Thoughts on Transitioning a Cover Crop into a Cash Grain Crop

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My grandfather (whom I nicknamed Fudd), left school after the 8th grade due to farm obligations and may not have had the largest vocabulary nor could write in any legible form (we always teased him that he was a M.D.), but he could rattle off math and markets like no ones business. Today farmers are running their own calculations and right now, corn and soybean margins are TIGHT to say the least.  A common question I have received over the last few days is how we can transition our cover crop acres into cash grain acres. Here a few thoughts to ponder:

  1. Is it legal?
    1. Determine if you have enrolled in any programs or cost-share that prohibit the sale of said crop.
    2. Check to see if there are any plant back restrictions due to previous herbicide or other pesticide use that limit the sale of said grain crop or livestock use of straw for feeding or bedding.
    3. Verify if the seed source has limits for sale due to PVP or genetic licenses.
  2. What cover crop specie(s) did you plant?
    1. Is this a cover crop mixture or a single species?
    2. A cover crop mixture will be difficult to manage for grain yield and straw yield and quality. We can only recommend considering transitioning your cover crop to a grain crop if it is a monoculture cover crop.
    3. Is it rye or wheat?
    4. Do I have a market for rye if I keep it for grain? See #1 above again.
    5. Do I have a market for the rye straw?
  3. What is your cost of production and required yield potential to actually make money? The common numbers I have floated are 90 bushels/acre of grain and 2 ton/acre of straw for wheat. For rye, the yield goals would be similar if not greater based on rye grain and straw price/value. Here are a few agronomic decisions that impact this threshold. These are suggestions generally for wheat. Rye we expect would be similar.
    1. Planting date matters: In WI, we start to lose yield after the last week in September at ~1 bu/acre/day.
      1. Here are a few scenarios to ponder:
        • Scenario #1. Drilled cover crop on October 15th and seeding rate was increased accordingly. There is a good chance we will hit our yield mark. If the cover crop was drilled, but not planted in a standard narrow row spacing (7.5”), grain and straw yields may be lower and weed control may be more challenging.
        • Scenario #2. Broadcast and lightly worked-in cover crop in mid-November. Poor chance we will hit our grain yield mark.
        • Scenario #3. Flew on cover crop into established corn or soybean before leaf drop. If you have less than 12 plants per square foot…tear it up…. poor chance you will hit your grain yield mark.
        • Scenario #4. Planted in August on prevent plant acres or following another small grain (oat or winter wheat). We don’t normally recommend a small grain followed by small grain but typically you can get by in year #2.
          1. Things to consider here: If you are selling for grain to an elevator watch out mixing grains. There is a good chance volunteers will come through and dockage can occur.
          2. Planting too early will put your crop at risk for Barley Yellow Dwarf Virus (BYDV). If the crop looks even and does not have irregular patterns across the field or in pockets you are likely good to go.
      2. For more information on establishment questions: Top 8 Recommendations for Winter Wheat Establishment in 2019
    2. Nitrogen timing matters. Get out there as soon as the ground is fit.
    3. Weed management matters. The value of this crop will be in both grain yield and straw yield and quality. Do not let the weeds get out of control. This is especially true if this was on prevent plant acres. Pay attention to herbicide labels for both crop growth stage and weed height restrictions. We don’t have many options for weed control in WI small grains. Here are a few tools to help in these decisions:
    4. Disease management matters for both grain and straw yield. Disease management is always a huge consideration in small grain production systems. This would even be more evident if this is a second year of small grain on small grain. We recommend scouting and watching the bottom line closely. The Feekes 5 timing that is often tied with a herbicide application is frankly a waste of money in WI unless significant early-season disease pressure is noted. We recommend scouting and estimating disease pressure at Feekes 9 (flag leaf) or Feekes 10.51 (anthesis or flowering). We have also measured an increase in straw yield (~0.5 tons of dry matter) with the Feekes 10.51 timing for fusarium head blight (FHB) or scab. Here are a few tools to help in these decisions:

By the way my grandfather nicknamed me Finkle, after Mr. Weatherman Earl Finkle. His reasoning for this was that I was correct almost as often as he was…. LOL!!

Winners of the 2019 WI Soybean Yield Contest are Announced

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The 1st place winner in Division 4, RnK DeVoe Farms of Monroe, grew Pioneer P28A42X and harvested 91.08 bu/a.  In second place, Venable Farms Inc. of Janesville grew Jung 1213R2X and harvested 87.48 bu/a.  In Division 3, Jim Salentine of Luxemburg harvested 92.44 bu/a with Stine 19BA23 and in 2nd place, Tim Gaffron of Twin Lakes harvested 89.13 bu/a with Pioneer P24A80X.  In Division 2, Wegner Farms of Sparta achieved 75.63 bu/a from Pioneer P23A15X for first place.  In 2nd place, David Lundgren of Amery harvested 64.13 bu/a from Asgrow AG11X8 soybeans.  No entries were submitted for Division 1.

RnK DeVoe Farms of Monroe was the winner of the Soybean Quality contest with 2,967 pounds of protein (34.9%) plus oil (19.4%) per acre from Pioneer P28A42X.

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 608-800-7056 or spconley@wisc.edu

Finalists for the 2019 WI Soybean Yield Contest are Announced

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The 2019 season had below average growing conditions for many growers.  We experienced lower entry numbers in the 2019 WSA/WSMB Soybean Yield Contest, likely due to delayed planting and harvest from wet weather causing maturity, time and logistic struggles.  The top two entries in each division (in no particular order) were:

Division 4:

  • Rick DeVoe, Monroe (planted Pioneer P28A42X)
  • Nick Venable, Janesville (planted Jung 1213R2X)

Division 3:

  • Tim Gaffron, Twin Lakes (planted Pioneer P24A80X)
  • Jim Salentine, Luxemburg (planted Stine 19BA23)

Division 2:

  • David Lundgren, Amery (planted Asgrow AG11X8)
  • Mike and Dean Wegner, Sparta (planted Pioneer P23A15X)

Division 1: 

*No entries were submitted for Division 1

The Soybean Quality Contest was optional for any Soybean Yield Contest entrant.  There are no geographical divisions for the Quality Contest.  One cash award will be presented statewide to the highest protein plus oil yield per acre (measured in lbs. per acre). The finalists for the Soybean Quality Contest are:

  • Rick DeVoe, Monroe (planted Pioneer P28A42X)
  • Jim Salentine, Luxemburg (planted Stine 19BA23)

The final ranking and awards will be presented at the Corn Soy Expo to be held at the Kalahari Convention Center, Wisconsin Dells on Thursday February 6th 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 608-800-7056 or spconley@wisc.edu

Dealing with Wet Frozen Soybeans

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Like many farmers the UW BeanTeam still has soybean sitting in the field. Both locations (FDL and East Troy) have not been fit to run since maturity and FDL had 7 inches of snow piled on top of standing water yesterday. Anyway…. once fields freeze and we can get back after the crop, here are a few things to consider. Check back as this information will likely be updated as I glean more information and receive audience feedback. This information is provided in greater detail in the below two excellent resources.

  1. Call and mail (i.e. paper trail) your crop insurance agent to let them know you may not be able to get the crop out before the deadline.
  2. Take what you can get this fall. Soybean does not “store” well in the field over the winter. Shatter and seed quality degradation may lead to an unmarketable crop if taken in the spring.
  3. Set the combine and check it often if you are running snow through the housing. The cold temperatures may be to our advantage as the snow should move easier.
  4. Header shatter will be an issue. Make sure you set the combine to manage flow. Remember for every 4 seeds per square foot on the ground that equates to roughly a bushel in yield loss.
  5. Double check your combine moisture with another device to verify correct moisture as this cold weather will wreak havoc with sensors. We pulled beans today and they were 16.4%.
  6. Call ahead and around. Verify what the elevators will take in terms of moisture content. Furthermore some elevators are assigning a wet bin to assist farmers in harvest.
  7. Do not harvest and store wet beans on farm. I have heard some coffee shop talk about cutting and “freeze blasting the soybean seed”. This is a bad idea.
  8. Don’t use too much heat. It appears that 100F is about the right temperature to minimize splits.

Drying and storing wet soybeans

Harvesting and storing soybeans

Updates from Brian Luck regarding combine settings:

Harvesting soybeans later than intended can present many challenges for minimizing harvest losses. These challenges are amplified when snow is on the ground and impacting harvest. Minimization of losses starts at the header. Checking that the sickle bar knives are sharp and the guards are adjusted properly will ensure the stems are being cut rather than broken or leaned over by the header. Generally, reel speed should be slightly faster than grounds speed to make certain the plants are being collected by the header. Another good practice for harvesting soybeans in wet and snow covered conditions is to reduce the combine ground speed while harvesting. This will give the machine extra time to cut the plants and ensure that they are transported to the throat of the machine with minimal damage or losses.

Concave clearances, rotor speeds, fan speeds, and sieve settings all depend on the condition of the crop at harvest. If the beans are generally dry but the stems, pods, and remaining leaves have increased moisture contents more aggressive threshing may be required to clean the plant material from the crop. More aggressive threshing can also lead to damage and reduced crop quality. Incremental adjustments of concave clearances (increase for wet conditions) then threshing rotor speed (increase for wet conditions) will help to find the optimal settings. Also, ensure that you have a uniform feed rate into the machine maintaining a consistent load on the threshing rotor to ensure optimal performance. Finally, increased fan speed can help pneumatically separate the soybeans from the plant material, however this can also lead to greater losses through the sieves if set too high.

Small adjustments to these combine settings can have a big impact on the performance of the machine. Check for losses behind the combine often to make certain that your harvest is as efficient as it can be in adverse conditions. Try to identify where losses are happening when operating the machine. If you can see beans leaving the header focus on minimizing that loss before making any other adjustments. Incorrect settings at multiple stages in the combine can significantly increase losses and will be difficult to identify.

References:

https://cropwatch.unl.edu/2017/tips-harvesting-soybeans-13-15-moisture

https://crops.extension.iastate.edu/cropnews/2016/09/consider-combine-adjustment-wet-field-conditions

https://www.canr.msu.edu/news/recommendations_for_a_late_soybean_harvest

https://agfax.com/2019/10/09/ohio-soybeans-is-a-late-harvest-in-your-future/

Harvest Considerations for Variable Soybean Maturity

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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?

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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

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Adapted from original article written 6/1/2015.

Commodity Classic is in full swing this week and even though it is virtual, there is a plethora of new product offerings available that guarantee you the farmer a 99.99999% probability of ROI.  This year the question of sugar has resurfaced again 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 an 0.8 bu per acre yield increase in soybean. If farmers are considering a pass for just the sugar application, the average cost of ground application is $7.90 and aerial is $9.65 per acre; 2020 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 with November beans trading at $12.11 per bu today, ROI is equally important under high commodity prices as it is low!

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 in 15 to 20 gal a-1 carrier. 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

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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.

Are Your Beans “Feelin the Burn”?

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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.