Results of the 2002 Iowa Crop Performance Test for soybeans are now available on the Internet at the Iowa Crop Improvement Association (ICIA) Web site: www.agron.iastate.edu/icia/ .
Trials include performance data on yield, maturity, height, lodging, emergence and iron deficiency chlorosis reaction. It also gives information on Phytophthora race resistance and field tolerance, brown stem rot resistance, soybean cyst nematode (SCN) resistance and protein and oil content.
The 2002 test evaluated 690 entries from 48 seed companies and Iowa State University. An entry was tested in one or more of three districts in the state, with three testing sites per district. Each district included separate tests for conventional herbicide varieties/brands and Roundup Ready varieties/brands. Five common checks were included in both tests. Yields were calculated as a percentage of these checks to allow comparisons across tests. Average site yields ranged from 38.9 bu/acre at Griswold to 71.5 bu/acre at Manly.
Entries identified as resistant to SCN were additionally evaluated for field performance at three SCN-infested sites per district. Average SCN-infested site yields ranged from 44.1 bu/acre at Lenox to 61.1 bu/acre at Manly.
One new disease rating was added in the 2002 trials. All entries identified as resistant to SCN were evaluated for cyst reproduction on their roots in a 32-day test conducted in a growth chamber. All entries were grown in infested soil collected from three different Iowa fields. The average cyst count on each entry was expressed as a percentage of Lee 74, the standard susceptible check. These ratings appear with the SCN entries in the infested and non-infested tables.
ICIA conducts the Iowa Crop Performance Tests in cooperation with the Iowa Agriculture and Home Economics Experiment Station at Iowa State University and ISU Extension. The program offers unbiased, third-party information to Iowa growers on commercial seed.