Allelopathic Potential of Green Manure Cover Crops on Germination and Early Seedling Development of Goose Grass [Eleusine indica (L.) Gaertn] and Blackjack (Bidens pilosa L.)

Green manure cover crops (GMCCs), which are recommended for improving soil fertility, also have the potential of reducing weed populations in cropping systems through allelopathy. The objective of this study was to evaluate the effect of eight GMCCs on the germination and seedling development of two weeds of divergent morphology, namely, goose grass [Eleusine indica (L.) Gaertn] and blackjack (Bidens pilosa L.). Aqueous leaf, stem, and root extracts of hyacinth bean (Lablab purpureus L), red sunnhemp [Crotalaria ochroleuca (G.) Don], showy rattlebox (Crotalaria grahamiana Wight & Arn.), common bean (Phaseolus vulgaris L.), common rattlepod (Crotalaria spectabilis Roth.), radish (Raphanus sativus L.), tephrosia (Tephrosia vogelii L.), and black sunnhemp (Crotalaria juncea L.) at 0, 1.25, 2.5, 3.75, and 5% wv−1 were applied to weed seeds in Petri dishes to determine their effect on germination, radicle and plumule growth, and germination vigor index. The experimental design was 3(tissue types) ∗ 5(concentrations) treatment combinations replicated four times in a completely randomized design. In the pot study, 25 seeds of either goose grass or blackjack were planted separately in approximately 400 g of soil mixed with cover crop tissue powder at 1% concentration per pot. The experimental design was cover crop residues + control replicated four times in randomized complete blocks. There was a significant ( p < 0.05 ) extract ∗ concentration interaction on all germination parameters across all GMCCs. The different cover crop aqueous extracts differentially reduced all germination parameters of both weeds in the order leaf > stem > root extract except for radish root extracts being most inhibitory to all germination parameters of goose grass. The leaf, stem, and root soil-incorporated residues of GMCCs significantly ( p < 0.05 ) affected seedling emergence, dry weight, and vigor indices of both weeds. Based on the results of this study, it was concluded that the different GMCC tissues contain allelochemicals that inhibit the emergence of both monocotyledonous and dicotyledonous weeds.

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Use of Crop Rotations, Cover Crops and Green Manures for Disease Suppression in Potato Cropping Systems

Global Journal of Agricultural Innovation Research & Development ◽

10.15377/2409-9813.2021.08.12 ◽

2021 ◽

Vol 8 ◽

pp. 153-168

Author(s):

Robert P. Larkin

Keyword(s):

Disease Control ◽

Microbial Activity ◽

Cover Crops ◽

Cover Crop ◽

Green Manure ◽

Cropping Systems ◽

Crop Rotations ◽

Disease Suppression ◽

Green Manures ◽

Rotation Crops

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.

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

Weed Science ◽

10.1017/s0043174500094376 ◽

1996 ◽

Vol 44 (3) ◽

pp. 579-584 ◽

Cited By ~ 46

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.

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Factors Associated with Leguminous Green Manure Incorporation and Fusarium Wilt Suppression in Watermelon

Plant Disease ◽

10.1094/pdis-08-15-0956-re ◽

2016 ◽

Vol 100 (9) ◽

pp. 1910-1920 ◽

Cited By ~ 3

Author(s):

J. Himmelstein ◽

J. E. Maul ◽

Y. Balci ◽

K. L. Everts

Keyword(s):

Soil Respiration ◽

Fusarium Wilt ◽

Cover Crops ◽

Trichoderma Harzianum ◽

Cover Crop ◽

Green Manure ◽

Arbuscular Mycorrhizae ◽

Green Manures ◽

Trifolium Incarnatum

Fall-planted Vicia villosa or Trifolium incarnatum cover crops, incorporated in spring as a green manure, can suppress Fusarium wilt (Fusarium oxysporum f. sp. niveum) of watermelon. During cover crop growth, termination, and incorporation into the soil, many factors such as arbuscular mycorrhizae colonization, leachate, and soil respiration differ. How these cover-crop-associated factors affect Fusarium wilt suppression is not fully understood. Experiments were conducted to evaluate how leachate, soil respiration, and other green-manure-associated changes affected Fusarium wilt suppression, and to evaluate the efficacy of the biocontrol product Actinovate AG (Streptomyces lydicus WYEC 108). General and specific suppression was examined in the field by assessing the effects of cover crop green manures (V. villosa, T. incarnatum, Secale cereale, and Brassica juncea) on soil respiration, presence of F. oxysporum spp., and arbuscular mycorrhizal colonization of watermelon. Cover crop treatments V. villosa, T. incarnatum, and S. cereale and no cover crop were evaluated both alone and in combination with Actinovate AG in the greenhouse. Additionally, in vitro experiments were conducted to measure the effects of cover crop leachate on the mycelial growth rates of F. oxysporum f. sp. niveum race 1 and Trichoderma harzianum. Soil microbial respiration was significantly elevated in V. villosa and Trifolium incarnatum treatments both preceding and following green manure incorporation, and was significantly negatively correlated with Fusarium wilt, suggesting that microbial activity was higher under the legumes, indicative of general suppression. Parallel to this, in vitro growth rates of F. oxysporum f. sp. niveum and Trichoderma harzianum on V. villosa leachate amended media were 66 and 213% greater, respectively, than on nonamended plates. The F. oxysporum spp. population (based on CFU and not differentiated into formae specialis or races) significantly increased in V. villosa-amended field plots. Additionally, the percentage of watermelon roots colonized by arbuscular mycorrhizae following V. villosa and Trifolium incarnatum green manures was significantly higher than in watermelon following bare ground (58 and 44% higher, respectively). In greenhouse trials where cover crops were amended to soil, Actinovate AG did not consistently reduce Fusarium wilt. Both general and specific disease suppression play a role in reducing Fusarium wilt on watermelon.

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Management of Meloidogyne hapla on Lettuce in Organic Soil with Sudangrass as a Cover Crop

Plant Disease ◽

10.1094/pdis.1998.82.8.945 ◽

1998 ◽

Vol 82 (8) ◽

pp. 945-952 ◽

Cited By ~ 46

Author(s):

Nicole M. Viaene ◽

George S. Abawi

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Green Manure ◽

Soil Amendment ◽

Egg Production ◽

Organic Soil ◽

Meloidogyne Hapla ◽

Nematode Reproduction ◽

Yellow Mustard ◽

Growing Seasons

Host suitability for Meloidogyne hapla of six cover crops was tested in the greenhouse. Sudan-grass cv. Trudan 8 and rye (mixture of cultivars) were nonhosts; oat cv. Porter was a poor host; and phacelia cv. Angelia, oilseed radish cv. Renova, and yellow mustard cv. Martigena were maintenance hosts. When incorporated as a green manure before planting of lettuce cv. Mon-tello, sudangrass was the most effective of the cover crops in reducing egg production of M. hapla. Soil amendment with all parts of sudangrass resulted in lower reproduction of M. hapla on lettuce than soil amendment with only roots of sudangrass. Soil incorporation of 2-month-old (or younger) tissues of sudangrass was more effective in reducing nematode reproduction on subsequent lettuce plants than incorporation of 3-month-old tissues. Sudangrass was grown as a cover crop after lettuce for three growing seasons in field microplots and incorporated as a green manure before the first fall frost. Weight of lettuce heads was significantly higher and reproduction of M. hapla was significantly lower in sudangrass-amended microplots compared with those left fallow between lettuce crops, but results varied with year and nematode infestation level.

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Effects of Cover Crop Species and Season on Population Dynamics of Escherichia coli and Listeria innocua in Soil

Applied and Environmental Microbiology ◽

10.1128/aem.03712-15 ◽

2016 ◽

Vol 82 (6) ◽

pp. 1767-1777 ◽

Cited By ~ 13

Author(s):

Neiunna L. Reed-Jones ◽

Sasha Cahn Marine ◽

Kathryne L. Everts ◽

Shirley A. Micallef

Keyword(s):

Escherichia Coli ◽

Cover Crops ◽

Cover Crop ◽

Green Manure ◽

Listeria Innocua ◽

Hairy Vetch ◽

Bacterial Populations ◽

Content Type ◽

E Coli ◽

Crimson Clover

ABSTRACTCover crops provide several ecosystem services, but their impact on enteric bacterial survival remains unexplored. The influence of cover cropping on foodborne pathogen indicator bacteria was assessed in five cover crop/green manure systems: cereal rye, hairy vetch, crimson clover, hairy vetch-rye and crimson clover-rye mixtures, and bare ground. Cover crop plots were inoculated withEscherichia coliandListeria innocuain the fall of 2013 and 2014 and tilled into the soil in the spring to form green manure. Soil samples were collected and the bacteria enumerated. Time was a factor for all bacterial populations studied in all fields (P< 0.001).E. colilevels declined when soil temperatures dipped to <5°C and were detected only sporadically the following spring.L. innocuadiminished somewhat but persisted, independently of season. In an organic field, the cover crop was a factor forE. coliin year 1 (P= 0.004) and forL. innocuain year 2 (P= 0.011). In year 1,E. colilevels were highest in the rye and hairy vetch-rye plots. In year 2,L. innocualevels were higher in hairy vetch-rye (P= 0.01) and hairy vetch (P= 0.03) plots than in the rye plot. Bacterial populations grew (P< 0.05) or remained the same 4 weeks after green manure incorporation, although initial reductions inL. innocuanumbers were observed after tilling (P< 0.05). Green manure type was a factor only forL. innocuaabundance in a transitional field (P< 0.05). Overall, the impacts of cover crops/green manures on bacterial population dynamics in soil varied, being influenced by bacterial species, time from inoculation, soil temperature, rainfall, and tillage; this reveals the need for long-term studies.

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Comparison of the Allelopathic Potential of Leguminous Summer Cover Crops: Cowpea, Sunn Hemp, and Velvetbean

HortScience ◽

10.21273/hortsci.42.2.289 ◽

2007 ◽

Vol 42 (2) ◽

pp. 289-293 ◽

Cited By ~ 23

Author(s):

Michael J. Adler ◽

Carlene A. Chase

Keyword(s):

Plant Height ◽

Cover Crops ◽

Cover Crop ◽

Dry Weight ◽

Bell Pepper ◽

Weed Species ◽

Crop Species ◽

Allelopathic Potential ◽

Sunn Hemp ◽

Germination And Growth

The phytotoxicity of aqueous foliar extracts and ground dried residues of sunn hemp (Crotalaria juncea L.), cowpea [Vigna unguiculata (L.) Walp. cv. Iron Clay], and velvetbean [Mucuna deeringiana (Bort) Merr.] to crop and weed germination and growth was evaluated to compare the allelopathic potential of the cover crops. By 14 days after treatment (DAT), goosegrass [Eleusine indica (L.) Gaertn.] germination with 5% aqueous extracts of all cover crops (w/v fresh weight basis) was similar and greater than 75% of control. However, with the 10% extracts, goosegrass germination was lowest with cowpea extract, intermediate with velvetbean extract, and highest with sunn hemp extract. Livid amaranth (Amaranthus lividus L.) germination declined to ≈50% with cowpea and sunn hemp extracts and even lower to 22% with velvetbean extract. The suppression of livid amaranth germination was greater with the 10% extracts than the 5% extracts. Bell pepper (Capsicum annuum L.) germination was unaffected by velvetbean extract, inhibited more by the 5% cowpea extract than the 10% extract, and was also sensitive to the 10% sunn hemp extract. All cover crop extracts resulted in an initial delay in tomato (Lycopersicon esculentum Mill.) germination, but by 14 DAT, inhibition of germination was apparent only with cowpea extract. The phytotoxicity of ground dried residues of the three cover crops on germination, plant height, and dry weight of goosegrass, smooth amaranth (A. hybridus L.), bell pepper, and tomato was evaluated in greenhouse studies. Goosegrass germination was inhibited in a similar manner by residues of the three cover crops to 80% or less of control. Smooth amaranth germination, plant height, and dry biomass were more sensitive to sunn hemp residues than to cowpea and velvetbean residues. Bell pepper germination, plant height, and dry weight were greater than 90% of control except for dry weight with cowpea residue, which was only 78% of control. The greatest effect of cover crop residue on tomato occurred with dry weight, because dry weights with cowpea and sunn hemp were only 76% and 69% of control, respectively, and lower than with velvetbean. There was more evidence of cover crop phytotoxicity with the weed species than with the crop species and cowpea extracts and residue affected all species more consistently than those of sunn hemp and velvetbean.

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Selected Legumes Used As Summer Cover Crops

EDIS ◽

10.32473/edis-in483-2003 ◽

1969 ◽

Vol 2003 (16) ◽

Author(s):

Jim Rich ◽

David Wright ◽

Jim Marois ◽

Dick Sprenkel

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Green Manure ◽

Cooperative Extension Service ◽

Extension Service ◽

Publication Date ◽

University Of Florida ◽

Wide Range ◽

Pest Suppression ◽

Green Manure Crops

Cover crops are generally planted after a primary (cash) crop for one or more of the following reasons: erosion control, organic matter accumulation, improved soil tilth, pest suppression (weed, disease, nematode, and insect), and nitrogen production. Optimally, a cover crop will provide a wide range of most or all of the previously mentioned benefits, even if the main reason for planting it was more specific. The eight cover/green manure crops described herein have been shown to provide several benefits to a succeeding crop. This document is ENY-688 (IN483), one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Publication Date: August 2003.

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The effect of cover crops on the yield of carrot (Daucus carota L.) in ploughless and conventional tillage

Horticultural Science ◽

10.17221/61/2017-hortsci ◽

2019 ◽

Vol 46 (No. 2) ◽

pp. 57-64

Author(s):

Marzena Błażewicz-Woźniak ◽

Dariusz Wach ◽

Elżbieta Patkowska ◽

Mirosław Konopiński

Keyword(s):

Experimental Design ◽

Cover Crops ◽

Cover Crop ◽

Positive Impact ◽

Conventional Tillage ◽

Positive Influence ◽

Soil Tillage ◽

Marketable Yield ◽

Crop Species ◽

Daucus Carota L

The experimental design included seven cover crop species and six kinds of soil tillage in the field cultivation of carrot. The use of cover crops had a positive impact on the yield of marketable roots of carrot in comparison with the cultivation without the cover crops. A significant increase of marketable yield was noted after phacelia, buckwheat, mustard and sunflower. The flat ploughless tillage significantly reduced the marketable yield of roots in comparison with traditional ploughing. The largest marketable yield of roots was obtained from cultivation on ridges after mixing the biomass of buckwheat or phacelia or mustard with the soil, and the smallest, after reduced spring tillage using aggregate without cover crops. The largest marketable yield in flat ploughless tillage was obtained when using grubber before winter, and the biomass of phacelia was mixed with soil. Growing carrot on the ridges had a positive influence on increasing the share of the marketable yield of roots in comparison with other variants of cultivation including the conventional tillage. The all cover crops with the exception of spring vetch significantly increased the share of marketable roots in the yield compared with cultivation without cover crops. The largest percentage of the marketable yield was noted after use of phacelia.

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

Weed Technology ◽

10.1614/wt-d-12-00056.1 ◽

2013 ◽

Vol 27 (1) ◽

pp. 212-217 ◽

Cited By ~ 29

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.

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Conyza sumatrensis allelopathy effect on Bidens pilosa (Asteraceae) seed germination

Botanical Sciences ◽

10.17129/botsci.2445 ◽

2020 ◽

Vol 98 (2) ◽

pp. 348-354 ◽

Cited By ~ 1

Author(s):

Paulo José Ferreira ◽

Patrícia da Costa Zonetti ◽

Alfredo Junior Paiola Albrecht ◽

Isac George Rosset ◽

André Felipe Moreira Silva ◽

...

Keyword(s):

Seed Germination ◽

Weed Management ◽

Total Flavonoids ◽

Aqueous Extracts ◽

Bidens Pilosa ◽

Allelopathic Potential ◽

Root Extracts ◽

Germination Process ◽

Germination Speed ◽

Allelopathic Compounds

Background: Other tools for weed management should be considered in addition to the use of herbicides. In this context, the identification and use of allelopathic compounds deserves attention. Question: To quantify phenolic compounds and evaluate the allelopathic potential of extracts of Conyza sumatrensis on the germination of Bidens pilosa. Studied species: Conyza sumatrensis (Retz.) E.Walker, Bidens pilosa L. (Asteraceae) Study site: Palotina, state of Paraná, Brazil. Methods: The aqueous extracts were prepared with shoot and root portions of C. sumatrensis in concentrations: 0, 1, 5 and 10 %. Germination and germination speed index were evaluated. The total flavonoids and phenols of the tested extracts were also quantified. Results: With increasing concentrations of the extracts there was an increased inhibition of germination of B. pilosa and delays in the germination process. The extracts from the shoot of C. sumatrensis had a more expressive effect on seed germination when compared to the extracts obtained from the root. At concentration of 10 %, the extract from the shoot reduced in 83 % the percentage of germination. This may be related to the higher concentration of total flavonoids and phenols found. Conclusion: The allelopathic potential of C. sumatrensis plants can be considered since both shoot and root extracts inhibited and/or reduced the germination of B. pilosa.

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