Update:
Project progress from 1 April 2020 through 30 September 2020 included:
- Received seed from seed and seed-treatment companies for 2020 field experiments, designed the 2020 field experiments, and packaged and organized the seeds for the various experiments. The variety names and numbers of varieties included in the 2020 SCN-resistant soybean variety trial experiments are from ASGROW (19), Beck’s (15), Cornelius Seed (8), Corteva/Pioneer (12), Dyna-Gro (9), Federal Hybrids (5), Four Star Seeds (4), GROWMARK FS HiSoy (9), Hoegemeyer (12), Jacobsen (5), Kruger (9), Latham (13), Legacy Seeds (3), LG Seeds (13), Merschman (15), NuTech (14), P3 Genetics (3), Stine (17), and Syngenta/NK (18).
- Set up, planted, soil sampled, and maintained nine field experiments located throughout Iowa to evaluate the yield enhancement and nematode control provided by 207 SCN-resistant soybean varieties (21 more than studied in 2019). The first field experiments were planted on April 18, 2020 - the earliest planting date ever for the Tylka field research program.
- Set up, planted, soil sampled, and maintained nine field experiments located throughout Iowa to evaluate the agronomic performance and nematode control provided by four different nematode-protectant seed treatments - namely Aveo (from Valent), Nemasect (from Beck’s), Saltro (from Syngenta), and Trunemco (from NuFarm).
- Extracted SCN cysts (egg-filled dead SCN females), then eggs, from soil samples collected at planting from all 9 resistant variety evaluation experiments and the 36 seed treatment experiments to determine initial SCN egg population densities.
- In early September, began trimming the field research plots at the 45 total field experiments in preparation for harvesting. And 25 experiments at 5 different locations (5 experiments per location) were harvested before the end of September this year.
- In late August, we contacted more than 50 seed companies and gathered information about SCN-resistant soybean varieties to use to update the ISU Extension publication titled “Soybean Cyst Nematode-Resistant Soybean Varieties for Iowa”. This publication will be compiled and released in PDF format by the end of October 2020.
- A research paper summarizing three years of coordinated ISA On-Farm Network and ISU small-plot experiments evaluating the agronomic benefit and nematode control provided by Ilevo seed treatment was published in the journal Plant Disease in September 2020 with ISA scientists Peter Kyveryga and Tristan Mueller are co-authors. The manuscript included yield difference graphs (with Ilevo versus without Ilevo) using Iowa Soybean Association’s online ISOFAST tool.
View uploaded report 
View uploaded report 2
Currently there are three options for managing SCN: 1) growing nonhost crops such as corn, 2) growing SCN-resistant soybean varieties, and 3) using nematode-protectant seed treatments on soybean seeds. The results of the experiments conducted in this project help Iowa soybean farmers decide which resistant varieties and seed treatments to purchase for use in fields infested with SCN. The results of the experiments conducted in 2020 are not yet available because not all of the experimental plots have been harvested by the date of this report and none of the end-of-season SCN soil samples have been processed and counted. The report of 2019 variety trial experiment results and the 2019 list of SCN-resistant soybean varieties for Iowa are attached to this final report.