Rush Skeletonweed (Chondrilla juncea) Control in Pacific Northwest Winter Wheat

2018 ◽  
Vol 32 (4) ◽  
pp. 360-363 ◽  
Author(s):  
John F. Spring ◽  
Mark E. Thorne ◽  
Ian C. Burke ◽  
Drew J. Lyon

AbstractRush skeletonweed is emerging as a regionally important weed of winter wheat production in eastern Washington. Field studies were conducted during the 2016 and 2017 crop years to evaluate several auxin herbicides applied at two seasonal timings (fall or spring) for control of rush skeletonweed in winter wheat. Clopyralid (210 g ae ha-1) provided>90% visual control of rush skeletonweed in both years of the study and aminopyralid (10 g ae ha-1) provided>80% visual control. Aminocyclopyrachlor, dicamba, and 2,4-D provided<55% control of rush skeletonweed. Season of application did not meaningfully affect efficacy of any herbicide tested. Wheat yields were reduced by 39 to 69% compared to the non-treated check when aminocyclopyrachlor was applied in the spring. Clopyralid is an effective option for control of rush skeletonweed in Pacific Northwest winter wheat.

2020 ◽  
Vol 34 (6) ◽  
pp. 857-862
Author(s):  
Jacob W. Fischer ◽  
Mark E. Thorne ◽  
Drew J. Lyon

AbstractRush skeletonweed is an aggressive perennial weed that establishes itself on land in the Conservation Reserve Program (CRP), and persists during cropping following contract expiration. It depletes critical soil moisture required for yield potential of winter wheat. In a winter wheat/fallow cropping system, weed control is maintained with glyphosate and tillage during conventional fallow, and with herbicides only in no-till fallow. Research was conducted for control of rush skeletonweed at two sites in eastern Washington, Lacrosse and Hay, to compare the effectiveness of a weed-sensing sprayer and broadcast applications of four herbicides (aminopyralid, chlorsulfuron + metsulfuron, clopyralid, and glyphosate). Experimental design was a split-plot with herbicide and application type as main and subplot factors, respectively. Herbicides were applied in the fall at either broadcast or spot-spraying rates depending on sprayer type. Rush skeletonweed density in May was reduced with use of aminopyralid (1.1 plants m−2), glyphosate (1.4 plants m−2), clopyralid (1.7 plants m−2), and chlorsulfuron + metsulfuron (1.8 plants m−2) compared with the nontreated check (2.6 plants m−2). No treatment differences were observed after May 2019. There was no interaction between herbicide and application system. Area covered using the weed-sensing sprayer was, on average, 52% (P < 0.001) less than the broadcast application at the Lacrosse location but only 20% (P = 0.01) at the Hay location. Spray reduction is dependent on foliar cover in relation to weed density and size. At Lacrosse, the weed-sensing sprayer reduced costs for all herbicide treatments except aminopyralid, with savings up to US$6.80 per hectare. At Hay, the weed-sensing sprayer resulted in economic loss for all products because of higher rush skeletonweed density. The weed-sensing sprayer is a viable fallow weed control tool when weed densities are low or patchy.


Weed Science ◽  
1986 ◽  
Vol 34 (S1) ◽  
pp. 2-6 ◽  
Author(s):  
Gary A. Lee

Rush skeletonweed (Chondrilla junceaL. CHOJU) infestations occur along the eastern seaboard and in several western states of the United States. This Eurasian species was inadvertently introduced prior to 1870, with established stands first reported in Maryland and West Virginia (16). These infestations (16) were assessed as lacking aggressive characteristics and posed little threat as a problem weed. Although rush skeletonweed was discovered in the Pacific Northwest as early as 1938, the species was not recognized as a potential weed problem until nearly three decades later (27). Subsequent surveys revealed that infestations occupied over 2.3 million ha in California, Idaho, Oregon, and Washington (6). Attempts to generate support for an organized control program in Idaho were met with little enthusiasm during the 1960's.


1985 ◽  
Vol 22 (3) ◽  
pp. 179
Author(s):  
D.E. Wilkins ◽  
R.R. Allmaras ◽  
J.M. Kraft ◽  
R.E. Ramig

2017 ◽  
Vol 31 (6) ◽  
pp. 822-827
Author(s):  
Thomas C. Mueller

Field studies were conducted in 2014 and 2015 in Tennessee to examine pyroxasulfone dissipation under field conditions of winter wheat production. Three formulations were examined: (1) a single component active ingredient in an 85% dry flowable, (2) dry flowable formulation in combination of pyroxasulfone+flumioxazin, and (3) a liquid SC formulation of pyroxasulfone+carfentrazone. The liquid formulation is a suspo-emulsion. When averaged across the three studies, the DT 50 were 34.4, 30.2 and 29.9 d for pyroxasulfone plus carfentrazone, pyroxasulfone, and pyroxasulfone plus flumioxazin, respectively. These trends would indicate that formulation had little or no effect on pyroxasulfone dissipation in this experiment. Pyroxasulfone DT 50 in all studies ranged from a low of 15.4 d to a high of 53.3 d, and loss was more rapid under warm, moist conditions. These results indicate that pyroxasulfone would last long enough to provide residual weed control, but would not persist excessively to injure rotational crops.


2021 ◽  
pp. 1-22
Author(s):  
Mark E. Thorne ◽  
Drew J. Lyon

Rush skeletonweed is an invasive weed in winter wheat (WW)/summer fallow (SF) rotations of the low to intermediate rainfall areas of the inland Pacific Northwest. Standard weed control practices are not effective, resulting in additional SF tillage or herbicide applications. The objective of this field research was to identify herbicide treatments that control rush skeletonweed during the SF phase of the WW/SF rotation. Trials were conducted near LaCrosse, WA in 2017-2019 and 2018-2020, and near Hay, WA in 2018-2020. The LaCrosse 2017-2020 trial was in tilled SF; the other two trials were in no-till SF. Fall post-harvest applications in October included clopyralid, clopyralid plus 2,4-D, clopyralid plus 2,4-D plus chlorsulfuron plus metsulfuron, aminopyralid, picloram, and glyphosate plus 2,4-D. Spring treatments of clopyralid, aminopyralid, and glyphosate were applied to rush skeletonweed rosettes. Summer treatments of 2,4-D were applied when rush skeletonweed initiated bolting. Plant density was monitored through the SF phase in all plots. Picloram provided complete control of rush skeletonweed through June at all three locations. Fall-applied clopyralid, clopyralid plus 2,4-D, and clopyralid followed by 2,4-D in summer reduced rush skeletonweed through June at the two LaCrosse sites but were ineffective at Hay. In August, just prior to winter wheat seeding, the greatest reductions in rush skeletonweed density were achieved with picloram and fall-applied clopyralid at the two LaCrosse sites. No treatments provided effective control into August at Hay. Wheat yield in the next crop compared to the nontreated control was reduced only at one LaCrosse site by a spring-applied aminopyralid treatment, otherwise no other reductions were found. Long-term control of rush skeletonweed in WW/SF may be achieved by a combination of fall application of picloram, after wheat harvest, followed by an effective burn-down treatment in August prior to winter wheat seeding.


2021 ◽  
pp. 1-22
Author(s):  
Marcelo L. Moretti

Abstract Italian ryegrass has become a problematic weed in hazelnut orchards of Oregon because of the presence of herbicide-resistant populations. Resistant and multiple-resistant Italian ryegrass populations are now the predominant biotypes in Oregon; there is no information on which herbicides effectively control Italian ryegrass in hazelnut orchards. Six field studies were conducted in commercial orchards to evaluate Italian ryegrass control with POST herbicides. Treatments included flazasulfuron, glufosinate, glyphosate, paraquat, rimsulfuron, and sethoxydim applied alone or in selected mixtures during early spring when plants were in the vegetative stage. Treatment efficacy was dependent on the experimental site. The observed range of weed control 28 d after treatment was 13 to 76 % for glyphosate, 1 to 72% for paraquat, 58 to 88% for glufosinate, 16 to 97 % for flazasulfuron, 8 to 94% for rimsulfuron, and 25 to 91% for sethoxydim. Herbicides in mixtures improved control of Italian ryegrass compared to single active ingredients based on contrast analysis. Herbicides in mixture increased control by 27% compared to glyphosate, 18% to rimsulfuron, 15% to flazasulfuron, 19% to sethoxydim, and 12% compared to glufosinate when averaged across all sites, but mixture not always improved ground coverage of biomass reduction. This complex site-specific response highlights the importance of record-keeping for efficient herbicide use. Glufosinate is an effective option to manage Italian ryegrass. However, the glufosinate-resistant biotypes documented in Oregon may jeopardize this practice. Non-chemical weed control options are needed for sustainable weed management in hazelnuts.


2021 ◽  
Vol 20 (6) ◽  
pp. 1687-1700
Author(s):  
Li-chao ZHAI ◽  
Li-hua LÜ ◽  
Zhi-qiang DONG ◽  
Li-hua ZHANG ◽  
Jing-ting ZHANG ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document