Skip to main content
APS Plant Health 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
ViewAttendees 1

POSTERS: Pathogen Dispersal II

P-504 - Modeling the Spatial-temporal Dynamics of Cucurbit Downy Mildew with Multiple Foci

Tuesday, August 5, 2025
10:15 AM - 11:00 AM HST
Location: Exhibit Hall 3
Abstract Text: Analyzing disease dispersal patterns resulting from multiple initial foci can provide insights into spatiotemporal population dynamics, significantly enhancing our ability to predict epidemic and design management strategies. Field experiments conducted in North Carolina in 2023 and 2024 investigated the dispersal gradients of cucurbit downy mildew in zucchini using multiple artificially inoculated foci. Treatments consisting of a control, one inoculation focus, and two inoculation foci were replicated across four blocks. Following inoculation, six disease assessments were conducted. The treatment-average disease severities across distances were fitted to multiple dispersal kernels. Function parameters were estimated using maximum likelihood estimation, followed by bootstrapping to estimate parameter uncertainty for the best-fitting model. For the single-focus condition, most disease gradients were best fitted by either a Power law or modified Exponential kernel. For the two-foci condition, most disease gradients were best fitted by either a two-foci Power law or two-foci Exponential kernel. Generally, Exponential and Gaussian models were more frequently selected as optimal in 2024, whereas Power law and modified Exponential models dominated in 2023. These differences might be due to the changes in placement of the foci between 2023 and 2024 experiments. This study advanced modeling and understanding complex dispersal patterns when multiple primary foci are involved. These insights into pathogen movement patterns will enable more precise plant disease management strategies.