scholarly journals Spatial and temporal variability in Powell amaranth (Amaranthus powellii) emergence under strip tillage with cover crop residue

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Erin R. Haramoto ◽  
Daniel C. Brainard
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Crop Residue ◽  
Field Experiments ◽  
Abiotic Factors ◽  
Planting Date ◽  
Spatial And Temporal Variability ◽  
Natural Rainfall ◽  
Strip Tillage ◽  
The Impact

The objectives of this research were to evaluate temporal and spatial variability in the impact of strip tillage and oat cover crop residue on Powell amaranth emergence and to determine the role of rainfall in mediating these effects. In field experiments conducted in 2010, 2011, and 2012, Powell amaranth seeds were sown in a fully factorial combination of two tillage types (strip tillage [ST] vs. full-width tillage [FWT]) and cover crop residue (oats vs. none) at either 0 d after tillage (DAT) or 7 to 13 DAT to monitor emergence at two timings. In ST plots, seeds were sown both in the tilled zone (“in-row,” IR), and between these tilled zones (“between-row,” BR). In 2011 and 2012, three levels of rainfall were simulated in subplots by either excluding rainfall, allowing natural rainfall, or supplementing rainfall with irrigation. In most cases, ST and oats residue either had no effect on or suppressed emergence of Powell amaranth sown at the early planting date. In contrast, the emergence response to ST and residue at the later planting date was generally smaller and more variable, with increases in emergence observed in several cases. Differences between tillage systems in emergence were most pronounced in the BR zone but also occurred IR in some cases, suggesting that interzonal effects on biotic or abiotic factors influenced emergence. Oat residue effects—but rarely tillage effects—were often mediated by simulated rainfall, with increases in emergence occurring mostly in dry conditions and decreases occurring more commonly in wetter conditions. These results demonstrate that the suppressive effects of cover crops and ST on weed emergence are inconsistent, temporally and spatially variable, and dependent on complex interactions with factors including rainfall.

scholarly journals Strip Tillage and Oat Cover Crops Increase Soil Moisture and Influence N Mineralization Patterns in Cabbage

HortScience ◽  
2012 ◽  
Vol 47 (11) ◽  
pp. 1596-1602 ◽  
Author(s):  
Erin R. Haramoto ◽  
Daniel C. Brainard
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Production Systems ◽  
Conservation Tillage ◽  
Inorganic Nitrogen ◽  
Marketable Yield ◽  
Strip Tillage

Strip tillage (ST) is a form of conservation tillage in which disturbance is limited to the crop rows while the rest of the soil remains undisturbed. Compared with conventional, full-width tillage (CT), ST may reduce tillage costs, protect soil from erosion, and benefit cool-season crops including cabbage (Brassica oleracea L. var. ‘capitata’) by improving water retention, reducing soil temperatures, and improving the synchrony of inorganic nitrogen (IN) supply with crop demand. Field experiments were conducted in 2010 and 2011 in central Michigan to assess the effects of tillage (CT vs. ST) and a preceding cover crop (none vs. oats, Avena sativa L. var. ‘Ida’) on soil temperature, moisture, N dynamics, and yields in transplanted cabbage. Oats were sown in April and terminated 2 to 3 weeks before cabbage transplanting in early July. In-row (IR) soil moisture, temperature, and IN content were assessed from transplanting until cabbage harvest in October. In 2010, IR soil moisture was higher season-long in ST compared with CT and in oat compared with non-oat treatments, but these effects were not detected in 2011. Tillage and oat residue had little or no effect on IR soil temperature. Shortly after tillage in both years, soil IN availability was greater in CT treatments without oats compared with both ST treatments and CT with oats. However, these differences dissipated after 3 to 4 weeks, and hypothesized improvements in N release patterns under ST were not observed. No differences in cabbage marketable yield were detected in either year, although the proportion of plants that produced a marketable head was lower in cover-cropped plots in 2010. These findings suggest that soil conservation and input savings potentially associated with ST production systems may be attained without a yield penalty. More research is needed to understand and optimize cover crop management in ST systems to realize potential benefits in N use efficiency, moisture retention, and soil temperature moderation.

Detection of pitted morningglory (Ipomoea lacunosa) by hyperspectral remote sensing. I. Effects of tillage and cover crop residue

Weed Science ◽  
2004 ◽  
Vol 52 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Clifford H. Koger ◽  
David R. Shaw ◽  
Krishna N. Reddy ◽  
Lori M. Bruce
Keyword(s):  
Cover Crop ◽  
Crop Residue ◽  
Field Experiments ◽  
Leaf Growth ◽  
Plant Size ◽  
Hyperspectral Reflectance ◽  
Discrimination Accuracy ◽  
Reflectance Measurement ◽  
Pitted Morningglory ◽  
Residue Systems

Field experiments were conducted to evaluate the potential of hyperspectral reflectance data collected with a hand-held spectroradiometer to discriminate soybean intermixed with pitted morningglory and weed-free soybean in conventional till and no-till plots containing rye, hairy vetch, or no cover crop residue. Pitted morningglory was in the cotyledon to six-leaf growth stage. Seven 50-nm spectral bands (one ultraviolet, two visible, four near-infrared) derived from each hyperspectral reflectance measurement were used as discrimination variables. Pitted morningglory plant size had more influence on discriminant capabilities than tillage or cover crop residue systems. Across all tillage and residue systems, discrimination accuracy was 71 to 95%, depending on the size of pitted morningglory plants at the time of data acquisition. The versatility of the seven 50-nm bands was tested by using a discriminant model developed for one experiment location to test discriminant capabilities for the other experiment, with discrimination accuracy across all tillage and residue systems of 55 to 73%, depending on pitted morningglory plant size.

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

2017 ◽  
Vol 32 (1) ◽  
pp. 60-65 ◽  
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.

scholarly journals Systemic Colonization by Metarhizium robertsii Enhances Cover Crop Growth

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.

scholarly journals The Perceived Benefits, Challenges, and Environmental Effects of Cover Crop Implementation in South Carolina

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 372
Author(s):  
Lucas Clay ◽  
Katharine Perkins ◽  
Marzieh Motallebi ◽  
Alejandro Plastina ◽  
Bhupinder Singh Farmaha
Keyword(s):  
South Carolina ◽  
Cover Crops ◽  
Cover Crop ◽  
Management Practice ◽  
Soil Health ◽  
Education Level ◽  
Limited Information ◽  
Best Management ◽  
Row Crop ◽  
The Impact

Cover crops are becoming more accepted as a viable best management practice because of their ability to provide important environmental and soil health benefits. Because of these benefits, many land managers are strongly encouraging the use of cover crops. Additionally, there is limited information on farmers′ perceptions of the benefits and challenges of implementing cover crops. Many farmers state that they do not have enough money or time to implement cover crops. In an attempt to gather more data about the adoption rate and perceptions of cover crops in South Carolina, a survey was sent to 3000 row crop farmers across the state. Farmers were asked whether they implement cover crops and their perceptions of the benefits and challenges associated with implementation. Furthermore, questions were asked regarding the impact of row cropping on their environment to gauge farmer′s education level on environmental impacts. Responses showed many people are implementing cover crops; however, there are still differences in perceptions about benefits and challenges between those who are adopting cover crops and those who are not. This research assesses these differences and aims to provide a baseline for focusing cover crop programs to tackle these certain challenges and promote the benefits.

Impact of Planting Date on Melanaphis sacchari (Hemiptera: Aphididae) Population Dynamics and Grain Sorghum Yield

2019 ◽  
Vol 112 (6) ◽  
pp. 2731-2736 ◽  
Author(s):  
Nicholas J Seiter ◽  
Anne D Miskelley ◽  
Gus M Lorenz ◽  
Neelendra K Joshi ◽  
Glenn E Studebaker ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Field Experiments ◽  
The United States ◽  
Grain Sorghum ◽  
Planting Date ◽  
Melanaphis Sacchari ◽  
Planting Dates ◽  
Sugarcane Aphid ◽  
Aphid Feeding ◽  
The Impact

Abstract The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), has become a major pest of grain sorghum, Sorghum bicolor (L.) Moench, in the United States in recent years. Feeding by large densities of sugarcane aphids causes severe damage, which can lead to a total loss of yield in extreme cases. Our objective was to determine the effect of grain sorghum planting date on sugarcane aphid population dynamics and their potential to reduce yields. We conducted field experiments from 2015 to 2017 in which an aphid-susceptible grain sorghum hybrid was planted at four different dates, which encompassed the typical range of planting dates used in Arkansas production systems. Plots were either protected from sugarcane aphid feeding using foliar insecticide sprays, or left untreated to allow natural populations of sugarcane aphids to colonize and reproduce freely. Planting date impacted both the magnitude and severity of sugarcane aphid infestations, with the highest population densities (and subsequent reductions in sorghum yield) generally occurring on plots that were planted in May or June. Sugarcane aphid feeding reduced yields in the untreated plots in two of the four planting date categories we tested. Earlier planting generally resulted in less sugarcane aphid damage and improved yields compared with later planting dates. While the effect of planting date on sugarcane aphid populations is likely to vary by region, sorghum producers should consider grain sorghum planting date as a potential cultural tactic to reduce the impact of sugarcane aphid.

scholarly journals Effects of Cover Crop Residue and Preplant Herbicide on Early Leaf Spot of Peanut

Plant Disease ◽  
2007 ◽  
Vol 91 (7) ◽  
pp. 822-827 ◽  
Author(s):  
E. G. Cantonwine ◽  
A. K. Culbreath ◽  
K. L. Stevenson
Keyword(s):  
Leaf Spot ◽  
Cover Crop ◽  
Crop Residue ◽  
Soil Surface ◽  
Bare Soil ◽  
Plant Tissues ◽  
Cercospora Arachidicola ◽  
Winter Cover Crop ◽  
Strip Tillage ◽  
Herbicide Glyphosate

Epidemics of early leaf spot, caused by Cercospora arachidicola, of peanut (Arachis hypogaea) are delayed in strip-tilled compared to conventionally tilled fields. This effect may be due to applications of glyphosate used to kill the winter cover crop in strip-tilled fields and/or the presence of cover crop residue at the soil surface of strip-tilled fields. Preplant herbicide (no herbicide, glyphosate, and paraquat), reciprocal residue (plus residue in conventionally tilled plots and minus residue in strip-tilled plots), and added straw mulch were evaluated to determine their effects on early leaf spot epidemics (AUDPC based on incidence and severity, and final percent defoliation) in conventionally tilled and strip-tilled plots. Additional experiments were conducted to characterize the effects of mulch (straw, fumigated straw, and plastic straw [Textraw]) treatments on disease, and to study tillage effects on disease in nonrotated peanut fields. Glyphosate and paraquat had no effect on AUDPC values or defoliation. The addition of straw to conventionally tilled plots significantly reduced disease levels. Cover crop and straw treatments had no significant effect on disease in the strip-tilled plots. AUDPC values were highest in the bare soil plots, lowest in the straw and fumigated straw plots, and intermediate in the plots with Textraw. Fewer initial infections were detected in the Textraw plots compared to the bare soil plots based on results of a trap leaf experiment. Strip-tillage did not consistently suppress early leaf spot epidemics in nonrotated fields. These results show that the presence of cover crop residue is partly responsible for the early leaf spot suppression observed in strip-tilled fields. Cover crop residue may interfere with the dispersal of primary inoculum from overwintering stroma in the soil to the plant tissues.

A review of economic considerations for cover crops as a conservation practice

2017 ◽  
Vol 34 (1) ◽  
pp. 62-76 ◽  
Author(s):  
Jason S. Bergtold ◽  
Steven Ramsey ◽  
Lucas Maddy ◽  
Jeffery R. Williams
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Crop Yields ◽  
Cropping Systems ◽  
Production Risk ◽  
Policy Makers ◽  
Conservation Practice ◽  
Farm Business ◽  
The Impact ◽  
Economic Considerations

AbstractOver the past few decades, farmers have increasingly integrated cover crops into their cropping systems. Cover-crop benefits can help a farmer to achieve sustainability or reduce negative environmental externalities, such as soil erosion or chemical runoff. However, the impact on farm economics will likely be the strongest incentive to adopt cover crops. These impacts can include farm profits, cash crop yields or both. This paper provides a review of cover-crop adoption, production, risk and policy considerations from an economic perspective. These dimensions are examined through a review of cover-crop literature. This review was written to provide an overview of cover crops and their impacts on the farm business and the environment, especially with regard to economic considerations. Through increasing knowledge about cover crops, the intent here is to inform producers contemplating adoption and policy makers seeking to encourage adoption.

Herbicide Programs for the Termination of Various Cover Crop Species

2017 ◽  
Vol 31 (4) ◽  
pp. 514-522 ◽  
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.

Influence of Deep Tillage and a Rye Cover Crop on Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Emergence in Cotton

2012 ◽  
Vol 26 (4) ◽  
pp. 832-838 ◽  
Author(s):  
Justin D. DeVore ◽  
Jason K. Norsworthy ◽  
Kristofor R. Brye
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Cultural Practices ◽  
Palmer Amaranth ◽  
Deep Tillage ◽  
Amaranth Seed ◽  
Soil Seedbank ◽  
Second Year ◽  
The Impact ◽  
Moldboard Plow

Glyphosate-resistant Palmer amaranth has become a major problem for cotton producers throughout much of the southern United States. With cotton producers relying heavily on glyphosate-resistant cotton, an alternative solution to controlling resistant Palmer amaranth is needed. A field experiment was conducted during 2009 and 2010 at Marianna, AR, in which a rye cover crop and no cover crop were tested in combination with deep tillage with the use of a moldboard plow and no tillage to determine the impact on Palmer amaranth emergence in cotton. To establish a baseline population, 500,000 glyphosate-resistant Palmer amaranth seeds were placed in a 2-m2area in the middle of each plot and incorporated into the soil, and emergence was evaluated five times during the season. In 2009, both tillage and the cover crop reduced Palmer amaranth emergence in cotton, but the combination of the two reduced emergence 85%. In the second year, only the cover crop reduced Palmer amaranth emergence in cotton, a 68% reduction. Cover crops and deep tillage will not eliminate glyphosate-resistant Palmer amaranth; however, use of these tools will likely reduce the risks of failures associated with residual herbicides along with selection pressure placed on both PRE- and POST-applied herbicides. Additional efforts should focus on the integration of the best cultural practices identified in this research with use of residual herbicides and greater focus on limiting Palmer amaranth seed production and reducing the soil seedbank.

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