cropping Systems ◽

The United States ◽

Weed Species ◽

North Central ◽

The North ◽

Central District ◽

Fair Act ◽

The Impact

The majority of cropland in the rain-fed region of the North Central District of Oklahoma in the US is seeded with winter wheat (Triticum aestivum) and most of it is in continuous wheat production. When annual crops are grown in monocultures, weed species and disease agents may become established and expensive to control. For many years prior to 1996, federal policy provided incentives for District producers to grow wheat and disincentives to diversify. In 1996, the Federal Agriculture Improvement and Reform (FAIR) Act (Freedom to Farm Act) was instituted, followed by the Farm Security and Rural Investment Act (FSRIA) in 2002. The objective of this study was to determine the impact of FAIR and FSRIA programs on crop diversity in the North Central District of Oklahoma. The economics of three systems, monoculture continuous winter wheat, continuous soybean (Glycine max) and a soybean–winter wheat–soybean rotation, were compared using cash market prices (CASH), CASH plus the effective loan deficiency payments (a yield-dependent subsidy) of the FAIR Act of 1996, and CASH plus the effective loan deficiency payments of the FSRIA of 2002. We found that the loan deficiency payment structure associated with FAIR provided a non-market incentive that favored soybean. However, under provisions of the 2002 FSRIA, the incentive for soybean was adjusted, resulting in greater expected returns for continuous wheat. Due to erratic weather, soybean may not be a good alternative for the region. Research is needed to identify crops that will fit in a rotation with wheat.

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A Survey for Diclofop-Methyl Resistance in Italian Ryegrass from Tennessee and How To Manage Resistance in Wheat

Weed Technology ◽

10.1614/wt-d-09-00035.1 ◽

2010 ◽

Vol 24 (3) ◽

pp. 303-309 ◽

Cited By ~ 21

Author(s):

Andrew T. Ellis ◽

Lawrence E. Steckel ◽

Christopher L. Main ◽

Marcel S. C. De Melo ◽

Dennis R. West ◽

...

Keyword(s):

Field Experiments ◽

Wheat Yield ◽

Acetolactate Synthase ◽

The United States ◽

Research Field ◽

Italian Ryegrass ◽

Cross Resistance ◽

Susceptible Population ◽

Application Timing ◽

Herbicide Programs

Italian ryegrass resistance to diclofop has been documented in several countries, including the United States. The purpose of this research was to screen selected putative resistant populations of Italian ryegrass for resistance to the acetyl-CoA carboxylase (ACCase)–inhibiting herbicides diclofop and pinoxaden and the acetolactate synthase (ALS)–inhibiting herbicides imazamox, pyroxsulam, and mesosulfuron in the greenhouse and to use field experiments to develop herbicide programs for Italian ryegrass control. Resistance to diclofop was confirmed in eight populations from Tennessee. These eight populations did not show cross-resistance to pinoxaden. One additional population (R1) from Union County, North Carolina, was found to be resistant to both diclofop and pinoxaden. The level of resistance to pinoxaden of the R1 population was 15 times that of the susceptible population. No resistance was confirmed to any of the ALS-inhibiting herbicides examined in this research. Field experiments demonstrated PRE Italian ryegrass control with chlorsulfuron (71 to 94%) and flufenacet + metribuzin (84 to 96%). Italian ryegrass control with pendimethalin applied PRE or delayed preemergence (DPRE) was variable (0 to 85%). POST control of Italian ryegrass was acceptable with pinoxaden, mesosulfuron, flufenacet + metribuzin, and chlorsulfuron + flucarbazone (> 80%). Application timing and herbicide treatment had no effect on wheat yield, except for diclofop and pendimethalin treatments, in which uncontrolled Italian ryegrass reduced wheat yield.

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Seed destruction of weeds in southern US crops using heat and narrow-windrow burning

Weed Technology ◽

10.1017/wet.2020.36 ◽

2020 ◽

Vol 34 (4) ◽

pp. 589-596

Author(s):

Jason K. Norsworthy ◽

Jeremy K. Green ◽

Tom Barber ◽

Trent L. Roberts ◽

Michael J. Walsh

Keyword(s):

Wind Speed ◽

Field Experiments ◽

Cropping Systems ◽

Palmer Amaranth ◽

Italian Ryegrass ◽

Weed Seed ◽

Weed Species ◽

Harvest Residues ◽

Southern Us ◽

Weed Seeds

AbstractNarrow-windrow burning has been a successful form of harvest weed seed control in Australian cropping systems, but little is known about the efficacy of narrow-windrow burning on weed seeds infesting U.S. cropping systems. An experiment was conducted using a high-fire kiln that exposed various grass and broadleaf weed seeds to temperatures of 200, 300, 400, 500, and 600 C for 20, 40, 60, and 80 s to determine the temperature and time needed to kill weed seeds. Weeds evaluated included Italian ryegrass, barnyardgrass, johnsongrass, sicklepod, Palmer amaranth, prickly sida, velvetleaf, pitted morningglory, and hemp sesbania. Two field experiments were also conducted over consecutive growing seasons, with the first experiment aimed at determining the amount of heat produced during burning of narrow windrows of soybean harvest residues (chaff and straw) and the effect of this heat on weed seed mortality. The second field experiment aimed to determine the effect of wind speed on the duration and intensity of burning narrow windrows of soybean harvest residues. Following exposure to the highest temperature and longest duration in the kiln, only sicklepod showed any survival (<1% average); however, in most cases, the seeds were completely destroyed (ash). A heat index of only 22,600 was needed to kill all seeds of Palmer amaranth, barnyardgrass, and Italian ryegrass. In the field, all seeds of the evaluated weed species were completely destroyed by narrow-windrow burning of 1.08 to 1.95 kg m−2 of soybean residues. The burn duration of the soybean harvest residues declined as wind speed increased. Findings from the kiln and field experiments show that complete kill is likely for weed seeds concentrated into narrow windrows of burned soybean residues. Given the low cost of implementation of narrow-windrow burning and the seed kill efficacy on various weed species, this strategy may be an attractive option for destroying weed seed.

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Pratylenchus neglectus Reduces Yield of Winter Wheat in Dryland Cropping Systems

Plant Disease ◽

10.1094/pdis-93-3-0263 ◽

2009 ◽

Vol 93 (3) ◽

pp. 263-271 ◽

Cited By ~ 36

Author(s):

Richard W. Smiley ◽

Stephen Machado

Keyword(s):

Winter Wheat ◽

Pacific Northwest ◽

Cropping Systems ◽

Spring Barley ◽

Wheat Yield ◽

Pratylenchus Neglectus ◽

Winter Wheat Yield ◽

Chemical Fallow ◽

Root Lesion Nematodes ◽

Increasing Trends

Wheat (Triticum aestivum) in low-precipitation regions of eastern Oregon and Washington is grown mostly as rainfed biennial winter wheat (10-month growing season) planted into cultivated fallow (14-month crop-free period). There are increasing trends for cultivated fallow to be replaced by chemical fallow and for spring cereals to be planted annually without tillage. Most fields are infested by the root-lesion nematodes Pratylenchus neglectus or P. thornei. A replicated multiyear experiment was conducted to compare cropping systems on soil infested by P. neglectus. Populations became greater with increasing frequency of the host crops mustard, pea, and wheat. Annual winter wheat had the highest P. neglectus populations, the lowest capacity to extract soil water, and a lower grain yield compared with wheat grown biennially or rotated with other crops. Populations of P. neglectus did not differ for cultivated versus chemical fallow. Lowest populations occurred in annual spring barley. Winter wheat yield was inversely correlated with the population of P. neglectus. Measures to monitor and to reduce the population of P. neglectus in Pacific Northwest wheat fields are recommended.

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Comparison of Herbicides for Control of Diclofop-Resistant Italian Ryegrass in Wheat

Agriculture ◽

10.3390/agriculture8090135 ◽

2018 ◽

Vol 8 (9) ◽

pp. 135 ◽

Cited By ~ 1

Author(s):

Taghi Bararpour ◽

Ralph Hale ◽

Gurpreet Kaur ◽

Jason Bond ◽

Nilda Burgos ◽

...

Keyword(s):

Triticum Aestivum ◽

Winter Wheat ◽

Lolium Perenne ◽

Wheat Yield ◽

Field Studies ◽

Triticum Aestivum L ◽

Italian Ryegrass ◽

Lolium Perenne L

Diclofop-resistant Italian ryegrass (Lolium perenne L. ssp. Multiflorum (Lam.) Husnot) is a dominant weed problem in non-irrigated winter wheat (Triticum aestivum L.) in mid-south USA. Field studies were conducted from 2001 to 2007 to evaluate the efficacy of herbicides for diclofop-resistant ryegrass control and effect on wheat yield. In 2001 through 2004, chlorsulfuron/metsulfuron at 0.026 kg ha−1 preemergence (PRE) followed by (fb) mesosulfuron at 0.048 kg ha−1 at 4-leaf to 2-tiller ryegrass provided 89% control of diclofop-resistant Italian ryegrass, resulting in the highest wheat yield (3201 kg ha−1). Flufenacet/metribuzin at 0.476 kg ha−1 applied at 1- to 2-leaf wheat had equivalent Italian ryegrass control (87%), but lesser yield (3013 kg ha−1). In 2005–2006, best treatments for Italian ryegrass control were chlorsulfuron/metsulfuron, 0.013 kg ha−1 PRE fb mesosulfuron 0.015 kg ha−1 at 3- to 4-leaf ryegrass (92%); metribuzin, 0.280 kg ha−1 at 2- to 3- leaf wheat fb metribuzin at 2- to 3-tiller ryegrass (94%); chlorsulfuron/metsulfuron (0.026 kg ha−1) (89%); and flufenacet/metribuzin at 1- to 2-leaf wheat (89%). Chlorsulfuron/metsulfuron fb mesosulfuron provided higher yield (3515 kg ha−1) than all other treatments, except metribuzin fb metribuzin.

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Italian Ryegrass (Lolium Multiflorum) Management Options in Winter Wheat in Oklahoma

Weed Technology ◽

10.1614/wt-06-038.1 ◽

2007 ◽

Vol 21 (1) ◽

pp. 151-158 ◽

Cited By ~ 8

Author(s):

Chad S. Trusler ◽

Thomas F. Peeper ◽

Amanda E. Stone

Keyword(s):

Winter Wheat ◽

Plant Density ◽

Control Strategies ◽

Lolium Multiflorum ◽

Wheat Yield ◽

Italian Ryegrass ◽

Wheat Crop ◽

Management Options ◽

Spike Density ◽

Herbicide Treatments

An experiment was conducted at three sites in central Oklahoma to compare the efficacy of Italian ryegrass management options in no-till (NT) and conventional tillage (CT) winter wheat. The Italian ryegrass management options included selected herbicide treatments, wheat-for-hay, and a rotation consisting of double-crop soybean seeded immediately after wheat harvest, followed by early season soybean, and then by wheat. In continuous wheat, before application of glyphosate or tillage, Italian ryegrass plant densities in mid-September were 12,300 to 15,000 plants/m2in NT plots vs. 0 to 500 plants/m2in CT plots. When applied POST, diclofop controlled more Italian ryegrass than tralkoxydim or sulfosulfuron. In continuous wheat, yields were greater in CT plots than in NT plots at two of three sites. None of the Italian ryegrass management options consistently reduced Italian ryegrass density in the following wheat crop. Of the Italian ryegrass control strategies applied to continuous wheat, three herbicide treatments in NT at Chickasha and all treatments in NT at Perry reduced Italian ryegrass density in the following wheat crop. Italian ryegrass plant density in November and spike density were highly related to wheat yield at two and three sites, respectively. No management options were more profitable than rotation to soybean.

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Transfer of resistance alleles from herbicide-resistant to susceptible grass weeds via pollen-mediated gene flow

Weed Technology ◽

10.1017/wet.2021.82 ◽

2021 ◽

pp. 1-51

Author(s):

Amit J. Jhala ◽

Hugh J. Beckie ◽

Carol Mallory-Smith ◽

Marie Jasieniuk ◽

Roberto Busi ◽

...

Keyword(s):

Gene Flow ◽

Herbicide Resistance ◽

Creeping Bentgrass ◽

Agricultural Landscapes ◽

Italian Ryegrass ◽

Weed Species ◽

Herbicide Resistant ◽

Wild Oats ◽

Rigid Ryegrass ◽

Grass Weed

Abstract The objective of this paper was to review the reproductive biology, herbicide-resistant (HR) biotypes, pollen-mediated gene flow (PMGF), and potential for transfer of alleles from HR to susceptible grass weeds including barnyardgrass, creeping bentgrass, Italian ryegrass, johnsongrass, rigid (annual) ryegrass, and wild oats. The widespread occurrence of HR grass weeds is at least partly due to PMGF, particularly in obligate outcrossing species such as rigid ryegrass. Creeping bentgrass, a wind-pollinated turfgrass species, can efficiently disseminate herbicide resistance alleles via PMGF and movement of seeds and stolons. The genus Agrostis contains about 200 species, many of which are sexually compatible and produce naturally occurring hybrids as well as producing hybrids with species in the genus Polypogon. The self-incompatibility, extremely high outcrossing rate, and wind pollination in Italian ryegrass clearly point to PMGF as a major mechanism by which herbicide resistance alleles can spread across agricultural landscapes, resulting in abundant genetic variation within populations and low genetic differentiation among populations. Italian ryegrass can readily hybridize with perennial ryegrass and rigid ryegrass due to their similarity in chromosome numbers (2n=14), resulting in interspecific gene exchange. Johnsongrass, barnyardgrass, and wild oats are self-pollinated species, so the potential for PMGF is relatively low and limited to short distances; however, seeds can easily shatter upon maturity before crop harvest, leading to wider dispersal. The occurrence of PMGF in reviewed grass weed species, even at a low rate is greater than that of spontaneous mutations conferring herbicide resistance in weeds and thus can contribute to the spread of herbicide resistance alleles. This review indicates that the transfer of herbicide resistance alleles occurs under field conditions at varying levels depending on the grass weed species.

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Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 2: grass species

Weed Science ◽

10.1017/wsc.2020.79 ◽

2020 ◽

pp. 1-19

Author(s):

Lauren M. Schwartz-Lazaro ◽

Lovreet S. Shergill ◽

Jeffery A. Evans ◽

Muthukumar V. Bagavathiannan ◽

Shawn C. Beam ◽

...

Keyword(s):

The United States ◽

Grass Species ◽

Annual Grass ◽

Weed Seed ◽

Weed Species ◽

Seed Shattering ◽

Physiological Maturity ◽

Rate Of Progression ◽

Multiple Regions ◽

Grass Weed

Abstract Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.

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