The Iowa Corn and Soybean Variety Test: New and Improved!

The corn and soybean variety testing programs administered by Iowa State University and the Iowa Crop Improvement Association have now been merged into a single program. This presents a unique opportunity to make some procedural changes that will economize our testing efforts. At the same time, we are making modifications to the configuration of the testing program to increase awareness of and participation in the tests. Current and upcoming changes will be described, beginning with a description of our basic operation. Seed companies from Iowa and surrounding states, who market seed in Iowa, are eligible to submit corn and soybean entries into our tests. Those who do so pay a nominal fee for our testing expenses. Public breeding programs from land grant institutions are eligible to submit entries at a reduced charge. Entries may be submitted for public or private testing. Data from public entries are published and made freely available in print and online, while data from private entries are returned to the applicant only. Our testing area is the entire state, subdivided into districts. All entries are tested at a minimum of three locations per district, with multiple replications per location. Data provided for the corn entries include yield, moisture, stand, and root and stalk lodging. To better understand how a hybrid performed with the other entries in a test, yield and moisture are also reported as a percent of mean so users can immediately determine the relative performance of a hybrid. For soybeans, data include yield, yield percent of mean, maturity date, lodging, and protein and oil composition. For entries advertised as having soybean cyst nematode resistance or tolerance, we also provide an SCN reproductive index, which is an indicator of SCN survival on resistant/tolerant lines compared to a susceptible variety. Our data are used by growers as a source of information when choosing which varieties to plant in their fields for the upcoming season. Seed companies use our data as a source of information for making advertising and marketing decisions