Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-21220-003-043-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jul 1, 2026
End Date: Nov 30, 2027
Objective:
1. Optimization of sampling strategy for detecting Spongospora subterranea in the soil.
2. Linking soil pathogen levels to disease outcomes.
Approach:
Field trials will be conducted at the Miller Research Experimental Farm near Acequia, ID, an established powdery scab site. Six potato cultivars with varying susceptibility (Shepody, Ranger Russet, Dakota Russet, Russet Burbank, Clearwater Russet, and Umatilla Russet) will be grown. Soil samples will be collected before planting and after harvest using a hand soil sampling probe. Pathogen levels will be quantified using LUDOX-based sporosori counts and qPCR assays. These data will be used to generate spatial maps of pathogen distribution and determine optimal sampling intensity and design.
Linking Soil Pathogen Levels to Disease Outcomes. Disease assessments will include root gall severity, tuber lesion incidence, and Potato mop-top virus-induced tuber necrosis at harvest. Plant vigor will be monitored throughout the growing season. Tubers will be harvested systematically with spatial tracking to preserve field location data. Yield and the proportion of tubers with powdery scab lesions or internal necrosis will be recorded.