The weather outside is delightful, but have you noticed weeds think so too?
Winter annual weeds like chickweed, henbit and purple deadnettle are good hosts for soybean cyst nematode, says GregTylka, Iowa State University nematologist.
"An important temperature to consider for soybean cyst nematode (SCN) is 50 degrees F," Tylka says. "SCN juveniles do not develop in roots when temperatures are below 50F. So cool fall and spring temperatures usually keep SCN reproduction on these winter annual weeds in check. Such may not be the case this fall."
Growers and agronomists managing SCN-infested fields with significant populations of winter annual weeds should be aware that considerable SCN reproduction could be occurring on these alternative hosts this year. See the ISU Soybean Cyst Nematode web page more information about the biology, scouting and management of SCN.
And what about volunteer soybeans that are also adding to the emerald green carpet beginning to cover the Midwest? "Interesting question," Tylka admits. "SCN could reproduce on volunteer soybean plants in a field. But I think the increase in SCN numbers would be very localized."
Rotation helps too. "I have never seen so many volunteer soybean plants in a corn field that reproduction on the soybean plants would have a widespread effect in the field," Tylka adds.