Project Overview

Reports

Commodities

• Additional Plants: flowers, native plants, ornamentals

• Agronomic: canola, corn, small grain, soybeans

Target Pests

Practices

• Pest Management: chemical control, cultural control, disease vectors, economic threshold, monitoring/scouting, pesticide application timing, prevention

Aster Yellows disease is a cyclical disease issue in the North Central Region and is thought to be driven by movement of aster yellows phytoplasma (AYP) infected insect vectors from the southern part of the United States into the northern Great Plains. Previous research conducted in Canada (Romero et al., 2023) has shown that in heavy disease years, AYP is able to reduce yields in canola and wheat by more than 15% and that many alternate hosts (such as row crops) are asymptomatic carriers of the disease. Furthermore, over the last several years, horticultural plants have been heavily affected by AYP causing mass removal of plants in home gardens and landscape settings. These factors combined with little existing information about AYP on the northern Great Plains region make management of this disease challenging and losses in both the horticultural and row crop world problematic.

We propose to document the movement of the disease through field surveys and sample collections from diagnostic clinics and the general public which we will use to map the distribution of the disease in the northern Great Plains. We then plan to examine the genetics of the phytoplasma infected samples to see if there are multiple strains in the northern Great Plains and if those strains infect both horticultural and agronomic cropping systems. Our objectives are: 1) Increase awareness and knowledge about aster yellows phytoplasma. Create distributable information packets and fact sheets to aid in the identification of AYP and its known vector; host webinar to educate about AYP and update with results from this project once completed. 2) Determine AYP and vector abundance under different crop production environments in the Great Plains over the course of one year. 3) Evaluate genetic diversity of AYP in the Great Plains and relate strain diversity to model disease spread.

Stakeholders that have been identified to directly benefit from this research include specialty crop and cut flower producers, row crop producers, botanic gardens/arboretums, home gardeners, and other producers that work with potential hosts such as vegetable producers. These various groups will benefit from this research by understanding how the disease is spreading, information on potential types of alternative hosts, learning non-chemical control options, better chemical control timings for leafhoppers, having a potential disease introduction and transmission timeline, and by understanding if the AYP that infects the home garden is the same as that which infects row crops. Information gained from this project will be communicated to stakeholders through factsheets, web articles, diagnostic clinics, a field day at a botanic garden, and one webinar planned for winter of 2026 that will summarize project findings.

Objective 1: Increase awareness and knowledge about aster yellows phytoplasma. Create distributable information packets and fact sheets to aid in the identification of AYP and its known vector; host webinar to educate about AYP and update with results from this project once completed.

Objective 2: Determine AYP and vector abundance under different crop production environments in the Great Plains over the course of one year.

OBJECTIVE 3: Evaluate genetic diversity of AYP in the Great Plains and relate strain diversity to model disease spread.