Soybean cyst nematode (SCN) is a serious and widespread pest of soybean throughout Iowa and the Midwest. Fortunately, SCN-resistant soybean varieties have been developed and are an effective management tool. To assist growers in choosing SCN-resistant varieties, Iowa State University Extension annually compiles and publishes a list of public and private SCN-resistant soybean varieties in maturity groups I, II, and III.
This year's list contains information on 586 varieties. Eighty-four percent of the varieties listed have SCN resistance derived solely from the soybean breeding line 'PI88788'. There are 35 varieties in the list that contain SCN resistance that traces back to 'Hartwig', nine that have resistance from 'Peking', and 10 that have two sources of resistance listed.
Approximately 83 percent of the varieties listed in the publication are resistant to glyphosate herbicide.
|Stunting and chlorosis caused by SCN.|
|Swollen soybean cyst nematode juvenile in root (large picture) and female SCN with egg mass (inset).|
Soybean check-off funds provided by the Iowa Soybean Promotion Board supported the cost of printing the publication, and the publication was distributed as a special insert in the November 2004 issue of the Iowa Soybean Review magazine. Additional single copies of the list, Iowa State University Extension publication PM 1649, can be obtained from the Iowa State University Extension Distribution Center by calling 515-294-5247.
Alternatively, the publication can be viewed on the web  (PDF).
Number of SCN-resistant soybean varieties available to Iowa growers and the proportion of varieties with resistance from 'PI88788' or some other source, 1991-2004.
This article originally appeared on page 132 of the IC-492(22) -- November 15, 2004 issue.