Integrating fall-planted cereal cover crops and preplant herbicides for glyphosate-resistant horseweed (Conyza canadensis) management in soybean

2020 ◽  
pp. 1-8
Author(s):  
John A. Schramski ◽  
Christy L. Sprague ◽  
Karen A. Renner
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Management Tool ◽  
No Tillage ◽  
Seeding Rate ◽  
Soybean Yield ◽  
Cereal Rye ◽  
Sites Of Action

Abstract Glyphosate-resistant horseweed is difficult to manage in no-tillage crop production fields and new strategies are needed. Cover crops may provide an additional management tool but narrow establishment windows and colder growing conditions in northern climates may limit the cover crop biomass required to suppress horseweed. Field experiments were conducted in 3 site-years in Michigan to investigate the effects of two fall-planted cover crops, cereal rye and winter wheat, seeded at 67 or 135 kg ha−1, to suppress horseweed when integrated with three preplant herbicide strategies in no-tillage soybean. The preplant strategies were control (glyphosate only), preplant herbicide without residuals (glyphosate + 2,4-D), and preplant herbicide with residuals (glyphosate + 2,4-D + flumioxazin + metribuzin). Cereal rye produced 79% more biomass and provided 12% more ground cover than winter wheat in 2 site-years. Increasing seeding rate provided 41% more cover biomass in 1 site-year. Cover crops reduced horseweed density 47% to 96% and horseweed biomass by 59% to 70% compared with no cover at the time of cover crop termination. Cover crops provided no additional horseweed suppression 5 wk after soybean planting if a preplant herbicide with or without residuals was applied, but reduced horseweed biomass greater than 33% in the absence of preplant herbicides. Cover crops did not affect horseweed suppression at the time of soybean harvest or influence soybean yield. Preplant herbicide with residuals and without residuals provided at least 52% and 20% greater soybean yield compared with the control at 2 site-years, respectively. Cereal rye and winter wheat provided early-season horseweed suppression at biomass levels below 1,500 kg ha−1, lower than previously reported. This could give growers in northern climates an effective strategy for suppressing horseweed through the time of POST herbicide application while reducing selection pressure for horseweed that is resistant to more herbicide sites of action.

Cover Crops Suppression of Palmer Amaranth (Amaranthus palmeri) in Cotton

2017 ◽  
Vol 32 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Matheus G. Palhano ◽  
Jason K. Norsworthy ◽  
Tom Barber
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Palmer Amaranth ◽  
Cotton Yield ◽  
Cotton Production ◽  
Seed Cotton ◽  
Cereal Rye ◽  
Seed Cotton Yield ◽  
Weed Emergence

AbstractWith the recent confirmation of protoporphyrinogen oxidase (PPO)-resistant Palmer amaranth in the US South, concern is increasing about the sustainability of weed management in cotton production systems. Cover crops can help to alleviate this problem, as they can suppress weed emergence via allelochemicals and/or a physical residue barrier. Field experiments were conducted in 2014 and 2015 at the Arkansas Agricultural Research and Extension Center to evaluate various cover crops for suppressing weed emergence and protecting cotton yield. In both years, cereal rye and wheat had the highest biomass production, whereas the amount of biomass present in spring did not differ among the remaining cover crops. All cover crops initially diminished Palmer amaranth emergence. However, cereal rye provided the greatest suppression, with 83% less emergence than in no cover crop plots. Physical suppression of Palmer amaranth and other weeds with cereal residues is probably the greatest contributor to reducing weed emergence. Seed cotton yield in the legume and rapeseed cover crop plots were similar when compared with the no cover crop treatment. The seed cotton yield collected from cereal cover crop plots was lower than from other treatments due to decreased cotton stand.

scholarly journals Systemic Colonization by Metarhizium robertsii Enhances Cover Crop Growth

2020 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
Imtiaz Ahmad ◽  
María del Mar Jiménez-Gasco ◽  
Dawn S. Luthe ◽  
Mary E. Barbercheck
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Negative Relationship ◽  
Crop Growth ◽  
Above Ground Biomass ◽  
Crop Species ◽  
Metarhizium Robertsii ◽  
Cereal Rye ◽  
Ground Biomass

Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, we observed a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures. Here, we report the effects of endophytic M. robertsii on three cover crop species under greenhouse conditions. We inoculated seeds of Austrian winter pea (Pisum sativum L., AWP), cereal rye (Secale cereale L.), and winter canola (Brassica napus L.) with conidia of M. robertsii to assess the effects of endophytic colonization on cover crop growth. We recovered M. robertsii from 59%, 46%, and 39% of seed-inoculated AWP, cereal rye, and canola plants, respectively. Endophytic M. robertsii significantly increased height and above-ground biomass of AWP and cereal rye but did not affect chlorophyll content of any of the cover crop species. Among inoculated plants from which we recovered M. robertsii, above-ground biomass of AWP was positively correlated with the proportion of colonized root but not leaf tissue sections. Our results suggest that winter cover crops may help to conserve Metarhizium spp. in annual cropping systems.

Herbicide Programs for the Termination of Various Cover Crop Species

2017 ◽  
Vol 31 (4) ◽  
pp. 514-522 ◽  
Author(s):  
Cody D. Cornelius ◽  
Kevin W. Bradley
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Crop Yields ◽  
Production Systems ◽  
Annual Ryegrass ◽  
Crop Species ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Herbicide Treatments

The recent interest in cover crops as a component of Midwest corn and soybean production systems has led to a greater need to understand the most effective herbicide treatments for cover crop termination prior to planting corn or soybean. Previous research has shown that certain cover crop species can significantly reduce subsequent cash crop yields if not completely terminated. Two field experiments were conducted in 2013, 2014, and 2015 to determine the most effective herbicide program for the termination of winter wheat, cereal rye, crimson clover, Austrian winter pea, annual ryegrass, and hairy vetch; and cover crops were terminated in early April or early May. Visual control and above ground biomass reduction was determined 28 d after application (DAA). Control of grass cover crop species was often best with glyphosate alone or combined with 2,4-D, dicamba, or saflufenacil. The most consistent control of broadleaf cover crops occurred following treatment with glyphosate +2,4-D, dicamba, or saflufenacil. In general, control of cover crops was higher with early April applications compared to early May. In a separate study, control of 15-, 25-, and 75-cm tall annual ryegrass was highest with glyphosate at 2.8 kg ha−1or glyphosate at 1.4 kg ha−1plus clethodim at 0.136 kgha−1. Paraquat- or glufosinate-containing treatments did not provide adequate annual ryegrass control. For practitioners who desire higher levels of cover crop biomass, these results indicate that adequate levels of cover crop control can still be achieved in the late spring with certain herbicide treatments. But it is important to consider cover crop termination well in advance to ensure the most effective herbicide or herbicide combinations are used and the products are applied at the appropriate stage.

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.

Winter Annual Weed Suppression in Rye–Vetch Cover Crop Mixtures

2012 ◽  
Vol 26 (4) ◽  
pp. 818-825 ◽  
Author(s):  
Zachary D. Hayden ◽  
Daniel C. Brainard ◽  
Ben Henshaw ◽  
Mathieu Ngouajio
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Dry Weight ◽  
Weed Suppression ◽  
Weed Species ◽  
Cereal Rye ◽  
Winter Annual ◽  
Winter Annual Weeds ◽  
Annual Weeds

Winter annual weeds can interfere directly with crops and serve as alternative hosts for important pests, particularly in reduced tillage systems. Field experiments were conducted on loamy sand soils at two sites in Holt, MI, between 2008 and 2011 to evaluate the relative effects of cereal rye, hairy vetch, and rye–vetch mixture cover crops on the biomass and density of winter annual weed communities. All cover crop treatments significantly reduced total weed biomass compared with a no-cover-crop control, with suppression ranging from 71 to 91% for vetch to 95 to 98% for rye. In all trials, the density of nonmustard family broadleaf weeds was either not suppressed or suppressed equally by all cover crop treatments. In contrast, the density of mustard family weed species was suppressed more by rye and rye–vetch mixtures than by vetch. Cover crops were more consistently suppressive of weed dry weight per plant than of weed density, with rye-containing cover crops generally more suppressive than vetch. Overall, rye was most effective at suppressing winter annual weeds; however, rye–vetch mixtures can match the level of control achieved by rye, in addition to providing a potential source of fixed nitrogen for subsequent cash crops.

scholarly journals The Effects of Cover Crop and Fertilizer Rate on Celery (Apium Graveolens L.) Growth and Development

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 865F-866
Author(s):  
Kevin Charles* ◽  
Mathieu Ngouajio ◽  
Darryl Warncke
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Growth And Development ◽  
Field Experiments ◽  
Apium Graveolens ◽  
Shoot Biomass ◽  
Hairy Vetch ◽  
Fertilizer Rate ◽  
Cereal Rye ◽  
Oilseed Radish

Cover crops are commonly used to improve soil fertility and enhance crop performance. Field experiments were conducted to determine the effects of different cover crops and fertilizer rates on celery growth and development. The experiment was a two-way factorial with a split plot arrangement. The main plot factor was cover crop and included cereal rye (Secale cereale), hairy vetch (Vicia villosa), oilseed radish [Raphanus sativus (L.) var. oleiferus Metzg (Stokes)], and no cover crop. The sub-plot factor was fertilizer rate with three levels: full (160, 80, 400), half (80, 40, 200), and low (80, 0, 0) kg/ha of N, P2 O5, K2 O, respectively. The cover crops were grown during Fall 2002 and incorporated prior to celery transplanting in May 2003. During celery growing season, stalk length, above and below ground biomass were assessed at 23, 43, 64, and 84 days after planting (DAP). The biomass produced by oilseed radish (719 g/m2) exceeded that of cereal rye (284 g/m2) and hairy vetch (181 g/m2). At 23 and 43 DAP, celery fresh root (4.8 and 11.4 g/root) and shoot (6.1 and 53.6 g/shoot) biomass of oilseed radish exceeded the values of all other cover crops. At 84 DAP however, celery shoot fresh weight was similar in all cover crop treatments. Celery plants were tallest in the cereal oilseed radish and rye treatments early in the season; however final plant height at harvest was not affected by type of cover crop. The amount of fertilizer applied had a significant effect on celery growth starting at 64 DAP and continued until harvest. These results suggest that the large biomass produced by oilseed radish played an important role in early season celery growth.

Rolled Mixtures of Barley and Cereal Rye for Weed Suppression in Cover Crop–based Organic No-Till Planted Soybean

Weed Science ◽  
2017 ◽  
Vol 65 (3) ◽  
pp. 426-439 ◽  
Author(s):  
Jeffrey A. Liebert ◽  
Antonio DiTommaso ◽  
Matthew R. Ryan
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Block Design ◽  
Weed Suppression ◽  
Management Tool ◽  
Weed Biomass ◽  
Cereal Rye ◽  
No Till ◽  
Lower Cover ◽  
Crop Biomass

Maximizing cereal rye biomass has been recommended for weed suppression in cover crop–based organic no-till planted soybean; however, achieving high biomass can be challenging, and thick mulch can interfere with soybean seed placement. An experiment was conducted from 2012 to 2014 in New York to test whether mixing barley and cereal rye would (1) increase weed suppression via enhanced shading prior to termination and (2) provide acceptable weed suppression at lower cover crop biomass levels compared with cereal rye alone. This experiment was also designed to assess high-residue cultivation as a supplemental weed management tool. Barley and cereal rye were seeded in a replacement series, and a split-block design with four replications was used with management treatments as main plots and cover crop seeding ratio treatments (barley:cereal rye, 0:100, 50:50, and 100:0) as subplots. Management treatments included high-residue cultivation and standard no-till management without high-residue cultivation. Despite wider leaves in barley, mixing the species did not increase shading, and cereal rye dominated cover crop biomass in the 50:50 mixtures in 2013 and 2014, representing 82 and 93% of the biomass, respectively. Across all treatments, average weed biomass (primarily common ragweed, giant foxtail, and yellow foxtail) in late summer ranged from 0.5 to 1.1 Mg ha−1in 2013 and 0.6 to 1.3 Mg ha−1in 2014, and weed biomass tended to decrease as the proportion of cereal rye, and thus total cover crop biomass, increased. However, soybean population also decreased by 29,100 plants ha−1for every 1 Mg ha−1increase in cover crop biomass in 2013 (P=0.05). There was no relationship between cover crop biomass and soybean population in 2014 (P=0.35). Soybean yield under no-till management averaged 2.9 Mg ha−1in 2013 and 2.6 Mg ha−1in 2014 and was not affected by cover crop ratio or management treatment. Partial correlation analyses demonstrated that shading from cover crops prior to termination explained more variation in weed biomass than cover crop biomass. Our results indicate that cover crop management practices that enhance shading at slightly lower cover crop biomass levels might reduce the challenges associated with excessive biomass production without sacrificing weed suppression in organic no-till planted soybean.

Effects of fall-planted cereal cover-crop termination time on glyphosate-resistant horseweed (Conyza canadensis) suppression

2020 ◽  
pp. 1-11
Author(s):  
John A. Schramski ◽  
Christy L. Sprague ◽  
Karen A. Renner
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Cover Crop ◽  
C:N Ratio ◽  
Early Termination ◽  
Conyza Canadensis ◽  
Herbicide Application ◽  
Upper Midwest ◽  
Cereal Rye ◽  
Termination Time

Abstract Integrated strategies for management of glyphosate-resistant (GR) horseweed are needed to reduce reliance on herbicides. Planting a cover crop after corn or soybean harvest in the Upper Midwest may reduce horseweed establishment and growth. Experiments were conducted in Michigan to determine if cereal rye and winter wheat, seeded at 67 or 135 kg ha−1, and terminated with glyphosate at 1.27 kg ae ha−1 1 wk before planting (early termination) or 1 wk after soybean planting (planting green) would suppress establishment and growth of GR horseweed. Cover-crop biomass was 212% to 272% higher when termination was delayed by planting green compared with early termination. At the time of termination, cover crops reduced GR horseweed biomass 41% to 89% compared with no cover. Planting green increased the C:N ratio of cover-crop residue, which improved residue persistence and GR horseweed suppression at the time of POST herbicide application, approximately 5 wk after planting. Planting green reduced GR horseweed biomass 46% to 93% compared with no cover at the time of POST herbicide application; early termination provided less consistent suppression. Cover crops alone did not suppress GR horseweed through soybean harvest. Soybean yield was 30% to 108% greater when planting green compared with early termination at 2 site-years. Cereal rye and winter wheat, seeded at 67 or 135 kg ha−1, provided early-season GR horseweed suppression. Results from this research indicate that the practice of planting green may improve GR horseweed suppression through the time of POST herbicide application.

The effects of integrating a cereal rye cover crop with herbicides on glyphosate-resistant horseweed (Conyza canadensis) in no-till soybean

Weed Science ◽  
2020 ◽  
Vol 68 (5) ◽  
pp. 527-533
Author(s):  
Alyssa I. Essman ◽  
Mark M. Loux ◽  
Alexander J. Lindsey ◽  
Anthony F. Dobbels ◽  
Emilie E. Regnier
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Plant Density ◽  
Field Studies ◽  
Planting Date ◽  
Conyza Canadensis ◽  
Seeding Rate ◽  
Cereal Rye ◽  
No Till ◽  
Herbicide Treatment

AbstractCurrent recommendations for the control of glyphosate-resistant horseweed [Conyza canadensis (L.) Cronquist var. canadensis] in soybeans [Glycine max (L.) Merr.] consist of comprehensive herbicide programs, which often include herbicide applications outside the soybean growing season. Integration of cover crops with herbicides could potentially improve C. canadensis control and allow for a reduction in herbicide inputs. Two separate field studies were conducted from 2016 through 2018 with the objectives of: (1) determining the effect of planting date and seeding rate of a cereal rye (Secale cereale L.) cover crop on C. canadensis population density and control in the subsequent soybean crop; and (2) determining whether the cover crop could replace a fall herbicide treatment or allow for a reduction in the use of spring-applied residual herbicides. There was no effect of rye planting date, late September versus late October, on C. canadensis density in either study. In 2016 to 2017, C. canadensis density was greater in the absence of a rye cover crop in both studies, but otherwise not affected by seeding rates of 50 versus 100 kg ha−1. In the 2017 to 2018 season, the presence of rye resulted in an increased C. canadensis density in the spring residual herbicide study (Study I), and had no effect in the fall herbicide study (Study II). Conyza canadensis densities were lowest in the treatments where a comprehensive spring residual or fall herbicide treatment had been applied, averaged over rye planting date and seeding rate. Earlier-planted rye at a higher seeding rate produced the most biomass but did not result in lower C. canadensis densities. These results suggest that cereal rye planted at a density of 50 kg ha−1 as a cover crop before no-till soybeans may be sufficient to reduce glyphosate-resistant C. canadensis plant density, but cannot be relied upon to reduce the need for fall herbicide treatments and spring residual programs.

Horseweed (Conyza canadensis) Suppression from Cover Crop Mixtures and Fall-Applied Residual Herbicides

2019 ◽  
Vol 33 (2) ◽  
pp. 303-311 ◽  
Author(s):  
Kara B. Pittman ◽  
Jacob N. Barney ◽  
Michael L. Flessner
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Field Experiments ◽  
Late Spring ◽  
Integrated Weed Management ◽  
Management Approach ◽  
Late Winter ◽  
Cereal Rye ◽  
Crimson Clover

AbstractHorseweed is a problematic weed to control, especially in no-tillage production. Increasing cases of herbicide resistance have exacerbated the problem, necessitating alternative control options and an integrated weed management approach. Field experiments were conducted to evaluate horseweed suppression from fall-planted cover crop monocultures and mixtures as well as two fall-applied residual herbicide treatments. Prior to cover crop termination, horseweed density was reduced by 88% to 96% from cover crops. At cover crop termination in late spring, cereal rye biomass was 7,671 kg ha–1, which was similar to cereal rye–containing mixtures (7,720 kg ha–1) but greater than legumes in monoculture (3,335 kg ha–1). After cover crops were terminated in late spring using a roller crimper, corn and soybeans were planted and horseweed was evaluated using density counts, visible ratings, and biomass collection until harvest. Forage radish winterkilled, offering no competition in late winter or biomass to contribute to horseweed suppression after termination. Excluding forage radish in monoculture, no difference in horseweed suppression was detected between cereal rye–containing cover crops and legumes (crimson clover and hairy vetch) in monoculture. Likewise, horseweed suppression was similar between monocultures and mixtures, with the exception of one site-year in which mixtures provided better suppression. In this experiment, the cover crop treatments performed as well as or better than the fall-applied residual herbicides, flumioxazin+paraquat and metribuzin+chlorimuron-ethyl. These results indicate that fall-planted cover crops are a viable option to suppress horseweed and can be an effective part of an integrated weed management program. Furthermore, cover crop mixtures can be used to gain the benefits of legume or brassica cover crop species without sacrificing horseweed suppression.

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