Diclofop-Resistant Italian Ryegrass (Lolium multiflorum) Control in Imidazolinone-Tolerant Wheat

Field research was conducted in Arkansas for 3 yr to evaluate imazamox for control of diclofop-resistant Italian ryegrass in imidazolinone-tolerant wheat. Italian ryegrass was controlled at least 89% 49 d after wheat emergence (DAE) in year 2 and 3 by imazamox at 36 g ai/ha applied to one- to two-leaf wheat (POST1), by imazamox at 54 g ai/ha applied sequentially at POST1 followed by (fb) application to three- to four-leaf wheat (POST2), by pendimethalin at 1120 g ai/ha preemergence (PRE) fb imazamox at 36 or 54 g/ha POST1, and by chlorsulfuron plus metsulfuron at 22 plus 4 g ai/ha PRE. Italian ryegrass was controlled at least 95% 150 DAE with all applications in year 1 because of extremely cold temperatures and snowfall in December and January. Only sequential imazamox applications or pendimethalin PRE fb imazamox POST1 equaled the commercial standard, chlorsulfuron plus metsulfuron, for control of Italian ryegrass 150 DAE in years 2 and 3. These treatments controlled Italian ryegrass greater than 80% 150 DAE. Sequential postemergence applications of imazamox or programs containing pendimethalin PRE fb imazamox POST1 are necessary to optimize Italian ryegrass control and wheat yield in an imidazolinone-tolerant wheat production system.

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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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Control of Italian Ryegrass (Lolium multiflorum) in Winter Wheat

Weed Technology ◽

10.1614/wt-03-118r3 ◽

2005 ◽

Vol 19 (2) ◽

pp. 261-265 ◽

Cited By ~ 8

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.

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Wheat (Triticum aestivum) Cultivar Tolerance and Italian Ryegrass (Lolium multiflorum) Control with Diclofop, BAY SMY 1500, and Metribuzin

Weed Technology ◽

10.1017/s0890037x00033844 ◽

1991 ◽

Vol 5 (4) ◽

pp. 776-781 ◽

Cited By ~ 10

Author(s):

David R. Shaw ◽

M. Todd Wesley

Keyword(s):

Lolium Multiflorum ◽

Wheat Yield ◽

Italian Ryegrass ◽

Silty Clay ◽

Application Timing ◽

Soft Red Winter Wheat ◽

Early Injury ◽

Winter Wheat Cultivars ◽

Tolerance Study ◽

Silty Clay Soil

In the field, 14 soft red winter wheat cultivars responded differently to 1.1 kg ai ha–1diclofop, 1.7 kg ai ha–1BAY SMY 1500, and 0.42 kg ai ha–1metribuzin applied POST. Diclofop and metribuzin did not injure any cultivar more than 10% on a silty clay soil. However, BAY SMY 1500 injured ‘Pioneer 2551’ and ‘Coker 983’ 39 and 21%, respectively, in March. All other cultivars were injured less than 10% by BAY SMY 1500. Early injury did not translate into yield loss in the cultivar tolerance study. In an application timing study for Italian ryegrass control, late-season ratings indicated better control with two-leaf applications than with PRE applications for all treatments. Delaying application to the three-tiller stage reduced control with BAY SMY 1500 or metribuzin, but not with diclofop. On the sandier soil at this location, wheat injury with 0.28 or 0.43 kg ha–1metribuzin or 2.2 kg ha–1BAY SMY 1500 was sufficient to reduce wheat yield compared with other treatments, despite good Italian ryegrass control.

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Resistance Profile of Diclofop-Resistant Italian Ryegrass (Lolium multiflorum) to ACCase- and ALS-Inhibiting Herbicides in Arkansas, USA

Weed Science ◽

10.1614/ws-08-003.1 ◽

2008 ◽

Vol 56 (4) ◽

pp. 614-623 ◽

Cited By ~ 31

Author(s):

Yong In Kuk ◽

Nilda R. Burgos ◽

Robert C. Scott

Keyword(s):

Lolium Multiflorum ◽

Acetolactate Synthase ◽

Italian Ryegrass ◽

Cross Resistance ◽

Southern United States ◽

Resistance Pattern ◽

Acetyl Coa Carboxylase ◽

Wheat Production ◽

Resistant Accession ◽

Als Inhibitors

Diclofop-resistant Italian ryegrass is a major weed problem in wheat production. This study aimed to determine the resistance pattern of diclofop-resistant Italian ryegrass accessions from the southern United States to the latest commercialized herbicides for wheat production, pinoxaden and mesosulfuron, and to other acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors. Twenty-nine of 36 accessions were resistant to the commercial dose of diclofop. The majority (80%) of diclofop-resistant accessions were also resistant to clodinafop. Of 25 diclofop-resistant accessions, 5 were resistant to pinoxaden. All accessions tested were susceptible to the commercial dose of clethodim and sethoxydim. The cross-resistance pattern of diclofop-resistant Italian ryegrass to other ACCase inhibitors was 20% for pinoxaden and none with clethodim or sethoxydim. One accession was resistant to mesosulfuron but not to diclofop. This mesosulfuron-resistant accession was cross-resistant to sulfometuron but not to imazamox. All diclofop-resistant accessions tested were susceptible to ALS inhibitors, mesosulfuron, sulfometuron, and imazamox. Therefore, diclofop-resistant Italian ryegrass in Arkansas can be controlled with imazamox (in Clearfield wheat) and can mostly be controlled with mesosulfuron and pinoxaden. It could also be controlled by other selective grass herbicides in broadleaf crops.

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A simple method to assess wheat yield loss by Italian ryegrass (Lolium multiflorum Lam.) in the fields

Journal of Weed Science and Technology ◽

10.3719/weed.55.174 ◽

2010 ◽

Vol 55 (3) ◽

pp. 174-182 ◽

Cited By ~ 6

Author(s):

Tomoko Suzuki ◽

Yusuke Adachi ◽

Minoru Ichihara ◽

Masayuki Yamashita ◽

Hitoshi Sawada ◽

...

Keyword(s):

Yield Loss ◽

Lolium Multiflorum ◽

Wheat Yield ◽

Italian Ryegrass ◽

Simple Method

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Net Returns from Italian Ryegrass (Lolium multiflorum) Control in Winter Wheat (Triticum aestivum)

Weed Technology ◽

10.1017/s0890037x00038847 ◽

1994 ◽

Vol 8 (2) ◽

pp. 317-323 ◽

Cited By ~ 16

Author(s):

Greg G. Justice ◽

Thomas F. Peeper ◽

John B. Solie ◽

Francis M. Epplin

Keyword(s):

Triticum Aestivum ◽

Field Experiments ◽

Lolium Multiflorum ◽

Wheat Yield ◽

Italian Ryegrass ◽

Row Spacing ◽

Herbicide Application ◽

Seeding Rate ◽

Net Returns ◽

Better Than

In field experiments at three locations, wheat row spacing, seeding rate, and herbicide treatment affected Italian ryegrass control, wheat yield, dockage in the grain, and net returns. Diclofop at 560 or 840 g ai/ha controlled Italian ryegrass better than chlorsulfuron at 18 or 26 g ai/ha. Net returns were increased at all locations by diclofop POST at either rate and at two locations by chlorsulfuron PRE at either rate. Although increasing the wheat seeding rate reduced dockage at two of three locations, net returns were maximized by herbicide application alone without increased seeding rates or reduced row spacing.

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