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.

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.

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.

Fall-sown cover crops as mulches for weed suppression in organic small-scale diversified vegetable production

2016 ◽  
Vol 32 (4) ◽  
pp. 349-357
Author(s):  
Eric Bietila ◽  
Erin M. Silva ◽  
Anne C. Pfeiffer ◽  
Jed B. Colquhoun
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Yields ◽  
Weed Suppression ◽  
Small Scale ◽  
Vegetable Production ◽  
Cereal Rye ◽  
Organic Vegetable Production ◽  
Manual Weeding

AbstractCover crop-based reduced tillage (CCBRT) has achieved positive impacts in organic row crop systems, contributing to the conservation of soil resources and the facilitation of weed management. This technique, which uses cover crop residues as mulches to suppress weeds, has shown more variable success in organic vegetable production systems. This experiment examined CCBRT for small-scale organic vegetable production in the upper Midwestern USA, specifically evaluating weed suppression, labor inputs and crop yields. Cereal rye (Secale cerealeL.) and winter wheat (Triticum aestivumL.) were fall-sown in 2012 and 2013 in a strip-plot design, including control treatments with no cover crop and spring-applied oat straw mulch. Cover crop plots were strip-tilled in mid-April to establish a planting zone, with cover crops terminated in late May at anthesis with a hand-tractor mounted sickle-bar mower. Bell peppers (Capsicum annuumL. var. ‘Revolution’), snap beans (Phaseolus vulgarisL. var. ‘Tavera’), and potatoes (Solanum tuberosumL. var. ‘Red La Soda’) were hand-planted either as transplants or seed in each treatment immediately following cover crop termination. During each summer growing season, weeds were completely eliminated from each plot by hand approximately every 10–14 days, with time for manual weeding recorded for each treatment. Vegetable crop yields and quality were measured at harvest during 2013 and 2014. Cereal rye and winter wheat produced similar biomass at the time of termination. Greater weed biomass was collected in the wheat treatment as compared with the cereal rye, increasing the in-season labor required for manual weeding. Bean yields were decreased in the all CCBRT treatments compared with control treatments in both years of the study. Pepper yields did not differ in CCBRT treatments as compared with the control in both 2012 and 2013, although the CCBRT treatments did yield lower marketable peppers compared with the straw mulch plots. Potato tuber yields were not different in the CCBRT treatments as compared with the control in 2012, but were lower in 2013. These data indicate that, if CCBRT is to be more widely adopted in small-scale vegetable production, further optimization of the system must be achieved to ensure consistent and adequate weed suppression while maintaining crop yield and quality.

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.

Evaluation of Chemical Termination Options for Cover Crops

2018 ◽  
Vol 32 (3) ◽  
pp. 227-235 ◽  
Author(s):  
Matheus G. Palhano ◽  
Jason K. Norsworthy ◽  
Tom Barber
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Agricultural Research ◽  
Yield Potential ◽  
Crop Acreage ◽  
Potential Cost ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
And Control

AbstractCover crop acreage has substantially increased over the last few years due to the intent of growers to capitalize on federal conservation payments and incorporate sustainable practices into agricultural systems. Despite all the known benefits, widespread adoption of cover crops still remains limited due to potential cost and management requirements. Cover crop termination is crucial, because a poorly controlled cover crop can become a weed and lessen the yield potential of the current cash crop. A field study was conducted in fall 2015 and 2016 at the Arkansas Agricultural Research and Extension Center in Fayetteville to evaluate preplant herbicide options for terminating cover crops. Glyphosate-containing treatments controlled 97% to 100% of cereal rye and wheat, but glyphosate alone controlled less than 57% of legume cover crops. The most effective way to control hairy vetch, Austrian winterpea, and crimson clover with glyphosate resulted from mixtures of glyphosate with glufosinate, 2,4-D, and dicamba. Higher rates of auxin herbicides improved control in these mixtures. Glufosinate alone or in mixture controlled legume cover crops 81% or more. Paraquat plus metribuzin was effective in terminating both cereal and legume cover crops, with control of cereal cover crops ranging from 87% to 97% and control of legumes ranging from 90% to 96%. None of these herbicides or mixtures adequately controlled rapeseed.

scholarly journals Timing of Glyphosate Applications to Wheat Cover Crops to Reduce Onion Stunting Caused by Rhizoctonia solani

Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1474-1481 ◽  
Author(s):  
Dipak Sharma-Poudyal ◽  
Timothy C. Paulitz ◽  
Lindsey J. du Toit
Keyword(s):  
Rhizoctonia Solani ◽  
Cover Crops ◽  
Cover Crop ◽  
Severity Index ◽  
Onion Bulb ◽  
Columbia Basin ◽  
Herbicide Application ◽  
Dna Concentration ◽  
Green Bridge ◽  
Bulb Crops

Stunting caused by Rhizoctonia spp. is economically important in irrigated onion bulb crops in the semiarid Columbia Basin of Oregon and Washington, where cereal winter cover crops commonly are planted the previous fall to prevent wind erosion of soil. The cover crop is killed with herbicide application just before or shortly after onion seeding, so that the dead rows of cereal plants provide a physical barrier tall enough to protect onion seedlings against wind and sand blasting but not tall enough to shade onion seedlings. However, the cover crop also serves as a green bridge for Rhizoctonia spp. on cereal roots to colonize the onion roots, potentially resulting in severe stunting of onion seedlings. To determine the effect of timing of application of the herbicide glyphosate to reduce this green bridge effect and, subsequently, onion stunting, three herbicide application intervals preceding onion planting were evaluated in a grower’s onion field in each of 2012 and 2014 in the Columbia Basin. The wheat cover crop was killed with a glyphosate application 27, 17, and 3 days before onion seeding in 2012 and 19, 10, and 3 days before seeding in 2014. As the interval between herbicide application and onion planting increased from 3 days to 19 and 27 days, the number of patches of stunted onion plants decreased by ≥55%, total area of stunted patches decreased by 54 to 63%, and patch severity index decreased by 59 to 65%. Similarly, the Rhizoctonia solani AG 8 DNA concentration in soil sampled from the dead cover crop rows declined as the interval between glyphosate application and onion seeding increased in the 2012 trial but not in the 2014 trial. R. solani AG 3 and AG 8 DNA concentrations in soil sampled from the cover crop rows were significantly positively correlated with the number of patches of stunted onion plants (r = 0.490 and 0.607 at P = 0.039 and 0.008, respectively), total area of stunted patches (r = 0.496 and 0.659 at P = 0.035 and 0.003, respectively), and patch severity index (r = 0.492 and 0.635 at P = 0.038 and 0.005, respectively) in the 2012 trial; however, these variables were only correlated significantly with R. solani AG 3 DNA concentration in the 2014 trial. Increasing the interval between herbicide application to the cover crop and onion planting provides a practical management tool for stunting in onion bulb crops.

EFFECT OF COVER CROPS ON WINTER SURVIVAL, COMMON ROOT ROT, AND YIELD OF WINTER WHEAT

1962 ◽  
Vol 42 (2) ◽  
pp. 286-293 ◽  
Author(s):  
A. D. Smith ◽  
J. S. Horricks ◽  
J. E. Andrews
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Root Rot ◽  
Cover Crop ◽  
Ammonium Phosphate ◽  
Winter Survival ◽  
Common Root ◽  
Common Root Rot

When four varieties of winter wheat (Yogo, Kharkov 22 M.C., Jones Fife, and Elgin) were sown into wheat, oat, or barley cover crops, the yields were lower than when they were sown on fallow. The yield of winter wheat sown into the different cover crops was highest in barley and lowest in wheat cover crop. When the growth of cover crops was abundant, the yield of winter wheat was reduced. Application of ammonium-phosphate-sulphate fertilizer (16-20-0) increased the yield of winter wheat and generally decreased the severity of common root rot. Winter survival was generally greater when winter wheat was sown into cover crops than when it was sown on fallow. Root rot was most severe in winter wheat sown into wheat cover and was progressively less severe when sown into fallow, barley, or oat cover. Neither blade-cultivating nor mowing the cover crop prior to seeding the winter wheat appreciably affected the yield.

Integration of residual herbicides with cover crop termination in soybean

2019 ◽  
Vol 34 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Derek M. Whalen ◽  
Lovreet S. Shergill ◽  
Lyle P. Kinne ◽  
Mandy D. Bish ◽  
Kevin W. Bradley
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Cover Crop ◽  
Biomass Accumulation ◽  
Field Studies ◽  
Italian Ryegrass ◽  
Cereal Rye ◽  
Herbicide Treatments ◽  
Residual Herbicide ◽  
Herbicide Programs

AbstractCover crops have increased in popularity in midwestern U.S. corn and soybean systems in recent years. However, little research has been conducted to evaluate how cover crops and residual herbicides are effectively integrated together for weed control in a soybean production system. Field studies were conducted in 2016 and 2017 to evaluate summer annual weed control and to determine the effect of cover crop biomass on residual herbicide reaching the soil. The herbicide treatments consisted of preplant (PP) applications of glyphosate plus 2,4-D with or without sulfentrazone plus chlorimuron at two different timings, 21 and 7 d prior to soybean planting (DPP). Cover crops evaluated included winter vetch, cereal rye, Italian ryegrass, oat, Austrian winter pea, winter wheat, and a winter vetch plus cereal rye mixture. Herbicide treatments were applied to tilled and nontilled soil without cover crop for comparison. The tillage treatment resulted in low weed biomass at all collection intervals after both application timings, which corresponded to tilled soil having the highest sulfentrazone concentration (171 ng g−1) compared with all cover crop treatments. When applied PP, herbicide treatments applied 21 DPP with sulfentrazone had greater weed (93%) and waterhemp (89%) control than when applied 7 DPP (60% and 69%, respectively). When applied POST, herbicide treatments with a residual herbicide resulted in greater weed and waterhemp control at 7 DPP (83% and 77%, respectively) than at 21 DPP (74% and 61%, respectively). Herbicide programs that included a residual herbicide had the highest soybean yields (≥3,403 kg ha−1). Results from this study indicate that residual herbicides can be effectively integrated either PP or POST in conjunction with cover crop termination applications, but termination timing and biomass accumulation will affect the amount of sulfentrazone reaching the soil.

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.

scholarly journals Temporal Change of Soil Carbon on a Long-Term Experimental Site with Variable Crop Rotations and Tillage Systems

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Ahmed Laamrani ◽  
Paul R. Voroney ◽  
Aaron A. Berg ◽  
Adam W. Gillespie ◽  
Michael March ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Soil Carbon ◽  
Cover Crops ◽  
Cover Crop ◽  
Red Clover ◽  
Conventional Tillage ◽  
Crop Rotations ◽  
Tillage Practices ◽  
No Till

The impacts of tillage practices and crop rotations are fundamental factors influencing changes in the soil carbon, and thus the sustainability of agricultural systems. The objective of this study was to compare soil carbon status and temporal changes in topsoil from different 4 year rotations and tillage treatments (i.e., no-till and conventional tillage). Rotation systems were primarily corn and soy-based and included cereal and alfalfa phases along with red clover cover crops. In 2018, soil samples were collected from a silty-loam topsoil (0–15 cm) from the 36 year long-term experiment site in southern Ontario, Canada. Total carbon (TC) contents of each sample were determined in the laboratory using combustion methods and comparisons were made between treatments using current and archived samples (i.e., 20 year and 9 year change, respectively) for selected crop rotations. Overall, TC concentrations were significantly higher for no-till compared with conventional tillage practices, regardless of the crop rotations employed. With regard to crop rotation, the highest TC concentrations were recorded in corn–corn–oats–barley (CCOB) rotations with red clover cover crop in both cereal phases. TC contents were, in descending order, found in corn–corn–alfalfa–alfalfa (CCAA), corn–corn–soybean–winter wheat (CCSW) with 1 year of seeded red clover, and corn–corn–corn–corn (CCCC). The lowest TC concentrations were observed in the corn–corn–soybean–soybean (CCSS) and corn–corn–oats–barley (CCOB) rotations without use of cover crops, and corn–corn–soybean–winter wheat (CCSW). We found that (i) crop rotation varieties that include two consecutive years of soybean had consistently lower TC concentrations compared with the remaining rotations; (ii) TC for all the investigated plots (no-till and/or tilled) increased over the 9 year and 20 year period; (iii) the no-tilled CCOB rotation with 2 years of cover crop showed the highest increase of TC content over the 20 year change period time; and (iv) interestingly, the no-till continuous corn (CCCC) rotation had higher TC than the soybean–soybean–corn–corn (SSCC) and corn–corn–soybean–winter wheat (CCSW). We concluded that conservation tillage (i.e., no-till) and incorporation of a cover crop into crop rotations had a positive effect in the accumulation of TC topsoil concentrations and could be suitable management practices to promote soil fertility and sustainability in our agricultural soils.

Sign in / Sign up

Export Citation Format

Share Document