Renewable Farming

With signs of soybean SDS and dying corn, how will big crops hold up until harvest?

USDA’s Crop Condition Reports reflect little change in Iowa soybean condition this week, but farmers studying bean fields around the state are describing early symptoms of Sudden Death Syndrome.

At the Aug. 30 barbecue meeting hosted by consultants Bob Streit and Marv Mortensen at Boone, IA, Bob challenged USDA crop reporters to adjust soybean conditions to reflect advances in SDS and other fungal diseases. 

Streit briefing farmers at supper following the Farm Progress Show



“Anyone who has flown over central Iowa at 400 feet has seen how rapidly the yellowing patches are showing up in soybeans,” he told farmers at the supper hosted by Central Iowa Agronomy and Supply Ltd.

Reports from our clients around Iowa confirm Bob’s observation. And on Sept. 2 we received the photo below from Dave Sutherland in Ontario, Canada. He said “Lots of soybean fields look like this.”  The yellowing is not maturity, it is fungal disease.


SDS and possibly other soybean fungal disease in southern Ontario












Update as of Sept. 4: Two photos shot in Black Hawk County and Grundy County, IA today confirm that soybeans are losing leaves faster than normal senescence. The leaf loss generally starts in patches that were wet earlier in the season, and spreads from there. Here’s an example:

SDS and resistant weeds… double whammy


There are apparently differences between soybean varieties on their susceptibility to SDS.  Here’s a test plot where differences in maturity don’t explain the variation in early leaf drop:

If the yellowing was consistent through the strip, it would probably be maturity. If not, disease.

Bob also briefed farmers on how to watch for the “new” Goss’ wilt on corn. He showed stalks which are dying from the ground up, taken from central Iowa fields. Observers say the corn “die-down” is not as early as in 2015. Farmers who applied Bio Empruv, a product we tested in 2014 and 2015, are seeing their corn remain green from top to bottom.

Adding 30 to 50 more active filling days to corn’s life is worth a bushel a day, says Bob. 

Last Friday, Aug. 26, Nebraska-based crop pathologists and other officials confirmed “Bacterial Leaf Streak” of corn in Nebraska, Iowa, Illinois, Kansas and Colorado.

“Initial observations and survey results suggest that it may be widely distributed throughout the Corn Belt,” say the plant health specialists in a news release by the Nebraska Institute of Agriculture and Natural Resources.