As of Sept. 10, 2016, our soybean research strips in Black Hawk County, northeast Iowa, are among the few bean fields which haven’t yellowed and dropped at least some leaves in broad, irregular swatches.
Below is one of our own research patches. This is a non-GMO eMerge Genetics E3192 bean, planted in mid-May. As of Sept. 10, it hasn’t shown any senescence or leaf loss. Pods are almost filled, even at the top. Some new pods are still forming on fresh growth. The only special treatment these beans had was in-furrow nutrition with a little potassium sulfate, and “Lignition” — a growth promoter we are testing for the third season. These beans were also sprayed in August with Cobra and WakeUP Summer to whack weed escapes. We’ve had abundant rain all summer, and weeds will find a way.
The fields around us, and across much of Iowa, look like the soybeans are dying — it’s not a uniform maturity that we’re seeing. It appears linked to drainage or soil types, indicating that stress through the season is involved.
Consultants say that’s Sudden Death Syndrome. It hits first and hardest where the fungal disease finds the lowest-immunity beans.
Here’s an example of a typical field not far from our place. It looked beautiful all season: Drilled with a GMO variety, sprayed with a GMO-linked weedkiller and not a weed in it. As of Sept. 10, some low-stress patches are still bright green. But widening areas have lost leaves. The grower did “everything right” here.