Wednesday, November 8, 2017

RR2Y® versus Xtend® Soybean Cultivar Performance in 2017…. A Lesson in Fuzziness

Authored by: Shawn P. Conley and Damon Smith

Tis the season of early booking promotions and seed discounts. These programs seem to get earlier and earlier each year just like Christmas music! Pretty soon growers will be getting a 25% discount to book their 2021 seed orders on a variety yet to be named…. Nevertheless, our 2017 Wisconsin Soybean Variety Performance Trials are posted and I wanted to give a brief update on the relative performance of RR2Y® versus Xtend® (RR2X) soybean platforms from this growing season. As you may recall, we tackled this topic last year in an article entitled: New Traits Don’t Automatically Translate to Highest Yield! I don’t want to rehash the whole story but in short we wanted to remind growers of the following:

  1. New doesn't always mean it is automatically better.
  2. Remember - every variety must stand on its own
  3. RR2X soybeans are a stack of herbicide traits and not yield traits (i.e... these traits protect yield, not enhance yield). Remember this point with all pest management traits!
  4. The RR2Y suite of varieties yielded 1.8 bu/acre better than Xtend in 2016.
So how did these platforms fare in 2017? Well, the story isn’t quite as clean and straightforward as 2016, when we had record yields across the state. First, we lost two of our variety performance trial sites in the southern part of WI. One was our Platteville no-till site that received such heavy and pounding rain that is sealed the soil. Yes you heard me correct a no-till site was crusted so badly our beans could not emerge. I am grateful there is no such thing as climate change so there is no chance this will ever happen to me again…. The other site was lost to off-target movement of herbicide. That left our flagship Arlington location as the only southern location and well…..that got hammered by white mold (stay tuned for more on this topic). Fortunately, our central and north central locations fared a bit better though we did get white mold at two irrigated sites; Hancock and Chippewa Falls (still stay tuned for this as well).

So what happened…..

In our statewide pooled data-set, we saw RR2Y® varieties yielding 2 bu/acre higher than the Xtend® varieties; a significantly higher yield (Figure 1). As stated above, this response difference is not as clean and straightforward as last year given the lost sites and white mold at three locations (almost there).


Figure 1. Pooled Herbicide Platform Performance Across Southern, Central, and North Central WI in 2017.

Within each region, we do see slightly more RR2Y® varieties having a star (starred varieties are not significantly different (0.10 level) than the highest yielding cultivar) over Xtend® varieties (Figure 2); though our data does show farmers have several varietal options under both platforms. ****Remember point 2 above each variety must stand on its own.


Figure 2. 2017 Regional Starred Varieties as a % of Varieties of Each Platform

What drove this yield disparity in 2017? Increased white mold incidence may have been the culprit. Across the three locations where we observed white mold (Arlington, Hancock, Chippewa Falls) we saw 8% greater incidence in the Xtend® suite of varieties than the RR2Y® (Figure 3).


Figure 3. Pooled White Mold Incidence at Alington, Hancock, and Chippewa Falls Sites Across Herbicide Platforms 2017.

Varieties across platforms varied greatly in white mold incidence and yield as the range of white mold in the trials was 1 to 95% (Figure 4).

Figure 4. Variation in white mold incidence among varieties and herbicide platforms.

Given that the average incidence of white mold at these three locations was 29%, an 8% difference between these platforms could easily explain the yield disparity. Remember, that every 10% increase in white mold incidence leads to 2-5 bu/a loss. Thus at these locations yield loss at 29% incidence is estimated to range from 6-15 bu/acre. For more information on individual variety performance and white mold ratings consult the 2017 Wisconsin Soybean Variety Performance Trials.

Lastly as you select soybean varieties for 2018 make sure to balance yield, disease risk, and the latest dicamba regulations for your specific farm needs. It is no big industry secret that margins are going to be tight again in 2018…choose wisely!

Friday, September 22, 2017

Harvest Considerations for Variable Soybean Maturity

Variable soil types, knolls, flooding and ponding, variable planting dates and late season 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 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 below $9.00 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)

Thursday, September 21, 2017

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


Ann MacGuidwin, Damon Smith and Shawn P. Conley 

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.  

For more information on SCN testing and management practices or to request a free soil sample test kits please contact: Jillene Fisch at (
freescntest@mailplus.wisc.edu) or at 608-262-1390.

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 11, 2017

Start Managing for Fusarium Head Blight Now Before You Plant the 2017/18 Winter Wheat Crop

By Shawn P. Conley and Damon Smith

Most WI winter wheat growers dodged the Fusarium head blight (FHB or scab) bullet again in 2017; though many farmers especially those in SW WI became so disgusted with dockage and rejections in both 2014 and 2015 they still didn't plant a single acre this year. Therefore as we prepare to put the 2018 wheat crop into the ground here are a few considerations for managing FHB before we drop a single seed.

1.      Crop rotation matters. Data from our long-term rotation studies indicate that wheat following soybean provides the greatest yields. The next best options are wheat following corn silage (6.5% less) then corn for grain (21% less). Wheat following alfalfa or another leguminous crop are also good options, though the N credits following alfalfa may best be served going to corn. Furthermore, background fungal pressure (residue on and in soil) from the FHB fungus will be greater following corn then soybean or another legume, however know that spores that infect your wheat crop can arrive from  outside the field. Please click to see more information on the Top 8 Recommendations for Winter Wheat Establishment in 2017.  
2.      Variety selection matters. Data from our 2015 and 2016, and 2017 WI Winter Wheat Performance Test shows variable yield and disease performance among the varieties listed. Select those varieties that have both good to excellent FHB (2015) and Stripe Rust (2016 & 2017) resistance and high yield. When evaluating disease resistance, low numbers for both incidence and severity can be helpful, but the major focus should be placed on  incidence (measure of the number of symptomatic plants in a stand).
3.      Application timing matters. One of the biggest challenges year in and year out is improper fungicide application timing. Our data suggests that on susceptible (Hopewell) or moderately susceptible varieties (Kaskaskia) equal efficacy of the fungicide Prosaro at a rate of 6.5 fl oz/acre can be achieved when applied between Feekes 10.5.1 (anthesis) and 5 days after anthesis. Given the variability of head emergence and anthesis across a landscape it may prove best to wait a few days until the whole field is flowering than to apply too soon.  If the extruded anthers have turned from yellow to white across the whole field then you are likely too late. Remember it roughly takes a wheat head 7 days to completely self-pollinate.
Fusarium head blight incidence ratings for four soft red winter wheat varieties treated with Prosaro SC fungicide at 6.5 fl oz/a at anthesis (Feekes 10.5.1), five days after anthesis, or not treated in Wisconsin in 2015.

Hopewell (Susceptible)
Kaskaskia (Moderately Susceptible)
Pro 200
(Moderately Resistant)
Sunburst (Moderately Resistant)
Prosaro SC @ 6.5 fl oz/a (Feekes 10.5.1)
9.5b
2b
0.5
4
Prosaro SC @ 6.5 fl oz/a (5 days after Feekes 10.5.1)
7.5b
5.25b
2.75
2.75
Non-treated control
31.25a
17.5a
3
1.5
Pr>F
0.01
0.01
ns
ns
LSD
6.44
6.44
ns
ns
4.      Choose the right fungicide class. Make sure you use the appropriate fungicide product and class to manage FHB. The label for products containing strobilurin active ingredients (FRAC group 11) ends prior to flowering. Late application can actually lead to increased mycotoxin levels. Triazole containing products (FRAC group 3) are recommended for FHB control. For a list of products and efficacy ratings, visit the Field Crops Fungicide Information Page
5.      Harvest timing and flash drying. The word on the street is that if FHB appears to be a problem in 2018 elevators will push growers to harvest early (18% moisture or higher) and subsequently dry grain to mitigate mycotoxin levels. While drying grain to 13% or less moisture is a good storage practice, know this process may kill the pathogen but any mycotoxin levels already in the grain will not dissipate. Vomitoxin is a very stable molecule and IS NOT degraded by heat, freezing, or drying.    

Monday, May 22, 2017

Rain Rain Go Away Do I Switch to Soybean From Zea May(s)

As growers begin to contemplate switching intended corn acres to soybean, here is a quick checklist of points and questions to consider or reconsider before making that switch.
  • Do I have a residual corn herbicide down that is not labeled for soybean? If the answer to this question is yes, then Don’t Switch Crops. It doesn't matter how much rain we have had. Plant back label restrictions must be followed.
  • What is my cost of production and weather outlook for finally getting this crop in the ground? Dr. Joe Lauer just posted his corn replanting and yield loss guide. Expected corn grain yield if planted in the next 8 days would range from ~70 to 85% of maximum yield. Soybean yield would roughly be 85 to 90% of maximum yield based on your maturity group and final planting date. Run your numbers, talk to your lender, and see what gives you the greatest ROI.
  • I already put out all my nitrogen (or for WI growers - I am following alfalfa). What potential impacts will that have on my soybean crop?
    • Dr. Emerson Nafziger did a great job shedding light on question #1 regarding N management... How Much Nitrogen is Gone
    • Knowing that most of the N will likely be available to the soybean crop, there is a risk of lush vegetative growth, possible lodging (harvest efficiencies) and higher risk for white mold. However soybean total dry matter and growth will be behind due to its late planting so this risk is lessened. I would most be concerned about white mold. Luckily, we have Dr. Damon Smith at UW Madison and he will keep us updated as to potential white mold risk this summer so stay tuned for possible next steps!
    • Soybean is very efficient at N uptake and partitioning so that N will likely still see its way to the elevator.
    • If you decide to plant soybeans into these high N fields, I would pull the inoculant from the seed treatment mix if this field has seen regular soybean cropping (2 years out of the last 5). Biological nitrogen fixation will be delayed due to free N availability and the soybean crop will rely on background soil rhizobia for subsequent infection. 
  • Will I be planting elite soybean genetics if I switch or will I be planting a dog? Even in late planted situations, we are still roughly at 90% maximum yield potential. Don't ditch your elite corn genetics to plant junk beans. Please see our Wisconsin Soybean Performance Trials for more information on variety selection.
  • Lastly, how much of my 2017 crop is marketed and how flexible are my options. Even though plantings of both crops are delayed, if we continue to see poor corn crop ratings across the ‘I'- states and then see another million acres of corn go to soybeans, I  believe this will put significant pricing pressure on both crops.

Friday, April 28, 2017

Soybean Management Strategies to Facilitate Timely Winter Wheat Establishment in 2017

Article written by Dr. Adam Gaspar and Dr. Shawn P. Conley
 
Winter wheat acres across WI have declined over the past few years due to late grain harvests, disease concerns (FHB or scab) and poor wheat prices, however anyone that lives and works in WI knows that a base number of cereal acres are needed to support the dairy industry (straw and land to summer haul manure). As farmers get ready to kick off the 2017 growing season here are a few suggestions to help get your 2017/18 winter wheat crop established on time.
  • Plant early. If weather and soil conditions allow for it plant the acreage you intend to go to winter wheat first. This is regardless of which crop you plan to follow (soybean, corn silage or field corn). Remember the optimal planting date window for most of our WI winter wheat acres is the last week of September through the first week in October. In table 1 below you will notice that for every 3 days planting is delayed we see ~1 day delay in beginning maturity (R7), so delaying planting by one week equates to about 2 days later maturing. However when planting is delaying past June 1st it turns in to more of a 1: 1 relationship. Also remember in WI it normally takes another 5-8 days for the soybean crop to move from R7 to R8 (full maturity). 
Table 1. Calendar date for reaching R5 (beginning seed fill) and R7 (beginning maturity) growth stage by planting date and maturity group for the 2014, 2015, and 2016 growing seasons at Arlington and Hancock, WI.
Date of Growth Stage Initiation
R5
R7
Planting Date
Maturity Group
Arlington
Hancock
Arlington
Hancock
May 1st
2.5
3-Aug
4-Aug.
14-Sept.
15-Sept.
2.0
30-July
1-Aug.
9-Sept.
14-Sept.
1.5
26-July
29-July
3-Sept.
9-Sept.
May 20th
2.5
7-Aug.
9-Aug.
18-Sept.
20-Sept.
2.0
3-Aug.
7-Aug.
14-Sept.
18-Sept.
1.5
3-Aug.
4-Aug.
6-Sept.
15-Sept.
June 1st
2.0
11-Aug.
12-Aug.
18-Sept.
24-Sept.
1.5
10-Aug.
9-Aug.
16-Sept.
18-Sept.
1.0
7-Aug.
8-Aug.
10-Sept.
14-Sept.
June 10th
2.0
15-Aug.
17-Aug.
25-Sept.
30-Sept.
1.5
14-Aug.
16-Aug.
20-Sept.
25-Sept.
1.0
11-Aug.
14-Aug.
16-Sept.
18-Sept.
June 20th
1.5
21-Aug.
21-Aug.
27-Sept.
2-Oct.
1.0
18-Aug.
18-Aug.
24-Sept.
26-Sept.
0.5
16-Aug.
16-Aug.
19-Sept.
22-Sept.

  • Consider an earlier maturity group soybean. Plant a high yielding, earlier maturity group soybean to help get that soybean crop harvested on time. Though later maturing varieties "on-average" produce the greatest yields, data from our 2016 WI Soybean Variety Test Results show the maturity group range that included a starred variety (starred varieties do not differ from the highest yield variety in that test) was 1.8-2.8, 1.4-2.4, and 0.8-1.8 in our southern, central and north central regions respectively. This suggests that the "relative" maturity group rating is trumped by individual cultivar genetic yield potential. Therefore growers have options to plant an early maturity group soybean that will be harvested on time and not sacrifice yield.
  • Crop rotation matters. Our long-term rotation data suggests winter wheat yields are greatest following soybean, followed by corn silage and lastly corn for grain.  Therefore plan your rotation accordingly to maximize yield and system efficiency.
  • Manage for the system not necessarily the crop. If you are serious about maximizing wheat grain and straw yield on your farm one of the biggest contributing factors for both of these in WI is timely wheat planting. Make management decisions to facilitate that. *We all know what inputs can extend maturity that don't necessarily guarantee greater yields. So instead of listing them and fielding angry emails I am being strategically vague here*  As a producer is it better to sacrifice 0-2 bushels of soybean yield or 10-20 bushels of wheat grain yield and 0.5 tons of straw?  
As we all know mother nature holds the ultimate trump card on whether we will get our winter wheat crop established in that optimal window. These aforementioned strategies are relatively low risk to the farmer and regardless of what weather patterns we run into are agronomically sound.