Mechanical Termination of Diverse Cover Crop Mixtures for Improved Weed Suppression in Organic Cropping Systems

Cover crops can provide many benefits in agroecosystems, including the opportunity for improved weed control. However, the weed suppressive potential of cover crops may depend on the species (or mixture of species) chosen, and the method of cover crop termination and residue management. The objective of this study was to determine the effects of cover crop mixture and mechanical termination method on weed biomass and density, and relative crop yield in an organic cropping system. A field experiment was conducted from 2009 to 2011 near Mead, NE, where spring-sown mixtures of two, four, six, and eight cover crop species were included in a sunflower–soybean–corn crop rotation. Cover crops were planted in late March, terminated in late May using a field disk or sweep plow undercutter, and main crops were planted within 1 wk of termination. Terminating cover crops with the undercutter consistently reduced early-season grass weed biomass, whereas termination with the field disk typically stimulated grass weed biomass relative to a no cover crop control (NC). The effects of cover crop mixture were not evident in 2009, but the combination of the undercutter and the eight-species mixture reduced early-season weed biomass by 48% relative to the NC treatment in 2010. Cover crops provided less weed control in 2011, where only the combination of the undercutter and the two-species mixture reduced weed biomass (by 31%) relative to the NC treatment. Termination with the undercutter resulted in relative yield increases of 16.6 and 22.7% in corn and soybean, respectively. In contrast, termination with the field disk resulted in a relative yield reduction of 13.6% in soybean. The dominant influence of termination method highlights the importance of appropriate cover crop residue management in maximizing potential agronomic benefits associated with cover crops.

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Evaluating Mustard Seed Meal for Weed Suppression in Potato (Solanum tuberosum)

Journal of Agricultural Science ◽

10.5539/jas.v10n2p48 ◽

2018 ◽

Vol 10 (2) ◽

pp. 48 ◽

Cited By ~ 2

Author(s):

Rick A. Boydston ◽

Steven F. Vaughn ◽

Charles L. Webber III ◽

Bernardo Chaves-Cordoba

Keyword(s):

Weed Control ◽

Cover Crops ◽

Weed Suppression ◽

Seed Meal ◽

Mustard Seed ◽

Weed Biomass ◽

Early Season ◽

Weed Density ◽

Late Season ◽

Grass Weed

Mustard seed meal (MSM) derived from Sinapis alba controls weeds for several weeks following application to soil, but also has potential to injure the planted crop. Producers of certified organic potatoes typically utilize a combination of cover crops, soil hilling, harrowing, and cultivation for weed control. Once the potato canopy nears row closure, most late emerging weeds are suppressed by the dense potato canopy. MSM may have value for early season weed suppression in potato, but has not been previously tested. Our objectives were to determine the weed control efficacy and potato tolerance to MSM. We evaluated response of potatoes and weeds to MSM applied at 1.1, 2.2, and 4.5 MT ha-1 applied in a band on the potato hill just after a shallow harrowing and prior to potato emergence as part of an integrated weed management program in potatoes. MSM applied at 2.2 and 4.5 MT ha-1 reduced early season grass and broadleaf weed density 73 to 99% and 54 to 98%, respectively, in potato and reduced late season broadleaf weed biomass 71 to 94% in all three years tested. Early season grass weed density in potato was reduced by MSM at 2.2 and 4.5 MT ha-1. Late season grass weed biomass was reduced by the highest rate of 4.5 MT ha-1. MSM at 4.5 MT ha-1 caused minor injury to potato (3 to 15%) at 3 weeks after emergence, but did not reduce total tuber yields or percentage of US No.1 tubers. MSM could be a component of an integrated weed control program in potato.

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Influence of a Rye Cover Crop on the Critical Period for Weed Control in Cotton

Weed Science ◽

10.1614/ws-d-14-00075.1 ◽

2015 ◽

Vol 63 (1) ◽

pp. 346-352 ◽

Cited By ~ 22

Author(s):

Nicholas E. Korres ◽

Jason K. Norsworthy

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Critical Period ◽

Yield Loss ◽

Growing Season ◽

Weed Biomass ◽

Weed Density ◽

Presence And Absence ◽

Weed Removal

Cover crops are becoming increasingly common in cotton as a result of glyphosate-resistant Palmer amaranth; hence, a field experiment was conducted in 2009 and 2010 in Marianna, AR, with a rye cover crop used to determine its effects on the critical period for weed control in cotton. Throughout most of the growing season, weed biomass in the presence of a rye cover crop was lesser than that in the absence of a rye cover crop. In 2009, in weeks 2 through 7 after planting, weed biomass was reduced at least twofold in the presence of a rye cover compared with the absence of rye. In 2009, in both presence and absence of a rye cover crop, weed removal needed to begin before weed biomass was 150 g m−2, or approximately 4 wk after planting, to prevent yield loss > 5%. Weed density was less in 2010 than in 2009, so weed removal was not required until 7 wk after planting, at which point weed biomass values were 175 and 385 g m−2in the presence and absence of a cover crop, respectively.

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Mechanical and thermal weed control in organic crops

10.32469/10355/63464 ◽

2017 ◽

Author(s):

◽

Ricardo Costa Silva

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Hot Water ◽

Limiting Factors ◽

Corn Yield ◽

Weed Biomass ◽

No Till ◽

Potential Alternative ◽

Grass Biomass

Effective weed control is one of the most yield-limiting factors in organic corn and soybean production. Additionally, the amount of tillage needed to control weeds in organic practice is often criticized for its negative impacts on soil quality. This research was conducted in central Missouri from 2016-2017 to compare cultivation, flame application, between-row mowing, and hot water spray for in-season weed control in organic corn and soybeans. Between-row mowing and hot water application were paired with notillage and a crimped winter cover crop of cereal rye (Secale cereale L.). When weeds reached 10.2 cm, weed control practices were implemented and repeated as necessary until canopy closure. Grass and broadleaf weed biomass between crop rows was determined at multiple dates throughout the 2016 and 2017 seasons and in-row weed levels were determined at the final collection date for each crop each year. Broadleaf weed biomass at the end of the soybean season in 2016 was lower in the two treatments utilizing no-till and cover crops as primary weed control and hot water and mowing as secondary control. Soybean yield was adversely affected by flaming but not significantly different for the cultivation, mowing and hot water treatments. In 2017, soybean had less between-row grass biomass in the cultivation and flaming treatments than in hot water and mowing, but broadleaf levels were the same in the mowed treatment as the cultivated and flamed treatments. In 2016, grass biomass was lower in the no-till treatments between corn rows and higher in the crop rows than the other two treatments. Weed control treatments led to no significant differences in corn yield in 2016 and higher yields in the no-till treatments in 2017. In-row weed levels were significantly higher in corn in 2017 for the hot water treatment. Hot water at the levels applied in this research was not an effective weed control method. Since the overuse of cultivation can decrease soil organic matter levels and increase soil erosion, alternatives techniques are important to grant farmers the possibility to use their land for a long time. The crimped cover crop used in the no-till treatments limited weed growth in early-season corn and soybean and when coupled with between-row mowing is a potential alternative to cultivation in organic crop production. Flaming is also a potential alternative to cultivation in corn production.

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Early Season Weed Competition Reduces Yield of Newly Planted Matted Row Strawberries

HortScience ◽

10.21273/hortsci.36.4.729 ◽

2001 ◽

Vol 36 (4) ◽

pp. 729-731 ◽

Cited By ~ 4

Author(s):

Marvin P. Pritts ◽

Mary Jo Kelly

Keyword(s):

Sorghum Bicolor ◽

Cover Crop ◽

Negative Impact ◽

Growing Season ◽

Weed Suppression ◽

Yield Reduction ◽

Weed Competition ◽

Weed Biomass ◽

Early Season ◽

Weed Growth

Competition from weeds and an interplanted sudangrass [Sorghum bicolor (L.) Moensch, formerly S. sudanense (Piper) Stapf.] cover crop was allowed to occur in newly-planted strawberries (Fragaria ×ananassa Duch.) for varying lengths of time, and at different times during the growing season. Newly planted strawberries were most susceptible to weed and cover crop competition during the first 2 months after planting, as both runnering (stolon formation) and subsequent yield were impacted. In 1994-95, 1 month of weed competition in June reduced yield by 20%, whereas 2 months of weed competition reduced yield by 65%. However, 1 month of uncontrolled weed growth later in the growing season had little to no impact on yield, although weed biomass was much less then. Herbicide (napropamide) use alone was insufficient to prevent weed competition and yield reduction. In our study, yield was reduced 0.67 t·ha-1 or 5.5% for each 100 g·m-2 of weed biomass. The data suggest that it is critical for growers to minimize weed competition early in the planting year when weed growth is greatest. Since an interplanted sudangrass cover crop displaced a portion of the weeds, it could be seeded later in the year to provide some weed suppression without a negative impact on yield. Chemical names used: N, N, Diethyl-2-(1-naphthalenyloxy)-propionamide (napropamide); N-(phosphonomethyl)glycine (glyphosate).

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Influence of a Cereal Rye Cover Crop and Conservation Tillage on the Critical Period for Weed Control in Cotton

Weed Technology ◽

10.1017/wet.2018.73 ◽

2018 ◽

Vol 32 (6) ◽

pp. 683-690 ◽

Cited By ~ 2

Author(s):

Andrew J. Price ◽

Nicholas E. Korres ◽

Jason K. Norsworthy ◽

Steve Li

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Critical Period ◽

Conservation Tillage ◽

Relative Yield ◽

Integrated Approach ◽

Conventional Tillage ◽

Cereal Rye ◽

Winter Fallow

AbstractCover crops are being increasingly recommended as an integrated approach to controlling glyphosate-resistant Palmer amaranth and other troublesome weeds. Thus, a field experiment was conducted in 2010 through 2012 to evaluate the critical period for weed control (CPWC) in cotton as affected by a cereal rye cover crop and tillage. The management systems evaluated included conventional tillage following winter fallow, conservation tillage (CT) following winter fallow, and CT following a cereal rye cover crop managed for maximum biomass. Throughout most of the growing season, weed biomass in cereal rye cover crop plots was less than the CT winter-fallow system in both years and less than both CT winter fallow and conventional tillage in 2012. The CPWC was shortest in 2010 following conventional tillage; however, in 2012, production system influences on CPWC were less. The presence of the rye cover crop delayed the critical timing for weed removal (CTWR) approximately 8 d compared with fallow treatment both years, while conventional tillage delayed CTWR about 2 wk compared with winter fallow. Relative yield losses in both years did not reach the 5% threshold limit until about 2 wk after planting (WAP) for CT following winter fallow, 3 WAP for CT following a cover crop, and 3.5 WAP following conventional tillage. Thus, CT following winter fallow should be avoided to minimize cotton yield loss.

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Glucosinolate and Isothiocyanate Production from Brassicaceae Cover Crops in a Plasticulture Production System

Weed Science ◽

10.1614/ws-d-10-00137.1 ◽

2011 ◽

Vol 59 (2) ◽

pp. 247-254 ◽

Cited By ~ 23

Author(s):

Sanjeev K. Bangarwa ◽

Jason K. Norsworthy ◽

John D. Mattice ◽

Edward E. Gbur

Keyword(s):

Weed Control ◽

Conversion Efficiency ◽

Cover Crops ◽

Cover Crop ◽

Bell Pepper ◽

Biologically Active ◽

Early Season ◽

Control Practice ◽

Yellow Nutsedge ◽

Pest Suppression

Brassicaceae cover crops are gaining attention as potential biofumigants for soil pest suppression because of their ability to release biologically active isothiocyanates (ITCs) and other compounds from hydrolysis of glucosinolates (GSLs). However, biofumigation potential of a Brassicaceae is related to its GSL and ITC profile and GSL to ITC conversion efficiency. Field and laboratory experiments were conducted to evaluate the biofumigation potential of seven Brassicaceae cover crops for weed control in plasticulture tomato and bell pepper. GSL concentration and composition varied among cover crops and between roots and shoots of each cover crop. Similar GSLs were produced in both years by roots or shoots of each cover crop, but GSL concentrations were variable between years. Total GSLs contributed to the soil by incorporation of Brassicaceae cover crop tissues were estimated between 47 to 452 nmol g−1soil. Highest ITC concentration was detected in soil at 3 h after cover crop incorporation, and concentration decreased at later timings. GSL to ITC conversion efficiency ranged from 1 to 39%, with variation among cover crops and between years. No injury was observed in tomato and bell pepper transplanted 1 wk after cover crop incorporation, indicating the tolerance of tomato and pepper to ITCs released by the cover crops. Early-season yellow nutsedge control from Brassicaceae cover crops was ≤ 53% at 2 wk after transplanting and declined to ≤ 18% later in the season. This research demonstrates that Brassicaceae cover crops have marginal potential for early-season weed control and cannot be used as a weed control practice in commercial tomato and bell pepper production.

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183 Influence of Cover Crops on Weed Control and Plant Growth in Strawberry (Fragaria × ananassa Duch.)

HortScience ◽

10.21273/hortsci.34.3.473e ◽

1999 ◽

Vol 34 (3) ◽

pp. 473E-473

Author(s):

Braja B. Datta ◽

Ray D William

Keyword(s):

Plant Growth ◽

Cover Crops ◽

Cover Crop ◽

Crop Residues ◽

Weed Suppression ◽

Root Competition ◽

Control Treatment ◽

Shoot Biomass ◽

Yield Reduction ◽

Weed Biomass

Fall-planted cover crops killed in spring is practiced in strawberry cultivation in different regions of the North America. These systems have shown significant weed suppression and conservation of soil without significant yield reduction in strawberry. During the establishment season, this study was initiated to assess weed suppression with cover crops (`Wheeler' rye and `Micah' and `Steptoe' barley) along with perlite, an artificial plant medium. Strawberry (`Selva' and `Totem') plant growth and weed biomass were measured during 1995-96 season. Small-seeded summer annual weeds were suppressed in cover crop treatments compared to control treatment. `Micah' barley in growth phase suppressed more than 81% of the total weed biomass compared to control plots with no cover crop in early spring. However, in early summer, cover crop residues failed to suppress different types of weeds 60 days after killing of cereal with herbicide (2% glyphosate). Distinct differences in strawberry plant growth were evident between the cover crop treatments and non-cover crop treatments including `Micah' applied on surface. Strawberry growth was doubled during 10 July to 15 Aug. in both cultivars. `Micah' barley applied on surface produced better growth in both strawberry varieties than the growth in other treatments. `Micah' barley applied on soil surface produced 50% more strawberry shoot biomass may indicate the root competition between cover crops and strawberry.

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Influence of Cover Crop and Herbicide Treatment on Weed Control and Yield in No-Till Sweet Corn (Zea maysL.) and Pumpkin (Cucurbita maximaDuch.)

Weed Technology ◽

10.1017/s0890037x00040069 ◽

1996 ◽

Vol 10 (2) ◽

pp. 341-346 ◽

Cited By ~ 20

Author(s):

Bethany A. Galloway ◽

Leslie A. Weston

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Sweet Corn ◽

Total Yield ◽

Weed Suppression ◽

Herbicide Application ◽

Weed Biomass ◽

Crimson Clover ◽

Herbicide Treatment

Sweet corn and pumpkin were planted no-tillage (NT) into cover crop residue treatments of vetch, rye, crimson clover, and ladino clover controlled with glyphosate, and a bare ground conventional tillage (CT) control. Objectives included evaluation of crop growth, yield, and weed suppression in NT versus CT treatments. Herbicide application was also investigated, with a plus and minus herbicide treatment (alachlor plus cyanazine for sweet corn, or ethalfluralin for pumpkin) as the main factor in the factorial experiment, and cover crops the subfactors. Weed control 4 wk after planting was dependent upon cover crop. The fewest weed numbers and least biomass were found in the ladino clover plots, but clover regrowth and subsequent competition with the cash crop were severe. Herbicides also affected weed biomass at 4 wk after vegetable planting, with least biomass in herbicide-treated plots. Neither cover crop nor herbicide treatment significantly affected weed weight by 8 wk after planting or pumpkin fruit weight at harvest. Pumpkin yield was not influenced by herbicide application. The vetch cover, although harboring greatest weed biomass, produced the greatest total yield (ear weight) in sweet corn. When averaged over cover crop, sweet corn yields were higher in herbicide-treated plots than in untreated ones. Both sweet corn and pumpkin maturity were generally delayed in the absence of herbicide treatments or in the presence of cover crop residues, especially clover and rye residues.

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Spring-planted cover crops for weed control in soybean

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000107 ◽

2021 ◽

pp. 1-8

Author(s):

Katja Koehler-Cole ◽

Christopher A. Proctor ◽

Roger W. Elmore ◽

David A. Wedin

Keyword(s):

Weed Control ◽

Biomass Production ◽

Cover Crops ◽

Weed Management ◽

Block Design ◽

Weed Suppression ◽

Crop Species ◽

Cold Temperatures ◽

Weed Biomass ◽

Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

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