Tag Archives: soybean

Workhorses, Racehorses, and Quarter horses

Today is the first day in 2 weeks that we’ve been able to harvest due to weather and a combine breakdown.  So, we are not that much farther along in getting variety test data to you than we were last week.  However, I hope to get out some preliminary data by Thanksgiving.

Last week, I indicated that certain relative maturities do better in some parts of Virginia than others.  This week, I I’ll get a little more specific and discuss choosing the best variety for a given yield potential.

First and foremost, I will continue to emphasize that variety selection should be based on multi-year multi-site data.  Basing your selection on a single test (maybe closest to you) and single year is a recipe for failure.  However, I don’t necessarily recommend always choosing a variety based on average yields over site-years – although a very good place to start.  This may seem a little contradictory, but let me explain.

Certain varieties do better under high-yielding environments.  I like to call these “racehorse” varieties.  Choose such a variety if you want to win a yield contest.  Other varieties may yield more than others under stressful conditions.  I refer to these as “workhorses”.  And there are some that tend to do well, regardless of the yield potential – I’ll call these “quarter horses” (quarter horses can run very fast for short distances and you can still ride them long distances over quite rugged terrain).

Last year, we analyzed 5 years of variety test data and classified all varieties that we tested as one of the above.  Examples of our results are shown below. The graphs represent the yield of a single variety versus the yield of all varieties tested at that site and year.  Each symbol represents a different site-year.

To summarize, the vast majority of varieties are neither racehorses or workhorses; they perform equally in all yield environments.  So, averages will work just fine in most cases.  But, if you know you have a great- or poor yielding soil or if you are irrigating, then you may want to look into those varieties that fit that situation.

We have all of these data in an excel spreadsheet.  If interested, let me know; I’ll be happy to share upon request.

What’s the Best Soybean Maturity Group for your Farm

Yields are coming in from our variety tests – yields are good, not great, but good, ranging from the upper 40’s to low 70’s.  I hope to get a summary of the maturity group (MG) 3 and 4 tests out soon.  Be looking for them.

In the meantime, a questions that continues to arise if “What is the best maturity group for my farm?”  Or “What’s the best maturity group for my field?”  This is a very valid question.  Some years MG 4’s will shine and other years the MG 5’s are best.  Occasionally, MG 3 or 6 look good (the 6’s have been performing very well lately – as long as the frost holds off until mid-Nov!

An attempt was recently made (and published) to redrawn the MG lines in the U.S (Mourtzinis and Conley, 2017) – see the map to the upper right.  The researchers used variety test data from nearly all states to come up with the map shown.  While this map is more-or-less accurate when looking at the U.S. as a whole, it is not when you look closer (i.e., at individual states).

To better answer your questions regarding MG’s in Virginia, we took 10 years of our variety test data (around 15,000 plots) and began evaluating the probability of:

  1. a relative maturity (RM) yielding at least as high as the other RM’s tested at that location
  2. a RM yielding significantly higher than the other RM’s tested at that location.

Results are shown in the following graphs. Note that we split the results into full-season and double-crop soybean.  We have also divided each MG into early-, mid-, and late-RM’s.  The total bar height answers question 1 – the probability that the RM does at least as well at the others.  For instance, as expected, there is an 80 to 100% probability that MG 5’s will yield at least as much as other relative maturities in Blackstone (Southern Piedmont, droughty clay soils).

The hatched part of the bars answer question 2 – the probability that the RM yields significantly more that the other RM’s.  Using the Blackstone example, the 5’s yield significantly more than other MG’s 30 to 60% of the time.

Of course the “devil is in the details”.  There are soil properties and environmental conditions that control which RM is best in a given year.  If interested, contact me; I’ll give you my preliminary thoughts on that.  Rainfall is definitely the biggest influence – not how much we receive but when it falls; but that is random in Virginia.  There are other issues.

 

To summarize:

  • MG 3’s and 4’s are best suited for the most northern and western location (Orange).
  • MG 5’s perform best in our most southerly locations (Blackstone and Suffolk).  But, the late 4’s can make a strong showing in some years, especially at Suffolk (I think I know why; its not just when the rain fell. Contact me.)
  • Both MG 4’s and 5’s perform well at Warsaw (we can’t explain the full-season late-4 results, yet).  Note that yield potential of the later 5’s decline with double-crop plantings at this northerly, but Coastal Plain site (probably frost damage).
  • All MG 4’s (early, mid, and late) perform best when planted in May at our Eastern Shore location (Painter).  There are curious things happening here (while not that far south, its our most easterly and probably the most consistently favorable environment for growing soybean).  Note that early- and mid-4’s are no better than 5’s when planted double-crop.

1st Attempt at a Relative Maturity Map in Virginia

I’ve made an attempt at drawing a Virginia map.  But do not read too much into this!  This is based only on 5 locations (although 10 site-years and thousands of plots at each location) and the “devils in the detail”.  An I did not use GIS to draw this map (the lines are not 100% accurately located).

Do not assume that I want you to plant only these RM in these areas, only that these tend to do best in most years.

How do you use these data?  Make most of your chosen varieties fit these results.  However, allocate a smaller acreage to those RM’s that can occasionally break records.

On a closing note, these data also indicate that early RM’s do better on our best, most productive land.  But, that’s a topic for next week.

What You’ll See in the Field at the Virginia Ag Expo

As another reminder, the Virginia Ag Expo is Thursday, Aug. 3 at Renwood Farms in Charles City.  The event opens at 7:30 am and will run through mid-afternoon.

There is something for all corn and soybean farmers in the field this year.  Go on the field tour and you will be able to chat with Extension Specialists, company reps, and others about the research being conducted or anything else on your mind.

As always, the Ag Expo is home of one of our numerous on-farm corn hybrid and soybean variety tests.  This year, you will view 31 corn hybrids from 11 companies and 47 soybean varieties from 14 companies.  Drs. Mike Flessner and Charlies Cahoon will demonstrate off-site herbicide injury with some of our newest seed/chemical technologies.  Dr. Wade Thomason is evaluating in-furrow and starter fertilizer in corn.  The soil fertility team, led by Dr. Mark Reiter, is investigating fertilizer recommendations to ensure optimum production for high yielding soybeans.  You will view one of Dr. David Holshouser’s seeding rate trials as he is in the process of establishing variable rate seeding recommendations.  You will also see an experiment that you may have viewed at last year’s Ag Expo investigating the interaction of planting date with relative maturities.  Companies are participating in our plots with in-furrow and foliar sprays that offer potential to enhance yield potential under high-yielding conditions.  Finally, you’ll go below ground to view Virginia’s state soil, a Pamunkey loam, and discuss this yield contest-winning properties with NRCS personnel.

This is a walking, go-at-your-own-pace tour designed to fit your interest and schedule.  Buses will be running continuously to take you to and from the plots.  Enjoy!

2017 Virginia Ag Expo Returns to Charles City County

Please note: the date for the Virginia Ag Expo is August 3, 2017.

“Focused on Productivity, Management and Stewardship” is the theme for the 2017 Virginia Ag Expo.  The Virginia Ag Expo, hosted by the Virginia Grain Producers Association and the Virginia Soybean Association in partnership with Virginia Cooperative Extension, is the largest agricultural field day held in the Commonwealth of Virginia.  As an educational, marketing and social event farmers and agribusiness look forward to the Virginia Ag Expo each year.

Renwood Farms, owned and operated by The Stanley Hula Family, will be hosting this year’s Ag Expo on August 3.  The Hula Family’s farm is a diversified operation growing over 6,000 acres of corn, soybeans and small grains; along with seed conditioning and sales.  A focus on management and productivity at Renwood Farms has produced the world record corn yield of 532 bushels per acre by David Hula.  In addition, the USG soybean seed that produced the world record yield of 172 bushels per acre was grown and conditioned at Renwood Farms.

Over 150 exhibitors and sponsors will have on display all of the most up to date equipment, goods and services for agricultural producers and property owners no matter how large or small.

The event opens at 7:30 am.  The field tour, starting at 8 am, is a walking, go-at-your-own-pace tour designed to fit your interest and schedule.  Buses will be running continuously to take you to and from the plots.

Breakfast and lunch will be provided by Virginia food vendors. Attendees will be able to eat any time from 6:30 AM to 2:00 PM.

Renwood Farms is located at 17303 Sandy Point Road, Charles City, VA 23030.

Soybean Planting Dates, Seeding Rates, Re-planting, Weeds, etc.

June is usually the time of the year when full season soybean is kicking into high gear and we begin planting double-crop soybean.  And like always, various issues are beginning to arise, whether its the weather or finding out mistakes made a few weeks earlier.

Unbelievably, double-crop soybean is wrapping up in many areas due to small grain maturing earlier than normal.  Out of necessity, we were forced to harvest wheat and plant soybean at the same time we were trying to make timely postemergence herbicide applications and generally trying to pay attention to the rapidly growing soybean that we planted in April and May.  But, issues such as these are not unusual.

This week, I thought I’d mention a few things that we are facing and continue to remind you of the need to plant as soon as possible and adjust seeding rates accordingly.

Planting Date.  We are now losing about 1/2 bushel per acre per day with each delay in soybean planting.  Plant as soon as possible, but don’t cause more serious problems by planting into too wet or dry soils.

Seeding Rate.  My data indicates that seeding rates now need to be at least 180,000 seed per acre, even on the best of soils.  I would bump those up about 20,000 seed for each week’s delay in planting.  See Soybean Seeding Rates for June and Later for more information.

Replanting.  Generally, replanting does not pay this time of the year (due to the planting date penalty) unless the stand is horrible.  For more information, see Soybean Replant Decisions or contact me.

Seed Treatments.  I’ve seen few benefits of fungicide or insecticide seed treatments this time of year.  Plants usually emerge and grow quickly.  The exception is wet soils – soybean will emerge very slow when soils are saturated.  With that in mind, you may consider a fungicide on the seed if you have poorly-drained soils, your soils are already wet, and rain is predicted.

Seeding Depth.  Those of you know that I usually don’t like to plant soybean greater than 1 inch.  But, I’ve found that planting soybean at 1.5 inch (and occasionally 2 inches) works just fine when soils are warm.  Sometimes, it’s better to plant deeper to hit moisture than to plant into dry soils.

Weeds.  First, Drs. Charlie Cahoon and Mike Flessner is who you need to consult regarding weeds, but here are a few of my observations.  We may have let a few weeds get too big for adequate control – this is especially a problem with glyphosate-resistant weeds.  Marestail continues to be a problem.  When this weed is glyphosate resistant and you’re not growing Liberty-Link soybean, about the only somewhat effective herbicide that we have left in our arsenal for Roundup Ready soybean is FirstRate, although a few other herbicides may burn the weed – just don’t expect very much from anything.  I’ll let you mull over your other options if you have planted Xtend soybean.  Finally, don’t depend on glyphosate alone – even if you weeds are not yet resistant, its a good practice to diversify to insure that they do not become so.

Greater Yields are Possible for Double-Crop Soybean in 2017!

It appears that wheat harvest will be 1 to 2 weeks ahead of schedule this year.  We actually harvested some high-moisture wheat and planted soybean plots behind it today (May 31) in northeast N.C.  This is good news for soybean.  Earlier planting means greater yields!  This is clearly shown by the recent data obtained from our multi-state, multi-year double-crop project.

With earlier planting, have my recommendations for double-crop soybean changed?  In general no.  But below are a few things to consider.

Seeding Rate:  In general, you can probably back off on your seeding rates from what you were planning if you get your double-crop soybean in by mid-June.  I’d suggest that you start out with 120-160,000 seed/acre (depending on when you start planting) and gradually ramp that up by 20-30,000 for each week delay in planting.  For more information, see my recent blog, Soybean Seeding Rates for June and Later.

Relative Maturity:  Actually, my standard recommendation still stands, more or less.  Plant as late of a relative maturity (RM) as possible that will mature before the frost.  However, there are now some caveats.   By planting a week earlier, you’ll gain about 3 days in maturity.  Although a slightly later RM may work, I wouldn’t count on it – frost date will affect this more than planting date.  So, don’t plant a later RM.

But, can you plant an earlier RM, say go from an early-5 to a late-4?  Possibly.  Why do I say this?  Two things.  First, by planting a week or two earlier you have greater yield potential (see the above graph), which is due to the ability to grow more leaves.  So your yields are not necessarily so dependent on leaf area as they are with a late-June to early-July planting.  A slightly earlier RM planting in early- to mid-June will only have slightly less leaf area than a later RM.  And, we have generally found that under greater yield potentials, early RM will yield more than later ones.  Still, these are not great reasons to change your RM.  Generally, stick with what you planned.

Soybean Seeding rates for June and Later

Due to the rainy weather over the past two weeks, we are still planting full-season soybean in some areas.  In addition, it appears that wheat harvest is not far off (some wheat at the Tidewater AREC was at 23% moisture today!).  So, should we be increasing our seeding rates?

In general, yes.  But, big increases probably will not be needed until late-June.  Below are some seeding rate data that we collected from soybean planted in early-June after barley.  First, we don’t have a lot of data of soybean grown after barley, so I don’t have as much confidence in the exact seeding rate needed.  Note that there is a wide range in the optimal seeding rates, illustrated by the area between the dotted lines in the graph.  Although, these data may not directly apply to full-season soybean (no small grain), it should be close.

I think that we should now be using 120,000 to 160,000 seed/acre.  The range will depend on the planting date.  In general, I’d suggest bumping up your seeding by 20-30,000 seed/acre per week through June.

If you remember the seeding rate data that I shared in this blog last month for May-planted soybean (see Soybean Seeding Rates – How Low Can We Go?), I stated that maximum yields could be obtained with only 95,000 to 110,000 seed/acre when the yield potential is greater than 40 bushels/acre.  That’s pretty low, but was adequate for maximum yield under good growth conditions.  For less than 40 bushel potential, seeding rates needed to be a little higher.   In the above graph, it appears that more seed is needed to obtain 55 to 70 bushels/acre after barley, I cannot fully explain why; therefore, I would assume that this response is primarily due to the location that we obtained the data (again, we don’t have a lot of data).

Once we get into mid- to late-June, I’d rather see a seeding rate of 180,000 to 220,000 seed/acre, depending on planting date.  This is based on the data to the right.    You’ll notice that, like full-season soybean, the optimal seeding rate falls with greater yields.  This is most likely due to greater leaf area with those high-yielding locations.  As I’ve stated often, the seeding rate response can usually be traced back to whether or not the crop developed enough leaf area to capture 90-95% of the light by early pod development.  Unfortunately, I don’t have any double-crop data planted following wheat with yields greater than 55 bushels/acre.  I hope to solve that problem this year with new experiments.

Soybean Seeding Rates – How Low Can We Go?

It seems that everything that you read about soybean seeding rates is that we are planting too many seed.  In general, I agree – at least for full-season soybean.  We still seem to have that mindset that it takes 1 bag of seed per acre.  But many of you have been listening and are taking the seeding rate down to 100,000 to 120,000 seed per acre, with no noticeable difference in yield.   But, can you go lower?  And how low can you go?

To help answer this question, we have re-analyzed about 10 years of data that we collected from dozens of experiments conducted from 2003 through 2011.  But instead of just looking at average yield response, we separated these responses into soybean yield potentials.

Why did we do this?  I’ve always thought that more seed is needed to maximize yield on low-yielding fields (or portions of fields) and less seed are needed or high-yielding fields or portions of fields.  Yes, this means that I’m asking you to spend more money on the least profitable fields and less money on the most profitable fields.  Still, this strategy will likely be more profitable over all acres.

There are a few things worth noting about the graphs to the left.  First, I’ve separated the data into low (20-40 Bu/A), medium (40-55 Bu/A), and high (55-70 Bu/A) groupings.  We decided on these levels by analyzing the data over and over at many different yield levels.  The resulting three levels were most stable and predictive.

Second, we used two statistical methods to fit a curve to the data to intentionally give us a range of seeding rates needed to maximize yield.  This allow us to recognize the variability in the data and reflects our confidence in the response.  Pay particular attention to the wide range of seeding rates necessary to maximize yield at the 20 to 35 bushel yield potential.  This reflects the yield variability and the variability in the response of yield to seeding rates that are common in low-yielding years or fields.  We just are not as confident in this set of data.  Some years or locations, we could get by with 100,000 seed/acre; in others, it took more than 140,000.  With the other yield potentials, the range is pretty tight.  In other words, I have more confidence in recommending 110,000 or even less than 100,000 seed/acre in these instances.

Finally, we see that it takes, in general, less seed at high yields – which verifies my earlier statement that less seed are needed for higher yield potentials.

So what have I settled on?  Below are my suggestions.

But, you may ask, “What about yields greater than 70 bushels per acre?  That’s a good question.  But, I cannot answer it confidently since we have little data in that range.  We are however conducting new experiments this summer to update our data.

But until that data is available, here are my thoughts.  I think that lower seeding rates will work until you get to the 100+ bushel yield range.  After that, I suspect that we are running low on reproductive nodes (node on the plant where pods can form).  For instance, if we only have 80,000 plants/acre, we would need 15 reproductive nodes containing 4 pods on every one of these nodes!  While this is possible, I’m assuming in this calculation that we will grow 2,500 seed/pound and 3.0 seed/pod. Taking that down to a more normal 2800 seed/pound and 2.5 seed/pod, that means we need 6 pods per node!  I think that we are starting the expect a little much from single plant in this case.

So, for 100+ bushel yield environments, I’d suggest to gradually increase your seeding rate from the ones suggested above.  I do understand that we have very few 100+ bushels fields, but I have seen parts of the field exceeding this when I’m watching a yield monitor.   An we commonly have plots within our small-plot tests exceeding 90 and 100 bushels.

Finally, am I suggesting that we may be able to vary our soybean seeding rate as we do corn?  Yes, I’m suggesting that.  We will be validating some variable-rate-seeding (VRS) on two farmer’s fields this year.  If you know of anyone who has VRS planters and who would like to participate in an on-farm test, let me know.

Scout now for marestail/horseweed

Recent mild temperatures and the mild winter are setting the stage for rapid development of marestail/horseweed (Conyza canadensis) this spring.  Marestail was particularly troublesome last year in soybeans.  Marestail can germinate in both the fall and the spring. It is more likely to overwinter in the rosette stage during mild winters.  If you wait until your typical burndown the marestail may start bolting and therefore be more difficult to control. Adding to this difficulty, many marestail populations are resistant to Roundup (and other glyphosate containing products). You should scout your fields targeted for soybeans now to identify overwintering marestail.  Marestail control can be achieved with 2,4-D  or dicamba now and still offer plenty of time to avoid plant back restrictions (up to 15 days for 2,4-D or up to 28 days for dicamba). Glyphosate resistant weeds and the difficulty in controlling more mature weeds underscore the need to scout fields earlier and use some alternative herbicides in your program.  Always consult the product label for specific instructions.

2016 Soybean Yield Contest

The Virginia Soybean Association in cooperation with Virginia Cooperative Extension would like to announce the 2016 Virginia Soybean Yield Contest. The purpose of the Virginia Soybean Yield Contest is to emphasize and demonstrate the practices necessary to produce maximum economic yields, to recognize those producers who grow high-yielding soybeans, and to gather data on the practices utilized by these outstanding producers. With the help of various seed companies, we reward and promote the achievements of Virginia’s most productive soybean farmers.

There are four Soybean Yield Contest categories: 1) Full-Season, Non-irrigated; 2) Double-Crop, Non-irrigated; and 3) Irrigated (Full-Season or Double-Crop; and 4) Most Efficient Yield (MEY). First, second, and third place winners of the full-season, double-crop, and irrigated contest will be recognized with appropriate trophies or plaques. In addition, cash awards of $200, $100, and $50 will be presented to the first, second, and third place winners in each of these categories. The winner of the MEY contest will receive a plaque declaring him or her the most efficient soybean producer in Virginia for that year.

Printable entry forms and contest details can be obtained from your County Agent or on the Soybean Extension and Research website.