Although I have published preliminary results of the 2017 Virginia Soybean Variety Tests in a previous blog, here are the final results. To obtain a copy of the full publication that contains other performance information, please contact me.
It was a challenging harvest season, but we harvested our last plot today. Yields were very good, ranging from the upper 40’s to upper 70’s. Across all maturity groups in our variety tests, full-season yields averaged 63.3 bushels/acre and double-crop averaged 60.0 bushels/acre.
Virginia soybean are now predicted to average 45 bushels/acre, a new state record. We are just shy of the predicted national average. Over the last 20 years, we have been increasing yields at a rate of 0.6 bushels/acre per year. This is quite a feat! While better genetics are part of this increase, I think that most of the increase is coming from better overall management of the crop. This management includes long term (e.g., better soil quality, etc.) and short term (e.g., timely planting, etc.).
Of course, we cannot forget the weather. It was relatively cool during the critical pod and seed development stages. More importantly, rain came at the right time.
2017 Virginia Soybean Variety Results
Below are some preliminary results to our soybean variety tests. I caution you that these are preliminary – some changes could still be made. But, I feel pretty good about the data presented here. Some double-crop data from Orange and Painter is still outstanding due to variability. We will be trying to determine its cause and have those data available ASAP.
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.
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:
- a relative maturity (RM) yielding at least as high as the other RM’s tested at that location
- 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.
- 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.
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.
Initial results from the 2016 Virginia state wheat and barley tests are available in excel format at:
The full document and summary is coming soon.
Virginia Soybean Variety Test yield data are now available and can be found at my website – Virginia Soybean Extension & Research.
If you have comments or questions, please contact me.
I had never seen fields as wet as they were back in the second week of July. But, things change very rapidly.
In August, it appeared that full-season yield potential was 60 to 80 bushels per acre. Growth was excellent and the crop was loaded with pods and seed. Likewise, corn yield potential was excellent. Double-crop soybean did not look nearly as good, struggling with general poor growth due late planting, wet feet early, and dry soils later.
Now the situation is just the opposite. Well almost – corn yields are coming in very good. But, pods and seed on our full-season soybean crop are rapidly aborting due to the dry weather. Leaves are falling. It appears that the crop is maturing more rapidly. This is not a good thing as yield strongly depends on the length of seed filling. I’ve even seen some soybean dying in the corners of center pivots on the Eastern Shore. Irrigation will definitely pay off this year. As shown in the precipitation deficit map, we are below our seasonal average rainfall over the past 60 days.
This photo was taken this past Tuesday 8:30 am in the Official Variety Test at our Eastern Shore AREC. It looks like maturity group 3 varieties will out-yield group 4s, which will yield better than group 5s. However, a timely rain this week may salvage the late 5s. I don’t expect yields to top 40 bushels and they could possibly be less than 20 bushels if the drought persists.
On the other hand, I feel much better about double-crop soybean. Although there is little growth, these soybean are not showing signs of drought, at least not to the extent of the full-season crop. This photo is from the field adjacent to the full-season soybean shown above.
The main reason for this lack of visual stress is less vegetative growth (usually not an advantage) pulling less moisture from the soil. We also started the season with a soil profile full of water, but not excessive moisture (probably because the wheat had more-or-less depleted the soil moisture by May). Furthermore, these double-crop soybean are just now entering the pod and seed development stages. The seed is not yet requiring great amounts of water. These soybean can also “wait” for a rain as, at this time, there are still excess pods on the plant.
Below are a few more images that show flower, pod, and seed abortion.
The number of seed per acre controls yield most – the number of seed is mainly controlled by the the number of pods at harvest; seed per pod has less effect. Seed size can also greatly affect yield, but not to the extent of seed number. With late-season rains, we can still increase seed size substantially, especially where there has been lots of seed and pod abortion.
Is there anything to be done about this? No, not really – short of irrigation. There’s nothing that you can apply to relieve the stress. But, we can learn from such devastating experience and apply these learnings to the future.
- First and foremost, diversify. Although early-maturing varieties don’t usually do as well in full-season systems as those best adapted to a given area, it may be worth it to devote some acreage to such varieties. It may also help to plant a few varieties that mature a little later than the ones you normally plant.
- Keep double-crop small grain-soybean systems in your cropping mix. Not only will it increase total income and improve your soils without a cover crop, it will reduce risks by diversifying your crop mix.
- Review university, on-farm, and company variety test results to help select drought-tolerant varieties. Not since 2010 have we seen drought to this extent in our variety tests; therefore, we have little information on how current varieties perform under drought stress conditions.
- Other stresses such as vascular disease and nematodes will greatly enhance the effects of drought. Identify those poor-yielding fields or parts of fields and take corrective actions next year.
- Improve your soils with no-till and cover crops. Better soil structure, more organic matter, and better chemical and biological activity will minimize drought stress.
VIRGINIA SOYBEAN FIELD DAY
Thursday August 20, 2015
Eastern Virginia Agricultural Research & Extension Center
2229 Menokin Road
Warsaw, VA 22572
Virginia Soybean Association
Virginia Agricultural Experiment Station
Virginia Cooperative Extension
Join us to see the latest research on soybean varieties, disease and weed management, IPM and sorghum varieties. Experts will also demonstrate no-till drill maintenance and update you on the mid-Atlantic double crop initiative. Registration begins at 8:00 am and field tours begin at 8:50 am. The program will end at noon with a delicious meal by Nixon Catering.
– Soybean Disease Management – Dr. Hillary Mehl
– Soybean Weed Management – Dr. Mike Flessner
– Soybean Insect IPM – Mr. Mike Parish and Drs. Sean Malone and Ames Herbert
– No-Till Drill Maintenance – Mr. Keith Burgess
– Grain Sorghum Management – Dr. Joseph Oakes
– Roundup-Ready Public Soybean Varieties – Dr. Bo Zhang
– Mid-Atlantic Double-Crop Soybean Initiative – Dr. David Holshouser
We hope to see you there!