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

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

Weed Science ◽

10.1614/ws-d-12-00066.1 ◽

2013 ◽

Vol 61 (1) ◽

pp. 162-170 ◽

Cited By ~ 30

Author(s):

Sam E. Wortman ◽

Charles A. Francis ◽

Mark A. Bernards ◽

Erin E. Blankenship ◽

John L. Lindquist

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Relative Yield ◽

Residue Management ◽

Yield Reduction ◽

Weed Biomass ◽

Early Season ◽

Species Mixture ◽

Grass Weed

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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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 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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Strategies to terminate summer cover crops for weed management in no-tillage vegetable production in southeast Brazil

Weed Science ◽

10.1017/wsc.2021.58 ◽

2021 ◽

pp. 1-26

Author(s):

Roberto Botelho Ferraz Branco ◽

Fernando de Carvalho ◽

João Paulo de Oliveira ◽

Pedro Luis da Costa Alves

Keyword(s):

Pearl Millet ◽

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Weed Suppression ◽

No Tillage ◽

Weed Biomass ◽

Jack Bean ◽

Organic Mulch ◽

Sunn Hemp

Abstract Cover crop residue left on the soil surface as organic mulch in no-tillage crop production provides several environmental benefits, including weed suppression. Thus, many farmers who use cover crops attempt to reduce the use of agricultural inputs, especially herbicides. Therefore, our objectives were to study the potential of different cover crop species to suppress weeds and produce an in situ organic mulch, and evaluate the effect of the organic mulch with and without spraying glyphosate on weed suppression for vegetable (tomato (Solanum lycopersicum L. and broccoli (Brassica oleracea L. var. botrytis) growth and yield. Five cover crop treatments (sunn hemp (Crotalaria juncea L.), jack bean [Canavalia ensiformis (L.) DC.], pearl millet [Pennisetum glaucum (L.) R. Br.], grain sorghum [Sorghum bicolor (L.) Moench ssp. bicolor] and a no-cover crop (control)) were used in the main plots; and spraying or no spraying glyphosate on the flattened cover crop in the sub plots of split-plot experimental design. Organic mulch from pearl millet, sorghum and sunn hemp resulted in lower weed biomass during the early season of both tomato and broccoli than jack bean and no-cover crop (control). Spraying glyphosate after roller crimping reduced weed biomass by 103 g m−2 and 20 g m−2 by 45 and 60 days after transplanting (DAT) of tomato, respectively and resulted in a better tomato yield compared to non spraying. Glyphosate reduced weed biomass by 110 g m−2 in the early season of broccoli (30 DAT), but did not affect yield. Terminating high biomass cover crops with a roller crimper is a promising technique for weed management in vegetable crops, which has the potential to reduce or even eliminate the need for herbicide.

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Cover Crop Effectiveness Varies in Cover Crop-Based Rotational Tillage Organic Soybean Systems Depending on Species and Environment

Agronomy ◽

10.3390/agronomy9060319 ◽

2019 ◽

Vol 9 (6) ◽

pp. 319 ◽

Cited By ~ 2

Author(s):

Laura Vincent-Caboud ◽

Léa Vereecke ◽

Erin Silva ◽

Joséphine Peigné

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Crop Yields ◽

Weed Suppression ◽

Future Research ◽

Weed Biomass ◽

Cereal Rye ◽

Cereal Grain ◽

Crop Biomass

Organic farming relies heavily on tillage for weed management, however, intensive soil disturbance can have detrimental impacts on soil quality. Cover crop-based rotational tillage (CCBRT), a practice that reduces the need for tillage and cultivation through the creation of cover crop mulches, has emerged as an alternative weed management practice in organic cropping systems. In this study, CCBRT systems using cereal rye and triticale grain species are evaluated with organic soybean directly seeded into a rolled cover crop. Cover crop biomass, weed biomass, and soybean yields were evaluated to assess the effects of cereal rye and winter triticale cover crops on weed suppression and yields. From 2016 to 2018, trials were conducted at six locations in Wisconsin, USA, and Southern France. While cover crop biomass did not differ among the cereal grain species tested, the use of cereal rye as the cover crop resulted in higher soybean yields (2.7 t ha−1 vs. 2.2 t ha−1) and greater weed suppression, both at soybean emergence (231 vs. 577 kg ha−1 of weed biomass) and just prior to soybean harvest (1178 vs. 1545 kg ha−1). On four out of six sites, cover crop biomass was lower than the reported optimal (<8000 kg ha−1) needed to suppress weeds throughout soybean season. Environmental conditions, in tandem with agronomic decisions (e.g., seeding dates, cultivar, planters, etc.), influenced the ability of the cover crop to suppress weeds regardless of the species used. In a changing climate, future research should focus on establishing flexible decision support tools based on multi-tactic cover crop management to ensure more consistent results with respect to cover crop growth, weed suppression, and crop yields.

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Cover Crop for Early Season Weed Suppression in Crops: Systematic Review and Meta-Analysis

Agronomy Journal ◽

10.2134/agronj2017.12.0752 ◽

2018 ◽

Vol 110 (6) ◽

pp. 2211-2221 ◽

Cited By ~ 22

Author(s):

O. Adewale Osipitan ◽

J. Anita Dille ◽

Yared Assefa ◽

Stevan Z. Knezevic

Keyword(s):

Systematic Review ◽

Cover Crop ◽

Meta Analysis ◽

Weed Suppression ◽

Early Season

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Cereal cover crops for weed suppression in a summer fallow-wheat cropping sequence

Canadian Journal of Plant Science ◽

10.4141/p99-099 ◽

2000 ◽

Vol 80 (2) ◽

pp. 441-449 ◽

Cited By ~ 19

Author(s):

J. R. Moyer ◽

R. E. Blackshaw ◽

E. G. Smith ◽

S. M. McGinn

Keyword(s):

Winter Wheat ◽

Weed Control ◽

Cover Crops ◽

Soil Conservation ◽

Cover Crop ◽

Wheat Yield ◽

Weed Suppression ◽

Wheat Crop ◽

Weed Growth ◽

Summer Fallow

Cropping systems in western Canada that include summer fallow can leave the soil exposed to erosion and require frequent weed control treatments. Cover crops have been used for soil conservation and to suppress weed growth. Experiments were conducted under rain-fed conditions at Lethbridge, Alberta to determine the effect of short-term fall rye (Secale cereale L.), winter wheat (Triticum aestivum L.) and annual rye cover crops in the fallow year on weed growth and subsequent wheat yield. Under favorable weather conditions fall rye was as effective as post-harvest plus early spring tillage or herbicides in spring weed control. Winter wheat and fall rye residues, after growth was terminated in June, reduced weed biomass in September by 50% compared to no cover crop in 1993 but had little effect on weeds in 1995. Fall-seeded cover crops reduced the density of dandelion (Taraxacum officinale Weber in Wiggers) and Canada thistle [Cirsium arvense (L.) Scop.] but increased the density of downy brome (Bromus tectorum L.), wild buckwheat (Polygonum convolvulus L.), and thyme-leaved spurge (Euphorbia serpyllifolia Pers.) in the following fall or spring. Wheat yields after fall rye and no cover crop were similar but yields after spring-seeded annual rye were less than after no cover crop. Spring-seeded annual rye did not adequately compete with weeds. Cover crops, unlike the no cover crop treatment, always left sufficient plant residue to protect the soil from erosion until the following wheat crop was seeded. Key words: Allelopathies, fall rye, nitrogen, soil conservation, soil moisture, weed control, spring rye, winter wheat

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Cover Crop Management and Weed Suppression in No-tillage Sweet Corn Production

HortScience ◽

10.21273/hortsci.39.6.1262 ◽

2004 ◽

Vol 39 (6) ◽

pp. 1262-1266 ◽

Cited By ~ 20

Author(s):

Lidia M. Carrera ◽

Aref A. Abdul-Baki ◽

John R. Teasdale

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Sweet Corn ◽

Crop Management ◽

Bare Soil ◽

Weed Suppression ◽

Corn Yield ◽

No Tillage ◽

Hairy Vetch ◽

Weed Biomass

Cover crops combined with conservation tillage practices can minimize chemical inputs and improve soil quality, soil water-holding capacity, weed suppression and crop yields. No-tillage production of sweet corn (Zea mays var. `Silver Queen') was studied for 2 years at the USDA Beltsville Agricultural Research Center, Md., to determine cover crop management practices that maximize yield and suppress weeds. Cover crop treatments were hairy vetch (Vicia villosa Roth), rye (Secale cereale L.) and hairy vetch mixture, and bare soil (no cover crop). There were three cover crop killing methods: mowing, rolling or contact herbicide paraquat. All plots were treated with or without atrazine and metolachlor after planting. There was a 23% reduction in sweet corn plant population in the rye-hairy vetch mixture compared to bare soil. Averaged over both years, sweet corn yield in hairy vetch treatments was 43% greater than in bare soil, whereas yield in the rye-hairy vetch mixture was 30% greater than in bare soil. There were no significant main effects of kill method or significant interactions between kill method and cover crop on yield. Sweet corn yields were not different for hairy vetch or rye-hairy vetch treatments with or without atrazine and metolachlor. However, yield in bare soil without the herbicides atrazine and metolachor were reduced by 63% compared to bare soil with these herbicides. When no atrazine and metolachlor were applied, weed biomass was reduced in cover crops compared to the bare soil. Regression analysis showed greater yield loss per unit of weed biomass for bare soil than for the vetch or rye-hairy vetch mixture. This analysis suggests that cover crops increased sweet corn yield in the absence of atrazine and metolachlor not only by reducing weed biomass, but also by increasing the competitiveness of corn to weeds at any given biomass.

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647 Aerial Mapping of Grapes for Analysis of Environmental Stress and Blackleaf Patterns

HortScience ◽

10.21273/hortsci.34.3.559c ◽

1999 ◽

Vol 34 (3) ◽

pp. 559C-559

Author(s):

N.S. Lang ◽

R. Smithyman ◽

L. Mills ◽

R.L. Wample ◽

J. Silbernagel ◽

...

Keyword(s):

Spatial Analysis ◽

Management Practices ◽

Negative Impact ◽

Uv Light ◽

Spectral Characteristics ◽

Spatial Location ◽

Remotely Sensed ◽

Geographical Information ◽

Yield Reduction ◽

Early Season

Blackleaf (a.k.a. chocolate leaf) is of worldwide concern in Vitis due to its negative impact on fruit ripening, yield reduction and overall stress on grapevines. Research suggests blackleaf is induced by high levels of UV radiation and overall light intensity, which induce color changes (purple-brown-black) in exposed leaves, resulting in >50% reduction in photosynthesis. The ability to detect blackleaf symptoms before expression can provide insight into metabolic stresses and the possibility of the use and/or timing of management practices to reduce its impact. Remotely sensed imagery and spatial analysis may elucidate reflectance-related processes and symptoms not apparent to the un-aided eye. In this research we mapped canopy growth (leaves/shoot and shoots/vine), metabolic triggers (photosynthesis, leaf water potential, soil moisture), and percent blackleaf expression within vineyards using global positioning system (GPS), infrared gas analyzer, and digital remotely-sensed images. Each image and data record was stored as an attribute associated with specific vine location within a geographical information system (GIS). Spatial maps were created from the GIS coverages to graphically present the progression of blackleaf across vineyards throughout the season. Analysis included summary statistics such as minimum, maximum, and variation of green reflectance, within a vineyard by image capture date. Additionally, geostatistics were used to model the degree of similarity between blackleaf values as a function of their spatial location. Continuing research will be aimed at identifying spectral characteristics of early season stresses due to UV light, water stress, and reduced photosynthetic capacity. Spatial relationships between early season stress and later blackleaf expression will be assessed using joint spatial dependence measures. Overall, information obtained through digital image and spatial analysis will supplement site level information for growers.

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Cover Crop Performance between Plastic-mulched Beds: Impacts on Weeds and Soil Resources

HortScience ◽

10.21273/hortsci14956-20 ◽

2020 ◽

Vol 55 (7) ◽

pp. 1069-1077

Author(s):

Alyssa R. Tarrant ◽

Daniel C. Brainard ◽

Zachary D. Hayden

Keyword(s):

White Clover ◽

Cover Crop ◽

Weed Suppression ◽

Italian Ryegrass ◽

Eragrostis Tef ◽

Total Biomass ◽

Plastic Mulch ◽

Living Mulch ◽

Cash Crop ◽

Weed Biomass

Growing a cover crop living mulch between plastic-mulched beds may reduce soil erosion while providing other agroecosystem services. However, information regarding the relative differences among living mulch species to maximize services and minimize competition for nutrients and water in adjacent plastic-mulched beds is limited. A 2-year experiment in Michigan evaluated nine living mulch species for biomass production, in-season weed suppression, and potential for cash crop competition. Species included three warm season grasses {Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot], teff [Eragrostis tef (Zuccagni) Trotter, and sudangrass [Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet & Harlan]}; three cool season grasses [barley (Hordeum vulgare L.), rye (Secale cereale L.), and wheat (Triticum aestivum L.)]; and three clover species grown in combination with rye {Dutch white clover (Trifolium repens L.), New Zealand white clover (T. repens L.) and yellow blossom sweet clover [Melilotus officinalis (L.) Lam.]}. Although all living mulch treatments significantly reduced in-season weed biomass relative to the weedy control in 2018, weeds were generally a dominant component of total biomass in all living mulch treatments other than teff. Weed biomass was negatively correlated with living mulch biomass, and teff exhibited both the greatest biomass and weed suppression in both years. However, despite spatial and physical separation, all living mulches demonstrated the potential to compete with a cash crop by reducing soil inorganic nitrogen and moisture levels in adjacent plastic mulch–covered beds. Growers interested in integrating living mulches into plasticulture systems must consider desired benefits such as enhanced weed suppression, soil quality, and harvesting conditions alongside potential risks to cash crop yields.

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