The proposed study is aimed at developing:
1) a DNA-based method to provide rapid diagnostics to identify FLS-resistance at no direct cost to growers in the next three years,
2) new information on the distribution and spread of fungicide resistant FLS in Nebraska, and
3) educational materials and outreach programs on resistance management practices.

1. Develop a DNA-based protocol for rapid identification of QoI resistant C. sojina.
2. Solicit FLS samples coming from Nebraska soybean grower fields by contacting crop consultants, commercial agronomists, and Extension educators, and use the DNA-based tool (from Obj. 1) for rapid diagnosis of FLS fungicide resistance at no cost to the grower.
3. Perform targeted follow-up sampling of selected soybean fields to be able to characterize the within-field distribution of fungicide resistance.
4. Characterize the population structure and genetic diversity of C. sojina populations (from Obj. 2 and 3) from soybean to better understand the epidemiology of resistance in Nebraska.
5. Develop/deliver educational materials and outreach programs on resistance management.

1. Develop a DNA-based protocol for rapid identification of QoI resistant C. sojina
2. Solicit FLS samples coming from Nebraska soybean grower fields by contacting crop consultants, commercial agronomists, and Extension educators, and use the DNA-based tool (from Obj. 1) for rapid diagnosis of FLS fungicide resistance at no cost to the grower
3. Perform targeted follow-up sampling of selected soybean fields to be able to characterize the within-field distribution of fungicide resistance
4. Characterize the population structure and genetic diversity of C. sojina populations (from Obj. 2 and 3) from soybean to better understand the epidemiology of resistance in Nebraska
5. Develop/deliver educational materials and outreach programs on resistance management

In 2019, resistance to QoI fungicides was confirmed in 10 isolates of C. sojina from 10 counties in Nebraska. Fungicide resistance is a serious concern because it threatens the ability to use QoI fungicides, which are some of the most effective and widely used fungicides for managing FLS. A major limitation is that we do not presently have capacity within Nebraska for QoI resistance screening of C. sojina.
The proposed study is aimed at:
1) developing a DNA-based method to provide rapid diagnostics to identify FLS-resistance at no direct cost to growers in the next three years,
2) developing new information on the distribution and spread of fungicide resistant FLS in Nebraska, and
3) develop educational materials and outreach programs on resistance management practices.