One objective of Latham’s SuperStrip plot program is to help evaluate experimental seed products. Now that the 2017 harvest data has been analyzed, it’s my pleasure to introduce three soybean lines as mid-season releases for the 2017-2018 sales year.

These new soybeans come from our research on a new herbicide trait, the HPPD inhibitors, or Herbicide Group 27 compounds. The active ingredient being targeted is isoxaflutole, which is the base chemistry in several corn herbicides like Corvus® and Balance® Flexx.

You may have seen early announcements that the “Balance™ GT” soybean trait had cleared regulatory processes. It’s important to understand that as of press time, the EPA has NOT approved any isoxaflutole compounds to be sprayed over the top of soybeans. We are releasing these three cultivars as “GT” soybeans since they are cleared to be sprayed with glyphosate products only.

Remember to check LathamSeeds.com for 2017 yield data on these newly released soybeans!

L 2187 GT
2.1 Relative Maturity
Carries the Rps1-c gene for Phytophthora, as well as Soybean Cyst Nematode (SCN) tolerance from PI 88788.vIts ratings for Sudden Death Syndrome (SDS) and White Mold ratings are excellent, and its Iron Chlorosis score is very good. This line ranked in the top three in every trial in which it was entered during both 2015 and 2016!

L 2458 GT
2.4 Relative Maturity
Produces excellent yields across Iowa and into Illinois. It carries the K-gene for Phytophthora and strong tolerance to SCN from PI 88788. The Brown Stem Rot rating is excellent. It also has very good scores for White Mold, SDS and Iron Chlorosis. It has a very attractive tawny color at harvest and is also tolerant to the STS family of herbicides.

L 2638 GT 
2.6 Relative Maturity
Carries the Rps1-k gene for Phytophthora and has strong tolerance to SCN from PI 88788. It’s a fairly bushy plant type that fills wider rows easily and has shown very consistent yields across all of Latham Country in 2015 and 2016 trials. Sudden Death, Brown Stem Rot, White Mold and Iron Chlorosis ratings are all very good to excellent.

The topic of green soybean stems at harvest was discussed at several of our post-harvest meetings. What makes this disorder especially frustrating is that the soybean pods and beans within those pods are fully mature and ready to harvest.

Unfortunately, all plants have a built-in mechanism that makes them want to shed their seeds on the ground when they’ve reached full maturity. This process is called dehiscence [di-’hi-s  n(t)s] in soybeans and has erroneously been referred to as “shattering” by many. Regardless of what it is called, lost yield and lost income results.

There are several theories about what causes Green Stem Syndrome (GSS) but an exact diagnosis has not been found.  Some researchers blame insects, diseases, foliar fungicides, nutrient deficiencies, low pH and even compaction. The bottom line, however, is that GSS has been proven to occur in the absence of all the above conditions. To make matters worse, the symptoms of GSS are not always the same.  There are cases where all that is left on the plant are green stems and pods, but there are other cases where even some leaves remain on the plant. One thing that has been noticed is that it usually happens within a given geographic area or “neighborhood.” Also, GSS has never been associated with just one soybean variety from a single company.

One of the more practical explanations for this problem is something happened during the growing season, probably after flowering, to cause pods to abort or not to fill properly. This produces an abnormal build-up of carbohydrates within the plant. Once that early-season stress has gone away, the plant wants to funnel those carbohydrates to the pods for seed-fill. However, the pods are
either not there or they can’t finish the process. Carbohydrates are then trapped within the stem of the plant for a longer-than-normal period, so the stem remains green.

There really isn’t any clear way to manage or prevent this problem. One thing I highly recommend is NOT to wait to harvest soybeans that are showing GSS, but to slow the combine down as much as necessary and get them out of the field. Waiting until the stems are dry almost always costs you in lost bushels.