Harvest Considerations for Variable Soybean Maturity

Variable soil types, knolls, flooding and ponding, variable planting dates and random pest pressure have left many growers with extreme (worst I have ever seen) in-field variability of soybean maturity in 2019.   There are areas in fields where the soybean seed is approaching maturity 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 a past article entitled 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 hovering near $8.00 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 early senescence 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)

High Value Straw and Weedy Wheat…What Do I Do?

Wet fields, thin stands and spotty winter-kill made spring weed control difficult to impossible in many winter wheat fields, and prolonged wet conditions have encouraged prolific weed growth from competitive broadleaf weeds like giant ragweed and lambsquarters. As we approach harvest in southern WI (week of July 21st) growers simply have limited herbicide options for preharvest weed management. The most popular ones are:

  1. 2,4-D products. There is a 14 day pre-harvest interval with this product. Pre-harvest treatment can be applied when grain is in the dough stage. Only one preharvest application per crop cycle allowed and a maximum of 0.5 lb 2,4-D acid equivalent per acre per application. Please read label for specific product used as there are differences among labels.
  2. Glyphosate products. There is also a 7 day pre-harvest interval with this product, and it can NOT be applied until the grain is at the hard-dough stage (30% moisture or less). Grain treated with glyphosate at this growth stage should not be used for seed as germination can be significantly lowered. Maximum of 0.77 lb glyphosate acid equivalent per acre per application (equivalent of 22 fl oz of Roundup PowerMax per acre).

Some benefits to applying preharvest 2,4-d or glyphosate may include desiccation of green weedy plants to enable an easier combine harvest and quicken the ability to bale straw following the grain harvest. However, drawbacks include a narrow window of application timing ahead of harvest, wheel tracks (if ground applied) will reduce grain yields, and moreover many of the weeds like giant ragweed, waterhemp and lambsquarters will be large and difficult to control. Drift is also a concern when spraying crops this late in the season, particularly with synthetic auxin herbicides such as 2,4-D. Thus, consider a preharvest 2,4-d or glyphosate application as a last resource because partial control of large weeds will greatly increase selection pressure for herbicide resistance. We already have several issues of herbicide resistance in Wisconsin (http://www.wiscweeds.info/post/herbicide-resistance-in-wisconsin-an-overview/).

Shawn P Conley and Rodrigo Werle

A Tank Full of Sugar Helps the Profits Go Down

Adapted from original article written 6/1/2015.

This growing season has been what I can best describe as “Craptacular“. Farmers are under severe economic stress and are looking to squeeze the highest yields possible out of whatever acres they were able to get planted. Across the Midwest post emergence herbicide applications are going out and farmers are considering what else to add into the tank to “help” their crops. This year the question of sugar has resurfaced so I thought I would dust off and re-post the below article originally entitled “Do Foliar Applications of Sugar Improve Soybean Yield”.

I also wanted to link to a few other articles from colleagues at the University of Nebraska “Sugar Applications to Crops – Nebraska On-Farm Research Network Results” and “Research Results: Sugar Applications to Crops“. In short the University of Nebraska team did not find a consistent yield increase in corn or sorghum and averaged 0.8 bu per acre in soybean. If farmers are considering a pass for just the sugar application the average cost of ground application in $7.65 and aerial is $10.75; 2019 Iowa Farm Custom Rate Survey and the average yield loss caused by sprayer wheel track damage in soybean in rows less than 20 inches is 1.9 or 1.3% with a 90 or 120 foot boom, respectively.

I also want to give credit to my colleague Chad Lee who wrote a nice article entitled “Could Sugar Help Drought Stressed Corn?” that discusses sugar rates, biological activity and actual costs of product.

I am certain this re-posted article will stir up the same severe indignation as the original, however when the local cash bids are averaging $8.42 ROI is more important than ever.

Do Foliar Applications of Sugar Improve Soybean Yield (Originally published: June 14th, 2011)

High commodity prices have led growers to consider many novel soybean inputs. One input that has garnered considerable attention is the foliar application of sugar products to increase soybean yield. The objective of this research was to evaluate soybean yield in response to various sources of foliar-applied sugar across four states in the Midwest. Field research studies were conducted at Arlington, Wisconsin; Urbana, Illinois; St. Paul, Minnesota; and West Lafayette, Indiana in 2010.The four sources of sugar evaluated in this study were:

  1. Granulated cane sugar
  2. High fructose corn syrup
  3. Molasses
  4. Blackstrap molasses.

All treatments were applied at the equivalent rate of 3 lb sugar a-1 and applied at 15 to 20 gal a-1. The treatments consisted of an untreated check, all four sources of sugar applied at V4, granulated cane sugar and blackstrap molasses applied at R1, granulated cane sugar applied at V4 and R1, and blackstrap molasses applied at V4 and R1.

No positive or negative (phytotoxic) effects were visually observed on the soybean foliage at any location within 10 days following foliar applications (data not shown). Furthermore, sugar did not increase soybean yield within location (data no shown) or across locations [P= 0.60 (Figure 1)], regardless of source. While this study cannot conclusively prove foliar applications of sugar will not increase soybean yield, the authors conclude that other management strategies to improve soybean yield should take precedence over applying sugar.

 

The source of this data is:

Furseth, B. J., Davis, V., Naeve, S., Casteel, S., and Conley, S. P. 2011. Soybean Seed Yield Was Not Influenced by Foliar Applications of Sugar. Crop Management. Accepted: 6/1/11.

Please visit: http://www.plantmanagementnetwork.org/sub/cm/brief/2011/sugar/ to view the entire manuscript.

Soybean and Corn are Considered Cover Crop Options in WI

Article written by Shawn P. Conley, Joe Lauer and Paul Mitchell

Today Joe Lauer and myself had the opportunity to travel to Door County and participate in an Extension meeting hosted by Annie Deutsch, Jamie Patton and Aerica Bjurstrom. We had great conversation with the group about the agronomic implications of the 2019 growing season. During this meeting we touched on the issues regarding prevent plant and what to do next. This is a obviously a complex issue but an interesting point was brought forward by Dan Muhlenbeck a crop insurance specialist… “Is soybean and/or corn considered a cover crop in WI?”  (I hope you all notice that in my blogs soybean always precedes corn..) Here are our thoughts.

For a crop to be considered a cover crop RMA states that “For crop insurance purposes, a cover crop is a crop generally recognized by agricultural experts as agronomically sound for the area for erosion control or other purposes related to conservation or soil improvement.” Soybean and corn both meet this requirement. However please remember that BMP’s must be followed to meet this requirement.

In a late planted, soybean cover crop situation, plant a minimum of 150,000 seeds per acre and strive to plant in narrow row spacings (<30 inches). This recommendation is intended to minimize soil erosion, maximize ground cover and weed suppression as well as provide adequate N fixation. I do however understand if a farm operation is limited by equipment restrictions (e.g. they only have a 30 inch row planter) I would not preclude them from being eligible to plant soybean as a cover crop. The next consideration is cost. Normally the cost of soybean seed to be used as a cover crop on a per acre basis would be cost prohibitive; however since soybean seed is usually not saved from year to year and treated seed is often devitalized it is often offered at a deep discount late in the year so shop around. Frankly with only 60% of the WI crop planted there should be some reasonably priced seed to be used as cover crops.Now lets talk about corn!

Although corn is not usually considered a cover crop due to 30-inch row spacing and slower early canopy growth than other crops, it is deep-rooted and by the end of the end of the growing season can produce more than 5 Tons DM/A of stover even when planted in July. Ultimately the decision to use corn as a cover crop is the cost of production. Typically, it would cost $400 to $450 per acre to establish corn. Production costs can be reduced by using seed that is not bioengineered, reducing N fertilizer to around 40 to 60 lb N/A, and using a narrower row corn planter (<30-inches), a twin-row planter, or grain drill to narrow row-spacing.

To be clear the intent of this article is to designate that soybean or corn can be considered as options for cover crops. The first thing you must do however is talk to your crop insurance agent and make no decisions without their input. Also please review this excellent article by Paul Mitchell entitled: Can I Use Corn or Soybeans as a Cover Crop on Prevented Plant Acres?

Farmers taking the full prevented plant indemnity should note that they cannot ever harvest the cover crop for grain or seed. RMA rules allow, only after September 1, grazing and harvest as hay (for bedding or feed) and now for silage, haylage or baleage. If a farmer wants to harvest it as grain or seed, then they should declare it as an alternative crop and only collected the partial (35%) prevented plant indemnity.”

With the aforementioned change to prevent plant indemnity the question of soybean as a forage popped into my mailbox multiple times today. From an agronomic perspective I think there are better forage options (higher tonnage) than soybean, but if this is an option for your farm here are some simple thoughts. Harvesting soybeans for forage between the R1 and R5 stage will result in a very high quality silage, but dry matter yields will be reduced significantly. Forage quality will be reduced from R5 soybean forward if a conditioning process is used during harvest as conditioning will cause significant seed shattering. According to our data early maturity group soybeans planted 6/20ish will likely already be at the R6/R7 stage so if you are intending to shoot for higher quality soybean forage go with a later maturity group soybean (~4.0).

Figure 1. Pooled Arlington and Hancock Data.

Figure 2. Spooner data.

 

This is a dynamic discussion so please check back as text and recommendations are subject to change as “to be frank” no one really has all the answers on this topic.

Soybean Flowers, Herbicide Labels, and Wheel Track Damage…Oh My!

Authored by Shawn P. Conley and Rodrigo Werle

We are starting to get the first reports of soybean beginning to flower (R1) in our early planted situations. As we enter the soybean reproductive growth phase there are a few things to keep in mind. The first is that soybean will produce flowers for ~3 to five weeks, depending upon planting date and environment. During that time soybean will abort anywhere from 20 to 80% of the flowers that they produce. Generally it is the first and last flush of flowers produced that are most likely to be aborted.

R1 soybean growth stage

Next, the timing window for many POST-emergence herbicide applications in our early planted soybean are quickly closing if not closed already. Glyphosate labels indicate that applications can be made through R2 or full flower, however the spread of glyphosate-resistant waterhemp and other weeds across Wisconsin and beyond has led several farmers to adopt soybean varieties containing the novel herbicide resistance traits (Xtend [which confers resistance to glyphosate and dicamba], Enlist E3 [glyphosate, glufosinate and 2,4-D] or LibertyLink GT27 [glyphosate and glufosinate]), which all provide effective herbicide options for POST-emergence broadleaf weed control. The application window for the POST-emergence herbicides associated with the aforementioned traits is also linked to soybean reproductive growth stages.

In Xtend systems, the registered dicamba herbicides Engenia, FeXapan and XtendiMax can be applied through 45 days after planting or up until R1 (first bloom; in other words, don’t apply if the soybeans are flowering), whichever comes first.

In LibertyLink systems (LL, LLGT27 or Enlist E3), glufosinate herbicides such as Liberty, Scout, Interline, etc. can be applied up to bloom or R1 growth stage (don’t apply if the soybeans are at R2 stage or advanced).

In Enlist E3 systems, the registered 2,4-D herbicides Enlist One and Enlist Duo should be applied no later than R2 or full flowering stage.

When deciding the best time for a POST application, target small weeds, follow all label requirements and don’t spray under adverse environmental conditions.

Soybean developmental note: on average it takes ~ 4 days to move from R1 (beginning flower) to R2 (full flower) and ~10 days from R2 to the start of R3 (beginning pod).

Last but not least, wheel track damage made from ground applications may start to reduce yield. Sprayer wheel traffic from first flower (R1) through harvest can damage soybean plants and reduce yield (Hanna et al. 2008). Our research suggests that an adequate soybean stand (more than 100,000 plants per acre) planted in late April though mid-May can compensate for wheel tracks made when a field is sprayed at R1. Yield loss can occur, however, when wheel tracks are made at R1 or later in thin soybean stands (less than 100,000 plants per acre) or late planted soybeans. Regardless of stand, plants could not compensate for wheel tracks made at R3 (early pod development) or R5 (early seed development). The average yield loss per acre is based on sprayer boom width (distance between wheel track passes). In our trials yield losses averaged 2.5, 1.9, and 1.3% when sprayer boom widths measured 60, 90, and 120 foot, respectively. Multiple trips along the same wheel tracks did not increase yield loss over the first trip.

Spraying soybean at the R1 crop growth stage
Wheel track damage to drilled soybean at R1

Hanna, S., Conley, S. P., Shaner, G., and Santini, J.  2008.  Fungicide application timing and row spacing effect on soybean canopy penetration and grain yield.  Agronomy Journal: 100:1488-1492.

Are Your Beans “Feelin the Burn”?

Adapted from original article posted 6/10/2018 by Shawn P. Conley and Damon Smith

Weed management has been a significant challenge for many farmers and retailers in 2019. The challenges range from short planting windows to shorter pre-emergence and post emergence herbicide application windows to early soybean flowering. As we approach the end of growth stage cutoffs for herbicide applications in early planted soybean can we expect any damage from herbicides and especially the Group 14 herbicides? Well unfortunately the answer to that question is the good ole Extension cop-out answer “Well folks that depends“…..

What we mean by that is as follows:

  1. What growth stage was the soybean crop at?
  2. Where in the United States are you located?
  3. Was the crop stressed before or more importantly after the application?
  4. What rate, a.i., adjuvants, carriers, tank mix partner, etc are we dealing with?
  5. What soybean variety did you plant?
  6. What phase is the moon in….well not really… but you all get the point.

Generally speaking as the soybean growth stage approaches R1 (flowering) the risk for yield loss increases. However this is a highly regional response as we have documented differential yield responses from a +1.2% yield gain in the south to a -4.7% to -4.1% yield loss from the I-states north (Table 1). Furthermore as we transition from specifically using lactofen as a “herbicide” to a tool in white mold management we also note a differential response.  In a recent meta-analysis where Dr. Smith focused on the 6 oz lactofen rate at R1 application he noted a 3.7% yield loss in low-to-moderate disease pressure, but a significant yield increase in high-pressure situations (Figure 1). In Dr. Smith’s meta-anlaysis he does want to emphasize they noticed A LOT of variability among varieties and environments tested  as you can see by the error bars around treatments in Figure 1.

In summary we would expect some level of yield loss in these late “hot” applications; however in-terms of long-term weed management we would rather see you take a small yield hit than allow herbicide resistant weeds go back to seed and replenish the weed seed bank. This is even more critical with expected tighter phytosanitory regulations centered around weed seeds.

Table 1. Percent relative yield change and break-even probabilities for Lactofen applications (12 fl. oz per a + 1%v/v COC) at V4 soybean compared to no application at multiple yield levels and soybean sale prices for studies be­tween 2012 and 2014.

   

Yield level

   

45 bu a-1

60 bu a-1

75 bu a-1

Region RYC (%)

$9

$12

$15

$9

$12

$15

$9

$12

$15

——————-% probability of break-even——————-

South

1.2

31

47

57

47

60

67

57

67

72

I-states

-4.7

0

0

0

0

0

0

0

0

0

North

-4.1 0 0 0 0 0 0 0 0

0

†RYC, percent relative yield change compared to the standard practice
South: Arkansas, Kansas, Kentucky

I-States: Indiana, Iowa, Illinois

North: Michigan, Minnesota, Wisconsin

Figure 1. Yield response to white mold management by disease pressure.

Literature cited:

J.M. Orlowski, B.J. Haverkamp, R.G. Laurenz, D.A. Marburger, E.W. Wilson, S.N. Casteel, S.P. Conley, S.L. Naeve, E.D. Nafziger, K.L. Roozeboom, W.J. Ross, K.D. Thelen, and C.D. Lee. 2016. High-input soybean management systems affect soybean yield, yield components, and economic break-even probabilities. Crop Sci. 56: 4: 1988-2004. doi:10.2135/cropsci2015.10.0620.

Willbur, J.F., Mitchell, P.D., Fall, M.L., Byrne, A.M., Chapman, S.A., Floyd, C.M., Bradley, C.A., Ames, K.A., Chilvers, M.I., Kleczewski, N.M., Malvick, D.K., Mueller, B.D., Mueller, D.S., Kabbage, M., Conley, S.P., and Smith, D.L. 2019. Meta-analytic and economic approaches for evaluation of pesticide impact on Sclerotinia stem rot control and soybean yield in the North Central U.S. Phytopathology. https://doi.org/10.1094/PHYTO-08-18-0289-R.

Soybean Replant Decisions: Just the Facts Jack!

Though farmers continue to struggle to get their crops established in #plant19 we are starting to see the first images of soybean beginning to crack and emerge. As farmers, agronomists and technical service providers begin to assess the 2019 soybean stands here are a few items to contemplate before re-plant recommendations are made.

  1. Get an accurate stand assessment. We are often drawn to the worst areas of fields and over-blow how bad the overall stand really is. You can go old school and use the tape or hula-hoop method or try a digital approach such as Bean Cam the WSMB funded soybean replant app!
    1. Link to the app store for iPhone and iPad
    2. Link to the app store for Android

      Bean Cam app calculations/results.

  2. An effective stand is obviously important to maximize soybean seed yield. However the downside yield risk for a sub-par stand is minimal until stands fall below 50,000 plants per acre. The synergy of early planting coupled with breeders adding 3x yield to soybean branches at low populations have effectively reduced the yield penalty for thins stands by 1/2 (Suhre et al. 2014) . Therefore we recommend the following.
    • Early planted soybean yield is maximized with stands that range from 100,000 (high yield environment) to 135,000+ (low yield environment) plants per acre.
    • When soybean stands are less than 50,000k plants per acre, inter-plant new seed with a similar maturity into the existing stand. DO NOT TEAR UP THE STAND AND START OVER.
    • When stands fall between optimal and 50,000k plants per acre Think Twice Before Replanting Soybeans! Our data shows a nominal ~2 bu yield increase in this situation. Even if you have a “free replant” guarantee the numbers don’t make economic sense. As a grower you are better off investing $$$ in an effective in-season residual herbicide to control weeds such as Palmer and waterhemp.

References:

Gaspar, A. and S.P. Conley. 2015. Responses of canopy reflectance, light interception and soybean seed yield to replanting sub-optimum stands. Crop Sci.55: 377-385. doi: 10.2135/cropsci2014.03.0200

Suhre, J.J., Weidenbenner, N., ‡Rowntree, S., Wilson, E., S., Naeve, S. Casteel, S.P. Conley, Diers, B., Esker, P., Specht, J., and Davis, V. 2014. Soybean Yield Partitioning Changes Revealed by Genetic Gain and Seeding Rate Interactions. Agron. J. 106:1631–1642.

First thoughts on managing your prevent plant acres

I want to start out this blog being very clear and honest…… I don’t exactly know what the right answer is! However as I have stated before, the best thing about blog articles is that it is a dynamic format and can be rapidly updated and changed. I am sure this blog article will change weekly (maybe daily) as we learn more and I get feedback on this article. So let’s get into it. I think we all agree we need to put something on these fields to not only hold the soil but also manage our weed populations, especially waterhemp. To that end I had two farmers call me this week and ask what would happen if they planted winter rye in June. That is a good question I said so I reached out to many colleagues and we all agreed that yes that was a good question, but none of us had done it to date. Our collective thought was that winter rye or winter wheat (I think rye would be better) would grow 18″ up to maybe 4′ tall, stool out and put out multiple tillers since the plant will not vernalize and induce reproduction. This should develop a fairly rapid and robust canopy that can be very competitive with weeds. Speaking with Fred Kolb at UI, he thought that oat would also be a good cover as it would develop well put out seed heads, and if worked into the soil in the fall, reseed the system and then winterkill so you wouldn’t need to worry about termination next spring. For all of these crops I would target 750,000 to 1,000,000 seeds per acre as a seeding rate (WAG). Obviously this is not a perfect system as there may be some herbicide carryover issues from last year’s crops and we would be planting 100’s to 1000’s of acres that may serve as a green bridge for plant pathogens, but that is potentially next years problems. I encourage anyone reading this article to send me thoughts, feedback or other ideas. I am sure someone has tried this and I would like to add in your experiences.