About

Pierce Paul is a Chair and Professor in the Department of Plant Pathology at The Ohio State University, based in Selby Hall, Wooster. His research focuses on Cereal Pathology and Epidemiology, contributing to the understanding and management of plant diseases affecting cereal crops. As a leading expert in his field, he plays a significant role in advancing knowledge related to plant health and disease control within cereal agriculture.

Research topics

• Agronomy
• Biology
• Horticulture
• Political Science
• Botany
• Geography
• Biotechnology
• Ecology

Selected publications

• Azole Resistance in <i>Aspergillus fumigatus</i> From Diverse Environments in Ohio, United States, Is Primarily Driven by TR34/L98H and TR46/Y121F/T289A Environmental Signatures

  Open Forum Infectious Diseases · 2026-03-30

  articleOpen access

  Abstract Aspergillus fumigatus is a leading global human fungal pathogen. Triazole antifungal drugs are used in clinical settings, while triazole demethylase inhibitor (DMI) fungicides are widely applied in the environment to combat plant fungal diseases. Environmental exposure to triazole fungicides may drive cross-resistance to clinical triazoles. To address limited data on environmental azole-resistant A fumigatus (ARAF) in the United States, we conducted surveillance across 75 sites in Ohio, including agricultural (57.3%), naturalized (25.3%), urban (16%), and commercial (1.3%) environments. Samples collected comprised air (n = 411), soil (n = 352), and compost (n = 42). Nested polymerase chain reaction of 397 airborne spore samples detected A fumigatus DNA in 62.7%, with 35.5% wild-type, 17.9% tandem repeat (TR), and 9.3% with mixed genotypes. TR genotype distribution did not differ by environment or DMI use. Aspergillus fumigatus was cultured from 18.1% of air samples, with 1.5% positive for ARAF. From soil and compost, A fumigatus was recovered from 41.4% of samples, of which 9.2% were positive for ARAF. Compost yielded higher A fumigatus (83.3%) and ARAF (21.4%) than soil (36.4% and 1.7%, respectively). ARAF prevalence was higher in urban (9.5%) than agricultural (2.8%) or naturalized (1.4%) environments. Generalized linear models suggested that compost and propiconazole exposure were significant predictors of ARAF occurrence. Among 72 ARAF isolates, 50% and 43% carried TR34/L98H and TR46/Y121F/T289A mutations, respectively, suggesting these mutations as key resistance signatures in Ohio environments. These findings identify compost and DMI exposure as a fertile milieu for ARAF development, highlight urban hotspots, and underscore the need for One Health approaches to resistance management.

  PublisherDOI

• Efficacy of Integrated Management Strategies for Fusarium Head Blight Control in Hard Red Winter Wheat

  Plant Disease · 2025-04-24 · 3 citations

  article

  Fusarium head blight (FHB) is a disease that threatens wheat production globally, and there is an important need to understand how fungicides combined with genetic resistance improve management, particularly in the hard red winter wheat growing region of the United States. To evaluate this, a field study was conducted across four years in two locations per year. The objectives were to compare the efficacy of Miravis Ace (13.7% pydiflumetofen + 11.4% propiconazole) with the industry-standard product Prosaro (19% prothioconazole + 19% tebuconazole) at two wheat growth stages (Feekes 10.3 and Feekes 10.5.1) in Kansas when combined with three levels of genetic resistance (moderately resistant, moderately susceptible, and susceptible). The highest level of FHB control was observed when the moderately resistant cultivar was combined with the Miravis Ace treatment at anthesis (Feekes 10.5.1), with a 98.7% reduction in visual FHB index and 93% reduction in the mycotoxin deoxynivalenol. The moderately resistant cultivar alone (no fungicide) was more effective in controlling FHB than applying any fungicide treatment to a susceptible cultivar, underscoring the value of genetic resistance. The highest mean yield improvement (compared with the non-treated, susceptible control) was observed when the moderately resistant variety was treated with Miravis Ace at anthesis (2,090.53 kg ha −1 ), and the lowest was observed when the susceptible variety was treated with Prosaro (638.64 kg ha −1 ). At these locations, we also observed a trend of higher FHB intensity with cooler average daily temperatures (between 18 and 21°C) and higher average relative humidity. Results from this study highlight the improved efficacy of Miravis Ace and the value of integrating fungicide applications with genetic resistance for FHB management.

  PublisherDOI

• Wheat Disease Loss Estimates from the United States and Canada — 2024

  2025-03-24 · 3 citations

  report
  PublisherDOI

• An Evaluation of Single and Two Sequential Fungicide Applications During Flowering for Fusarium Head Blight Management in Winter Wheat in Kansas

  Plant Health Progress · 2025-01-01

  article

  Fusarium head blight (FHB), caused primarily by Fusarium graminearum Schwabe, remains a devastating disease of wheat. In this study, experiments were conducted across six location-years to evaluate the efficacy of sequential fungicide applications during the flowering period for FHB control, yield, deoxynivalenol (DON) reduction, and profitability in hard red winter wheat. The sequential treatments consisted of an application of Miravis Ace (propiconazole + pydiflumetofen) at Feekes 10.5.1 followed 4 days later by an application of either Prosaro Pro (prothioconazole + fluopyram + tebuconazole), Sphaerex (prothioconazole + metconazole), or TebuStar (tebuconazole). The sequential treatments were compared with single applications of Prosaro 421 SC (prothioconazole + tebuconazole), Sphaerex, Prosaro Pro, and Miravis Ace at Feekes 10.5.1. A covariance analysis was used to evaluate the influence of the FHB index (%) in the nontreated check on yield, DON, and net profit provided by the fungicide treatments. When the FHB index was low (10%), there were no significant yield or DON improvements. At higher FHB index levels of 30 and 40%, all fungicide treatments resulted in improved DON and improved yield relative to the nontreated check. Treatments including an application of Miravis Ace resulted in higher net profit and yields compared with the other treatments evaluated. The sequential fungicide application programs did not result in a significant yield benefit over a single application of Miravis Ace alone at any FHB index level. The results of this study underscore the importance of a single, well-timed application of Miravis Ace for FHB management in Kansas.

  PublisherDOI

• Corn Disease Loss Estimates from the United States and Ontario, Canada — 2024

  2025-02-18 · 7 citations

  report
  PublisherDOI

• Corn Yield Loss Estimates Due to Diseases in the United States and Ontario, Canada, from 2020 to 2023

  Plant Health Progress · 2025-11-05

  article

  Corn ( Zea mays L.) was planted on 375.1 million acres (151.8 million hectares) cumulative from 2020 to 2023 in the United States and Ontario, Canada. During these 4 years, 59.6 billion bushels (1.5 billion metric tons) of grain were produced, valued at 325.9 billion U.S. dollars (USD). Plant pathogens that cause diseases limit annual grain production and reduce associated economic returns while also increasing management costs to prevent potential losses. Plant pathologists representing 29 U.S. states and Ontario, Canada, were asked to estimate annual percent yield losses caused by 37 pathogens or pathogen groups through an online survey. Grain contaminated by mycotoxins was also estimated. According to survey results, estimated overall annual percent losses ranged from negligible in Texas in 2023 to 15.8% in Michigan in 2021 and averaged 3.0% across all surveyed regions for the 4-year period. Diseases reduced corn yield by an estimated 2.5 billion bushels (63.7 million metric tons) across participating locations, with tar spot (caused by Phyllachora maydis), Fusarium stalk rot (caused by Fusarium spp.), and plant-parasitic nematodes causing the most significant losses. The total estimated economic loss caused by diseases was 13.8 billion USD, and the average economic loss was 37.76 USD per acre (93.30 USD per hectare) across all years and locations. Survey data and the resulting analysis can help inform corn disease management and guide pathology education, policy, and research priorities among scientists, government representatives, Extension educators, and other stakeholders.

  PublisherDOI

• Estimated Yield Reductions and Economic Losses on Wheat Caused by Disease from 2018 Through 2021

  Plant Health Progress · 2025-01-01 · 4 citations

  article

  Wheat ( Triticum aestivum L.) yield and economic losses caused by pathogens were estimated annually by plant pathologists from 29 U.S. states and Ontario, Canada, from 2018 through 2021. During this 4-year period, plant pathogens caused an estimated reduction of 560 million bushels, with an estimated loss value of US$2.9 billion. Annual losses ranged from 111 million bushels in 2018 to 188 million bushels in 2019. Based on the number of acres planted, the average per-acre loss caused by plant pathogens was US$18.10 across all years and state/province recording estimates. Fusarium head blight (caused by multiple species of Fusarium) was responsible for the greatest overall estimated reduction in yield, followed by stripe rust (caused by Puccinia striiformis) and leaf rust (caused by P. triticina). Although important disease management costs, such as pesticide application, were not considered, the results show the importance of continued plant disease education and research. Quantifying estimated losses associated with plant pathogens impacting wheat remains an important endeavor. Estimates provided by this group of experts are expected to be used as a guide to influence funding for plant disease research by directing Extension and research through both applied and basic efforts. Moreover, the continued effort to quantify plant diseases and their influence on yield losses, as well as the economics of managing plant diseases, will help inform the industries that influence plant disease management and shape on-farm disease management efforts.

  PublisherDOI

• Corn Disease Loss Estimates from the United States and Ontario, Canada — 2023

  2024-03-12 · 4 citations

  report
  PublisherDOI

• Tar spot of maize in the Americas is caused by a complex of closely related Phyllachora species which vary in their host and geographic range

  2024-01-31

  preprint

  The genus Phyllachora contains numerous obligate fungal parasites that produce raised, melanized structures called stromata on their plant hosts. Most members of this genus are not of significant economic concern, with the exception of P. maydis, the causal agent of tar spot of maize (Zea mays). Tar spot of maize has emerged as a major threat to maize production throughout the Americas and continues to spread throughout North America. To date, species designations for Phyllachora have been based on host associations and morphology, and the origin and diversity of the pathogen that causes tar spot is unknown. We assessed the sequence diversity of 186 single stroma isolates collected from 16 hosts representing 15 countries by amplification of the ITS and LSU gene regions. Samples included both herbarium and contemporary strains that covered a temporal range from 1905-2019. These 186 isolates were grouped into 5 distinct species with strong bootstrap support. We found three closely related, but genetically distinct groups of Phyllachora are capable of infecting maize in the United States, we refer to these as the P. maydis species complex. Based on herbarium species, we hypothesize that these three groups in the P. maydis species complex originated from Central America, Mexico and the Caribbean. Although two of these groups were only found on maize, the third and largest group contained contemporary strains found on maize and other grass hosts, as well as herbarium specimens from maize and other grasses that include 10 species of Phyllachora. The herbarium specimens were identified based on morphology and host association, but our data indicates there may be significant synonymy in the Phyllachora genus and additional work on species delineation and host specificity should be considered.

  PublisherDOI

• Effect of ahfad2 genes on oil profile of advanced breeding lines in groundnut (Arachis hypogaea L.)

  Research Square · 2024-12-30

  preprintOpen access1st authorCorresponding
  PublisherOA PDFDOI

Frequent coauthors

• L. V. Madden

  108 shared

• Paul D. Esker

  Pennsylvania State University

  98 shared

• D. A. Shah

  Kansas State University

  75 shared

• Alison E. Robertson

  Iowa State University

  71 shared

• Carl A. Bradley

  University of Kentucky

  70 shared

• Shawn P. Conley

  University of Wisconsin–Madison

  60 shared

• Anne E. Dorrance

  The Ohio State University

  41 shared

• E. D. De Wolf

  Kansas State University

  38 shared

Labs

• Paul LabPI

Education

• Ph.D., Plant Pathology

  The Ohio State University

  1990

• M.S., Plant Pathology

  The Ohio State University

  1986

• B.S., Botany

  The Ohio State University

  1982

Awards & honors

• Syngenta Award (outstanding recent contributions to plant pa…
• American Phytopathological Society Distinguished Junior Facu…
• Ohio Agricultural Research and Development Center William Bo…
• Certificate of Excellence in the Agronomy Society of America…