Soybean Cyst Nematode is in the news again, especially in Ohio. This little silent yield robber has kept county yields in the 40's where they could be in the 60's or more.
"As researchers expected, SCN has expanded in Ohio — from the western to the eastern borders of the state. In addition, researchers are identifying more fields in the state with populations above the economic thresholds. SCN populations of 1,500 eggs per cup of soil lead to 25% to 50% yield loss without any above ground symptoms.
“We’re identifying fields where the counts are getting way out of line, up in the 18,000 to 25,000 eggs per cup of soils. The cautionary tale is that folks really need to keep track of the SCN populations and sample,” said Anne Dorrance, Ohio State University Extension plant pathologist.
“SCN is an obnoxious little thing. You can’t even see the difference in the field and you are losing 15% to 20% of your yield. People think 40 or 45 bushels is not bad, but the yield potential for these varieties is 70 or 80 bushels. With SCN, you can get 10 extra bushels with just some simple changes in variety selection. You really are not going to know until you sample. Just sample the lowest yielding spots on your yield maps — a quart of soil from the same depth as a fertility sample.
I need to send them more soil because it has been awhile since I did this. Corn and wheat in rotation has kept the populations down but as we move to more soybeans we see yields stagnant and the populations are probably going up.
Sampling is not hard work but it is work. It is easy for me or anyone to get complacent. I've seen my populations go down as I plant radish with wheat. The root gases from the radish throw soybean cyst for a loop. Good rhizobia populations from good inoculation practices also increase yields in Ohio and probably throw the cysts for another loop.
What is soybean cyst nematode costing you?