P-471 - Rice False Smut, an Emerging Threat: Global Risk Assessment Using the R2M Plant Health Toolbox

Monday, August 4, 2025

4:30 PM - 5:15 PM HST

Location: Exhibit Hall 3

Presenting Author(s)

AA

Ashish Adhikari, PhD (he/him/his)

Plant Pathology Department, University of Florida
Gainesville, Florida, United States

Author(s)

AP

Aaron IsaÃ Plex SulÃ¡, BS

PhD Student
Plant Pathology Department, Global Food Systems Institute, 3Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
Gainesville, FL, USA
RM

Romaric Armel Mouafo-Tchinda, PhD

PhD
Plant Pathology Department, Global Food Systems Institute, 3Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
GAINESVILLE, Florida, United States
JR

Jacobo Robledo

Plant Pathology Department, University of Florida
Gainesville, Florida, United States
BE

Berea Etherton, PhD

University of Florida
Gainesville, Florida, United States
KA

Katelin Alcock, BS

Student
University of Florida
Gainesville, Florida, United States
RF

Robert Fontan, BS

RA
University of Florida
Gainesville, Florida, United States
TS

Theodore J. Stronkowsky, BS in Mathmatics

Student
University of Florida
Gainesville, Florida, United States
KG

Karen A. Garrett, PhD

Preeminent Professor
Plant Pathology Department, Global Food Systems Institute, 3Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
Gainesville, Florida, United States

Abstract Text: Rice is a staple food for over half the world’s population. Rice false smut, caused by Ustilaginoidea virens, is an emerging global threat, affected by changes in rice varieties and climate shifts, such as altered rainfall patterns and temperatures. Previously considered a minor disease, false smut now presents significant risks due to its increasing prevalence, leading to yield reductions. There is interest in strengthening global risk assessments and monitoring for the disease.
This study aims to (1) identify candidate locations for surveillance, (2) assess the risk of spread through seed trade systems, and (3) map climate suitability for the pathogen. We used the open-source R2M Plant Health Toolbox to evaluate risk based on cropland connectivity, trade networks and synthesize expert knowledge about the disease in Nepal. In Nepal, our findings indicate that the Terai rice-growing regions maintain strong connectivity with neighboring countries, while Nepal’s informal seed trade is highly clustered, elevating epidemic risks.
We also developed a risk map based on environmental parameters during rice vulnerability to false smut. Key factors included temperature, humidity, and precipitation. These analyses can be used as a baseline to enhance rice false smut surveillance and inform targeted interventions. More broadly, use of computational tools like R2M in global risk assessment frameworks can provide a baseline for plant disease forecasting and support proactive management.