Impact of Five Cover Crop Green Manures and Actinovate on Fusarium Wilt of Watermelon

Triploid watermelon cultivars are grown on more than 2,023 ha in Maryland and in Delaware. Triploid watermelon cultivars have little host resistance to Fusarium wilt of watermelon (Fusarium oxysporum f. sp. niveum). The effects of four different fall-planted cover crops (Vicia villosa, Trifolium incarnatum, Secale cereale, and Brassica juncea) that were tilled in the spring as green manures, and bare ground, were evaluated alone and in combination with the biocontrol product Actinovate (Streptomyces lydicus) on Fusarium wilt severity and watermelon fruit yield and quality. Six field experiments were conducted over 3 years in Beltsville and Salisbury, MD and Georgetown, DE. Both V. villosa and T. incarnatum significantly suppressed Fusarium wilt of watermelon as much as 21% compared with watermelon in nonamended plots. However, no suppression of Fusarium wilt occurred at low disease levels or where low cover crop biomass was present. In general, Beltsville, MD had lower disease levels than Salisbury, MD and Georgetown, DE. T. incarnatum was the only cover crop that yielded significantly more fruit than nonamended treatments (129% more fruit per hectare) but only for one field trial. The Actinovate product either did not reduce Fusarium wilt or the magnitude of the reduction was nominal. Actinovate significantly reduced Fusarium wilt by 2% in 2009 and as much as 7% in 2010, and increased Fusarium wilt severity by 2.5% in 2011. Actinovate significantly increased yield for one field trial but only when applied to nonamended or Secale cereal-amended plots. This is the first report of a reduction in Fusarium wilt following a T. incarnatum cover crop incorporated as a green manure.

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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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COVER CROP AND NITROGEN FERTILIZER RATE INFLUENCES ON YIELDS OF SEQUENTIALLY PLANTED VEGETABLES

HortScience ◽

10.21273/hortsci.27.6.570c ◽

1992 ◽

Vol 27 (6) ◽

pp. 570c-570

Author(s):

Owusu A. Bandele ◽

Marion Javius ◽

Byron Belvitt ◽

Oscar Udoh

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Fertilizer Rate ◽

Vicia Villosa ◽

Trifolium Incarnatum ◽

Crimson Clover ◽

Summer Squash ◽

Nitrogen Fertilizer Rate ◽

Mustard Green ◽

N Rates

Fall-planted cover crops of hairy vetch (Vicia villosa Roth), Austrian winter pea (Pisum sativum subsp. arvense L. Poir), and crimson clover (Trifolium incarnatum L.) were each followed by spring-planted 'Sundance' summer squash [Cucurbita pepo var. melopepo (L.) Alef.] and 'Dasher' cucumber (Cucumis sativus L.). Squash and cucumber crops were followed by fall 'Florida Broadleaf mustard green [Brassica juncea (L.) Czerniak] and 'Vates' collard (Brassica oleracea L. Acephala group), respectively. The same vegetable sequences were also planted without benefit of cover crop. Three nitrogen (N) rates were applied to each vegetable crop. Squash following winter pea and crimson clover produced greater yields than did squash planted without preceding cover crop. Cucumber following crimson clover produced the greatest yields. No cover crop effect was noted with mustard or collard. Elimination of N fertilizer resulted in reduced yields for all crops, but yields of crops with one-half the recommended N applied were generally comparable to those receiving the full recommended rate.

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Winter legume cover-crop root decomposition and N release dynamics under disking and roller-crimping termination approaches

Renewable Agriculture and Food Systems ◽

10.1017/s1742170515000113 ◽

2015 ◽

Vol 31 (3) ◽

pp. 214-229 ◽

Cited By ~ 12

Author(s):

Arun D. Jani ◽

Julie Grossman ◽

Thomas J. Smyth ◽

Shuijin Hu

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Root Decomposition ◽

Inorganic N ◽

Vicia Villosa ◽

Soil Inorganic N ◽

N Release ◽

Legume Cover Crop ◽

Soil Inorganic

AbstractSeveral approaches can be used to terminate legume cover crops in the spring prior to planting summer crops, but the effect that these methods have on decomposition and nitrogen (N) release dynamics of legume cover-crop roots is poorly understood. The main objectives of this study were to: (i) quantify decomposition and N release of roots from pea (Pisum sativum), clover (Trifolium incarnatum) and vetch (Vicia villosa Roth); (ii) determine if roots decompose and release N faster when cover crops are terminated by disking compared with roller-crimping; and (iii) determine if roots decompose and release N faster under higher soil inorganic N levels. Two field experiments were conducted in Goldsboro and Kinston, North Carolina in the summer of 2012. Cover crops at these sites were terminated in spring by disking or roller-crimping and planted to unirrigated corn. Air-dried roots placed in litterbags were buried in their corresponding cover-crop plots and in plots where cover crops had not been grown that had either synthetic N fertilizer added at burial or had no fertilizer addition. Root litterbags were collected over 16 weeks at both sites. Cover-crop plots terminated by disking had up to 117 and 49% higher soil inorganic N than roller-crimped plots in Goldsboro and Kinston, respectively. However, roots did not appear to contribute significantly to these increases, as measured root decomposition and N release was not affected by termination approach at either site. Roots decomposed rapidly at both sites, losing up to 65% of their original biomass within 4 weeks after burial. Root N release was also rapid at both sites, with vetch generally releasing N fastest and clover slowest. It was estimated that cover-crop roots supplied 47–62 and 19–33 kg N ha−1 during the corn cycle in Goldsboro and Kinston, respectively. Our results indicate that under the warm, humid summer conditions of the Southeastern USA, legume cover-crop roots decompose and release N rapidly.

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Potassium application to the cover crop prior to cotton planting as a fertilization strategy in sandy soils

Scientific Reports ◽

10.1038/s41598-020-77354-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Fábio Rafael Echer ◽

Vinicius José Souza Peres ◽

Ciro Antonio Rosolem

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Cropping Systems ◽

Short Fiber ◽

Yield And Quality ◽

No Till ◽

Fiber Maturity ◽

K Fertilization

AbstractUrochloa grasses are used as cover crops in tropical cropping systems under no-till to improve nutrient cycling. We hypothesized that potassium (K) applied to ruzigrass (Urochloa ruziziensis) grown before cotton in a sandy soil could be timely cycled and ensure nutrition, yield and quality of cotton cultivars with no need to split K application. Field experiments were performed with different K managements, applied to ruzigrass, to cotton grown after grass and without grass, or split as it is done conventionally. No yield differences were observed on K fertilized treatments. At 0 K, cotton yields were low, but they increased by 16% when ruzigrass was grown before, and short fiber content was lower when there was more K available. Ruzigrass grown before cotton increased micronaire as much as the application of 116 kg ha−1 of K without the grass. Fiber maturity was higher when K was applied to the grass or split in the grass and sidedressed in cotton. Growing ruzigrass before cotton allows for early K fertilization, i.e., application of all the fertilizer to de grass, since the nutrient is recycled, and cotton K nutrition is not harmed. Eventually K rates could be reduced as a result of higher efficiency of the systems.

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Cover Crops Suppression of Palmer Amaranth (Amaranthus palmeri) in Cotton

Weed Technology ◽

10.1017/wet.2017.97 ◽

2017 ◽

Vol 32 (1) ◽

pp. 60-65 ◽

Cited By ~ 4

Author(s):

Matheus G. Palhano ◽

Jason K. Norsworthy ◽

Tom Barber

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Palmer Amaranth ◽

Cotton Yield ◽

Cotton Production ◽

Seed Cotton ◽

Cereal Rye ◽

Seed Cotton Yield ◽

Weed Emergence

AbstractWith the recent confirmation of protoporphyrinogen oxidase (PPO)-resistant Palmer amaranth in the US South, concern is increasing about the sustainability of weed management in cotton production systems. Cover crops can help to alleviate this problem, as they can suppress weed emergence via allelochemicals and/or a physical residue barrier. Field experiments were conducted in 2014 and 2015 at the Arkansas Agricultural Research and Extension Center to evaluate various cover crops for suppressing weed emergence and protecting cotton yield. In both years, cereal rye and wheat had the highest biomass production, whereas the amount of biomass present in spring did not differ among the remaining cover crops. All cover crops initially diminished Palmer amaranth emergence. However, cereal rye provided the greatest suppression, with 83% less emergence than in no cover crop plots. Physical suppression of Palmer amaranth and other weeds with cereal residues is probably the greatest contributor to reducing weed emergence. Seed cotton yield in the legume and rapeseed cover crop plots were similar when compared with the no cover crop treatment. The seed cotton yield collected from cereal cover crop plots was lower than from other treatments due to decreased cotton stand.

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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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Systemic Colonization by Metarhizium robertsii Enhances Cover Crop Growth

Journal of Fungi ◽

10.3390/jof6020064 ◽

2020 ◽

Vol 6 (2) ◽

pp. 64

Author(s):

Imtiaz Ahmad ◽

María del Mar Jiménez-Gasco ◽

Dawn S. Luthe ◽

Mary E. Barbercheck

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Negative Relationship ◽

Crop Growth ◽

Above Ground Biomass ◽

Crop Species ◽

Metarhizium Robertsii ◽

Cereal Rye ◽

Ground Biomass

Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, we observed a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures. Here, we report the effects of endophytic M. robertsii on three cover crop species under greenhouse conditions. We inoculated seeds of Austrian winter pea (Pisum sativum L., AWP), cereal rye (Secale cereale L.), and winter canola (Brassica napus L.) with conidia of M. robertsii to assess the effects of endophytic colonization on cover crop growth. We recovered M. robertsii from 59%, 46%, and 39% of seed-inoculated AWP, cereal rye, and canola plants, respectively. Endophytic M. robertsii significantly increased height and above-ground biomass of AWP and cereal rye but did not affect chlorophyll content of any of the cover crop species. Among inoculated plants from which we recovered M. robertsii, above-ground biomass of AWP was positively correlated with the proportion of colonized root but not leaf tissue sections. Our results suggest that winter cover crops may help to conserve Metarhizium spp. in annual cropping systems.

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Suppression of Fusarium Wilt of Watermelon Enhanced by Hairy Vetch Green Manure and Partial Cultivar Resistance

Plant Health Progress ◽

10.1094/php-2006-0405-01-rs ◽

2006 ◽

Vol 7 (1) ◽

pp. 23 ◽

Cited By ~ 6

Author(s):

X. G. Zhou ◽

K. L. Everts

Keyword(s):

Fusarium Wilt ◽

Green Manure ◽

Fruit Yield ◽

Management Tool ◽

Hairy Vetch ◽

Vicia Villosa ◽

Combined Use ◽

Triploid Watermelon ◽

Marketable Fruit ◽

Soil Fumigants

Hairy vetch (Vicia villosa Roth) green manure is a newly-described potential management tool for Fusarium wilt of watermelon, but control is insufficient when watermelon, especially triploid watermelon, is grown in severely infested soils. A field experiment in a split-split-plot design was conducted over two years to evaluate efficacy of hairy vetch green manure alone and in combination with a moderately wilt-resistant (MR) triploid watermelon cultivar for wilt suppression compared with preplant soil fumigants. Either the soil-incorporated hairy vetch winter cover crop or the MR cultivar was effective in reducing wilt incidence, promoting plant vine growth, and increasing fruit yield. However, neither approach alone resulted in disease reductions sufficient to obtain an acceptable level of marketable fruit yield. An additive effect was observed when both treatments were combined and was greater than that obtained with the fumigants methyl bromide or metam sodium. Stem colonization by Fusarium oxysporum f. sp. niveum was lower following hairy vetch green manure than in fallow treatments, and was lowest in the MR cultivar grown in green-manured plots. The combined use of hairy vetch green manure and a MR cultivar can enhance suppression of Fusarium wilt in triploid watermelon. Accepted for publication 25 February 2006. Published 5 April 2006.

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Reduced-Herbicide Weed Management Systems for No-Tillage Corn (Zea mays) in a Hairy Vetch (Vicia villosa) Cover Crop

Weed Technology ◽

10.1017/s0890037x00037921 ◽

1993 ◽

Vol 7 (4) ◽

pp. 879-883 ◽

Cited By ~ 29

Author(s):

John R. Teasdale

Keyword(s):

Weed Control ◽

Weed Management ◽

Cover Crop ◽

Field Experiments ◽

Standard Treatment ◽

Corn Yield ◽

No Tillage ◽

Hairy Vetch ◽

Treatment Control ◽

Vicia Villosa

Weed management treatments with various degrees of herbicide inputs were applied with or without a hairy vetch cover crop to no-tillage corn in four field experiments at Beltsville, MD. A hairy vetch living mulch in the no-treatment control or a dead mulch in the mowed treatment improved weed control during the first 6 wk of the season but weed control deteriorated in these treatments thereafter. Competition from weeds and/or uncontrolled vetch in these treatments without herbicides reduced corn yield in three of four years by an average of 46% compared with a standard PRE herbicide treatment of 0.6 kg ai/ha of paraquat plus 1.1 kg ai/ha of atrazine plus 2.2 kg ai/ha of metolachlor. Reducing atrazine and metolachlor to one-fourth the rate of the standard treatment in the absence of cover crop reduced weed control in three of four years and corn yield in two of four years compared with the standard treatment. Hairy vetch had little influence on weed control or corn yield with any herbicide treatments.

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Herbicide Programs for the Termination of Various Cover Crop Species

Weed Technology ◽

10.1017/wet.2017.20 ◽

2017 ◽

Vol 31 (4) ◽

pp. 514-522 ◽

Cited By ~ 5

Author(s):

Cody D. Cornelius ◽

Kevin W. Bradley

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Crop Yields ◽

Production Systems ◽

Annual Ryegrass ◽

Crop Species ◽

Cereal Rye ◽

Crimson Clover ◽

Herbicide Treatments

The recent interest in cover crops as a component of Midwest corn and soybean production systems has led to a greater need to understand the most effective herbicide treatments for cover crop termination prior to planting corn or soybean. Previous research has shown that certain cover crop species can significantly reduce subsequent cash crop yields if not completely terminated. Two field experiments were conducted in 2013, 2014, and 2015 to determine the most effective herbicide program for the termination of winter wheat, cereal rye, crimson clover, Austrian winter pea, annual ryegrass, and hairy vetch; and cover crops were terminated in early April or early May. Visual control and above ground biomass reduction was determined 28 d after application (DAA). Control of grass cover crop species was often best with glyphosate alone or combined with 2,4-D, dicamba, or saflufenacil. The most consistent control of broadleaf cover crops occurred following treatment with glyphosate +2,4-D, dicamba, or saflufenacil. In general, control of cover crops was higher with early April applications compared to early May. In a separate study, control of 15-, 25-, and 75-cm tall annual ryegrass was highest with glyphosate at 2.8 kg ha−1or glyphosate at 1.4 kg ha−1plus clethodim at 0.136 kgha−1. Paraquat- or glufosinate-containing treatments did not provide adequate annual ryegrass control. For practitioners who desire higher levels of cover crop biomass, these results indicate that adequate levels of cover crop control can still be achieved in the late spring with certain herbicide treatments. But it is important to consider cover crop termination well in advance to ensure the most effective herbicide or herbicide combinations are used and the products are applied at the appropriate stage.

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