August 15, 2008

Learn How to Identify and Manage Infestations

Last year, soybean cyst nematodes (SCN) reduced yields for Nebraska farmers by an estimated 2.3 million bushels worth over $25 million. And often, the pest was never detected.

SCN Field Day Schedule Tuesday, August 19, 6:30 p.m., at the L J Keithley farm, near Falls City. Directions: From Hwy 73 67 junction northwest of Falls City go 2 miles east of Highway 73, then 1 mile north on 650th Avenue.   Friday, August 22, 10:00 a.m., on ground farmed by Gene Olson and sons near Minden. Directions: From Minden go 9 miles north on Highway 10 (or 3 miles south of I 80 exit 279), 2 miles east on V Road, then 3/4 mile south on 34 Road.   Wednesday, September 3, 6:30 p.m., on ground farmed by Bruce Luebbe near Goehner. Directions: From the Goehner I-80 exit (No. 373): Go 1/2 mile north on 364th Road (to Goehner), 2 miles west on Holdrege Road, then 1/2 mile north on 392nd Road.   Thursday, September 4, 6:30 p.m., on ground farmed by Dave Ellinghausen near West Point. Directions: From the Hwy 275 and 32 junction south of West Point go 5 miles south on Highway 275, 3 miles east on B Road, then 1/4 mile south on 20th Road.

Yield losses of 20%-30% have been documented in the state with no above ground symptoms on the plant. While soybean rust has received much attention, SCN has earned the title of "The Silent Yield Robber."

In late August and early September UNL Extension will host four field days to alert growers to the damage caused by soybean cyst nematodes in Nebraska. Farmers and agricultural professionals can learn how to identify and manage SCN to minimize its impact on yields.

If SCN caused holes, lesions, spots or other plant abnormalities, it would be much easier to convince producers to test for and manage it. However, infested plants usually look healthy. The first indication of a problem is soybean yields that have leveled off or even started to drop while corn or other crop yields in the same field continue to improve.

Originally identified in counties bordering the Missouri River, SCN has been identified in 45 counties in eastern and central Nebraska as far west as Boyd, Holt, Valley Buffalo, Kearney and Red Willow counties. As soybean production has moved across the state, so has the distribution of soybean cyst nematodes.

At each field day, participants will be able to:

• See SCN resistant and susceptible soybean varieties
• Examine cysts on infested soybean plant roots
• Learn how to identify and manage SCN infestations
• Receive a kit for one free SCN analysis ($20 value)
• Get answers to questions on SCN

In 2006 and 2007 at eight sites infested with SCN, resistant varieties outyielded susceptible varieties by an average of five bushels per acre. These infested sites had low to moderate levels of infestation. There was no difference in yield between the same susceptible and resistant varieties at a site which was not infested with SCN.

The Soybean Cyst Nematode Field Days are presented by UNL Extension with support from the Nebraska Soybean Board. For more information, contact your local UNL Extension office.

John Wilson
Extension Educator, Burt County