Wednesday, November 26, 2014

Should We Be Using Soybean Maturity Group as a Tool for Variety Selection?

Over the last decade I have noticed a subtle shift across much of the northern soybean growing region towards planting later maturity group soybeans. This shift, either conscious or unconscious, may be attributed to earlier planting dates, relatively favorable fall harvest windows, and the drive for maximum yield as influenced by high commodity prices. As with all trends sooner or later, we have a correction year: 2014 was that year for many farmers. As farmers, consultants, and the battered and bruised seed suppliers sort through the plethora of product offerings for 2015, a common question arises: "In 2015, how much weight should we really give to maturity group in these seed decisions?". For those of you with short attention spans like me, the short answer for soybean is not much....for the rest of you please read on to understand my reasoning.

In 2011, the WI Soybean Research Program published an article in the journal Crop Management entitled: "Optimal Soybean Maturity Groups for Seed Yield and Quality in WI" (Furseth et al, 2011). In this data set we looked at 893 varieties across 6 growing seasons (2004-2009) and three production regions in WI . Within each region we identified the optimal maturity group range for maximum yield. Those were 2.6-2.9, 2.1-2.4, and 2.0-2.2 for our southern, central and north central regions respectively.  After I make this provocative statement this is usually where the audience either falls asleep, starts texting their neighbor about the lame and inept speaker (me), or uses the restroom and fails to hear as the great Paul Harvey would say ......the rest of the story.

Within each figure below you will also notice a maroon line directly below the black yield regression slope. This maroon line indicates the range of maturity groups that lie within 10% of maximum yield. These figures suggest that regardless of growing region in WI growers can select a variety that is almost one full maturity group earlier than the optimal maturity group range for maximum yield and still be within 10% of maximum yield.

These data further support Joe Lauer's assertion that "Every hybrid (or in our case cultivar or variety) must stand on its own" (Happy Thanksgiving JGL, you were positively quoted in a soybean article). In our recently released 2014 WI Soybean Variety Test Results book the maturity group range that included a starred variety (starred varieties do not differ from the highest yield variety in that test) was 1.9-2.8, 1.1-2.4,and 0.9-2.0 in our southern, central and north central regions respectively. This amplifies my assertion that the "relative" maturity group rating is trumped by individual cultivar genetic yield potential.


Lastly, since I brought it up lets also discuss our "relative" soybean maturity group rating system. If anyone has ever observed a multi-company variety trial in the fall, they may have notice many differences in maturity amongst varieties that have the same MG rating. For example in our 2014 Southern Region Glyphosate Tolerant Soybean Test we noted a 7 day maturity date range among all the 2.4 maturity group varieties listed. This may not seem important at the end of September, but in years when we plant late (Table 1), have a cool growing season and apply a fungicide those few days may matter. 

As seed decisions are made for 2015, it is fine to keep the relative maturity rating on your check list, just don't have it near the top!

Table 1. Calendar date for reaching R5 (beginning seed fill) and R7 (beginning maturity) growth stage (G.S.) by planting date and maturity group (M.G.) for the 2014 growing season at Hancock WI.

Timing of G.S. Initiation
Planting Date M.G. R5 R7
5-May 1.9 29-Jul 3-Sep

2.1 3-Aug 13-Sep

2.1 29-Jul 3-Sep

2.1 29-Jul 3-Sep

2.3 29-Jul 3-Sep

2.3 1-Aug 6-Sep

2.4 3-Aug 6-Sep

2.5 29-Jul 6-Sep

2.5 30-Jul 6-Sep

2.5 31-Jul 13-Sep
22-May 1.9 12-Aug 12-Sep

2.1 9-Aug 20-Sep

2.1 12-Aug 16-Sep

2.1 12-Aug 20-Sep

2.3 12-Aug 20-Sep

2.3 9-Aug 20-Sep

2.4 12-Aug 16-Sep

2.5 12-Aug 16-Sep

2.5 12-Aug 20-Sep

2.5 12-Aug 20-Sep
11-Jun 1.9 23-Aug 27-Sep

2.1 23-Aug 2-Oct

2.1 23-Aug 30-Sep

2.1 23-Aug 2-Oct

2.3 23-Aug 2-Oct

2.3 23-Aug 30-Sep

2.4 23-Aug 1-Oct

2.5 23-Aug 2-Oct

2.5 23-Aug 2-Oct
2.5 23-Aug 2-Oct


Literature cited: 
Furseth, B. J., Zhao, Y., Conley, S. P., Martinka, M., and Gaska, J. 2011. Optimum Soybean Maturity Groups for Seed Yield and Quality in Wisconsin. Crop Management. Online. Crop Management doi:10.1094/CM-2011-0622-01-RS.

Tuesday, November 25, 2014

Finalists for the 2014 WI Soybean Yield Contest are Announced

The 2014 growing season proved to be yet another challenging year for many WI soybean growers.  Given these widespread challenges, we again experienced great interest in the 2014 WSA/WSMB Soybean Yield Contest.  The top two entries in each division (in no particular order) were:

Division 4: 
  • Tim McComish, Shullsburg (planted Channel 2402R2 Brand)
  • Kevin Bahr, Darlington (planted Channel 2402R2 Brand)
Division 3:
  • Travis Van De Hey, Kaukauna (planted DuPont Pioneer P22T69R)
  • Ron Ellis, Walworth (planted Jung 1250RR2)  
  • *WI Bean Team (Adam Gaspar, David Marbuger, Ethan Smidt), Madison (planted DuPont Pioneer P28T33R) 
*The WI Bean Team is ineligible for official prizes as they are grad students of Dr. Conley; however their efforts are still unofficially recognized.  

Division 2:
  • Steven Stetzer, Melrose (planted NK Brand 17G8) 
  • Steven Kloos, Stratford (planted  DuPont Pioneer 91Y90) 
Division 1: 
  • Paul Graf, Sturgeon Bay (planted DuPont Pioneer 90Y90) 
  • Jerry Koser, Almena (planted DuPont Pioneer 91M10)
The final ranking and awards will be presented at the 2015 Corn Soy Expo to be held at the Kalahari Convention Center, Wisconsin Dells on Thursday January 29th during the WSA/WSMB annual meeting.

The contest is sponsored by the WI Soybean Program and organized to encourage the development of new and innovative management practices and to show the importance of using sound cultural practices in WI soybean production.

For more information please contact Shawn Conley, WI State Soybean Specialist at 608-262-7975 or spconley@wisc.edu


Thursday, September 18, 2014

Fall is Still a Good Time to Sample for SCN and Other Plant Parasitic Nematodes

The WI Soybean Marketing Board (WSMB) sponsors free nematode testing to help producers stay ahead of the most important nematode pest of soybean, the soybean cyst nematode (SCN). Eggs of SCN persist in the soil between soybean crops so a sample can be submitted any time that is convenient. The soil test report indicates the number of eggs in the sample and is useful for selecting the right variety for the next soybean crop. Retests of fields planted with SCN-resistant varieties over multiple years shows how the nematode population is responding to variety resistance and provides an early warning should the nematode population adapt to host genetics.

In the spring of 2012, the WSMB expanded the nematode testing program to include other pest nematodes in addition to SCN. These nematodes are less damaging to soybean than SCN but can cause enough yield loss to warrant treatment. As is the case for SCN, there are no rescue treatments for nematodes so the primary purpose of this year’s soil test is to plan for next year’s crop. Soil samples collected in corn for nematode analysis have predictive value for explaining yield if they are collected before the corn V6 growth stage. Sampling early in the season will provide information about the risk potential for the current corn crop AND the next soybean crop.

The assays used to recover nematode pests other than SCN in soil require that the nematodes are alive. So, it is important to keep the samples moist and at least room temperature cool. Collecting a sample that includes multiple cores ensures that there will be plenty of root pieces to assay. It is not necessary to include live plants in the sample. The soil test report will indicate which pest nematodes are present and at what quantities and their damage potential to soybean and corn based on the numbers recovered.  

Free soil sample test kits are available now and can be requested from Jillene Fisch at (freescntest@mailplus.wisc.edu) or at 608-262-1390.
For more information on SCN testing and management practices to help reduce the losses from this pest, please contact: Shawn Conley: spconley@wisc.edu; 608-262-7975 or visit www.coolbean.info.

Remember the first step in fixing a nematode problem is to know if you have one! The WSMB sponsored nematode testing program provides you that opportunity.

Monday, September 15, 2014

Harvest Considerations for Variable Soybean Maturity

Variable soil types, knolls, flooding and drought have left many growers with extreme in-field variability of soybean maturity.   There are areas in fields where the soybean seed is 13% or less moisture adjacent to areas with green seed.  The prevailing question is “When should the grower harvest?” Obviously there is no simple answer, as each field is different. However here are a set of guidelines to consider:
1.    The easiest answer is harvest the field at two different times. Take what is dry today and come back in two weeks and harvest the rest. The challenge with this approach is that today’s equipment is large and not easily moved from field to field. Furthermore many growers rent or own land over large areas where this is impractical and the whole field must be taken at once. So……
2.     The next simple answer is wait until the whole field is ready to go. As noted in our article Drought Induced Shatter, we are seeing areas across the Midwest where shattering is occurring. The general rule of thumb is 4 seeds per square foot = one bushel yield loss. At local cash prices dipping below $10.00 per bushel this is hard to see happen and not harvest. Furthermore, waiting will also lead to moisture loss in the field. As we learned the past few years, you do not get compensated for harvesting below 13% moisture. So…..
3.     If growers are concerned with shatter and/or other harvest losses the next logical approach is harvest ASAP. This opens a whole new can of worms. Harvesting ASAP will lead to a mixture of dry, wet, and immature (green) soybean seed. Be aware that if you harvest this mixture regardless of the ratio, your combine moisture sensor may not detect the correct moisture, be prepared for that initial shock when the elevator tests the grain. Next be prepared for the dockage. Most combines will leave more beans in the pod when they are wet or immature.   These beans may end up on the ground or in the grain tank as unthreshed soybeans. Harvesting seed with this variability will be very similar to handling frosted soybean seed so discounts may occur due to moisture shrink, damage (green beans are considered damage), foreign material (this is usually higher when harvesting wet beans), test weight, and heating. If you choose on farm storage to address some of the dockage concerns please refer to Soybean Drying and Storage for questions.  

4.  The last consideration I would bring forward is that the mature areas are likely going to be the low yielding pockets due to drought whereas the yet to mature areas will likely be the higher yielding areas within the field. So, in short, which yield environment would you rather focus your time and efforts to protect?  

      The question ultimately comes down to the bottom line and where you make the most $$$. If shatter is not occurring and you have good equipment that does not incur significant harvest loss, will harvesting grain that is over-dry make you more money than harvesting seed that may incur significant dockage? My guess is yes but you tell me!
Image 1. Variable Maturity (M. Rankin)

Monday, September 8, 2014

Odds My Soybean Crop Will Mature Before A Killing Frost Hits

The Wisconsin soybean crop is slowly starting to mature, however many growers and crop consultants are still concerned about the risk of frost damage to late planted fields.  In soybean an extended period (several hours) of temperatures 28 degrees F or lower is required to completely kill a soybean plant, though temperatures 32 degrees or less can still damage top growth. Those growers considering the state of their soybean crop and wondering the odds of making it to maturity before significant yield loss occurs must first correctly identify the soybean growth stage.

Once the crop growth stage has been determined we can estimate the number of days it will take for your field to reach R7 or physiological maturity.  Across our Arlington and Hancock field sites in 2014 it has taken 5-8 days to go from R3 to R4, 7-8 days to go from R4 to R5, 10-14 days from R5 to R6 and 15-20 days from R6 to R7. As a point of reference our June 20th planted soybean at both locations just hit R6 this week. Next using the three figures below that show the 10th percentile, median, and 90th percentile date when you can expect a freeze event you can estimate the risk of a frost based on your crop growth stage.

For example: If you lived in SW Marathon county there is a 10% chance that a freeze event would have occurred prior to September 11-20, a 50/50 chance that a freeze event would occur prior to September 21-30, and a 90% chance a freeze event would have occurred prior to October 1-10. So if your soybean crop just entered the R5 crop growth stage today 9/8/14 there is a greater than a 50/50 chance that crop won't make grain based on historical weather data.

Lastly if you are concerned about a freeze event please refer to Table 1 below that provides yield loss estimates of freeze damage by crop crop stage. This may help you decide whether you should risk taking the late planted soybean field as a grain crop or would that field be more valuable as a forage or green manure?


Table 1. Soybean Response to Freeze Damage
Growth Stage
Yield Reduction
R4 - Full pod
70%-80%
R5 - Beginning seed
50%-70%
R6 - Full seed
15%-30%
R7 - Beginning maturity
0%-5%
R8 - Full maturity
0%
Source: Saliba et. at. Kansas State University, 1982




Friday, August 29, 2014

Do Not Plant Saved Wheat Seed This Fall!

The race to turn the 2014 wheat crop into 2014/15 seed is on and early lab samples confirm that the percent germination from on farm sampled wheat is low. The Wisconsin Crop Improvement Association has received over 100 samples to date and over 30% have exhibited visual signs of Fusarium Head Scab (FHB) or scab. The % germ from the infected samples range from 53 to 98% (variety dependent) with an average % germ of 79%. First class certified wheat requires a minimum % germ of 85%. Furthermore invest in a wheat fungicide seed treatment this fall. Seed applied fungicides can increase % germination. On a small sample size (N = 4) the average percent germination from the addition of a seed applied fungicide increased average germination from 76 to 93%. Lastly all signs point to a late wheat establishment season. With that in mind remember to plant certified or private new seed, use a fungicide seed treatment and starting increasing your seeding rate after October 1. For more information on wheat establishment please see: Top 7 Recommendations for Winter Wheat Establishment in 2014.

Wednesday, August 6, 2014

2014 WI Soybean Yield Contest Entry Deadline is September 1

Wisconsin soybean growers have until September 1, 2014 to enter the Wisconsin Soybean Yield Contest. Two winners from each of four geographical districts in the state will receive awards (Image 1.).  "Please note the divisional lines were redrawn for 2014 based on a rolling 10 year average yield".   The first place award in each district includes a $1,000 cash prize; second-place honors include a $500 prize. Winners will be selected for having the highest soybean yield based on bushels per acre at 13% moisture. The awards ceremony is scheduled for January 29, 2015 during the Corn/Soy Expo at WI Dells.  

For more detailed information regarding the program and contest rules please visit www.coolbean.info or 2014 Wisconsin Soybean Yield Contest Rules

Entry forms can be found at 2014Wisconsin Soybean Yield Contest Entry Form.

A list of the 2013 winners and a management summary of their practices is also provided. 

For more information please contact Dr. Conley at spconley@wisc.edu. Good luck and have a safe and productive 2014 growing season!


Image 1. Geographic Division Map.