scholarly journals Allelopathy of Cover Crops on the Germination and Initial Development of Euphorbia heterophylla

2019 ◽  
Vol 11 (14) ◽  
pp. 74 ◽  
Author(s):  
Alexandre Bianchini ◽  
Pedro Valério Dutra de Moraes ◽  
Juliana Domanski Jakubski ◽  
Cristiana Bernardi Rankrape ◽  
Elyoenay Gadyel ◽  
...  
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Aerial Part ◽  
Chenopodium Quinoa ◽  
Aqueous Extracts ◽  
Germination Test ◽  
Initial Development ◽  
Allelopathic Potential ◽  
Avena Strigosa

Cover crop is a important way for weed management in agriculture. The objective of this study was to investigate the effects of aqueous extracts of the aerial part of Avena strigosa, Cichorium intybus, Chenopodium quinoa and Fagopyrum esculentum in different concentrations on the germination and development of Euphorbia heterophylla. The experimental design was completely randomized, in factorial 4 × 5 with four replicates. Factor A-aqueous extracts of the aerial part of the cover plants and factor B-concentrations of 0%; 1%, 2.5%, 5% and 10%. A total of 25 E. heterophylla seeds, arranged in gerboxes, were used and 15 ml of the extracts were added according to the treatments. The germination test was performed in a growth chamber (BOD) with photoperiod of 12/12 light/dark hours and constant temperature of 25±1 °C. The data were submitted to analysis of variance by the F test, a comparison was made between means and the concentration factor of the extracts and the regression analysis. The C. quinoa aqueous extracts (10%) presented greater allelopathic potential than the other extracts in the variables tested for E. heterophylla. C. intybus presented allelophatic potential with results superior to A. strigosa and F. esculentum. The C. quinoa and C. intybus extracts have allelopathic potential when compared to the control with the highest dose (10%), interfering mainly in the root portion of E. heterophylla.

scholarly journals Cover Crops for Weed Management in Southern Reduced-Tillage Vegetable Cropping Systems

2013 ◽  
Vol 27 (1) ◽  
pp. 212-217 ◽  
Author(s):  
Andrew J. Price ◽  
Jason. K. Norsworthy
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Agricultural Land ◽  
Organic Production ◽  
Reduced Tillage ◽  
Management Options ◽  
Allelopathic Potential ◽  
Systems Research ◽  
Future Production

With growing agricultural demands from both conventional and organic systems comes the need for sustainable practices to ensure long-term productivity. Implementation of reduced- or no-till practices offers a number of environmental benefits for agricultural land and maintains adequate yield for current and future production. Concerns over satisfactory pest control options, particularly weed control, have contributed to the slow adoption of conservation practices in many areas. To identify effective alternative weed management options for use in conservation systems, research in the Southeast has continued to evaluate the use of cover crops in conjunction with reduced-tillage practices. A number of cover crop species, including cereal grains, legumes, and Brassicaceae species, that have potential to suppress weeds through direct crop interference or allelopathic potential have been investigated. Many recent research projects in the Midsouth and southeastern United States have assessed the success of cover crops in reduced-tillage row crop settings with promising outcomes in some systems. However, continued research is necessary to identify appropriate cover crop and tillage systems for use in other agricultural settings, such as vegetable crops and organic production systems.

scholarly journals Rye (Secale cereale L.) and squarrose clover (Trifolium squarrosum L.) cover crops can increase their allelopathic potential for weed control when used mixed as dead mulch

2021 ◽  
Author(s):  
Lara Abou Chehade ◽  
Carolina G. Puig ◽  
Carlos Souto ◽  
Daniele Antichi ◽  
Marco Mazzoncini ◽  
...  
Keyword(s):  
Cover Crops ◽  
Secale Cereale ◽  
Cover Crop ◽  
Crop Residues ◽  
Aqueous Extracts ◽  
Inhibitory Effects ◽  
Weed Species ◽  
Allelopathic Potential ◽  
Better Than

Cover crops are essential tools in agroecosystems for reducing the reliance on synthetic inputs and associated environmental risks. Alongside their benefits to soil fertility, cover crops can control weeds by their competitive and allelopathic attributes. Laboratory and field experiments were conducted to assess the allelopathic potential of two cover crop species, rye (Secale cereale L.) and squarrose clover (Trifolium squarrosum L.), alone or in  mixture, on seed germination and growth of arable weeds. Aqueous extracts of the two cover crops and their mixture were tested in a bioassay on Conyza canadensis (L). Cronq., Amaranthus retroflexus L. and Digitaria sanguinalis (L.) Scop. In vitro effects of aqueous extracts varied in a dose-dependent manner, with cover crops and weed species. All three extracts were able to reduce the germination of A. retroflexus (-87%) considerably. Inhibitory effects by rye and mixture extracts on radicle growth of all weed species ranged between 51 and 82%.  Rye extract was the best at reducing shoot length of C. canadensis and D. sanguinalis (-39 to 44%), while squarrose clover was more effective on A. retroflexus (-79%). Plant extracts also delayed the germination time of weed species with substantial effect of the mixture on C. canadensisseeds. In the field experiment, no significant weed suppression was provided by cover crop residues incorporated as green manure compared to control plots, despite tillage being more effective in reducing weed density. Still, the cover crop mixture mulch controlled weed emergence significantly better than single cover crop mulches. The chemical characterization of cover crop residues, both shoots and roots, revealed a notable richness of allelopathic phenolic acids and flavonoids, that through slow decomposition may constitute potential natural herbicides. From the analysis of the aqueous extracts, other non-analyzed and/or unidentified water-soluble allelopathic compounds should underlie the phytotoxicity observed in vitro, at least for rye. For cover crop mixture, positive interactions among plant materials leading to a better release of allelochemicals and weeding effectiveness are discussed according to chemical profiles and field data. Our study demonstrated the allelopathic activity of the cover crops and their potential to be included in weed management strategies according to cropping system needs. Additional trials are needed to confirm the performance of cover crop residues under field conditions.   Highlights - Rye and squarrose clover are cover crops with potential allelopathic effects. - Aqueous extracts of residues of rye, squarrose clover and their mixture reduced and/or slowed weed germination of A. retroflexus and C. canadensis in in vitro bioassays. - The aqueous extracts, depending on the concentration of residues, had inhibitory effects on radicle and shoot growth of A. retroflexus, C. canadensis and D. sanguinalis. - Under field conditions, mulch of a mix of rye and squarrose clover suppressed weeds better than the single species.

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

2011 ◽  
Vol 26 (4) ◽  
pp. 342-353 ◽  
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.

scholarly journals Germination and initial development of canola and radish submitted to castor leaves aqueous extracts

2016 ◽  
Vol 7 (1) ◽  
pp. 104
Author(s):  
Carlos Alberto Gonsiorkiewicz Rigon ◽  
Adriana Tourinho Salamoni ◽  
Luan Cutti ◽  
Adalin Cezar Morais de Aguiar
Keyword(s):  
Seed Germination ◽  
Castor Bean ◽  
Ricinus Communis ◽  
Initial Growth ◽  
Aqueous Extracts ◽  
Brassica Napus L ◽  
Initial Development ◽  
Allelopathic Potential ◽  
Ricinus Communis L ◽  
Radish Seed

This study aimed to evaluate the allelopathic activity of aqueous extracts of castor bean (Ricinus communis L.) leaves on germination and initial growth of canola (Brassica napus L.) and radish (Raphanus sativus L.) seedlings. Two experiments were conducted, usingcanola seeds for the first, which was installed in a 2x7 factorial scheme (with two photoperiods – dark and light and seven extracts concentrations - 0, 1, 2, 4, 8, 16 and 32%). The second experiment consisted of an evaluation of radish seed germination submitted to seven concentrations of the extracts in the dark photoperiod. The germination of the canola seeds was reduced in the dark, and the use of extracts at concentrations of 16% and 32%inhibited seeds germination for both studied photoperiods. The radish seed germination was completely inhibited when the concentration of 32% was used, however, at the concentrations of 4, 8 and 16% a reduction on rootand hypocoyl development of the seedlings were observed, affirming the high allelopathic potential of castor bean aqueous extracts on canola and radish.

Allelopathic Influence of Germinating Seeds and Seedlings of Cover Crops on Weed Species

Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 579-584 ◽  
Author(s):  
Melinda L. Hoffman ◽  
Leslie A. Weston ◽  
John C. Snyder ◽  
Emilie E. Regnier
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Resource Competition ◽  
Petri Dish ◽  
Dry Weight ◽  
Weed Species ◽  
Allelopathic Potential ◽  
Below Ground ◽  
Allelopathic Interference ◽  
Radicle Length

Bioassays using binary mixtures that included a cover crop with known allelopathic potential and a weed species were employed to determine the importance of allelopathy compared to resource competition as interference mechanisms. Responses of weed species germinated with cover crops in a petri dish were measured. Interference between weed and cover crop seedlings was determined in a greenhouse experiment using the additive design, which included partitions to reduce above- and below-ground competition and used capillary mat subirrigation to control moisture and fertilizer availability. Germinating sorghum reduced radicle length of weeds, whereas germinating rye tended to increase weed radicle length. Methods limited above-ground competition, so likely interference mechanisms were below-ground competition and allelopathy. Germination with a cover crop had little effect on germination and shoot length of weeds. Increased density of rye but not of sorghum reduced growth of barnyardgrass seedlings. Reduced number of barnyardgrass leaves in the presence of rye was likely due to allelopathy. Suppression of barnyardgrass dry weight attributed to allelopathic interference by rye was successfully separated and compared to the combined effects of competition and allelopathy.

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

Weed Science ◽  
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.

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

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 319 ◽  
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.

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

2009 ◽  
Vol 23 (4) ◽  
pp. 556-563 ◽  
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.

scholarly journals How Do Intensification Practices Affect Weed Management and Yield in Quinoa (Chenopodium quinoa Willd) Crop?

2020 ◽  
Vol 12 (15) ◽  
pp. 6103
Author(s):  
Ali reza Safahani Langeroodi ◽  
Roberto Mancinelli ◽  
Emanuele Radicetti
Keyword(s):  
Seed Yield ◽  
Cover Crops ◽  
Weed Management ◽  
Cropping Systems ◽  
Soil Layer ◽  
Chenopodium Quinoa ◽  
Conventional Tillage ◽  
Amaranthus Retroflexus ◽  
No Tillage ◽  
Weed Seeds

Quinoa cultivation is well-adapted to sustainable cropping systems, even if seed yield could be severely limited due to several constraints, such as weeds. Field trials were performed in Gorgan (Iran) to quantify the effects of agro-ecological service crops (rye, CCr; winter vetch, CCw; and no cover, CC0), tillage regimes (conventional tillage, CT; and no-tillage, ZT), and herbicide rates (100% rate, H100; 75% rate, H75; and without herbicide, H0). Weed characteristics and quinoa yield were measured. Quinoa seed yield was the highest in CCw-ZT-H100. Seed yield in H100 and H75 were higher compared with H0 (2.30 vs. 1.58 t ha−1, respectively). Under conventional tillage, 46% of weed seeds were observed in the 0–10 cm soil layer and 54% in 10–20 cm soil layers, respectively, while, under no-tillage, about 63% of weed seeds were located up to 10 cm of soil. Amaranthus retroflexus L. was the most abundant species. The total weed density was the lowest in CCr-ZT-H100 and tended to be higher in CC0 (30.9 plant m−2) and under CT (29.0 plant m−2). These findings indicate that cover crops have potential for managing weeds in quinoa; however, their inclusion should be supported by chemical means to maintain high seed.

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

2018 ◽  
Vol 32 (3) ◽  
pp. 244-250 ◽  
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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