Ecological Mowing: An Option for Sustainable Weed Management in Young Citrus Orchards

The citrus yield in Brazil is not ranked among the best in the world, potentially due to inadequate management by citrus growers. The low adoption of conservation agriculture (CA) techniques and the improper application of herbicides are also well-known problems. Thus, this study evaluated the use of CA techniques, and twoUrochloaspecies (ruzi grass and signal grass) were used as cover crops. Two different types of mowers (ecological, EM; conventional, CM) launched the mowed biomass into different positions within a young Tahiti acid lime orchard (up to four years old). In addition, the integration of glyphosate into this management system was evaluated, with (GLY) and without (NO GLY) glyphosate application. This experiment was conducted across three growing seasons (2011-2014), in Mogi Mirim, São Paulo State, Brazil. The cover crop biomass yields and the effects of the mowing treatments, weed density, vegetative growth and fruit yields of the Tahiti acid lime trees were evaluated. In terms of major results, signal grass produced higher biomass yield values (up to 64%) than ruzi grass; EM promoted higher mowed biomass values in the intra-row (up to 5.1 ton ha−1, 9.0 times higher than CM), and a higher canopy volume (up to 33% than CM). These results were enhanced when ruzi grass was associated with the EM (56% lower weed density; 126% higher fruit yield than CM) and with GLY (52% higher fruit yield than NO GLY); and EM with GLY (43% lesser weed density and 107% higher fruit yield than NO GLY). Overall, ruzi grass was a good cover crop because it provided less competition for the citrus trees, EM provided a mulch layer in the intra-row of the citrus trees, and associated with GLY, these approaches could provide options for an integrated and more sustainable weed management, primarily for young Tahiti acid lime orchards.

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Weed Management in Organically Grown Kale Using Alternative Cover Cropping Systems

Weed Technology ◽

10.1614/wt-08-119.1 ◽

2009 ◽

Vol 23 (1) ◽

pp. 81-88 ◽

Cited By ~ 7

Author(s):

Husrev Mennan ◽

Mathieu Ngouajio ◽

Emine Kaya ◽

Dogan Isık

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Agricultural Research ◽

Cropping Systems ◽

Grain Sorghum ◽

The Black Sea ◽

Hairy Vetch ◽

Weed Density ◽

Dry Biomass

Organic vegetable producers have limited options for managing weeds. They cite weed management as their number one research priority. Studies were conducted in 2004 and 2005 at the Black Sea Agricultural Research Institute, Samsun, Turkey, to determine the weed suppressive effects of summer cover crops in organic kale production. Treatments consisted of grain sorghum, sudangrass, hairy vetch, grain amaranth, pea, and fallow. Weed density and total weed dry biomass were assessed before and at 14, 28, and 56 d after incorporation (DAI) of the cover crops. Kale was transplanted 14 DAI and hand weeded once after last weed evaluation (56 DAI). All cover crops produced at least 1 ton/ha (t/ha) biomass; grain sorghum produced more dry matter than all other cover crops in both years. After incorporation of the cover crops, hairy vetch and sorghum treatments showed fewer species, lower weed density, and total weed dry biomass compared with other treatments. Cover crops suppressed emergence of common purslane, common lambsquarters, redroot pigweed, European heliotrope, field pennycress, annual sowthistle, black nightshade, shepherd's-purse, wild mustard, sun spurge, Persian speedwell, annual mercury, and jimsonweed up to 56 DAI. Total kale yield in hairy vetch treatments was more than double that of the no cover crop, and was significantly higher than yield from the other cover crop treatments. These results indicate that hairy vetch, grain sorghum, and sudangrass have ability to suppress early-season weeds in organic kale production.

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Herbicide and Cover Crop Residue Integration forAmaranthusControl in Conservation Agriculture Cotton and Implications for Resistance Management

Weed Technology ◽

10.1614/wt-d-11-00127.1 ◽

2012 ◽

Vol 26 (3) ◽

pp. 490-498 ◽

Cited By ~ 23

Author(s):

Andrew J. Price ◽

Kip S. Balkcom ◽

Leah M. Duzy ◽

Jessica A. Kelton

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Management Practices ◽

Field Experiments ◽

Conservation Tillage ◽

Conservation Agriculture ◽

Integrated Weed Management ◽

Early Season ◽

Density And Biomass

Conservation agriculture (CA) practices are threatened by glyphosate-resistant Palmer amaranth. Integrated control practices including PRE herbicides and high-residue CA systems can decreaseAmaranthusemergence. Field experiments were conducted from autumn 2006 through crop harvest in 2009 at two sites in Alabama to evaluate the effect of integrated weed management practices onAmaranthuspopulation density and biomass, cotton yield, and economics in glyphosate-resistant cotton. Horizontal strips included four CA systems with three cereal rye cover crop seeding dates and a winter fallow (WF) CA system compared to a conventional tillage (CT) system. Additionally, vertical strips of four herbicide regimes consisted of: broadcast, banded, or no PRE applications ofS-metolachlor (1.12 kg ai ha−1) followed by (fb) glyphosate (1.12 kg ae ha−1) applied POST fb layby applications of diuron (1.12 kg ai ha−1) plus MSMA (2.24 kg ai ha−1) or the LAYBY application alone. Early-seasonAmaranthusdensity was reduced in high-residue CA in comparison to the CA WF systems in 2 of 3 yr.Amaranthusdensities in herbicide treatments that included a broadcast PRE application were lower at three of five sampling dates compared to banding early-season PRE applications; however, the differences were not significant during the late season and cotton yields were not affected by PRE placement. High-residue conservation tillage yields were 577 to 899 kg ha−1more than CT, except at one site in 1 yr when CT treatment yields were higher. CA utilizing high-residue cover crops increased net returns over CT by $100 ha−1or more 2 out of 3 yr at both locations. High-residue cover crop integration into a CA system reducedAmaranthusdensity and increased yield over WF systems; the inclusion of a broadcast PRE application can increase early-seasonAmaranthuscontrol and might provide additional control when glyphosate-resistantAmaranthuspopulations are present.

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How cover crop residue management and herbicide rate affect weed management and yield of tomato (Solanum lycopersicon L.) crop

Renewable Agriculture and Food Systems ◽

10.1017/s1742170518000054 ◽

2018 ◽

Vol 34 (6) ◽

pp. 492-500 ◽

Cited By ~ 2

Author(s):

Alireza Safahani Langeroodi ◽

Emanuele Radicetti ◽

Enio Campiglia

Keyword(s):

Cover Crops ◽

Weed Management ◽

Aboveground Biomass ◽

Cover Crop ◽

Crop Residue ◽

Crop Residues ◽

Soil Surface ◽

Residue Management ◽

Crop Residue Management ◽

Weed Density

AbstractIn the conventional cropping systems, increased costs and resource pollution are attributed to the intensive use of chemical inputs. The adoption of cover crops could be a part of a suitable strategy for improving the sustainability of the agro-ecosystems due to their ability to affect nutrient and weed management. A 2-yr field experiments were conducted in Gorgan, North of Iran, with the aim of assessing the effect of cover crop residue management and herbicide rates on weed management and the yield of tomato crop. The treatments consisted in: (a) three winter soil management: two cover crops [annual medic (Medicago scutellata L.) and barley (Hordeum vulgare L.)] and no covered soil; (b) two soil tillage (no-tillage, where cover crop residues were left in strips on the soil surface, and conventional tillage, where cover crop residues were green manured at 30 cm of soil depth); and (c) three pre-emergence herbicide rates (no-herbicide application, half rate recommended or full rate recommended ). Cover crops were sown in early September and mechanically suppressed in March about 2 weeks before tomato transplanting. At cover crop suppression, annual medic showed the highest aboveground biomass [569 g m−2 of dry matter (DM)], while barley showed the lowest weed content (32 g m−2 of DM). At tomato harvesting, weed density and aboveground biomass ranged from 6.9 to 61.5 plants m−2 and from 33.6 and 1157.0 g m−2 of DM, respectively. Cover crop residues placed on soil surface suppressed weeds more effectively than incorporated residues, especially in barley, mainly due to the physical barrier of residues which reduced the stimulation of weed germination and establishment. As expected, herbicide rate decreased both weed density and biomass, even if the adoption of annual medic and barley cover crops before the tomato cultivation could allow a possible reduction of herbicide rate while maintaining similar fruit yield. Tomato yield was higher in annual medic than barley and no cover regardless of tillage management (on average 62.3, 51.8 and 50.1 t ha−1 of fresh matter, respectively) probably due to an abundant availability of soil nitrogen throughout the tomato cultivation. This was confirmed by high and constant values of tomato N status grown in annual medic and evaluated using SPAD chlorophyll meter. Although further research of cover crop residue management is required to obtain a better understanding on herbicide rate reduction, these preliminary results could be extended to other vegetable crops which have similar requirements of tomato.

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Preplant Cover Crops Affect Weed and Vine Growth in First-year Vineyards

HortScience ◽

10.21273/hortsci.32.6.1040 ◽

1997 ◽

Vol 32 (6) ◽

pp. 1040-1043 ◽

Cited By ~ 16

Author(s):

Bruce P. Bordelon ◽

Stephen C. Weller

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Dry Mass ◽

Weed Suppression ◽

First Year ◽

Hairy Vetch ◽

Vicia Villosa ◽

Weed Density ◽

Vine Growth

Use of in-row cover crops for weed management in first-year vineyards was investigated in two studies. In the first study, rye (Secale cereal L. 'Wheeler') was fall-planted, overwintered, then managed by three methods before vine planting. Rye was either herbicide-desiccated with glyphosate and left on the surface as a mulch, mowed, or incorporated into the soil (cultivated). Weed density and growth of grapevines (Vitis spp.) were evaluated. Herbicide desiccation was superior to the other methods for weed suppression, with weed densities 3 to 8 times lower than for mowed or cultivated plots. Vine growth was similar among treatments, but the trend was for more shoot growth with lower weed density. In a second study, four cover crops, rye, wheat (Triticum aestivum L. 'Cardinal'), oats (Avena sativa L. 'Ogle'), and hairy vetch (Vicia villosa Roth), were compared. Wheat and rye were fall- and spring-planted, and oats and vetch were spring-planted, then desiccated with herbicides (glyphosate or sethoxydim) after vine planting and compared to weed-free and weedy control plots for weed suppression and grapevine growth. Cover crops provided 27% to 95% reduction in weed biomass compared to weedy control plots. Total vine dry mass was highest in weed-free control plots, was reduced 54% to 77% in the cover crop plots, and was reduced 81% in the weedy control. Fall-planted wheat and rye and spring-planted rye plots produced the highest vine dry mass among cover crop treatments. Spring-planted rye provided the best combination of weed suppression and vine growth. Chemical names used: N-(phosphonomethyl) glycine (glyphosate isopropylamine salt); 2-[l-(ethoxyimino)butyl]5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim).

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Labile carbon and other soil quality indicators in two tillage systems during transition to organic agriculture

Renewable Agriculture and Food Systems ◽

10.1017/s1742170511000147 ◽

2011 ◽

Vol 26 (4) ◽

pp. 342-353 ◽

Cited By ~ 21

Author(s):

David Bruce Lewis ◽

Jason P. Kaye ◽

Randa Jabbour ◽

Mary E. Barbercheck

Keyword(s):

Soil Quality ◽

Cover Crops ◽

Organic Agriculture ◽

Weed Management ◽

Cover Crop ◽

Transition Period ◽

Interactive Effects ◽

Labile Carbon ◽

Initial Field ◽

Soil Attributes

AbstractWeed management is one of the primary challenges for producers transitioning from conventional to organic agriculture. Tillage and the use of cover crops are two weed control tactics available to farmers transitioning to organic management, but little is known about their interactive effects on soil quality during the transition period. We investigated the response of soils to tillage and initial cover crop during the 3-year transition to organic in a cover crop–soybean (Glycine max)–maize (Zea mays) rotation in the Mid-Atlantic region of the USA. The tillage treatment contrasted full, inversion tillage with moldboard plowing (FT) versus reduced tillage with chisel plowing (RT). The cover crop treatment contrasted annual versus mostly perennial species during the first year of the rotation. The experiment was initiated twice (Start 1 and Start 2), in consecutive years in adjacent fields. By the end of the experiment, labile carbon, electrical conductivity, pH and soil moisture were all greater under RT than under FT in both starts. Soil organic matter and several other soil attributes were greater under RT than under FT in Start 1, but not in Start 2, perhaps owing to differences between starts in initial field conditions and realized weather. Soil attributes did not differ between the two cover crop treatments. Combining our soils results with agronomic and economic analyses on these plots suggests that using RT during the organic transition can increase soil quality without compromising yield and profitability.

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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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Canada Thistle (Cirsium arvense) Suppression with Buckwheat or Sudangrass Cover Crops and Mowing

Weed Technology ◽

10.1614/wt-09-050.1 ◽

2009 ◽

Vol 23 (4) ◽

pp. 556-563 ◽

Cited By ~ 21

Author(s):

Abram J. Bicksler ◽

John B. Masiunas

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Initial Density ◽

Farming Systems ◽

Shoot Density ◽

Intensive Management ◽

Canada Thistle ◽

Growth And Survival ◽

Growing Seasons

Canada thistle is a perennial spreading weed that is difficult to control in farming systems with reduced reliance upon herbicides for weed management. Experiments were conducted from 2006 to 2008 at Champaign, IL, to evaluate the combined effects of summer annual cover crops and mowing on Canada thistle growth and survival. Whole plot treatments were fallow, buckwheat, sudangrass–cowpea mixture (MIX), and sudangrass. The subplot treatments were mowing frequencies (0 to 2 times). Cover crop and mowing did not interact to suppress Canada thistle. MIX and sudangrass produced more standing biomass, greater regrowth, and more surface mulch following mowing than the buckwheat. A single season with sudangrass or MIX reduced Canada thistle shoot density and mass to less than 20% of the initial values through two growing seasons. Mowing alone only suppressed Canada thistle shoot density and mass on the site with greater initial density. A sudangrass or MIX cover crop alone or combined with mowing suppresses Canada thistle, but intensive management must continue for several years to eliminate patches.

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Suppression of Glyphosate-resistant Canada Fleabane (Conyza canadensis) in Corn with Cover Crops Seeded after Wheat Harvest the Previous Year

Weed Technology ◽

10.1017/wet.2018.19 ◽

2018 ◽

Vol 32 (3) ◽

pp. 244-250 ◽

Cited By ~ 7

Author(s):

Taïga B. Cholette ◽

Nader Soltani ◽

David C. Hooker ◽

Darren E. Robinson ◽

Peter H. Sikkema

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Management Strategies ◽

Late Summer ◽

Growing Season ◽

Integrated Weed Management ◽

Crop Species ◽

Herbicide Resistant ◽

Crimson Clover

AbstractGlyphosate-resistant (GR) and multiple herbicide–resistant (groups 2 and 9) Canada fleabane have been confirmed in 30 and 23 counties in Ontario, respectively. The widespread incidence of herbicide-resistant Canada fleabane highlights the importance of developing integrated weed management strategies. One strategy is to suppress Canada fleabane using cover crops. Seventeen different cover crop monocultures or polycultures were seeded after winter wheat harvest in late summer to determine GR Canada fleabane suppression in corn grown the following growing season. All cover crop treatments seeded after wheat harvest suppressed GR Canada fleabane in corn the following year. At 4 wk after cover crop emergence (WAE), estimated cover crop ground cover ranged from 31% to 68%, a density of 124 to 638 plants m–2, and a range of biomass from 29 to 109 g m–2, depending on cover crop species. All of the cover crop treatments suppressed GR Canada fleabane in corn grown the following growing season from May to September compared to the no cover crop control. Among treatments evaluated, annual ryegrass (ARG), crimson clover (CC)/ARG, oilseed radish (OSR)/CC/ARG, and OSR/CC/cereal rye (CR) were the best treatments for the suppression of GR Canada fleabane in corn. ARG alone or in combination with CC provided the most consistent GR Canada fleabane suppression, density reduction, and biomass reduction in corn. Grain corn yields were not affected by the use of the cover crops evaluated for Canada fleabane suppression.

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