We have received 562 samples from 48 Illinois counties to date. Of the test fields, 89 percent were positive for soybean cyst nematode (SCN). Sample counts have ranged from 0 SCN eggs per 100 cubic centimeters to 27,600 per 100 cubic centimeters. The mean egg count was 1,648 eggs per 100 cubic centimeters. We plan to continue to process requests for kits as growers plan for their spring activities. We also plan to conduct Hg type tests for samples with egg counts above 3,000 eggs per 100 cubic centimeters. The Hg type test will tell us if the SCN population in the sample can reproduce on soybean varieties with SCN resistance, and if so, on which sources. For example, most commercial soybean varieties derive their resistance from PI 88788. However, there are several varieties that derive their resistance from ‘Peking’. Both sources of resistance are tested in the HG type test.
Data will, hopefully, be collected from all 102 counties so we can track SCN populations around the state. To date, we’ve collected data from 48 counties. Representation so far: Adams Co. (20), Bureau (10), Calhoun (4), Cass (2), Champaign (55), Clark (3), Coles (4), Dekalb (31), Douglas (1), Edgar (2), Effingham (27), Fayette (5), Ford (2), Franklin (2), Gallatin (11), Greene (1), Grundy (2), Hancock (5), Henry (32), Iroquois (3), Jasper (4), Jefferson (5), Kane (19), La Salle (18), Lee (1), Macoupin (6), Madison (16), Marshall (18), Mason (7), Mcdonough (12), Mclean (22), Mercer (10), Montgomery (2), Ogle (20), Peoria (38), Piatt (6), Pike (9), Saint Clair (2), Saline (2), Schuyler (4), Scott (1), Stark (36), Tazewell (14), Vermillion (7), Warren (3), Washington (14), Whiteside (4), Woodford (23).
Growers interested in testing for SCN should contact freeSCNtesting@illinois.edu for sampling bags and information for submitting samples. Processing times usually take 2-3 weeks.