A5080091181- Weed Control and Herbicide Applications
- Pesticide and Herbicide Environmental Studies
- Agronomic Practices and Intercropping Systems
- Soybean genetics and cultivation
- Legume Nitrogen Fixing Symbiosis
- Genetically Modified Organisms Research
- Allelopathy and phytotoxic interactions
- Plant tissue culture and regeneration
- Crop Yield and Soil Fertility
- Nematode management and characterization studies
- Plant and animal studies
- Biological Control of Invasive Species
- Seed Germination and Physiology
- Pesticide Residue Analysis and Safety
- Turfgrass Adaptation and Management
- Soil Carbon and Nitrogen Dynamics
- Agricultural Innovations and Practices
- Insect Resistance and Genetics
- Plant Surface Properties and Treatments
- Agriculture, Plant Science, Crop Management
- Plant Disease Management Techniques
- CRISPR and Genetic Engineering
- Plant Parasitism and Resistance
- Fungal Plant Pathogen Control
- Botany, Ecology, and Taxonomy Studies
Iowa State University
2015-2025
Colorado State University
1997-2016
University of Nebraska–Lincoln
2009
University of Delaware
2007
State Library of Iowa
2006
Directorate of Weed Research
1997-2003
University of Missouri
1995
Herbicides have been the principal means of weed control in developed countries for approximately 50 yr because they are most cost-effective method. Such general use herbicides has resulted resistance to herbicides, which continues be a growing problem. Within past decade, evolution once-dominant herbicide glyphosate major concerns about future ability weeds many crop systems. Moreover, species evolved multiple mechanisms action. Given dearth new with novel action, it appears inevitable that...
Understanding abundance and distribution of weed species within the landscape an agroecosystem is important goal for science. Abundance a measure number or frequency individuals in area. Distribution geographical range species. The study population's helpful determining how population changes over time response to selective pressures applied by our agronomic practices. Accurate estimates, however, these two key variables are very if we manage agricultural land both productivity biodiversity.
Transformation of soybean [ Glycine max (L.) Merr.] with a gene encoding glyphosate‐tolerance 5‐enolpyruvylshikimate‐3‐phosphate synthase enzyme from Agrobacterium sp. strain CP4 resulted in the development glyphosate‐tolerant line 40‐3‐2. Glyphosate ( N ‐phosphonomethyl glycine) is active ingredient Roundup herbicide. Line 40‐3‐2 was yield tested at 17 locations 1992,23 1993, and 18 1994. At those locations, broadcast applications glyphosate various rates were made over or its derivatives...
A phone survey was administered to 1,195 growers in six states (Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina). The measured producers' crop history, perception of glyphosate-resistant (GR) weeds, past present weed pressure, tillage practices, herbicide use as affected by the adoption GR crops. This article describes changes practice reported survey. a cropping system resulted large increase percentage using no-till reduced-till systems. Tillage intensity declined more...
Horseweed emergence and survival were evaluated in no-tillage soybean corn at Rosemount, MN, Ames, IA, from the fall of 1992 through summer 1995. Most horseweed both locations emerged fall. Winter fall-emerged seedlings ranged 59 to 91%. Timing extent spring varied by year location. Spring 5 32% total emergence, with greater Rosemount than Ames. Emergence occurred as late early June May Results indicated that may emerge well into growing season, should be considered weed management systems...
A telephone survey was conducted with growers in Iowa, Illinois, Indiana, Nebraska, Mississippi, and North Carolina to discern the utilization of glyphosate-resistant (GR) trait crop rotations, weed pressure, tillage practices, herbicide use, perception GR weeds. This paper focuses on results regarding decisions made during 2005 cropping season. Less than 20% respondents fall applications. The most frequently used herbicides for applications were 2,4-D glyphosate, these also preplant...
Corn and soybean growers in Illinois, Indiana, Iowa, Mississippi, Nebraska, North Carolina, as well cotton Mississippi were surveyed about their views on changes problematic weeds weed pressure cropping systems based a glyphosate-resistant (GR) crop. No using GR system for more than 5 yr reported heavy pressure. Over all investigated (continuous soybean, continuous cotton, corn/GR soybean/non-GR crop, corn/non-GR crop), 0 to 7% of survey respondents greater after implementing rotations...
Dramatic growth in herbicide-resistant (HR) weeds the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR move across boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation manage such effectively. We investigate scope for cooperative management using responses national survey on weed issues test recursive model of three preconditions collective action: (1)...
Abstract Field experiments were conducted in soybeans ( Glycine max L.) to determine the effects of a cereal rye Secale cereale cover crop (CC), two CC termination timings (TTs), and four herbicide programs (HP) on emergence, biomass, seed production waterhemp Amaranthus tuberculatus [Moq.] J.D. Sauer) horseweed Erigeron canadensis L.). The early occurred seven days (d) before soybean planting, late 12 after planting. presence CC, regardless TT, reduced emergence by 39% 44% compared no at 5...
Abstract Foliar-applied postemergence applications of glufosinate are often applied to glufosinate-resistant crops provide nonselective weed control without significant crop injury. Rainfall, air temperature, solar radiation, and relative humidity near the time application have been reported affect efficacy. However, previous research may not captured full range weather variability which be exposed prior or following application. Additionally, climate models suggest more extreme will become...
A survey of farmers from six U.S. states (Indiana, Illinois, Iowa, Nebraska, Mississippi, and North Carolina) was conducted to assess the farmers' views on glyphosate-resistant (GR) weeds tactics used prevent or manage GR weed populations in genetically engineered (GE) crops. Only 30% thought were a serious issue. Few field tillage and/or using non-GR crop rotation with crops would be an effective strategy. Most did not recognize role that recurrent use herbicide plays evolution resistance....
Waterhemp is an increasingly problematic weed in the U.S. Midwest, having now evolved resistances to herbicides from six different site-of-action groups. Glyphosate-resistant waterhemp Midwest especially concerning given economic importance of glyphosate corn and soybean production. Amplification target-site gene, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) was found be mechanism resistance Palmer amaranth, a species closely related waterhemp. Here, relationship between EPSPS gene...
Resistance has evolved to single transgenic traits engineered into crops for arthropod and herbicide resistances, can be expected evolve the more recently introduced pathogen resistances. Combining transgenes against same target pest is being promoted as solution problem. This will work if used pre-emptively, but where resistance one member of a stack, should easily second gene in most cases. We propose elaborate criteria that could evaluate value stacked management. Stacked partners must:...
Research was initiated to determine (a) whether a common waterhemp population resistant acetolactate synthase (ALS) inhibiting herbicides, (b) the percentage of that ALS-inhibitor resistant, (c) resistance mechanism, and (d) effectiveness whole plant assay detect resistance. confirmed in near Davis City, IA. The City cross both imidazolinone sulfonylurea but not lactofen. Approximately 10% sensitive rate imazaquin 4 times normal field rate. isolated ALS much less primisulfuron inhibition...
Common waterhemp, giant foxtail, and velvetleaf seed germination in response to temperature was studied with a two-way thermogradient plate. Seeds were maintained under dark wet conditions at 4 C for 12 wk, seeds scarified before the experiments conducted. The germinated 25 different treatments. Minimum optimum temperatures approximately 8 24 C, respectively. Temperature alternation did not affect of this species. minimum 10 common waterhemp 14 foxtail. foxtail occurred but variable...
Abstract Cultural practices used for crop management can influence numbers of weed seeds in the soil seed bank. This paper reports results field experiments conducted 6 yr to examine changes due practices. We evaluated effect tillage, herbicide application, and interrow cultivation on a soybean [ Glycine max (L.) Merr.]/corn ( Zea mays L.) rotation continuous corn. Treatment effects were more repetitive soybean/corn than Foxtails Setaria spp.) class most affected by treatments. Weed...
Growth, seed production, and dormancy of velvetleaf in response to shading were evaluated the field. Velvetleaf plant height, leaf number, number branches, dry weight decreased linearly with increasing shade. No differences observed for leaves, or branches/plant when plants shaded 30% not throughout growing season. However, 76% shade treatment reduced height (1984 only), stem weight. These reductions greater 1984 than 1985 except that by 88% each year. The capsules seeds/plant levels, while...
Transfer of herbicide resistance genes between crops and weeds is relatively well documented; however, far less information exists for weed-to-weed interactions. The hybridization the weedy diploids Conyza canadensis (2n = 18) C. ramosissima was investigated by monitoring transmission allele conferring to N-phosphonomethyl glycine (glyphosate). In a multivariate quantitative trait analysis, we described phylogenic relationship plants, whereas tested seed viability assess potential...