Source: IOWA STATE UNIVERSITY submitted to NRP
SEED BIOLOGY IN AGROECOLOGY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1002803
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Apr 15, 2014
Project End Date
Apr 14, 2019
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
IOWA STATE UNIVERSITY
2229 Lincoln Way
AMES,IA 50011
Performing Department
Agronomy
Non Technical Summary
In 2005, the global market for seeds was estimated to be $21 billion. Nearly all of the major seed companies have significant production and/or research facilities in Iowa. In total, this industry and farmers demand research and extension information on topics including seed production, harvesting, drying, storage, quality assurance, cultivar development, and seed physiology/molecular biology. Obviously, this industry is critical to agriculture worldwide as well as a critical component of the Iowa economy. Iowa State University must be prepared, through a strong research base, to participate in the dialogue regarding the development and application of new seed technologies. Furthermore, with greater adoption of conservation tillage practices, early planting, increasing interest in biofuels, and efforts to diversify cropping systems, agronomic problems and opportunities will evolve rapidly. Seeds impact agronomic issues ranging from crop establishment to weed management, and are impacted by efforts to change grain composition. Seeds are important to agriculture in other ways as well. The size and nature of the seed banks subtending grazing areas and the germination parameters of individual species are crucial components of agriculture productivity and an important element of the resilience of the system. In a similar fashion, the nature of seed banks comprised of weed species are a critically important component of the yearly weed pressures in crops. The genetic control of dormancy development, perpetuation, and dissolution are critical aspects of integrated weed management programs. Thus, it is important to understand seed bank dynamics. Weed seed leave seed banks by several paths. For instance, seed consumption by rodents, insects, and other animals that live in crop fields can regulate weed population density and may promote reductions in herbicide use, thereby reducing crop protection costs and contributing to improvements in environmental quality. This research project will identify crop types and tillage practices that maximize weed seed consumption by seed predators during the period from weed seed dispersal in the fall until crop planting the following spring. Therefore, seeds are a fundamental agronomic input, form the basis of current and future industries, and are an important component of efforts to improve the sustainability of agriculture via the application of integrated, ecologically based management systems. Understanding seed performance from the basic biological to the ecological scale is important to the future success of agriculture as it relates to food, feed, fiber, and fuel. The research will: further our understanding of seed biology as it relates to seed development and maturation, germination, dormancy, and vigor and deterioration; define seed bank dynamics to improve the efficacy of integrated weed management systems; and characterize the influence of various abiotic stresses on subsequent seed and seedling performance.
Animal Health Component
45%
Research Effort Categories
Basic
30%
Applied
45%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2031510102010%
2031510105010%
2062300114010%
2051060114025%
2042410105025%
2042410104010%
2132410106010%
Knowledge Area
206 - Basic Plant Biology; 204 - Plant Product Quality and Utility (Preharvest); 205 - Plant Management Systems; 203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants; 213 - Weeds Affecting Plants;

Subject Of Investigation
1060 - Kiwi; 1510 - Corn; 2410 - Cross-commodity research--multiple crops; 2300 - Weeds;

Field Of Science
1040 - Molecular biology; 1060 - Biology (whole systems); 1140 - Weed science; 1020 - Physiology; 1050 - Developmental biology;
Goals / Objectives
1) Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination. 2) Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa. 3) Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators. 4) Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds. 5) Study seed germination and seedling development under stressful conditions. 6) Study the acquisition of desiccation tolerance in select orthodox seed species. 7) Identify soil, plant, climate, and management factors influencing final stand density of red clover or alfalfa intercropped in winter cereal grains.
Project Methods
Maize seed with differential cold tolerance will be used to assess variation for cold tolerance traits which will include basic physiological measurements as indicated by growth and development parameters. To evaluate freezing tolerance, inbred seeds with different seed composition will be harvested at different moisture percentages. Relationships between seed composition and freezing tolerance will be evaluated. Total RNA will be purified from seed powder and seedlings to identify frost-related, differentially expressed sequences using Quantitative reverse transcription polymerase chain reaction PCR (qRT-PCR). Red clover or alfalfa will be frost-seeded into existing winter cereal grain stands by farmers. Boundaries legume seeded areas will be collected on-site with a GPS unit. Aerial canopy images will be taken when the cereal grain canopy density is greatest. Images of the legume stand will be collected about six weeks after cereal grain harvest. Arial imagery data will be analyzed relative to the success of legume establishment. Georeferencing provides for spatial analysis and correlations will be made between legume stand density and the cereal grain and legume imagery. These data will also be analyzed relative to soil properties and equipment patterns. Seed of Vicia sativa L. will be grown in greenhouses to study dormancy. Seeds will be harvested at five development stages, dried at various rates and then stored at 5°C. Seeds for soluble sugar analysis will be frozen and stored at -20°C. Standard germination will be conducted as described by ISTA. Relationships between composition and germination will be investigated.

Progress 04/15/14 to 04/14/19

Outputs
Target Audience:Seed scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate students trained, professional society meetings attended, presentations given, and manuscripts and articles written. ? How have the results been disseminated to communities of interest?Professional meetings, grower meetings, scientific talks, refereed journal articles. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Overall impact statement: Seed germination and stand establishment are the foundation of successful production of many crop species. Seed quality overall and seed vigor are critical elements to achieving optimal stands. The effects of stand failure can include significant monetary losses and increased expenses. Alternatively, seed dormancy and other biological variables influence weed seed production and weed seed banks in production systems. Seed biology affects other attributes, including planting seasons, end-use, and the need to apply some chemical seed treatments. This research integrated biological investigations from basic biology to the organismal level. Lack of diversity in the agricultural landscape has contributed to a decline in pollinators, including the monarch butterfly. The lack of pollinators negatively impacts seed production. This research evaluated low-cost approaches to enhance the diversity of areas outside of crop fields. While sub-lethal herbicide rates increased forb establishment in perennial sods, the suppression increased the likelihood of invasion by weedy species. We furthered our understanding of the role of genetics and environment on physiological seed quality, further elucidated some of the QTLs associated with low-temperature stress germination. Work accomplished in this project has also clarified how environmental variables interact with weed seed germination/dormancy to enhance weed population control. Our research into genome fluidity in soybean seed proves, for the first time, that new genotypic and phenotypic soybean forms can occur in one or two generations as a result of environmental stress. The completed studies explain why some chlorophyll deficient plants can survive while others die. The studies also report on stress-induced phenotypic variation observed in soybeans growing under different environmental stresses. Understanding these genetic, cytological, and physiological processes in mutants will help scientists understand the normal function of a healthy plant. Objective 1... Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination We are collaborated (and continue to collaborate) with two other labs using metabolomic techniques to continue to refine our search for metabolic processes, and ultimately genes, associated with cold tolerance. We produced our first set of seeds from varieties putatively with increased tolerance to cold stress. The metabolism of seeds of resistant lines during low-temperature germination will be compared to that of the control lines, MO17 and B73. Objective 2... Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa Our research team isolated and characterized the Aconitase 4 gene. Aconitase catalyzes the irreversible isomeration of citrate and isocitrate in the Krebs cycle. Using the chlorophyll-deficient mutants yellow-viable and yellow-lethal soybean seed originating from our stress research, we also were able to map the genetic differences between these mutants and the normal green phenotype. Both these genes are essential for energy synthesis and photosynthesis. We are exploring the effect of plant defoliation on seed corn viability and vigor. Phenotypic variation in soybean was observed under different environmental stress factors. Some stress factors induced greater phenotypic variation than others. Some of these changes were fixed in subsequent generations. We also examined soybean seed quality changes associated with disease pressure (biotic stress). Soybean plants grown under Sudden Death Syndrome (SDS) pressure produced fewer seed. However, seed viability and vigor of the seed produced remained good, and protein content increased when compared to the non-infected control. Our research also mapped a total of 168 QTL for seed quality over two populations and 105 of these OTLs were novel. We also identified 14 QTL for seed vigor, making this research the first to identify soybean seed vigor QTLs. Bacteriophages were capable of controlling Goss's Wilt causal bacteria (Clavibacter michiganense subsp. nebraskense) in corn. Seed were artificially infected and coated with the bacteriophages. The formation of a dead zone around these artificially infected and coated seed corn coated plated on media evidenced the efficacy of the coating in reducing bacterial load. Objective 3... Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators Studies were completed to assess the impact of crop rotation on seed predation of important Midwestern weeds. Objective 4... Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds Research to determine the impact of the maternal environment and genetic background on seed quality (i.e., viability) and dormancy was conducted. Specifically, the heritability of multiple herbicide resistance(s) in Amaranthus tuberculatus has been assessed. Furthermore, the fecundity of lines of A. tuberculatus and seed quality have been investigated. The measurement of inherent fitness costs attributable to the multiple herbicide resistance(s) has been initiated. The potential hybridization between A. tuberculatus and A. palmeri is being investigated with a focus on seed quality. Objective 5... Study seed germination and seedling development under stressful conditions Our research team is evaluating the effects of plasma-activated water on soybean and corn seed germination and seedling performance. We are also evaluating the effect of seed uniformity on field emergence in corn. Methods for suppressing perennial grasses in order to enhance establishment of native forbs were evaluated. While sub- lethal herbicide rates increased forb establishment, the suppression increased the likelihood of invasion by weedy species. Objective 6... Study the acquisition of desiccation tolerance in select orthodox seed species Seed desiccation tolerance of defoliated corn plants is on-going. Early defoliation in seed corn production fields reduces the photosynthetic area of the plant and reduces source carbohydrates availability for seed formation. Undergraduate students' research showed seed physiological energy was unchanged by defoliation. Visiting graduate student, Everton Zambiazzi, used microscopy to determine that seed corn cellular reorganization of defoliated plants was unchanged while undergoing acquisition of desiccation tolerance. This research determined, for the first time, that the seed corn industry may stop the normal development of the seed before physiological maturity without jeopardizing seed quality. High seed quality is essential to the success of a new crop in farmers' fields. Objective 7... Identify soil, plant, climate, and management factors influencing final stand density of red clover or alfalfa intercropped in winter cereal grains No progress

Publications


    Progress 10/01/17 to 09/30/18

    Outputs
    Target Audience:Rural landowners, farmers, conservation organizations, seed producers, students, general public. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The seed quality research has trained and graduated five (5) MS students in Agronomy and three (3) in Seed Technology and Business. A PhD student is currently in the program.Multiple outreach and continuing education opportunities were provided for seed industry personnel. The training included a guest lecture by PI Goggi at the prestigious Monsanto Fellows Symposium in Saint Louis, MO. How have the results been disseminated to communities of interest?Through publications in peer reviewed journals, field days, professional improvement workshops, web and other mass media report. What do you plan to do during the next reporting period to accomplish the goals?The projects are on-going.

    Impacts
    What was accomplished under these goals? Overall impact statement: Research into genome fluidity in soybean seed proves, for the first time, that new genotypic and phenotypic soybean forms can occur in one or two generations as a result of environmental stress. The completed studies explain why some chlorophyll deficient plants can survive while others die. The studies also report on stress-induced phenotypic variation observed in soybean growing under different environmental stresses. Understanding these genetic, cytological, and physiological processes in mutants, will help scientists understand the normal function of a healthy plant. Breeder's choices significantly impact seed quality characteristics. These seed quality changes might be detrimental to seedling growth and establishment in farmers' fields. It is essential to evaluate these seed characteristics for the advancement of new cultivars and for the success of new parental lines in new hybrid development and release. The use of organic and chemical seed treatments and their impact on seed quality are of vital importance to farmers and stakeholders. The indiscriminate use of antibiotics has promoted the development of "super bugs" or antibiotic-resistant bacteria.Natural enemies, such as bacteriophages, may be a great tool for antibiotic-resistance management. Lack of diversity in the agricultural landscape has contributed to a decline in pollinators, including the monarch butterfly. Research evaluated low-cost approaches to enhance diversity of areas outside of crop fields. While sub-lethal herbicide rates increased forb establishment in perennial sods, the suppression increased the likelihood of invasion by weedy species.Establishment of forbs will increase the ecosystem services provided by these areas. Objective 1) Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination. We published work on mesocotyl elongation in maize native to the Southwestern US which could help in the development of genotypes better able to emerge from deep planting. Also, we are initiating cold tolerance to germination and seedling growth studies in a mapping population in collaboration with a maize geneticist. This has the potential to help us further understand the genes responsible for low temperature stress. Objective 2) Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa. Phenotypic variation in soybean was observed under different environmental stress factors.Some stress factors induced greater phenotypic variation than others. Some of these changes were fixed in subsequent generations.We also examined soybean seed quality changes associated with disease pressure (biotic stress).Soybean plants grown under Sudden Death Syndrome (SDS) pressure produced fewer seed.However, seed viability and vigor of the seed produced remained good, and protein content increased when compared to the non-infected control. Our research also mapped a total of 168 QTL for seed quality over two populations and 105 of these OTLs were novel. We also identified 14 QTL for seed vigor, making this research the first to identify soybean seed vigor QTLs. Bacteriophages were capable of controlling Goss's Wilt causal bacteria (Clavibacter michiganense subsp. nebraskense) in corn.Seed were artificially infected and coated with the bacteriophages.The formation of a dead zone around these artificially infected and coated seed corn coated plated on media evidenced the efficacy of the coating in reducing bacterial load. Objective 3) Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators. Nothing to report this period Objective 4) Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds. No report this period Objective 5) Study seed germination and seedling development under stressful conditions. Our research team is evaluating the effects of plasma-activated water on soybean and corn seed germination and seedling performance. We are also evaluating the effect of seed uniformity on field emergence in corn. Methods for suppressing perennial grasses in order to enhance establishment of native forbs were evaluated. While sub-lethal herbicide rates increased forb establishment, the suppression increased the likelihood of invasion by weedy species. Objective 6) Study the acquisition of desiccation tolerance in select orthodox seed species. Nothing to report this period Objective 7) Identify soil, plant, climate, and management factors influencing final stand density of red clover or alfalfa intercropped in winter cereal grains. Nothing to report this period

    Publications

    • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Lizotte-Hall, S. 2018. Investigations into the function of common milkweed (Asclepias syriaca) in the agricultural landscape. Iowa State University M.S. Thesis.
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Simma, B., A. Polthanee, A. S. Goggi, B. Siri, A. Promkhambut, P. C. Caragea. 2017. Wood vinegar seed priming improves yield and suppresses weeds in dryland direct-seeding rice under rainfed production. Agronomy for Sustainable Development 37: 56.
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Bousselot, J.M, Muenchrath, D., Knapp, A.D., and Reeder, J.D. 2017. Emergence and Seedling Characteristics of Maize Native to the Southwestern US. Amer. J. Plant. Sci.:1304-1318
    • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Kimmelshue, Chad Louis. 2017. Bioactive seed coatings against Goss⿿s wilt using stabilized bacteriophages in polymers. Iowa State University. MS Thesis.
    • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Knight, Josh. 2017. Effect of soybean sudden death syndrome on seed quality and agronomic trait QTLs. Iowa State University. MS Thesis.


    Progress 10/01/16 to 09/30/17

    Outputs
    Target Audience:Growers, Students, Scientists, industry scientists and field personnel Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Obj 2) Grace Kaudzu successful completed her PhD program and has returned home to her government position as seed regulatory officer for Malawi. Obj 6) Two undergraduate students, Katharina Wigg and Ashley Dean, completed their degrees and are now in graduate school at UW at Madison and ISU. Everton Zambiazzi, a visiting graduate student from Brazil, conducted research on this project. Research by 2015-16 visiting graduate student from Thailand was published in 2017. How have the results been disseminated to communities of interest?Oral presentations, posters, and peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?We plan to continue investigations on the active objectives as dictated by research already analyzed and reported here.

    Impacts
    What was accomplished under these goals? Overall impact statement: Our group continues work to understand how genotype and environment influence crop performance especially during germination and early seedling growth. Establishing a uniform and vigorous stand of seedlings forms the platform upon which yield is built. Understanding the impacts of environmental stress, the role of aconitase in energy formation, the impact of defoliation on seed quality and delineating the development of herbicide resistance and seed dormancy will provide the basis for improving agriculture production stability in the fact of environmental stresses such as those experienced as the result of climate change. Objective 1) Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination. We continue our interest in cold tolerance and will likely be collaborating with another lab this fall using genomic techniques to continue to refine our search for genes involved in cold tolerance. This, of course, is a logical continuation of our QTL work. Collaborations with a plant breeder on early sunflower root development may result in improved sunflower genotypes. Objective 2) Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa. Our research team has isolated and characterized the Aconitase 4 gene. Aconitase catalyzes the irreversible isomeration of citrate and isocitrate in the Krebs cycle. Using the chlorophyll-deficient mutants yellow-viable and yellow-lethal soybean seed originating from our stress research, we also were able to map the genetic differences between these mutants and the normal green phenotype. Both these genes are essential for energy synthesis and photosynthesis. We are exploring the effect of plant defoliation on seed corn viability and vigor. Objective 3) Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators. Nothing to report this period. Objective 4) Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds. Research to determine the impact of the maternal environment and genetic background on seed quality (i.e., viability) and dormancy continues. Results indicate that herbicide resistances are dominant or semi-dominant traits. As additional herbicide resistance traits are inherited in waterhemp populations, previously inherited traits are conserved even when the specific herbicides that selected for the resistances are no longer used. Furthermore, the fecundity of lines of A. tuberculatus as well as seed quality has been investigated. When compared to a known herbicide-sensitive waterhemp population, herbicide-resistant waterhemp populations are similarly fecund and there is no negative impact on seed quality. Of interest is the measurement of inherent fitness costs attributable to the multiple herbicide resistance(s) has been initiated. Initial findings support the fact that waterhemp with evolved herbicide resistance(s) do not exhibit a fitness penalty when compared to a herbicide-sensitive waterhemp population. The potential hybridization between A. tuberculatus and A. palmeri is being investigated with a focus on seed quality. Initial results do not indicate that hybridization between A. turbuculatus and A. palmeri occurs. Thus, there is no seed production. However, it is possible that seeds produced by apomixes will have seed quality problems. This investigation is underway. Objective 5) Study seed germination and seedling development under stressful conditions. Our research team has determined soybean plant damage due to the detrimental effect of toxic nanoparticles in soils. Objective 6) Study the acquisition of desiccation tolerance in select orthodox seed species. Early defoliation in seed corn production fields reduces the photosynthetic area of the plant and reduces source carbohydrates availability for seed formation. Undergraduate students' research showed seed physiological energy was unchanged by defoliation. Visiting graduate student, Everton Zambiazzi, used microscopy to determine that seed corn cellular reorganization of defoliated plants was unchanged while undergoing acquisition of desiccation tolerance. This research determined, for the first time, that seed corn industry may stop the normal development of the seed before physiological maturity without jeopardizing seed quality. High seed quality is essential to the success of a new crop in farmers' fields. Manuscript in preparation. Objective 7) Identify soil, plant, climate, and management factors influencing final stand density of red clover or alfalfa intercropped in winter cereal grains. No activity in this are for this period

    Publications

    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Owen, Micheal D.K. 2016. Diverse approaches to herbicide-resistant weed management. Weed Sci. 64 (sp1): 570-584
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Gressel, Jonathan, Aaron Gassman and Micheal Owen. 2017. How well will stacked transgenic pest/herbicide resistances delay pests from evolving resistance? Pest Manag. Sci. 73(1):22-34
    • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Kruse, Raymond, Ajay Nair and Micheal Owen. 2016. Fall cover crop influence on weed population density, soil nitrogen and potato yield. Hort. Sci. (submitted).
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mueller, T., E. Parker, L. Steckel, S. A. Clay, M. Owen, W. Curran, R. Currie, R. Scott, C. Sprague, D. Stephenson, D. Miller, E. Prostko, W. Grichar, J. Martin, L. Krutz, K. Bradley, M. Bernards, P. Dotray, S. Knezevic, V. Davis, R. Klein. 2016. Enhanced Atrazine Degradation is Widespread Across the United States. Pest Manag Sci. published on line 19 April 2017 (10.1002/ps.4566).
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Priester, J.H., S. C. Moritz, K. Espinosa, Y. Ge, Y. Wang, R. M. Nisbet, J. P. Schimel, A.S. Goggi, J. L. Gardea-Torresdey, and P. A. Holden. 2017. Damage assessment for soybean cultivated in soil with either CeO2 or ZnO manufactured nanomaterial. Science of The Total Environment 579: 1756-1768.
    • Type: Journal Articles Status: Published Year Published: 2017 Citation: Coleman, Z., J. Boelter, K. Espinosa, A. S. Goggi, R. G. Palmer, and D. Sandhu. 2017. Isolation and characterization of Aconitate hydratase 4 (Aco4) from soybean. Canadian Journal of Plant Science 97(4): 684-691
    • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Owen, Micheal D.K. 2015. Weed management update for 2016 and other thoughts. Proc.Integrated Crop Management Conference. Iowa State University. 27:91-96
    • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Owen, Micheal D.K. 2016. Weed management for 2017 and beyond. Proc. Integrated Crop Management Conference. Iowa State University. 28:85-92
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Owen, Micheal D.K. 2017. Weed management for 2018 and beyond: the more things change. Proc. Integrated Crop Management Conference. Iowa State University. 29:77-88
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Kohlhase, D., M. Owen and M. Graham, 2017. De novo transcriptome assembly and analysis of 4-hydroxyphenylpyruvate dioxygenase inhibitor herbicide resistance in Amaranthus tuberculatus. Abs. WSSA. 57:182
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Norsworthy, J. K., M. Owen, J. Gunsolus, W. J. Everman, D. E. Ervin, G. Frisvold, T. Hurley, R. Jussaume, S. Wechsler. 2017. A survey of BMP adoption ofr resistance management in U.S. row crops. Abs. WSSA. 57:252
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Frisvold, G., D. E. Ervin, W. J. Everman, J. Gunsolus, T. Hurley, R. Jussaume, J. K. Norsworthy, M. Owen, and K. Dentzman. 2017. Socio-economic factors affecting farmer use of weed best management practices. Abs. WSSA. 57:254.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Owen, M. D., W. J. Everman, J. Gunsolus, J. K. Norsworthy, K. Dentzman, G. Frisvold, R. Jussaume, T. Hurley, and S. Wechsler. 2017. Farmer perspectives and expectations: What is thought about herbicide-resistant weed management. Abs. WSSA. 57:269
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ervin, D. E., K. Dentzman, W. J. Everman, G. Frisvold, J. Gunsolus, R. Jussaume, J. K. Norsworthy, T. Hurley, M. Owen and S. Wechsler. 2017. Neighbor and community effects of herbicide resistance management: a national survey of farm operators. Abs. WSSA. 57:271
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Kohlhase, D. R., M.D.K. Owen and M. A. Graham. 2017. An RNA-seq based genoic analysis of Amaranthus tuberculatus resistant to 4-hydroxyphenylpyruvate dioxygenase. Proc. Global Herbicide Resistance Challenge. 90
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Jones, E.A.L. and M.D.K. Owen. 2017. Investigating a putative HPPD (4-hydroxyphenylpyruvate dioxygenase) inhibiting herbicide resistant Ambrosia trifida population. Proc. Global Herbicide Resistance Challenge. 116
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Frisvold, G. and M.D.K. Owen. 2017. Socioeconomics and human dimensions of herbicide resistance. Proc. Global Herbicide Resistance Challenge. 27
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Owen, M.D.K. and J. Gressel. 2017. The herbicide dose conundrum regarding the evolution and delaying of weed resistance. Proc. Global Herbicide Resistance Challenge. 59.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Owen, Micheal D.K. 2017. IPM and weed management for the future. Proc. 14th International symposium on the biosafety of genetically modified organisms. 14:97.
    • Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2017 Citation: Owen, Micheal D.K. 2017. Sustainable weed management  what is next after glyphosate? Proc. 3rd OECD International Congress. In press.


    Progress 10/01/15 to 09/30/16

    Outputs
    Target Audience:Farmers, Scientists, Students, Industry personnel. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Oral presentations, posters, and peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?The study of genome-wide changes in soybean as a result of environmental stress is on-going. The effects of early defoliation in seed corn production fields are being investigated. Various studies on weed seed germination and the development of resistance will continue. Efforts to better understand elements of seed germination under stress and collaborations on root development in sunflowers will continue.

    Impacts
    What was accomplished under these goals? IMPACT: The seed is the is the foundation of most crop species. From a commercial perspective,seeds provide the vehicle for the delivery of new genetics. The biology of seeds impacts germination, establishment, seed bank formation, planting seasons, end use and many other attributes. This research has integrated biological investigations from the organismal level to the basic biology. We further defined germination parameters, futhered our understanding of the role of genetics and environment on physiological seed quality, and further ellucidated some of the QTLs associated with low temperature stress germination. With this latter project, wehope to reduce the need for chemical seed treatments during germination and establishment. Seed dormancy is a critical element of seed perserverance and therefore an especially important element in controlling weed establishments. Work accomplished in this project has further ellucidated how environmental variables interact with weed seed germination in an effort to enhance weed population control. Objective 1... Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination. We have completed the initial stages of the investigation of QTLs on seed germination at low temperatures involving an IBM population of recombinant inbred lines. We are also collaborating on a project with a plant breeder to help understand root development among accessions of sunflowers. Objective 2... Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa. Our research team has identified the essential proteins required for the correct development and function of chloroplasts. Chlorophyll metabolism is essential for photosynthesis and, consequently, for plant growth and reproduction. The relationship between genotypic changes in response to environmental is on-going. Objective 3... Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators. Nothing to report this period. Objective 4... Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds. Research to determine the impact of the maternal environment and genetic background on seed quality (i.e., viability) and dormancy continues. Specifically, the heritability of multiple herbicide resistance(s) in Amaranthus tuberculatus has been assessed. Furthermore, the fecundity of lines of A. tuberculatus as well as seed quality has been investigated. Of interest is the measurement of inherent fitness costs attributable to the multiple herbicide resistance(s) has been initiated. The potential hybridization between A. tuberculatus and A. palmeri is being investigated with a focus on seed quality. Objective 5... Study seed germination and seedling development under stressful conditions. Nothing to report this period. Objective 6... Study the acquisition of desiccation tolerance in select orthodox seed species. Seed desiccation tolerance of defoliated corn plants is on-going.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Wu, Chenxi and Micheal D.K. Owen. 2015. When is the best time to emerge-II: Seed Mass, Maturation and After-ripening of Common Waterhemp (Amaranthus tuberculatus (Moq) Sauer) natural cohorts Weed Sci. 63:846-854.
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Van der Laat, Rocio, Micheal D.K. Owen, Matthew Liebman and Ramon G. Leon. 2015. Post-dispersal weed seed predation and invertebrate activity-density in three tillage regimes. Weed Sci. 63:828-838.
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Schwartz, Lauren M., David J. Gibson, Karla L. Gage, Joseph L. Matthews, David L. Jordan, Micheal D.K. Owen, David R. Shaw, Stephen C. Weller, Robert G. Wilson and Bryan G. Young. 2015. Seedbank and field emergence in glyphosate-resistant cropping systems in the United States. Weed Sci. 63(2):425-439
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Owen, Micheal D.K., Hugh J. Beckie, Julia Y. Leeson, Jason K. Norsworthy and Larry E. Steckel. 2015. Integrated Pest Management and Weed Management in the US and Canada. Pest Manag. Sci. 71:357-376.
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Gibson, David J., Bryan G. Young, Micheal D.K. Owen, Karla L. Gage, Joseph L. Matthews, David, L Jordan, David R. Shaw, Stephen C. Weller and Robert G. Wilson. 2016. Benchmark study on glyphosate-resistant cropping systems in the United States. Part 7: Effects of weed management strategy (grower practices versus academic recommendations) on the weed soil seedbank over 6 years. Pest. Manag. Sci. 72:692-700
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Liu, Chun, Melissa Bridges, Shiv Kaundun, Les Glasgow, Micheal Owen, and Paul A. Neve. 2016. A generalised individual-based algorithm for modelling the evolution of quantitative herbicide resistance in arable weed populations. Pest Manag. Sci. (Published on line 21 June 2016 DOI  10.1002/ps.4317).
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Lamichhane, Jay Ram, Yann Devos, Hugh Beckie, Micheal Owen, Pascal Tillie, Antione Messean and Per Kudsk. 2016. Integrated weed management systems with herbicide-tolerant crops in the European Union: lessons learned from overseas. Critical Reviews in Biotechnology (Published on line 12 May 2016 - DOI 10.1080/07388551.2016.1180588).
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Gressel, Jonathan, Aaron Gassman and Micheal Owen. 2016. How well will stacked transgenic pest/herbicide resistances delay pests from evolving resistance? Pest Manag. Sci. (Published on line 20 October 2016  DOI 10.1002/ps.4425).
    • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Mueller, T. C., W. S. Curran, R. Scott, C. Sprague, D. Stephenson, D. Miller, E. Prostko, W. Grichar, J. Martin, L. Krutz, K. Bradley, L. E. Steckel, M. L. Bernards, M. D. Owen, P. A. Dotray, R. Currie, S. A. Clay, S. Z. Kenzeic, V. M. Davis, and R. Klein. 2015. Does previous atrazine history enhance atrazine degradation in US soils? Abs. WSSA. 55:265.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Beres, Z. T., E. E. Ernst, A. A. Snow, J. T. Parrish, M. D. Owen, B. A. Ackley and M. M. Loux. 2015. Screening for resistance to 20X glyphosate in biotypes of Conyza canadensis from soybean fields and non-agricultural habitats in Ohio and Iowa. Abs. WSSA. 55:85.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: McGregor, Kevin R. and Michael D. Owen. 2015. Effect of cleanout method on the persistence of auxinic herbicide residues. Proc. North Cent. Weed Sci. Soc. 70:49
    • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Schmitt, Virgil, Robert Hartzler, Meaghan Anderson, Angela Rieck-Hinz, Paul Kassel, Micheal Owen, Terrance Basol, and Brent Pringnitz. 2015. Weeds Week Herbicide resistant weed management education in Iowa. Proc. North Cent. Weed Sci. Soc. 69:170.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Kohlhase, Daniel R., Mike D. Owen and Michelle A. Graham. 2016. Transcriptome expression analysis of 4-hydroxyphenylpyruvate dioxygenase inhibitor herbicide resistance in Amaranthus tuberculatus using RNA-sequencing. Proc. North Cent. Weed Sci. Soc.71:1209
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Samarah, N. H., R. E. Mullen, S. Cianzio, R. Gladon, A. S. Goggi. Ethylene evolution from podded and depodded seeds of soybean in relationship with seed desiccation tolerance during maturation. Seed Science and Technology 44 (1): 53-63
    • Type: Journal Articles Status: Published Year Published: 2016 Citation: Sandhu, D., T. Atkinson, A. Noll, C. Johnson, K. Espinosa, J. Boelter, S. Abel, B. K. Dhatt, T. Barta, E. Singsaas, S. Sepsenwol, A. S. Goggi and R. Palmer. 2016. Soybean proteins GmTic110 and GmPsbP are crucial for chloroplast development and function. Plant Science 252: 7687
    • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Priester, J.H., S. C. Moritz, K. Espinosa, Y. Ge, Y. Wang, R. M. Nisbet, J. P. Schimel, A.S. Goggi, J. L. Gardea-Torresdey, and P. A. Holden. Stress and damage assessment for soybean (Glycine max) cultivated in soil amended with either CeO2 or ZnO manufactured nanomaterial. Science of The Total Environment; http://dx.doi.org/10.1016/j.scitotenv.2016.11.149


    Progress 10/01/14 to 09/30/15

    Outputs
    Target Audience:Farmers, agriculture professionals, agricultural scientists, students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Information from the research was used in extension meetings, outreach meetings, in the class room, and has been disseminated via oral presentations, popular press articles, scientific presentations, and in industry meetings. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

    Impacts
    What was accomplished under these goals? Much of agriculture depends on seeds and seed performance. Whether it is optimum performance of crops seeds or understanding seed biology to enhance control of weeds, the impact of seed research global in scale. This research has the potential to improve the production of biofuel crops such as Miscanthus sinensis by understanding its seed biology. It has also advanced our understanding of the role of abiotic stresses (e.g. low temperatures) on germination and mitochondrial respiration in maize, on the soybean genome and sought to develop a testing procedure to screen for varietal differences in cold tolerance. Finally, the research on herbicide resistance and the biology of weed seeds is critical. Such work may help preserve the value of useful herbicides and to evolve cultural methods to assist in the control of weeds. Objective 1) Understand the basic biology, biochemistry/physiology and molecular biology of seed development, maturation, dormancy, and germination. The germination requirements for successful germination of Miscanthus sinensis and Jerusalem artichoke were determined, and a seed development and maturation timeline for Miscanthus was developed. The effect of stress on soybean plants showed genome-wide changes such as single and double allele-switching in a single seed within a pod, as well as single-base changes and genome insertions/deletions. Some of these changes were stable and inherited into the next generation. Herbicide resistance in economically important weeds has become a significant problem. Specifically, resistance to HPPD inhibitor herbicides as well as glyphosate is critically important. Studies are underway to determine the impact of these resistances on the competitiveness of Amaranthus tuberculatus which reflects not only seed fecundity but also the biochemistry of this weed. Understanding the impact of herbicide resistance on biology and biochemistry will provide a better opportunity for farmers to sustainably manage this weed. Objective 2) Understand the influence of the seed production environment and genetic background on seed quality and dormancy in a range of crop and forage species important to Iowa. Nothing to report. Objective 3) Determine how different crop habitats and timing of tillage affect over-winter losses of weed seeds to predators. Studies have been completed to assess the impact of crop rotation on seed predation of important Midwestern weeds. Understanding how to manipulate the crop environment will enhance weed management and thus improve crop profitability. Objective 4) Understand the influence of the maternal environment and genetic background on seed quality and dormancy of important Iowa weeds. Herbicide resistance in Amaranthus tuberculatus has become a serious problem for production agriculture. Studies are underway to determine the heritability of herbicide resistance and the impact on seed characteristics. A better understanding of herbicide resistance genetics will improve tactics farmers can adopt to better manage this economically important problem. Objective 5) Study seed germination and seedling development under stressful conditions. A laboratory germplasm-selection protocol for cold tolerance in exotic sorghum was tested, thus minimizing field space requirements and accelerating the selection process for cold tolerance. Also the influence of low temperature and seed treatments on mitochondrial respiration of maize seedlings has been studied. Objective 6) Study the acquisition of desiccation tolerance in select orthodox seed species. Nothing to report. Objective 7) Identify soil, plant, climate, and management factors influencing final stand density of red clover or alfalfa intercropped in winter cereal grains. Nothing to report.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Owen, M.D., Beckie, H.J., Leeson, J.Y., Norsworthy, J.K. and Steckel, L.E. (2015) Integrated pest management and weed management in the United States and Canada. Pest. Manag. Sci. 71:357376. doi: 10.1002/ps.3928.
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Chatham, L.A., K.W. Bradley, G.R. Kruger, J.R. Martin, M.D.K. Owen, D.E. Peterson, J. Mithila, and P.J. Tranel. 2015. A multi-state study of the association between glyphosate resistance and EPSPS gene amplification in waterhemp (Amaranthus tuberculatus). Weed Sci. 63:569-577.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Wu, Chenxi and Micheal D.K. Owen. 2014. When is the Best Time to Emerge: Reproductive Phenology and Success of Natural Common Waterhemp (Amaranthus tuberculatus (Moq) Sauer) Cohorts in the Midwest United States? Weed Sci. 62:107-117
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Edwards, C. Blake, David L. Jordan, Michael D.K. Owen, Philip M. Dixon, Bryan G. Young, Robert G. Wilson, Steven C. Weller and David R. Shaw. 2014. Benchmark study on glyphosate-resistant crop systems in the United States. Economics of herbicide resistance management practices in a 5 year field-scale study. Pest. Manag. Sci. pp. 6. (published on line 6 February 2014).
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Werle, R., L.D. Sandell, D.D. Buhler, R.G. Hartzler and J.L. Lindquist. 2014. Predicting emergence of 23 summer annual weed species. Weed Science. 62:267-279.
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Sun, M., A.S. Goggi, K. Matson, R.G. Palmer, K. Moore, S.R. Cianzio. 2015. Thin plate spline regression model used at early stages of soybean breeding to control field spatial variation. J. of Crop Improvement 29:333-352. DOI: 10.1080/15427528.2015.1026623
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Beavers, A.W., A.S. Goggi, M.B. Reddy, A.M. Lauter, M.P. Scott. 2015. Recurrent selection to alter grain phytic acid concentration and iron bioavailability. Crop Science, doi: 10.2135/cropsci2014.12.0807
    • Type: Journal Articles Status: Published Year Published: 2015 Citation: Espinosa, K., J. Boelter, S. Lolle, M. Hopkins, A. S. Goggi, R. G. Palmer and D. Sandhu. 2015. Evaluation of spontaneous generation of allelic variation in soybean in response to sexual hybridization and stress. Canadian Journal of Plant Science 95:405-415; doi:10.4141/CJPS-2014-324).
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Reed, S., T. Atkinson, C. Gorecki, K. Espinosa, S. Przybylski, A.S. Goggi, R.G. Palmer and D. Sandhu. 2014. Candidate gene identification for a lethal chlorophyll-deficient mutant in soybean. Agronomy 4:462-469; doi:10.3390/agronomy4040462.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Salas-Fernandez, M.G., G.R Schoenbaum, and A.S. Goggi. 2014. Novel germplasm and screening methods for early cold tolerance in sorghum. Crop Science 54:1-8.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Puttha, R., A. S. Goggi, M. L. Gleason, S. Jogloy, T. Kesmala, N. Vorasoot, P. Banterng, and A. Patanothai. Pre-chill with gibberellic acid overcomes seed dormancy in Jerusalem artichoke. 2014. Agronomy for Sustainable Development J. 34: 869878; doi: 10.1007/s13593-014-0213-x.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Christian, E.J., A.S. Goggi, and K.J. Moore. 2014. Temperature and light requirements for Miscanthus sinensis germination. Crop Science 54:791-795.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Anderson, M.D. and B. Hartzler. 2014. Proceedings of the Northcentralk Weed Science Society. 68:125.


    Progress 04/15/14 to 09/30/14

    Outputs
    Target Audience: Farmers, ag professionals, agricultural scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Information from the research was used in extension meetings, outreach meetings, and in the classroom. How have the results been disseminated to communities of interest? The information has been disseminated via oral presentations, popular press articles, scientific presentations, and in industry meetings. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

    Impacts
    What was accomplished under these goals? Our increased understanding of weed seed germination characteristics has led to increased understanding of how the environment, including agronomic management practices, influences the establishment of both seed banks and weed species. Along with these considerations, the research and surveys conducted on herbicide resistance in this project have provided a statistically valid estimate of the herbicide resistance in Iowa this will enable newly initiated research on heritability and hybridization to assess how widely and rapidly the resistance might spread. Research has helped understand seed responses to germination stress at different temperatures, illuminated the cause of seed quality problems in some doubled haploid inducers, and the role of certain seed treatments on seedling growth and metabolism. Finally, a seed development, maturation and moisture content timeline for Miscanthus sinesis seed was developed; and dormancy breaking techniques in Jerusalem artichoke identified. These findings will facilitate the production of high quality seed attributes for this important biomass-based ethanol production crop. We also developed new, laboratory screening methods for corn germplasm. This method will allow a preliminary screening for and the identification of potentially important cold tolerance genes in sorghum.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Wu, Chenxi and Micheal D.K. Owen. 2014. When is the Best Time to Emerge: Reproductive Phenology and Success of Natural Common Waterhemp (Amaranthus tuberculatus (Moq) Sauer) Cohorts in the Midwest United States? Weed Sci. 62:107-117.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Edwards, C. Blake, David L. Jordan, Michael D.K. Owen, Philip M. Dixon, Bryan G. Young, Robert G. Wilson, Steven C. Weller and David R. Shaw. 2014. Benchmark study on glyphosate-resistant crop systems in the United States. Economics of herbicide resistance management practices in a 5 year field-scale study. Pest. Manag. Sci. pp. 6. (published on line 6 February 2014).
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Young, B.G., D.J. Gibson, K.L. Gage, J.L. Matthews, D.L. Jordan, M.D.K. Owen, D.R. Shaw, S.C. Weller, and R.G. Wilson. 2013. Agricultural weeds in glyphosate-resistant cropping systems in the United States. Weed Sci. 61(1):85-97.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Werle, R., L.D. Sandell, D.D. Buhler, R.G. Hartzler and J.L. Lindquist. 2014. Predicting emergence of 23 summer annual weed species. Weed Science. 62:267-279.
    • Type: Journal Articles Status: Published Year Published: 2014 Citation: Owen, M.D., Beckie, H.J., Leeson, J.Y., Norsworthy, J.K. and Steckel, L.E. 2014. Integrated pest management and weed management in the United States and Canada. Pest. Manag. Sci. doi: 10.1002/ps.3928
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Anderson, M.D. and B. Hartzler. 2014. Cereal Rye Cover Crop Effects on Common Waterhemp and Common Lambsquarters Emergence. Proceedings of the North Central Weed Science Society. 69:
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Owen, Micheal D.K., David R. Shaw, Stephen C. Weller, Philip M. Dixon, Bryan G. Young, David L. Jordan and Robert G. Wilson. 2013. The Benchmark Study  a field scale project demonstrating the sustainability of glyphosate-based crop Production. Proc. Global Herb. Resis. Challenge. 1:33.
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Edwards, B., D. R. Shaw, M. D. Owen, P. Dixon, B. Young, R. Wilson, D. Jordan and S. Weller. 2013. Benchmark Study: A long-term assessment of the economic viability of herbicide resistance management programs. Abs. WSSA. 53:34
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Owen, M. D. 2013. Update of herbicide resistances in common waterhemp: an Iowa perspective. Abs. WSSA. 53:265.
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Owen, Micheal D.K. 2013. Iowa survey of herbicide resistances in common waterhemp including glyphosate and other herbicides. Abs. Amer. Chem. Soc. 246:99.
    • Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Owen, Micheal D.K. 2013 Repercussions of crop production in Iowa: evolved pest resistances. Proc. Manitoba Agronomists Conf. 2013:18.