Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Weed management (2)
- Abiotic influences on seed dormancy (1)
- Aboveground biomass (1)
- Air-propelled grit (1)
- Brassica oleracea (1)
-
- Broccoli (1)
- Capsicum annuum (1)
- Cattle (1)
- Density (1)
- Economic threshold (1)
- Forage utilization (1)
- Geostatistics (1)
- Hydrothermal time (1)
- Incremental yield loss (1)
- Kriging (1)
- Maize (1)
- Maize (Zea mays) (1)
- Mob grazing (1)
- Nitrogen management (1)
- Nonlinear mixed effects models (1)
- Organic farming (1)
- Pepper (1)
- Plant-plant interaction (1)
- Precision agriculture (1)
- Preemergence herbicides (1)
- Regional environmental variation (1)
- Rotational grazing (1)
- Seedling recruitment phenology. (1)
- Shoot dry weight (1)
- Site-specific weed management (1)
Articles 1 - 30 of 33
Full-Text Articles in Life Sciences
Herbicide And Additive Impacts On Bradyrhizobium Japonicum Growth In Solution, Joy Amajioyi, Thandiwe Nleya, Senthil Subramanian, Sharon A. Clay
Herbicide And Additive Impacts On Bradyrhizobium Japonicum Growth In Solution, Joy Amajioyi, Thandiwe Nleya, Senthil Subramanian, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Plant biostimulants include beneficial fungi and bacteria, and are often applied to foliage to improve crop growth, yield, and/or crop quality. Crop improvements due to biostimulant addition may be modest; therefore, solo applications may not be economical or climate smart. However, biostimulants combined with other postemergence treatments, such as herbicides, may provide an alternative application method, if mixtures do not harm the living organism(s). The growth of Bradyrhizobium japonicum, as a biostimulant surrogate, was assessed in solutions of glyphosate [N-(phosphonomethyl)glycine] and dicamba (3,6-dichloro-2-methoxybenzoic acid), with and without common spray additives (ammonium sulfate [AMS] and nonionic surfactant) in laboratory studies over …
Weed-Induced Crop Yield Loss: A New Paradigm And New Challenges, David Horvath, Sharon A. Clay, Clarence J. Swanton, James V. Anderson, Wun S. Chao
Weed-Induced Crop Yield Loss: A New Paradigm And New Challenges, David Horvath, Sharon A. Clay, Clarence J. Swanton, James V. Anderson, Wun S. Chao
Agronomy, Horticulture and Plant Science Faculty Publications
Direct competition for resources is generally considered the primary mechanism for weed-induced yield loss. A re-evaluation of physiological evidence suggests weeds initially impact crop growth and development through resource-independent interference. We suggest weed perception by crops induce a shift in crop development, before resources become limited, which ultimately reduce crop yield, even if weeds are subsequently removed. We present the mechanisms by which crops perceive and respond to weeds and discuss the technologies used to identify these mechanisms. These data lead to a fundamental paradigm shift in our understanding of how weeds reduce crop yield and suggest new research directions …
Auxin-Based Herbicide Program For Weed Control In Auxin Resistant Soybean, Joy Amajioyi, Thandiwe Nleya, Graig Reicks, Janet Moriles- Miller, David Clay, Sharon Clay
Auxin-Based Herbicide Program For Weed Control In Auxin Resistant Soybean, Joy Amajioyi, Thandiwe Nleya, Graig Reicks, Janet Moriles- Miller, David Clay, Sharon Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Soybean [Glycine max (L.) Merr.] cultivars resistant to synthetic auxin herbicides have provided another mode of action for the postemergence broadleaf weed control. This field study was conducted at three South Dakota locations [Northeast, NERF; east-central, ARF; and Southeast, SERF) in 2019 and two locations (ARF and SERF) in 2020. The Enlist E3 and Roundup Ready 2 Xtend cultivars were planted at three dates (early, mid-, and late season) to examine weed control, agronomic characteristics, nodulation, and yield. Preemergence (PRE) treatment was flumioxazin + metribuzin + S-metolachlor + glyphosate + pendimethalin. Two postemergence (POST) treatments, based on cultivar, were compared …
Near Term Challenges For Global Agriculture - Herbicide Resistant Weeds, Sharon Clay
Near Term Challenges For Global Agriculture - Herbicide Resistant Weeds, Sharon Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Prior to the 1950s weeds were controlled by a wide variety of mechanical and cultural methods with limited use of inorganic chemicals at very high rates (100s kg ha–1). With the advent of selective carbon-based herbicides in the 1950s, herbicide weed management became the norm throughout much of the world using grams to a few kg of active ingredient per ha. However, with the benefits, there are problems. A few resistant weeds were recognized in the 1970s, but today, in 2021, 521 unique cases of resistance have been documented throughout the world. It is imperative for farmers to rethink the …
Abrasive Weeding As A Vehicle For Precision Fertilizer Management In Organic Vegetable Production, Tran Kim Ngan Luong, Frank Forcella, Sharon A. Clay, Michael S. Douglass, Sam E. Wortman
Abrasive Weeding As A Vehicle For Precision Fertilizer Management In Organic Vegetable Production, Tran Kim Ngan Luong, Frank Forcella, Sharon A. Clay, Michael S. Douglass, Sam E. Wortman
Agronomy, Horticulture and Plant Science Faculty Publications
Abrasive weeding is a nonchemical weed control tactic that uses small, gritty materials propelled with compressed air to destroy weed seedlings. Organic fertilizers have been used successfully as abrasive grits to control weeds, but the goal for this study was to explore the effects of fertilizer grit, application rates, and background soil fertility on weeds, plant available nitrogen (N) uptake, and crop yield. Field trials were conducted in organic ‘Carmen’ sweet red pepper (Capsicum annuum) and organic ‘Gypsy’ broccoli (Brassica oleracea var. italica) and treatments included organic fertilizer grit (8N–0.9P–3.3K vs. 3N–3.1P–3.3K), grit application rates (low …
Teosinte (Zea Mays Ssp Parviglumis) Growth And Transcriptomic Response To Weed Stress Identifies Similarities And Differences Between Varieties And With Modern Maize Varieties, S. A. Bruggeman, D. P. Horvath, A. Y. Fennell Dr, J. A. Gonzalez-Hernandez, S. A. Clay
Teosinte (Zea Mays Ssp Parviglumis) Growth And Transcriptomic Response To Weed Stress Identifies Similarities And Differences Between Varieties And With Modern Maize Varieties, S. A. Bruggeman, D. P. Horvath, A. Y. Fennell Dr, J. A. Gonzalez-Hernandez, S. A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Transcriptomic responses of plants to weed presence gives insight on the physiological and molecular mechanisms involved in the stress response. This study evaluated transcriptomic and morphological responses of two teosinte (Zea mays ssp parviglumis) (an ancestor of domesticated maize) lines (Ames 21812 and Ames 21789) to weed presence and absence during two growing seasons. Responses were compared after 6 weeks of growth in Aurora, South Dakota, USA. Plant heights between treatments were similar in Ames 21812, whereas branch number decreased when weeds were present. Ames 21789 was 45% shorter in weedy vs weed-free plots, but branch numbers were similar between …
Varying Weed Densities Alter The Corn Transcriptome, Highlighting A Core Set Of Weed-Induced Genes And Processes With Potential For Manipulating Weed Tolerance, David P. Horvath, Sharon A. Clay, Stephanie A. Bruggeman, James V. Anderson, Wun S. Chao, Kathleen Yeater
Varying Weed Densities Alter The Corn Transcriptome, Highlighting A Core Set Of Weed-Induced Genes And Processes With Potential For Manipulating Weed Tolerance, David P. Horvath, Sharon A. Clay, Stephanie A. Bruggeman, James V. Anderson, Wun S. Chao, Kathleen Yeater
Agronomy, Horticulture and Plant Science Faculty Publications
The phenological responses of corn (Zea mays L.) to competition with increasing densities of winter canola (Brassica napus L.) as the weedy competitor were investigated. Changes in the corn transcriptome resulting from varying weed densities were used to identify genes and processes responsive to competition under controlled conditions where light, nutrients, and water were not limited. Increasing densities of weeds resulted in decreased corn growth and development and increased the number and expression intensity of competition-responsive genes. The physiological processes identified in corn that were consistently induced by competition with weeds included protein synthesis and various transport functions. …
Using Abrasive Grit For Weed Management In Field Crops, Michael Carlson, Frank Forcella, Sam Wortman, Sharon A. Clay
Using Abrasive Grit For Weed Management In Field Crops, Michael Carlson, Frank Forcella, Sam Wortman, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Abrasive grit, applied at high pressure and directed at plant base, can control weeds and increase yield. We evaluated fertilizer [pelletized turkey (Meleagris gallopavo) litter] and non-fertilizer [walnut (Juglans regia) shell] grits for maize and soybean in-row (IR) weed management. Grits were applied at V1 and V5 of maize, and V1 and V3 of soybean. Between-row weed cultivation was done alone (BR), or in combination with grit (I/B), after grit application. Small weeds (<4 >cm) were controlled after grit treatment, but, larger broadleaf weeds, grass weeds (treated when growing points were below ground), and later emerging …
Air-Propelled Abrasive Grit Can Damage The Perennial Weed Quackgrass, Frank Forcella, Daniel Humburg, Samuel E. Wortman, Sharon A. Clay
Air-Propelled Abrasive Grit Can Damage The Perennial Weed Quackgrass, Frank Forcella, Daniel Humburg, Samuel E. Wortman, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
our field experiments were conducted during 2016 and 2017 to evaluate the efficacy of preemergence herbicides to control glyphosate-resistant common ragweed in corn. Dicamba, dicamba/atrazine, mesotrione + atrazine, isoxaflutole + atrazine, saflufenacil/dimethenamid-P, and S-metolachlor/mesotrione/bicyclopyrone/atrazine were the most efficacious herbicides, providing 94%–100% control of GR common ragweed and reducing density and biomass 98%–100%.
Weed Presence Altered Biotic Stress And Light Signaling In Maize Even When Weeds Were Removed Early In The Critical Weed‐Free Period, David P. Horvath, Stephanie Bruggeman, Janet Moriles-Miller, James V. Anderson, Munevver Dogramaci, Brian E. Scheffler, Alvaro G. Hernandez, Michael E. Foley, Sharon Clay
Weed Presence Altered Biotic Stress And Light Signaling In Maize Even When Weeds Were Removed Early In The Critical Weed‐Free Period, David P. Horvath, Stephanie Bruggeman, Janet Moriles-Miller, James V. Anderson, Munevver Dogramaci, Brian E. Scheffler, Alvaro G. Hernandez, Michael E. Foley, Sharon Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Weed presence early in the life cycle of maize (typically, from emergence through the 8 to 12 leaf growth stage) can reduce crop growth and yield and is known as the critical weed‐free period (CWFP). Even if weeds are removed during or just after the CWFP, crop growth and yield often are not recoverable. We compared transcriptome responses of field‐grown hybrid maize at V8 in two consecutive years among plants grown under weed‐free and two weed‐stressed conditions (weeds removed at V4 or present through V8) using RNAseq analysis techniques. Compared with weed‐free plant responses, physiological differences at V8 were identified …
Propelled Abrasive Grit For Weed Control In Organic Silage Corn, Mauricio Erazo-Barradas, Fran Forcella, Dan Humburg
Propelled Abrasive Grit For Weed Control In Organic Silage Corn, Mauricio Erazo-Barradas, Fran Forcella, Dan Humburg
Agronomy, Horticulture and Plant Science Faculty Publications
Weed management in organic farming requires many strategies to accomplish acceptable control and maintain crop yields. This 2-yr field study used air propelled abrasive grit for in-row weed control in organically certified silage corn (Zea mays L.). Corncob grit was applied as a single application at corn vegetative growth stages V1 (one true leaf; numbers correspond to number of true leaves at the corn vegetative stage), V3, or V5 (in 2013) and V3, V5, and V7 (in 2014) and in double and triple combinations at these stages. Between-row weed control was accomplished by flaming or cultivation after the last grit …
Mob Vs. Rotational Grazing: Impact On Forage Use And Artemisia Absinthium, Heidi Reed, Alexander Smart, David E. Clay, Michelle Ohrtman, Sharon A. Clay
Mob Vs. Rotational Grazing: Impact On Forage Use And Artemisia Absinthium, Heidi Reed, Alexander Smart, David E. Clay, Michelle Ohrtman, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Short duration (≤24 h), high stocking density grazing systems (e.g., mob grazing) mimics historic prairie grazing patterns of American bison (Bison bison), and should minimize selective grazing. We compared mob [125 cow-calf pairs on either 0.65 ha for 12 h; or 1.3 ha for 24 h] vs. rotational [25 cow-calf pairs on 8.1 ha for 20 days starting in mid-May with or without 2,4-D application prior to grazing; and 15 days starting mid-April (no herbicide)] grazing systems based on forage utilization and impact to Artemisia absinthium (absinth wormwood) in a tall grass pasture of Eastern South Dakota. Grass …
Propelled Abrasive Grit Applications For Weed Management In Transitional Corn Grain Production, Mauricio Enzo-Barradas, Claire N. Friedrichsen, Frank Forcella, Dan Humberg, Sharon A. Clay
Propelled Abrasive Grit Applications For Weed Management In Transitional Corn Grain Production, Mauricio Enzo-Barradas, Claire N. Friedrichsen, Frank Forcella, Dan Humberg, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Weed control is challenging to farmers who are transitioning from production systems that use synthetic herbicides to organic systems. A 2-year field study examined air-propelled corncob grit abrasion for in-row weed control efficacy and effect on corn yield. Grit was applied based on corn vegetative developmental stages with one (V1, V3 or V5), two (V1 + V3, V1 + V5, or V3 + V5), or three (V1 + V3 + V5) applications. Flame-weeding or cultivation was used after the V5 application for between-row weed control. Grit applications decreased in-row weed densities by about 60% (α = 0.05) and biomass up …
Identification Of Differential Agronomic Traits In Early Stage Teosinte, Flint, Dent, And Sugar (Sweet) Corn Varieties In Competition With Weeds, S.A. Hansen, S. A. Clay, David Horvath, S. Flint-Garcia
Identification Of Differential Agronomic Traits In Early Stage Teosinte, Flint, Dent, And Sugar (Sweet) Corn Varieties In Competition With Weeds, S.A. Hansen, S. A. Clay, David Horvath, S. Flint-Garcia
Agronomy, Horticulture and Plant Science Faculty Publications
Weed competition reduces corn yield. Today’s corn monoculture relies heavily on herbicide inputs to maintain yield. However, teosinte, corn’s ancestor, was successfully grown in mixed production systems. Harnessing genes and traits that allow teosinte to be a better competitor but which may have been lost during corn domestication could help producers reduce herbicide inputs and maintain yield. The first step to finding those genes is to identify varieties of corn and lines of teosinte that have a higher tolerance of weeds or greater weed suppressive ability. Five introductions of teosinte and 14 varieties of corn (including dent, heritage, and sweet …
Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Frank Forcella, John Lundquist, Christy Sprague
Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Frank Forcella, John Lundquist, Christy Sprague
Agronomy, Horticulture and Plant Science Faculty Publications
Robust predictions of weed seedling emergence from the soil seedbank are needed to aid weed management. A common seed accession (Illinois) of giant ragweed was buried in replicate experimental gardens over 18 site years in Illinois, Michigan, Kansas, Nebraska, Ohio, and South Dakota to examine the importance of site and climate variability by year on seedling emergence. In a nonlinear mixed-effects modeling approach, we used a flexible sigmoidal function (Weibull) to model giant ragweed cumulative seedling emergence in relation to hydrothermal time accumulated in each site-year. An iterative search method across a range of base temperature (Tb ) and base …
Local Conditions, Not Regional Gradients, Drive Demographic Variation Of Giant Ragweed (Ambrosia Trifida) And Common Sunflower (Helianthus Annuus) Across Northern U.S. Maize Belt, Sam E. Wortman, Adam S. Davis, Brian J. Schutte, John L. Lindquist, John Cardina, Joel Felix, Christy L. Sparague, Anita Dille, Analiza H.M. Ramirez, Graig Reicks, Sharon A. Clay
Local Conditions, Not Regional Gradients, Drive Demographic Variation Of Giant Ragweed (Ambrosia Trifida) And Common Sunflower (Helianthus Annuus) Across Northern U.S. Maize Belt, Sam E. Wortman, Adam S. Davis, Brian J. Schutte, John L. Lindquist, John Cardina, Joel Felix, Christy L. Sparague, Anita Dille, Analiza H.M. Ramirez, Graig Reicks, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Knowledge of environmental factors influencing demography of weed species will improve understanding of current and future weed invasions. The objective of this study was to quantify regional-scale variation in vital rates of giant ragweed and common sunflower. To accomplish this objective, a common field experiment was conducted across seven sites between 2006 and 2008 throughout the north central U.S. maize belt. Demographic parameters of both weed species were measured in intra- and interspecific competitive environments, and environmental data were collected within site-years. Site was the strongest predictor of belowground vital rates (summer and winter seed survival and seedling recruitment), indicating …
Microarray And Growth Analyses Identify Differences And Similarities Of Early Corn Response To Weeds, Shade, And Nitrogen Stress, Janet Moriles, Stephanie Hansen, David P. Horvath, Graig Reicks, David E. Clay, Sharon A. Clay
Microarray And Growth Analyses Identify Differences And Similarities Of Early Corn Response To Weeds, Shade, And Nitrogen Stress, Janet Moriles, Stephanie Hansen, David P. Horvath, Graig Reicks, David E. Clay, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Weed interference with crop growth is often attributed to water, nutrient, or light competition; however, specific physiological responses to these stresses are not well described. This study's objective was to compare growth, yield, and gene expression responses of corn to nitrogen (N), low light (40% shade), and weed stresses. Corn vegetative parameters from V2 to V12 stages, yield parameters, and gene expression using transcriptome (2008) and quantitative polymerase chain reaction (qPCR) (2008/09) analyses at V8 were compared among the stresses and with nonstressed corn. N stress did not affect vegetative parameters, although grain yield was reduced by 40% compared with …
The Influence Of Biochar Production On Herbicide Sorption Characteristics, Sharon A. Clay, Douglas D. Malo
The Influence Of Biochar Production On Herbicide Sorption Characteristics, Sharon A. Clay, Douglas D. Malo
Agronomy, Horticulture and Plant Science Faculty Publications
Biochar is the by-product of a thermal process conducted under low oxygen or oxygen-free conditions (pyrolysis) to convert vegetative biomass to biofuel (Jha et al., 2010). There are a wide variety of end-products that can be manufactured depending on processing parameters and initial feedstocks (Bridgewater, 2003). The pyrolytic process parameters such as temperature, heating rate, and pressure can change the recovery amounts of each end-product, energy values of the bio-oils, and the physico-chemical properties of biochar (Yaman, 2004).
Early Season Weed Suppression In Buckwheat Using Clopyralid, Ona Sakaliene, Sharon A. Clay, William C. Koskinen, Gediminas Almantas
Early Season Weed Suppression In Buckwheat Using Clopyralid, Ona Sakaliene, Sharon A. Clay, William C. Koskinen, Gediminas Almantas
Agronomy, Horticulture and Plant Science Faculty Publications
Currently there are no herbicides registered for direct application to buckwheat for broadleaf weed control. This 4-yr Lithuanian study examined weed control using several rates of clopyralid alone or combined with a single rate of desmedipham. Most applications were applied at the 1-leaf stage of crop growth, however, one rate of clopyralid was applied pre-emergence (PRE) in 2 of the 4 yr. Buckwheat injury was evident within a few days after application (or emergence) with all treatments, but by harvest, no symptoms were evident. In the 2 yr with greatest weed densities, densities were reduced with increasing clopyralid rates alone …
Early Season Weed Suppression In Buckwheat Using Clopyralid, Ona Sakaliene, Sharon A. Clay, William C. Koskinen, Gediminas Almantas
Early Season Weed Suppression In Buckwheat Using Clopyralid, Ona Sakaliene, Sharon A. Clay, William C. Koskinen, Gediminas Almantas
Agronomy, Horticulture and Plant Science Faculty Publications
Currently there are no herbicides registered for direct application to buckwheat for broadleaf weed control. This 4-yr Lithuanian study examined weed control using several rates of clopyralid alone or combined with a single rate of desmedipham. Most applications were applied at the 1-leaf stage of crop growth, however, one rate of clopyralid was applied pre-emergence (PRE) in 2 of the 4 yr. Buckwheat injury was evident within a few days after application (or emergence) with all treatments, but by harvest, no symptoms were evident. In the 2 yr with greatest weed densities, densities were reduced with increasing clopyralid rates alone …
Common Waterhemp Growth And Fecundity As Influenced By Emergence Date And Competing Crop, E. Uscanga-Mortera, S. Clay, F. Forcella, J. Gunsolus
Common Waterhemp Growth And Fecundity As Influenced By Emergence Date And Competing Crop, E. Uscanga-Mortera, S. Clay, F. Forcella, J. Gunsolus
Agronomy, Horticulture and Plant Science Faculty Publications
Common waterhemp (Amarathus rudis Sauer) is a frequent weed in glyphosate-resistant (GR) crops in the midwestern USA due, in part, to the delayed emergence of its seedlings. Variable waterhemp emergence was simulated by transplanting seedlings into both corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] and bare plot areas at differing crop growth stages during two growing seasons in western Minnesota. Growth and fecundity were measured. As expected, late planted weeds produced little dry matter and few seeds, and competition from corn or soybean reduced waterhemp dry weight and fecundity by 90% compared with isolated plants. Interestingly, common …
Microarray Analysis Of Late-Season Velvetleaf (Abutilon Theophrasti) Effect On Corn, David P. Horvath, Robert Gulden, Sharon A. Clay
Microarray Analysis Of Late-Season Velvetleaf (Abutilon Theophrasti) Effect On Corn, David P. Horvath, Robert Gulden, Sharon A. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Microarray analysis was used to identify changes in gene expression in corn leaves collected from plants at the V11–14 growth stage that resulted from competition with velvetleaf. The plants were grown in field plots under adequate N (addition of 220 kg N ha1) and irrigation to minimize N and water stress. Consequently, only differences resulting from competition for micronutrients, light, and perhaps allelopathic stress were anticipated. Genes involved in carbon and nitrogen utilization, photosynthesis, growth and development, oxidative stress, signal transduction, responses to auxin and ethylene, and zinc transport were repressed in corn growing in competition with velvetleaf. …
Spatial Distribution, Temporal Stability, And Yield Loss Estimates For Annual Grasses And Common Ragweed (Ambrosia Artimisiifolia) In A Corn/Soybean Production Field Over Nine Years, Sharon A. Clay, Bruce Kreutner, David E. Clay, Cheryl Reese, Jonathan Kleinjan, Frank Forcella
Spatial Distribution, Temporal Stability, And Yield Loss Estimates For Annual Grasses And Common Ragweed (Ambrosia Artimisiifolia) In A Corn/Soybean Production Field Over Nine Years, Sharon A. Clay, Bruce Kreutner, David E. Clay, Cheryl Reese, Jonathan Kleinjan, Frank Forcella
Agronomy, Horticulture and Plant Science Faculty Publications
Weeds generally occur in patches in production fields. Are these patches spatially and temporally stable? Do management recommendations change on the basis of these data? The population density and location of annual grass weeds and common ragweed were examined in a 65-ha corn/soybean production field from 1995 to 2004. Yearly treatment recommendations were developed from field means, medians, and kriging grid cell densities, using the hyperbolic yield loss (YL) equation and published incremental YL values (I ), maximum YL values (A), and YL limits of 5, 10, or 15%. Mean plant densities ranged from 12 to 131 annual grasses m22 …
Sampling Weed Spatial Variability On A Fieldwide Scale, Sharon A. Clay, G. Jason Lems, Frank Forcella, Michael M. Ellsbury, C. Gregg Carlson, David E. Clay
Sampling Weed Spatial Variability On A Fieldwide Scale, Sharon A. Clay, G. Jason Lems, Frank Forcella, Michael M. Ellsbury, C. Gregg Carlson, David E. Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Site-specific weed management recommendations require knowledge of weed species, density, and location in the field. This study compared several sampling techniques to estimate weed density and distribution in two 65-ha no-till Zea mays–Glycine max rotation fields in eastern South Dakota. The most common weeds (Setaria viridis, Setaria glauca, Cirsium arvense, Ambrosia artemisiifolia, and Polygonum pensylvanicum) were counted by species in 0.1-m2 areas on a 15- by 30-m (1,352 points in each field) or 30- by 30-m (676 points in each field) grid pattern, and points were georeferenced and data spatially analyzed. Using different sampling approaches, weed populations were estimated by …
Influence Of Deleterious Rhizobacteria On Leafy Spurge (Euphorbia Esula) Roots, Mark A. Brinkman, Sharon A. Clay, Robert J. Kremer
Influence Of Deleterious Rhizobacteria On Leafy Spurge (Euphorbia Esula) Roots, Mark A. Brinkman, Sharon A. Clay, Robert J. Kremer
Agronomy, Horticulture and Plant Science Faculty Publications
Rhizobacteria have been shown to be phytotoxic to leafy spurge in laboratory assays. This field study investigated the influence of two strains of Pseudomonas fluorescens [Trevisan, (Migula)], deleterious rhizobacteria (DRB), on root weight, root bud number, and root carbohydrate content of leafy spurge at three sites located in northeast and north-central South Dakota. Soils were inoculated with 2 g of starch-based granules containing no bacteria or starch granules containing 108colony-forming units (cfu)/g of either bacterial strain LS102 (Montana origin) or LS174 (South Dakota origin). Bacterial strains were detected on root samples from treated areas. Root weight and root carbohydrate content …
Influence Of Crop Rotation, Tillage, And Management Inputs On Weed Seed Production, George O. Kegode, Frank Forcella, Sharon Clay
Influence Of Crop Rotation, Tillage, And Management Inputs On Weed Seed Production, George O. Kegode, Frank Forcella, Sharon Clay
Agronomy, Horticulture and Plant Science Faculty Publications
Approaches to crop production that successfully reduce weed seed production can benefit farming systems by reducing management inputs and costs. A 5-yr rotation study was conducted in order to determine the effects that interactions between crop rotation, tillage, and amount of herbicide and fertilizer (management inputs) have on annual grass and broad-leaved weed seed production and fecundity. There were 10 crop rotation and tillage system combinations and three levels of management inputs (high, medium, and low). Green and yellow foxtail were the major weed species, and together they yielded between 76 and 93% of collected weed seeds. From 1990 to …
Leafy Spurge Biological Control Using Black Dot Flea Beetles And Deleterious Rhizobacteria: Final Report Submitted To South Dakota Department Of Agriculture Weed And Pest Control, Sharon A. Clay, Mark A. Brinkman, Robert J. Kramer, Jan J. Jackson, Nels H. Granholm
Leafy Spurge Biological Control Using Black Dot Flea Beetles And Deleterious Rhizobacteria: Final Report Submitted To South Dakota Department Of Agriculture Weed And Pest Control, Sharon A. Clay, Mark A. Brinkman, Robert J. Kramer, Jan J. Jackson, Nels H. Granholm
Agronomy, Horticulture and Plant Science Faculty Publications
Size of leafy spurge (Euphorbia esula L) roots and their location in the soil profile are important factors relating to survival offirst-instar black dot flea beetle (Aphthona nigriscutis Foudras) larvae. First-instar larvae must find leafy spurge roots between 1 to 4 mm diam in the first 2 days after hatching from eggs for survival. In field studies, we ddermined that most flea beetle larvae reside within 7.6 em ofthe soil surface. Their location in the upper areas ofthe soil profile allows accessibility to desirable size roots, however the larvae are more susceptible to freezing temperatures in this region. Overall, there …
Weed Seed Bank Emergence Across The Corn Belt, Frank Forcella, Robert G. Wilson, Jack Dekker, Robert J. Kramer, John Cardina, Randy L. Anderson, David Alm, Karen A. Renner, R. Gordon Harvey, Sharon Clay, Douglas D. Buhler
Weed Seed Bank Emergence Across The Corn Belt, Frank Forcella, Robert G. Wilson, Jack Dekker, Robert J. Kramer, John Cardina, Randy L. Anderson, David Alm, Karen A. Renner, R. Gordon Harvey, Sharon Clay, Douglas D. Buhler
Agronomy, Horticulture and Plant Science Faculty Publications
Field experiments, conducted from 1991 to 1994, generated information on weed seedbank emergence for 22 site-years from Ohio to Colorado and Minnesota to Missouri. Early spring seedbank densities were estimated through direct extraction of viable seeds from soil cores. Emerged seedlings were recorded periodically, as were daily values for air and soil temperature, and precipitation. Percentages of weed seedbanks that emerged as seedlings were calculated from seedbank and seedling data for each species, and relationships between seedbank emergence and microclimatic variables were sought. Fifteen species were found in 3 or more site-years. Average emergence percentages (and coefficients of variation) of …
Leafy Spurge - A Review, Sharon A. Clay, Chad M. Scholes
Leafy Spurge - A Review, Sharon A. Clay, Chad M. Scholes
Agronomy, Horticulture and Plant Science Faculty Publications
Leafy spurge (Euphorbia esula L.) is a perennial herbaceous weed that infests millions of acres of range and pasture in the northern Great Plains. It outcompetes grasses and lowers land productivity because cattle will not graze infested areas even if spurge makes up only 10% of the vegetative biomass. This presentation will cover the history, taxonomy, and phenology of leafy spurge. A discussion of chemical, mechanical, and biocontrol techniques that aid in leafy spurge management will also be included.
Analysis Of Spatial Distribution Of Canada Thistle (Cirsium Arvense) In Notill Soybean (Glycine Max), B. L. Broulik, J. Lems, S. A. Clay, D. E. Clay, M. M. Ellsbury
Analysis Of Spatial Distribution Of Canada Thistle (Cirsium Arvense) In Notill Soybean (Glycine Max), B. L. Broulik, J. Lems, S. A. Clay, D. E. Clay, M. M. Ellsbury
Agronomy, Horticulture and Plant Science Faculty Publications
The nonuniform spatial distribution of weeds across a field landscape complicates sampling and modeling, but allows site specific rather than broadcast management of weed populations. Where weeds are aggregated, densities measured at random locations are not independent, but rather spatially related or autocorrelated. Geostatistical methods were used to describe and map nonrandom distribution and variation of shoot density across ten well established patches of Canada thistle, a perennial weed, in a 65 hectare notillage soybean field in Moody county, South Dakota in 1996. Canada thistle densities were determined by counting the number of shoots present in a 20 by 50 …