Browsing by Author "Esker, Paul D."

Now showing 1 - 8 of 8
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    Beyond Yield: Plant disease in the context of ecosystem services
    Cheatham, M. R.; Rouse, M. N.; Esker, Paul D.; Ignacio, S.; Pradel, W.; Raymundo, R.; Sparks, Adam H.; Forbes, Gregory Allan; Gordon, T. R.; Garrett, Karen A. (2009)
    The ecosystem services concept provides a means to define successful disease management more broadly, beyond short-term crop yield evaluations. Plant disease can affect ecosystem services directly, such as through removal of plants providing services, or indirectly through the effects of disease management activities, including pesticide applications, tillage, and other methods of plant removal. Increased plant biodiversity may reduce disease risk if susceptible host tissue becomes less common, or may increase risk if additional plant species are important in completing
  • Ecology and epidemiology in R: Disease forecasting and validation
    Esker, Paul D.; Sparks, Adam H.; Campbell, L.; Guo, Z.; Rouse, M. N.; Silwal, S. D.; Tolos, S.; Van Allen, B.; Garrett, Karen A. (St. Paul, MN: The American Phytopathological Society, 2008)
    This online training module shows how to approach plant disease forecasting and validation using the free R programming environment. It gives an overview of the background of plant disease forecasting, the current ways plant disease forecasting is currently being implemented, and teaches students of the limitations of this method. This module also teaches students techniques to apply, modify and interpret the output from disease forecasting.
  • Ecology and epidemiology in R: Disease progress over time
    Sparks, Adam H.; Esker, Paul D.; Bates, M.; Dall'Acqua, W.; Guo, Z.; Segovia, V.; Silwal, S. D.; Tolos, S.; Garrett, Karen A. (St. Paul, MN: The American Phytopathological Society, 2008)
    This online training module shows how to analyze disease progress over time using the free R programming environment. Students reading this module will be able to assess and interpret disease progress, and apply modeling methods to analyze the data.
  • Ecology and epidemiology in R: Modeling dispersal gradients
    Esker, Paul D.; Sparks, Adam H.; Bates, M.; Dall'Acqua, W.; Frank, E. E.; Huebel, L.; Segovia, V.; Garrett, Karen A. (The American Phytopathological Society, 2007)
    This training module shows how to model and analyze pathogen dispersal using the free R programming environment.
  • Ecology and epidemiology in R: Spatial pattern analysis
    Sparks, Adam H.; Esker, Paul D.; Antony, G.; Campbell, L.; Frank, E. E.; Huebel, L.; Rouse, M. N.; Van Allen, B.; Garrett, Karen A. (St. Paul, MN: The American Phytopathological Society, 2008)
    This online training module shows how to analyze disease spatial patterns using the free R programming environment. Students reading this module will learn the types of spatial patterns, and be able to differentiate between them so they can apply their knowledge to different spatial analysis methods.
  • An introduction to the R programming environment
    Garrett, Karen A.; Esker, Paul D.; Sparks, Adam H. (The American Phytopathological Society, 2007)
    This training module provides an introduction to how to use the free R programming environment.
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    Neonicotinoid seed treatments of soybean provide negligible benefits to US farmers
    Mourtzinis, Spyridon; Krupke, Christian H.; Esker, Paul D.; Varenhorst, Adam; Arneson, Nicholas J.; Bradley, Carl A.; Byrne, Adam M.; Chilvers, Martin, I.; Giesler, Loren J.; Herbert, D. Ames Jr.; Kandel, Yuba R.; Kazula, Maciej J.; Hunt, Catherine; Lindsey, Laura E.; Malone, Sean M.; Mueller, Daren S.; Naeve, Seth; Nafziger, Emerson D.; Reisig, Dominic D.; Ross, William J.; Rossman, Devon R.; Taylor, Sally V.; Conley, Shawn P. (Springer Nature, 2019-09-09)
    Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST+NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST+NST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST+ NST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike.
  • Plant pathology in the context of ecosystem services
    Rouse, M. N.; Cheatham, M. R.; Esker, Paul D.; Cardenas, S. I.; Pradel, W.; Raymundo, R.; Sparks, Adam H.; Forbes, Gregory Allan; Gordon, T. R.; Garrett, Karen A. (St. Paul, MN: The American Phytopathological Society, 2007)
    Ecosystem services are processes by which the environment supplies resources that benefit humans. Evaluations of interactions between humans and the environment, such as the Millennium Ecosystem Assessment, are increasingly using the ecosystem services framework. We develop a conceptual model for plant disease within the context of ecosystem services. For example, greater plant biodiversity may provide the service of reducing disease risk in agricultural and natural systems; rice variety mixtures have been successful for managing rice blast. When tillage or the removal of other plant species is motivated by plant disease management, plant disease indirectly results in the reduction of the ecosystem services provided by plants and plant debris, such as regulating soil erosion and provisioning wildlife habitat. Disease may extirpate plant species provisioning food; the loss of chestnut trees due to chestnut blight has reduced the mass produced in Eastern North American forests. Plant pathologists can contribute to evaluation of ecosystem services by clarifying the role of plant disease and to maintenance of ecosystem services by developing disease management methods that optimize for multiple services.