A5017906453- Weed Control and Herbicide Applications
- Agronomic Practices and Intercropping Systems
- Crop Yield and Soil Fertility
- Soil Carbon and Nitrogen Dynamics
- Legume Nitrogen Fixing Symbiosis
- Soybean genetics and cultivation
- Pesticide and Herbicide Environmental Studies
- Bioenergy crop production and management
- Ecology and Vegetation Dynamics Studies
- Allelopathy and phytotoxic interactions
- Plant tissue culture and regeneration
- Plant and animal studies
- Plant nutrient uptake and metabolism
- Nematode management and characterization studies
- Climate change impacts on agriculture
- Rice Cultivation and Yield Improvement
- Genetically Modified Organisms Research
- Plant Water Relations and Carbon Dynamics
- Growth and nutrition in plants
- Greenhouse Technology and Climate Control
- Genetics and Plant Breeding
- Plant Parasitism and Resistance
- Genetic Mapping and Diversity in Plants and Animals
- Plant responses to elevated CO2
- Plant Pathogens and Fungal Diseases
University of Nebraska–Lincoln
2015-2024
University of Wisconsin–Madison
2011
University of Minnesota
1996-2010
Montana State University
1989
Cover crops (CCs) can provide multiple soil, agricultural production, and environmental benefits. However, a better understanding of such potential ecosystem services is needed. We summarized the current state knowledge CC effects on soil C stocks, erosion, physical properties, water, nutrients, microbial weed control, crop yields, expanded uses, economics highlighted research needs. Our review indicates that CCs are multifunctional. increase organic stocks (0.1–1 Mg ha −1 yr ) with...
The critical period for weed control (CPWC) is a in the crop growth cycle during which weeds must be controlled to prevent yield losses. Knowing CPWC useful making decisions on need and timing of achieving efficient herbicide use from both biological economic perspectives. An increase herbicide-tolerant crops, especially soybean resistant glyphosate, has stimulated interest concept CPWC. Recently, several studies examined this glyphosate-resistant corn across midwestern United States....
Accurate measurement of crop growth and radiation use efficiency (RUE) under optimal conditions is required to predict plant dry matter accumulation grain yield near the genetic potential. Research was conducted quantify biomass leaf area index (LAI) accumulation, extinction coefficient, RUE maize ( Zea mays L.) growth. Maize grown in two environments over five growing seasons (1998–2002). Total aboveground at maturity ranged from 2257 g m −2 1998 2916 2001; values that are considerably...
The critical period for weed control (CPWC) is the in crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. Field studies were conducted 1999 and 2000 eastern Nebraska evaluate influence of nitrogen application on CPWC dryland corn competition with a naturally occurring population. Nitrogen fertilizer was applied at rates equivalent 0, 60, 120 kg N ha−1. A quantitative series treatments both increasing duration interference length weed-free imposed...
Previous studies have demonstrated benefits of individual cover crop species, but the value diverse mixtures has received less attention. The objectives this research were to determine effects spring‐sown mixture diversity and mechanical termination method on and/or cash productivity, soil moisture N, profitability in an organic cropping system. An experiment was conducted between 2009 2011 near Mead, NE, where two (2CC), four (4CC), six (6CC), eight (8CC) or a summer annual weed included...
Achieving agronomic and environmental benefits associated with cover crops often depends on reliable establishment of a highly productive crop community. The objective this study was to determine if mixtures can increase productivity stability compared single species crops, identify those components most active in contributing or detracting from mixture productivity. A rainfed field experiment conducted near Mead, NE, 2010 2011. Eight individual (in either the Brassicaceae [mustard] Fabaceae...
First- and second-year seedbank emergence of 23 summer annual weed species common to U.S. corn production systems was studied. Field experiments were conducted between 1996 1999 at the Iowa State University Johnson Farm in Story County, Iowa. In fall again 1997, 1,000 seeds for most planted plastic crates. Seedling counted weekly a 2-yr period following seed burial (starting early spring). Soil temperature 2 cm depth estimated using soil moisture model software (STM ). The Weibull function...
The crop-weed interference relationship is a critical component of bioeconomic weed management models. Multi-year field experiments were conducted at five locations to determine the stability corn-velvetleaf relationships across years and locations. Two coefficients (I A) hyperbolic equation estimated for each data set using nonlinear regression procedures. I A represent percent corn yield loss as velvetleaf density approaches zero, maximum loss, respectively. coefficient was stable two...
Competitive outcome between crops and weeds is affected by partitioning of new biomass to above- belowground plant organs in response nutrient supply. This study determined the fraction partitioned roots vs. shoots corn velvetleaf nitrogen (N) Pots measuring 28 cm diam 60 deep were embedded ground each contained one either or velvetleaf. Each received three N treatments: 0, 1, 3 g applied as ammonium nitrate 2001, 2, 6 2002. Measurements total made at 10 sampling dates during growing season....
The diversity-productivity, diversity-invasibility, and diversity-stability hypotheses propose that increasing species diversity should lead, respectively, to increased average biomass productivity, invasion resistance, stability. We tested these three in the context of cover crop mixtures, evaluating effects mixture on aboveground biomass, weed suppression, Twenty forty treatments were replicated or four times at eleven sites using eighteen representing each from six pre-defined functional...
Abstract Gene flow is an important component in evolutionary biology; however, the role of gene dispersal herbicide-resistant alleles among weed populations poorly understood. Field experiments were conducted at University Nebraska-Lincoln to quantify pollen-mediated (PMGF) from glyphosate-resistant (GR) -susceptible (GS) common waterhemp using a concentric donor-receptor design. More than 130,000 plants screened and 26,199 confirmed resistant glyphosate. Frequency all distances, directions,...
Abstract Nitrogen (N) supply can limit the yields of soybean [ Glycine max (L.) Merr.] in highly productive environments. To explore physiological mechanisms underlying this limitation, seasonal changes N dynamics, aboveground dry matter (ADM) accumulation, leaf area index (LAI) and fraction absorbed radiation ( f APAR) were compared crops relying only on biological 2 fixation available soil (zero‐N treatment) versus receiving fertilizer (full‐N treatment). Experiments conducted seven...
Abstract Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, climate. Cereal rye (S ecale cereale ) is the most common winter United States its hardiness, low seed cost, high production. We compiled data on cereal metrics, properties across eastern half of States. The dataset includes a total 5,695 observations 208 site-years between...
Weed competitiveness can be quantified with the concept of competitive index (CI), a relative scale weed competitiveness. Field studies were conducted in 2002 and 2003 northeastern southeastern Nebraska to evaluate influence soybean row spacing emergence time on major species soybean. Ten seeded spaced 19 76 cm apart at planting, emergence, first trifoliate leaf stages Total dry matter (TDM), plant volume, percent yield loss arbitrarily selected as base for determining CI each species....
Cover crops can provide many benefits in agroecosystems, including the opportunity for improved weed control. However, suppressive potential of cover may depend on species (or mixture species) chosen, and method crop termination residue management. The objective this study was to determine effects mechanical biomass density, relative yield an organic cropping system. A field experiment conducted from 2009 2011 near Mead, NE, where spring-sown mixtures two, four, six, eight were included a...
Common waterhemp is one of the most commonly encountered and troublesome weeds in midwestern United States. It well known that water stress adversely affects crop growth yield; however, effects on weed seed production are poorly understood. The objective this study was to determine degree duration growth, development, fecundity two common biotypes greenhouse experiments conducted at University Nebraska–Lincoln. No difference observed between response stress; therefore, data were combined....
Despite the potential to increase soil organic matter, cycle nutrients, and suppress weeds, there is a concern that cover crops (CCs) water use negatively impacts subsequent in water-limited environments. Cover crop management practices such as planting termination timing may mitigate detrimental of CCs semi-arid cropping systems. To determine effects under environments, we evaluated total CC biomass produced fall spring, content during maize growing season, weed density biomass, residue,...
A simulation model of rice-barnyardgrass competition for light was used two management applications. First, simulations using 47 weather data sets from four locations in Asia were conducted to evaluate the influence variation on single year economic threshold densities barnyardgrass. Second, rapid leaf area expansion and index evaluated as potential indicators improved rice competitiveness tolerance Influence thresholds small under assumption that only. Increasing early rate reduced...
Abstract Crops that better tolerate weed competition or preempt resources from weeds may reduce dependence on herbicides for control and benefit an integrated management program. Irrigated field experiments were conducted to identify morphological traits of corn ( Zea mays L.) enhance its tolerance suppressive ability. Two old (circa 1940) two modern hybrids grown in mixture with five target densities velvetleaf Abutilon theophrasti Medik.) years. Corn height leaf area index (LAI) measured...
An improved understanding of the effects nitrogen (N) on crop–weed interactions is needed for development integrated weed management systems where responsible use N fertilizers considered. Field experiments conducted in 1999 and 2000 at two locations eastern Nebraska quantify increasing duration interference corn growth development. A naturally occurring population weeds was allowed to compete with crop lengths time three rates application (0, 60, 120 kg ha−1). Weed withholding applied...
Weed seedbanks have been studied intensively at local scales, but to date, there no regional-scale studies of weed seedbank persistence. Empirical and modeling indicate that reducing persistence can play an important role in integrated management. Annual 13 summer annual species was from 2001 through 2003 eight locations the north central United States one location northwestern States. Effects seed depth placement, tillage, abiotic environmental factors on were examined regression...
Background Despite the decades-long use of Bacillus atrophaeus var. globigii (BG) as a simulant for biological warfare (BW) agents, knowledge its genome composition is limited. Furthermore, ability to differentiate signatures deliberate adaptation and selection from natural variation lacking most bacterial agents. We characterized lineage BGwith long history BW operations, focusing on classical bacteriological markers, metabolic profiling whole-genome shotgun sequencing (WGS). Results...