P-305 - Sustainable solutions for potato early die management in Idaho.

Monday, August 4, 2025

3:45 PM - 4:30 PM HST

Location: Exhibit Hall 3

Presenting Author(s)

AM

Alan Malek

Agricultural Technician
University of Idaho
Aberdeen, Idaho, United States

Author(s)

KM

Katie Malek

Research Specialist
University of Idaho
Aberdeen, Idaho, United States
BB

Breianne Bauer

Scientific Assistant
University of Idaho
Aberdeen, Idaho, United States
JW

James Woodhall

University of Idaho
Parma, Idaho, United States
KD

Kasia M. Duellman, PhD

Associate Professor, Extension Specialist
University of Idaho - Idaho Falls Research & Extension Center
Idaho Falls, Idaho, United States
PW

Phillip S. Wharton, PhD

Associate Professor
University of Idaho
Aberdeen, Idaho, United States

Abstract Text: Potato early die complex (PED) is an annual concern for commercial potato growers, particularly in Idaho, where yield losses of up to 50% can occur in sandy soils, although 20-30% losses are more common. The primary causal agent of PED is Verticillium dahliae. While PED can occur alone, earlier onset occurs when V. dahliae and the root lesion nematode (Pratylenchus spp.) are both present. Other causal agents, such as Colletotrichum coccodes, Botytis cinerea, and Fusarium oxysporum, have also been implicated. Soil fumigation is an effective tool for managing PED in potatoes. While the U.S. industry relies on fumigation to produce marketable crops with maximum yields, society is pushing towards reducing soil fumigation. In 2024, a variety x fungicide trial was conducted to investigate conventional and biofungicide spray programs in conjunction with two different varieties, Ranger russet and Huckleberry gold, for their efficacy against PED. PED symptoms were visually assessed, and soil and plant stems were collected for qPCR analysis. The results showed that all fungicide programs tested significantly reduced levels of PED compared to the untreated control. Levels of PED were significantly lower in Ranger russet than Huckleberry gold, and in half of the programs, fungicide treatment significantly increased yields.