Once you have it, you have it! Because sudden death syndrome (SDS) is caused by a soil-borne fungus, there’s no getting rid of it. Farmers must manage it to protect yield. Keep in mind that SDS was widespread in 2016, and many of those acres will be planted once again to soybeans in 2018.

The most promising tactic for SDS management is ILeVO® seed treatment. Numerous university trials have shown ILeVO effectively reduces SDS severity and protects yield. In addition, Latham’s own research confirms the findings.

With the help of many of Latham® soybean SuperStrip cooperators, our first company-wide trial using ILeVO was held in 2016. That year SDS was widespread, so many farmers across Latham Country lost significant yield to the disease. Our 26 plots showed an average yield benefit of about 3.5 bushels per acre.

This past growing season, however, SDS was not nearly as severe. Certain counties in Central and Eastern Iowa were impacted greatly by the disease but, in general, it was a season where SDS showed up late and didn’t cause as much lost yield.

We doubled the number of side-by-side plots from 2016 to 2017, and we added a few more varieties to the test. Results varied quite a bit by location due to disease severity and the soybean that was used in the study.

Following are a few observations based on the data gathered in 2017:

• The highest yield benefit was seen in a plot in Hancock County, Iowa, where L 1858 R2 was the soybean treated and came in at 8.27 bushels per acre benefit.
• Although SDS severity was down from 2016, we saw some significant differences in response between soybean varieties. Products like L 1858 R2 and L 2558 L, which are not known for their SDS tolerance, showed the most benefit from the ILeVO.
• In 2016, we saw a few plots where the ILeVO seed treatment showed a negative response. Statistically, this is not unusual nor unexpected. We saw this again in 2017 but not to the magnitude observed in 2016. Both L 2084 R2 and L 1787 L averaged a negative response (-0.9 and -0.6 respectively).
• Across the 51 plots, we saw about a ½ bushel per acre yield benefit for applying ILeVO seed treatment.

We plan to conduct another ILeVO trial in 2018. Feel free to contact me or your Latham RSM if you’re interested in being an ILeVO plot cooperator.

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.