The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens

Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

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Effect of planting into a green winter cereal rye cover crop on growth and development, seedling disease and yield of corn

Plant Disease ◽

10.1094/pdis-04-21-0836-re ◽

2021 ◽

Author(s):

Jyotsna Acharya ◽

Thomas B Moorman ◽

Thomas C Kaspar ◽

Andrew W. Lenssen ◽

Stefan NA Gailans ◽

...

Keyword(s):

Cover Crops ◽

C:N Ratio ◽

Root Disease ◽

Corn Yield ◽

Potential Yield ◽

Winter Cereal ◽

Cold Temperatures ◽

Seedling Disease ◽

Cereal Rye ◽

Seedling Root

Terminating winter cereal rye (Secale cereale L.) cover crops (CCs) 10 or more days before planting corn is recommended to minimize seedling disease and potential yield loss. In Iowa, cold temperatures and frequent precipitation can prevent farmers from following that recommendation and sometimes forcing them to plant corn while the rye plants are still green, referred to as planting green (PG). A field trial was established to evaluate the effect of rye termination shortly before or after corn planting on growth, seedling root disease, and yield of corn. A rye CC was terminated 17 and 3 days before planting (DBP), and 6 and 12 days after planting (DAP) corn; corn planted following no rye was included as a control. Rye biomass, C:N ratio, and N accumulation increased when terminated 6 or 12 DAP corn compared with rye terminated 17 or 3 DBP corn. Corn seedlings were taller from the PG treatments. More radicle root rot was observed when rye was terminated 3 DBP, 6 DAP, and 12 DAP corn than for the 17 DBP treatment and the no-rye control. Generally, greater Pythium Clade B populations were detected on radicles and seminal roots of corn from the PG treatments. Corn populations, ears, or barren plants were not affected by the treatments. In both years, the no-rye control had the greatest corn yield and the 12 DAP treatment had the lowest yield. Our results suggest that PG increased corn seedling root disease and contributed to reduced corn yield.

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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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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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Integrating fall and spring herbicides with a cereal rye cover crop for horseweed (Conyza canadensis) management prior to soybean

Weed Technology ◽

10.1017/wet.2019.116 ◽

2019 ◽

Vol 34 (1) ◽

pp. 64-72 ◽

Cited By ~ 1

Author(s):

Austin D. Sherman ◽

Erin R. Haramoto ◽

J. D. Green

Keyword(s):

Cover Crops ◽

Weed Management ◽

Field Experiments ◽

Production Systems ◽

Conyza Canadensis ◽

Cereal Rye ◽

Potential Interactions ◽

Herbicide Programs ◽

Spring Emergence ◽

Residual Control

AbstractHorseweed is one of Kentucky’s most common and problematic weeds in no-till soybean production systems. Emergence in the fall and spring necessitates control at these times because horseweed is best managed when small. Control is typically achieved through herbicides or cover crops (CCs); integrating these practices can lead to more sustainable weed management. Two years of field experiments were conducted over 2016 to 2017 and 2017 to 2018 in Versailles, KY, to examine the use of fall herbicide (FH; namely, saflufenacil or none), spring herbicide (SH; namely, 2,4-D; dicamba; or none), and CC (namely, cereal rye or none) for horseweed management prior to soybean. Treatments were examined with a fully factorial design to assess potential interactions. The CC biomass in 2016 to 2017 was higher relative to 2017 to 2018 and both herbicide programs reduced winter weed biomass in that year. The CC reduced horseweed density while growing and after termination in 1 yr. The FH reduced horseweed density through mid-spring. The FH also killed winter weeds that may have suppressed horseweed emergence; higher horseweed density resulted by soybean planting unless the CC was present to suppress the additional spring emergence. If either FH or CC was used, SH typically did not result in additional horseweed control. The SH killed emerged plants but did not provide residual control of a late horseweed flush in 2017 to 2018. These results suggest CCs can help manage spring flushes of horseweed emergence when nonresidual herbicide products are used, though this effect was short-lived when less CC biomass was present.

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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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Cover Crop and Postemergence Herbicide Integration for Palmer amaranth Control in Cotton

Weed Technology ◽

10.1017/wet.2017.10 ◽

2017 ◽

Vol 31 (3) ◽

pp. 348-355 ◽

Cited By ~ 3

Author(s):

Matthew S. Wiggins ◽

Robert M. Hayes ◽

Robert L. Nichols ◽

Lawrence E. Steckel

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Field Experiments ◽

Palmer Amaranth ◽

Cereal Rye ◽

Crimson Clover ◽

Annual Grasses ◽

Winter Annual ◽

Hand Weeding

Field experiments were conducted to evaluate the integration of cover crops and POST herbicides to control glyphosate-resistant Palmer amaranth in cotton. The winter-annual grasses accumulated the greatest amount of biomass and provided the most Palmer amaranth control. The estimates for the logistic regression would indicate that 1540 kg ha−1would delay Palmer amaranth emerging and growing to 10 cm by an estimated 16.5 days. The Palmer amaranth that emerged in the cereal rye and wheat cover crop treatments took a longer time to reach 10 cm compared to the hairy vetch and crimson clover treatments. POST herbicides were needed for adequate control of Palmer amaranth. The glufosinate-based weed control system provided greater control (75% vs 31%) of Palmer amaranth than did the glyphosate system. These results indicate that a POST only herbicide weed management system did not provide sufficient control of Palmer amaranth, even when used in conjunction with cover crops that produced a moderate level of biomass. Therefore, future recommendations for GR Palmer amaranth control will include integrating cover crops with PRE herbicides, overlaying residual herbicides in-season, timely POST herbicide applications, and hand weeding in order to achieve season-long control of this pest.

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Effects of cover crop presence, cover crop species selection and fungicide seed treatment on corn seedling growth

Renewable Agriculture and Food Systems ◽

10.1017/s1742170517000345 ◽

2017 ◽

Vol 34 (2) ◽

pp. 93-102 ◽

Cited By ~ 4

Author(s):

Lara A. Schenck ◽

Matthew G. Bakker ◽

Thomas B. Moorman ◽

Thomas C. Kaspar

Keyword(s):

Environmental Quality ◽

Cover Crops ◽

Cover Crop ◽

Seed Treatment ◽

Disease Development ◽

Crop Species ◽

Cereal Rye ◽

Seedling Root ◽

Corn Seedling ◽

Negative Impacts

AbstractCover crops can offer erosion protection as well as soil and environmental quality benefits. Cereal rye (Secale cerealeL.) is the most commonly used winter cover crop in corn–soybean rotations in the upper Midwest of the USA because of its superior winter hardiness and growth at cool temperatures. Cereal rye cover crops, however, can occasionally have negative impacts on the yield of a following corn crop, which discourages broader adoption and introduces substantial risk for corn farmers employing cover crops. We hypothesized that because cereal rye shares some pathogens with corn, it may be causing increased disease in corn seedlings planted soon after cereal rye termination. To test this, we performed a series of experiments in a controlled environment chamber to assess the response of corn seedlings with and without a commercial fungicide seed treatment to the presence of cereal rye or other species of cover crops that were terminated with herbicide prior to corn planting. Our results indicate that under cool and wet conditions, cereal rye reduces corn seedling growth performance and increases incidence of corn seedling root disease. Fungicide seed treatment had limited efficacy in preventing these effects, perhaps because environmental conditions were set to be very conducive for disease development. However, hairy vetch (Vicia villosaRoth) and winter canola (Brassica napusL.) cover crops had fewer negative impacts on corn seedlings compared with cereal rye. Thus, to expand the practice of cover cropping before corn, it should become a research priority to develop alternative management practices to reduce the risk of corn seedling root infection following cereal rye cover crops. Over the longer term, testing, selection and breeding efforts should identify potential cover crop species or genotypes that are able to match the winter hardiness, growth at cool temperatures and the conservation and environmental quality benefits of cereal rye, while avoiding the potential for negative impacts on corn seedlings when environmental conditions are suitable for disease development.

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Cover Crop Rotation Effects on Growth and Development, Seedling Disease, and Yield of Corn and Soybean

Plant Disease ◽

10.1094/pdis-09-19-1904-re ◽

2020 ◽

Vol 104 (3) ◽

pp. 677-687 ◽

Cited By ~ 1

Author(s):

Jyotsna Acharya ◽

Thomas B. Moorman ◽

Thomas C. Kaspar ◽

Andrew W. Lenssen ◽

Alison E. Robertson

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Growth And Development ◽

Root Disease ◽

Winter Rye ◽

Negative Effects ◽

Winter Cereal ◽

Cereal Rye ◽

Soybean Seedlings ◽

Seedling Roots

The effects of winter cover crops on root disease and growth of corn and soybeans are poorly understood. A 3-year field experiment investigated the effect of winter cereal rye (Secale cereale L.) and winter camelina (Camelina sativa [L.] Crantz), used either in all three years or in rotation with each other, on corn (Zea mays L.) and soybean (Glycine max. [L.] Merr.) growth, root disease, and yield. Corn following a cover crop of camelina had reduced root disease, a lower Pythium population in seedling roots, and greater growth and yields compared with corn following a rye cover crop. Camelina and rye cover crops before soybean had either a positive or no effect on soybean growth and development, root disease, and yield. Moreover, Pythium clade B populations were greater in corn seedlings after a rye cover crop compared with those following a camelina cover crop, whereas clade F populations were greater on soybean seedlings following a camelina cover crop compared with seedlings following a rye cover crop. A winter camelina cover crop grown before corn had less-negative effects on corn seedling growth, root disease, and final yield than a winter rye cover crop before corn. Neither cover crop had negative effects on soybean, and the cover crop in the preceding spring had no measurable effects on either corn or soybean.

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Winter Annual Weed Suppression in Rye–Vetch Cover Crop Mixtures

Weed Technology ◽

10.1614/wt-d-12-00084.1 ◽

2012 ◽

Vol 26 (4) ◽

pp. 818-825 ◽

Cited By ~ 45

Author(s):

Zachary D. Hayden ◽

Daniel C. Brainard ◽

Ben Henshaw ◽

Mathieu Ngouajio

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Dry Weight ◽

Weed Suppression ◽

Weed Species ◽

Cereal Rye ◽

Winter Annual ◽

Winter Annual Weeds ◽

Annual Weeds

Winter annual weeds can interfere directly with crops and serve as alternative hosts for important pests, particularly in reduced tillage systems. Field experiments were conducted on loamy sand soils at two sites in Holt, MI, between 2008 and 2011 to evaluate the relative effects of cereal rye, hairy vetch, and rye–vetch mixture cover crops on the biomass and density of winter annual weed communities. All cover crop treatments significantly reduced total weed biomass compared with a no-cover-crop control, with suppression ranging from 71 to 91% for vetch to 95 to 98% for rye. In all trials, the density of nonmustard family broadleaf weeds was either not suppressed or suppressed equally by all cover crop treatments. In contrast, the density of mustard family weed species was suppressed more by rye and rye–vetch mixtures than by vetch. Cover crops were more consistently suppressive of weed dry weight per plant than of weed density, with rye-containing cover crops generally more suppressive than vetch. Overall, rye was most effective at suppressing winter annual weeds; however, rye–vetch mixtures can match the level of control achieved by rye, in addition to providing a potential source of fixed nitrogen for subsequent cash crops.

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Evaluation of Three Winter Cereals for Weed Control in Conservation-Tillage Nontransgenic Cotton

Weed Technology ◽

10.1614/wt-04-245r1.1 ◽

2005 ◽

Vol 19 (3) ◽

pp. 731-736 ◽

Cited By ~ 46

Author(s):

D. Wayne Reeves ◽

Andrew J. Price ◽

Michael G. Patterson

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Field Experiments ◽

Conservation Tillage ◽

Cotton Production ◽

Winter Cereal ◽

Winter Cereals ◽

Fallow System ◽

Winter Fallow

The increased use of conservation tillage in cotton production requires that information be developed on the role of cover crops in weed control. Field experiments were conducted from fall 1994 through fall 1997 in Alabama to evaluate three winter cereal cover crops in a high-residue, conservation-tillage, nontransgenic cotton production system. Black oat, rye, and wheat were evaluated for their weed-suppressive characteristics compared to a winter fallow system. Three herbicide systems were used: no herbicide, preemergence (PRE) herbicides alone, and PRE plus postemergence (POST) herbicides. The PRE system consisted of pendimethalin at 1.12 kg ai/ha plus fluometuron at 1.7 kg ai/ha. The PRE plus POST system contained an additional application of fluometuron at 1.12 kg/ha plus DSMA at 1.7 kg ai/ha early POST directed (PDS) and lactofen at 0.2 kg ai/ha plus cyanazine at 0.84 kg ai/ha late PDS. No cover crop was effective in controlling weeds without a herbicide. However, when black oat or rye was used with PRE herbicides, weed control was similar to the PRE plus POST system. Rye and black oat provided more effective weed control than wheat in conservation-tillage cotton. The winter fallow, PRE plus POST input system yielded significantly less cotton in 2 of 3 yr compared to systems that included a winter cover crop. Use of black oat or rye cover crops has the potential to increase cotton productivity and reduce herbicide inputs for nontransgenic cotton grown in the Southeast.

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