Notes from Soybean Observation Travels

It’s that time of year when Latham Product Teams are looking at SuperStrip™ and other research plots. Our SuperStrip trials are replicated in several plots across multiple locations to help us determine which products to either advance or keep in our lineup.

Below are a few things I am noticing in soybean fields as I travel across Latham Country:

• Soybean Gall Midge: The larval stage of this relatively new insect pest can attack soybeans at the base of the plant, weaken it and cause it to break off at ground level. It was first reported in Nebraska in 2011 and South Dakota in 2015. For 2020, it was first spotted June 10 in Cass County, Nebraska, just east of Lincoln. Farmers in eastern Nebraska, southeast South Dakota, northwest Iowa and southwest Minnesota especially should be on the lookout for this pest. Focus on the edges of soybean fields and look for stunted and/or wilting plants that have a blackened area at the base of the stem. Peel back the outer layer of the stem and use a magnifying glass to see if you can find the white or light-orange colored larvae that look like maggots. State Extension personnel are requesting that all populations of Soybean Gall Midge be reported to them, so they can better track the spread of this devastating insect.
• Soybean Aphid: The dry weather that most of Latham Country has experienced of late has slowed the infestation of this pest. I have seen very few aphids and none of the fields I’ve walked are even close to threshold for an application of insecticide. There have been, however, a few scattered reports of fields sprayed in south central Minnesota and western Wisconsin. Remember, research has proven that severe damage to soybean plants only comes when aphid levels are at or above 600 aphids per plant!This is significantly higher than the recommended economic threshold over the entire field of 250 aphids per plant at R5 or earlier with an actively increasing population. Don’t get fooled into thinking that if you estimate you have 300 aphids per plant at the above stage of growth that you have already lost significant yield. It just means that it is probably time to pull the trigger on an insecticide application if all the other factors are in line. Recent rains in some areas may increase the likelihood that Soybean Aphids will increase this year. Levels can change very quickly, so scout early and scout often!
• Other notes: I expect we’ll see some scattered patches of Sudden Death Syndrome (SDS) and White Mold. Continue to scout your fields all the way to maturity, so you don’t have any big surprises come harvest. Although we planted soybean fields earlier than normal in 2020, I’m seeing pod fill begin at a slower pace than normal. I suspect the cold weather we had in mid-May combined with lack of rain in July and early August is to blame.

This year has certainly provided all of us with challenges. As always, we keep putting one foot ahead of the other. “We were made for this.” We soon will be accepting seed beans at our Alexander location, and that is always an exciting time of year. As we head into harvest, stay safe!