Author Archives: David Holshouser

About David Holshouser

David serves as Associate Professor & Extension Agronomist at Virginia Tech’s Tidewater Agricultural Research and Extension Center. He provides leadership for agronomic extension and research programs that lead to profitable and environmentally-responsible agriculture.

Seeding Rates for Late-Planted Soybean

The cool and wetter weather earlier in the month has delayed some soybean planting into June. In addition, some cotton growers have switched to soybean due to the same reason. The question that came to me often this week was “Should I increase my seeding rate?”

In general, our research has not found a dramatic yield response to more seed per acre until mid-June. This largely reflects the lack of decrease in yield due to late planting dates until about the same time. If planted by the first week of June, the soybean usually has time to build a canopy great enough to capture most of the light by flowering, and does not need the extra plants.

However, I usually recommend that you begin increasing seeding rates by about 20,000 seed per week beginning the first of June.

Therefore, I would suggest the following:

This week (June 1-6): 120,000 – 140,000 seed/acre

June 7-13: 140,000-160,000 seed/acre

June 14-20: 160,000-180,000 seed/acre

June 21-27: 180,000-220,000 seed/acre

On your better soils or with later maturing varieties, use the lower seeding rate. On your less-productive soils or with earlier varieties, use the higher rate. This will insure that you you have enough leaf area to maximize the yield for those planting date.

Will the cold weather harm my soybean this weekend?

The weather reports of near-freezing temperatures in some parts of Virginia has many concerned about their wheat, corn, emerged and non-emerged soybean. I’m one of them, but we must try to be optimistic about this threat.

My weather apps seem to indicate lows in the lower 30’s in some of most northern and western growing areas on Friday and Saturday nights. This is never good, especially in May. A frost may burn off some leaves if the air remains calm, but a slight breeze during the night can keep the air temperature surrounding the plants above freezing, and in-turn the soybean plant above freezing. And as long as the temperatures don’t drop below freezing for an extended period of time, I think that our soybean will be O.K.

Why do I say this? Usually, it will take air temperatures of 28 F or less to cause permanent damage. Why is this? First, the soil temperatures are warm, in the 50’s and 60’s and the soil will not warm as fast as the air. The air nearest to the soil won’t be as cold due to this; there will be a buffer area. Even if temperatures do get down to 31-32 F, plant cells will not freeze because they contain solutes, which lowers the freezing point of the tissues. For a more thorough explanation of freeze damage to soybean, I recommend this article on the University of Wisconsin’s Cool Bean website.

Just in case, we do have some soybean damage, Purdue University has an excellent article on the subject for corn and soybean, Symptoms of Low Temperature Injury to Corn and Soybean, which include some good photos of injury. The photos show likely seedling soybean survival and death examples. If our soybean have several leaves (V1-V2) and there are some out there, it’ll take very cold temperature to freeze the entire plant. Even if frost burns the leaves off, the growing points in the nodes of these leaves will likely survive and regenerate a new stem, leading to a bushier but healthy plant. But, we can worry about that next week.

The seed that are in the ground will survive. Again, the soil temperature will not drop dramatically with the cold weather. Still, soil temperatures in the 50’s is not warm. You’ll need a fungicide seed treatment protecting them. No seed treatment? We will have to wait and see. For more details, see my last article, Soybean Planting Tips for Cool Weather

Should you stop planting? We are not. I have a planter in the field today. But my seed are treated with a fungicide. But neither do you need to be in such a hurry. We generally don’t see a drastic yield decrease until planting is delayed after June.

Soybean Planting Tips for Cool Weather

It looks as if we have come out of the unusually warm pattern we experienced during late-March thru early-April and fallen back into a cooler one. I’ve watched unusually warm soil temperatures fall rapidly during that period. Although long-term weather forecasts are speculative, it appears that the next week or so will be cooler-than-average. Below are the GFS (U.S.) and European model predictions thru next Thursday. Although today (Thursday) is very warm (& wet), notice that both models are showing below-average temperatures.

Temperature anomaly predictions from 4/29 – 5/9, 2020. Screen captured 4/29.

These low temperatures are also predicted to persist thru mid-May, as shown below.

Temperature anomaly predictions from 4/29 – 5/14, 2020. Screen captured 4/29

Keep in mind that the predictability of these models are quite low past 1 week, so this could change substantially. Still, we are dealing with some relatively cool soils and that need to affect our planting decisions once things dry up.

When soils are cool, we must get the plants up and out of the ground as soon as possible. The longer a sprouted seed is in the ground, the more likely it will be infected with numerous seedling diseases. We must always strive for rapid emergence.

Before we get into too big of a hurry to plant, we must recognize that yields will not decrease drastically for over a month. Although the date when such a decline takes place will vary with the year, my data and experience indicates that this date will not occur to the first week of June. Depending on the number of acres you need to plant, you may not need to get in that big of a hurry. If the same 2-week pattern of cold then warm periods continue, I expect to see a warm-up and warmer soils by the second week of May.

If you must plant into cool soils, I suggest that you use fungicide-treated soybean seed. This will provide some protection if the seed does remain in the soil for an extended period. Below is a table that Dr. Hillary Mehl used this winter listing the effectiveness of several active ingredients with diseases that commonly occur in Virginia. Rhizoctonia and Fusarium have traditionally been our most troublesome. Pythium can also raise it’s head occasionally. Note that only one of these treatments listed are good on sudden death syndrome (SDS), but there is now at least one other product available . I caution that nematodes are often involved with SDS, so additional measures will likely be needed to fully manage that disease.

E=excellent; VG=very good; G=good; F=fair; P=poor; NR=not rated
1 Products may vary in efficacy against different Fusarium and Pythium species.
2 Areas with mefenoxam or metalaxyl insensitive populations may see less efficacy with these products.
3 Listed seed treatments do not have efficacy against Fusarium virguliforme, causal agent of sudden death syndrome

Finally, don’t plant the seed too deep. 3/4 to 1 inch deep is enough. Planting deeper will delay emergence.

Full-Season Soybean Planting Dates, Maturity Groups, Seeding Rates, and Seed Depth

Best Planting Dates & Maturity Groups (MG). If you’ve seen some of my presentations in the past, the best maturity groups will largely depend on location, but also on field productivity. Still, we cannot talk about maturity groups without a discussion on planting date, as they influence each other. Here are some general full-season guidelines:

Planting Date x Relative Maturity Experiment in Caroline County, VA, 2019

Planting Date. On average, there is little advantage, although no disadvantage, to planting in April if using adapted varieties. My data indicate that late-MG 4s and early 5’s are generally the best choice at both planting dates. But note my comments below regarding field productivity.

Location and Maturity Group. On average and most consistently, late-MG 4 and early- to mid-MG 5 varieties have yielded more than other relative maturities when planted in May in most of Virginia. Exceptions are the Northern Piedmont and Eastern Shore. In the Northern Piedmont, late-3s through late-4s yield more than 5s. On the Eastern Shore, early- and mid-4s appear to have the advantage.

Note that these comment are based on relative maturity and planting date studies over the last 3 years and from 10 years of variety test data. This does not mean that you will see similar results every year on every field. There are always exceptions, including the following.

Early planting dates and maturity groups work best on the most productive field. By planting early with an earlier-than-adapted relative maturity will place the most critical time of soybean growth and development, the pod and seed stages, earlier in the year. We generally experience more water and heat stress earlier in the summer; therefore, a more productive field/better soil type will better tolerate the stress (and better take advantage of the longer days).

Later planting dates and later maturity groups work best on less productive soils. By planting later (up to the first week of June) and with later maturity groups (mid- to late-5s), we can avoid the most stressful time of the year, placing the critical pod and seed development into a less stressful time of the year.

Full-Season Seeding Rates: In general, 100,000 to 140,000 seed/acre (assuming at least 75% emergence) is enough to maximize soybean yield when planted in April and May. I’ve even maximized yield with less seed when early-season growth is good. All we are trying to do is grow enough leaves to get 90 to 95% light interception by early pod fill (R3).

A more detailed analysis of my data however revealed that under relatively low-yielding conditions (less than 35 bushels/acre), we need the greater seeding rates. And the lower rates sufficed under higher yielding conditions. Others have found the same thing in the Midwest and South America. What does this mean as far as adjusting your seeding rates?

First, on historically poor-yielding land, use 130,000 to 140,000 seed/acre. On historically better-yielding land, you can reduce that rate down to 100,000 to 110,000.

Note that the later you plant, as you approach June, greater seeding rates will more likely insure maximum yields.

Also note that plant emergence may be less when planted on cold, wet soils; therefore, increase the seeding rate by 10% or so.

Seed Depth. My philosophy on seed depth is plant into moisture at a depth that will give you the best and fastest emergence. Note that the longer the soybean is in the ground, the more likely it will be affected by a seedling disease. I usually recommend 1 inch deep to the bottom of the seed. Under cool and moist soils, plant as shallow as 1/2 to 3/4 inch deep. This will hasten emergence.

Once the soil warms up, you can plant deeper since germination and emergence will take place faster. But, try not to plant over 1.5 inches deep, especially in April or May. Only do so if the soil is very warm and there is little moisture in the top 1 to 1.5 inches.

Northern Neck Crops Conference – Warsaw, VA

The 2020 Northern Neck Crops Conference will be held Thursday, Jan. 16 at the Cobham Park Baptist Church, 13829 History Land Hwy Route 3, Warsaw, VA 22572. This year’s conference will include pesticide certification training, updates from FSA, NRCS, and SWCD, and several Specialists and Agents from Virginia Cooperative Extension that will cover a wide variety of topics. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Category 90 & 91, and Commercial Categories 1A, 10, and 60.  The conference has also been approved for 1.0 Virginia Nutrient Management CEU and 4.0 CCA-CEU credits.

9:00 – 9:05           Welcome – Trent Jones, VCE – Northumberland & Lancaster

9:05 – 9:50           Using Cover Crops for Weed Control – Michael Flessner, VCE – Weed Science Specialist

9:50 – 10:35        Market Update Robert Harper, Virginia Farm Bureau -Grain Division Manager

10:35 – 10:40      Irrigation Resources – Julie Shortridge, VCE – Biological Systems Engineering Specialist

10:40 – 10:55      BREAK – Please visit with our sponsors!

10:55 -11:40       IPM Updates – Sally Taylor, VCE – Entomology Specialist

11:40 – 12:35      Weathering the Storm: How to Cultivate a Productive Mindset – Jeremy Daubert, VCE – Rockbridge County

12:35 – 1:15         LUNCH

1:15 – 1:20           Program Updates – Scott Hammond, NRCS – Soil Conservationist

1:20 – 1:25           Program Updates – Brandon Dillistin, NNSWCD – District Technical Manager

1:25 – 2:15           Corn and Small Grain Production Update – Wade Thomason, VCE – Grains Specialist

2:15 – 2:30           Break & Evaluations

2:30 – 3:00           Legal Updates – Robert Christian, Pesticide Investigator – VDACS

3:00 – 3:30           Safety Updates – Trent Jones & Stephanie Romelczyk, VCE – Northern Neck

3:30 – 3:40           Wrap Up & Paperwork

2020 Five County Agricultural Conference – King William, VA

The 2020 Five County Agricultural Conference will be held Wednesday, Jan. 15 at the King William Ruritan Club Building, 156 Ruritan Lane, King William, Virginia 23086. This year’s conference will include pesticide certification training, updates from FSA, NRCS, and SWCD, several Specialists and Agents from Virginia Cooperative Extension that will cover a wide variety of topics, and precision agriculture round-table discussion. In addition, you will be able to get your dicamba herbicide certification with training being offered by Don Cline of BASF. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Category 90 and Commercial Categories 1A, 10, and 60.  The conference has also been approved for 1.5 Virginia Nutrient Management CEU, 2.5 Integrated Pest Management and 1.5 Crop Management CCA-CEU credits.

7:45 a.m.             Registration

8:15 a.m.             Grain Market Update, Robert Harper, Manager, Virginia Farm Bureau Grain Division

8:45 a.m.             Corn Update and Hybrid Selection – Dr. Wade Thomason

9:15 a.m.             Break

9:30 am.              Soybean basics and Soybean Variety Selection- Dr. David Holshouser, Extension Soybean Agronomist

10:00 a.m.           Crop Fertility and Fertilizers – Dr. Hunter Frame

10:30 a.m.           Precision Ag Discussion

11:45 a.m.            Cooperating Agencies (FSA, NRCS, and SWCD)

12:30 p.m.          Sponsored Lunch (Participants not seeking pesticide applicator recertification or Dicamba Certification are welcome

 to adjourn following lunch)

1:15 p.m.             Dicamba Certification – Don Cline, BASF Crop Protection

1:45 p.m.             Legal Update – Robert Christian, VDACS Pesticide Investigator

2:15 p.m.             Spill Response Activity – Robbie Longest/Mike Broaddus, Extension Agents, ANR, Essex and Caroline

3:00 p.m.             Wrap up paperwork and adjourn

2020 Four Rivers Agricultural Conference – Providence Forge, VA

The 2020 Four Rivers Agricultural Conference will be held Tuesday, Jan. 14 at Providence Forge Recreation Center: 9900 Carriage Rd, Providence Forge, 23140. This year’s conference will include pesticide certification training, several Specialists and Agents from Virginia Cooperative Extension that will cover a wide variety of topics, and others. In addition, you will be able to get your dicamba herbicide certification with training being offered by Don Cline of BASF. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Category 90 and Commercial Categories 1A, 10, and 60.  The conference has also been approved for 2.5 Virginia Nutrient Management CEU and 2.0 Contact hours for DCR Conservation Planner Re-Certification

9:00        Registration Opens/Meet with Vendors

9:30        Welcome

9:35        Controlling your Drops highlighting dicamba and glyphosate– Laura Maxey-Nay, Hanover Ag Agent

10:00     Pesticide Training – droplet size/playdough- Ed Olsen, Henrico Ag Agent

10:30     Pesticide Legal Update – Robert Christian, VDACS

11:00     2nd round of registration for those not needing pesticide recertification credit

11:15     Dicamba Certification – Don Cline, BASF

12:15     Sponsored Lunch/Meet with Vendors

1:00        Agency updates

1:15        Grain Market Update- Robert Harper, Manager, Virginia Farm Bureau Grain Division

1:45        What I learned from Argentina Agriculture, pest control and nutrient management –Paul Davis

2:05        Corn Update and Hybrid Selection, Dr. Wade Thomason, Extension Grain Agronomist

2:35        Break (visit with sponsors)

2:50        Positioning Your Full-Season Soybean for Maximum Yields, Dr. David Holshouser, Extension Soybean Agronomist

3:20        Making insect management decisions now by purchasing seed for next season, Sally Taylor, Extension Grain Entomologist

3:50       Nematode Panel, various specialists will discuss current nematode control practices.

4:50       Adjourn and paperwork

Tri-County Crop Production Conference – Carson, VA

The 2020 Tri-County Crop Production Conference will be held Tuesday, Jan. 14 at the Carson Volunteer Fire Department on 19806 Halifax Rd in Carson, VA. This year’s conference will host several Specialists from Virginia Tech that will cover a wide variety of topics. In addition, you will be able to get your dicamba herbicide certification with training being offered by Don Cline of BASF. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

9:00 – 9:05          Welcome and Announcements

9:05 – 9:40         Positioning Your Full-Season Soybean for Maximum Yields– Dr. David Holshouser

There are many things we can do to increase full-season soybean yield, but decisions made before planting are the most important.  This presentation will focus on site-specifically positioning your crop to best take advantage of the limiting resources of water, light, and nutrients.

9:40-10:20          Plant disease management – Dr. David Langston

Nematode and disease interaction issues in soybeans.  Update on fungicide and seed treatments available for corn and soybeans.  Common diseases occurring in 2019.

10:20-10:40       Break

10:40 – 11:10    Update on insect pest management – Dr. Sally Taylor

Review of major insect pests in 2019.  Recommendations for preparing for 2020, scouting tips to use throughout the season, and updates on insecticides available for use.

11:10 – 11:40   Small Grain and Corn Update – Dr. Wade Thomason

Review of the latest research in corn and small grain production in Virginia. 

11:40 – 12:00     Getting Started with Irrigation and Irrigation Survey – Dr. Julie Shortridge

Irrigation is not used on a wide scale in Virginia.  This presentation will introduce our new water specialist and a irrigation survey for growers.

12:00 -12:45       Lunch

12:45 – 1:15       Pesticides in VA update – Robert Christian, VDACS

Update on federal record keeping and worker protection standard. Additional information on changes in pesticide labeling for VA.  PPE review for commonly used pesticides.  Changes to paraquat labeling, handling, and training.

1:15 – 1:35         Weed control update – Scott Reiter

Roundup resistant common ragweed is common in our soybean cropping systems.  There are also 4 different herbicide technology systems in play for the 2020 season.  We will cover the options available and the stewardship needed to keep the herbicides on the target crops.

1:35 – 1:55          Cover crops – Mike Parrish

Cover crops have many uses in our production systems.  Soil erosion control, soil health properties, weed control, and moisture retention.  Presentation will cover results from local cover crop plots and impact on these properties.

1:55 – 3:00          On Target Academy – Don Cline, BASF

This session will cover the required training for using dicamba herbicide in post-emerge applications to Xtend soybeans and cotton.  Applicator & recordkeeping requirements, nozzle selection and technology, buffer requirements, weather conditions, and tank mix additives will be explained in detail

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Commercial Categories 1A, 10, and 60. 

Soybean Yield & Quality – My Predictions, Cautions,

I’ve been very hesitant to write this article and I’ve held off for several weeks, hoping to have more yield results in before saying anything. But I’ve seen enough so far in my observations of our variety tests as well as other fields that I think what I’m about to write is fairly accurate. My main concern all along was how much the Aug and September drought hurt us. Below is the rainfall anomalies in the U.S. It’s easy to see that we were way below average with the exception of southeast Virginia and parts of the Eastern Shore.

First, the maturity group 3 and early-4 soybean should be the cream of the crop this year. The yields that we are seeing is impressive and I’m hearing the same from others. These maturities appeared to avoid the drought for the most part. Plus the seed quality is very good (somewhat unusual for early-maturing varieties) due to the lack of September rain although we experienced another warmer-than-average September. This is us harvesting in Orange County last week – yields were in the 60’s and 70’s.

What about the later-maturing varieties that we grow the most of? A casual look at the soybean remaining in the field seem to indicate that we have a pretty good pod load in most cases, with late-planted soybean being the exception. Although the drought did hurt us, it’s somewhat hard to see now. Again, that’s from a casual observation. A closer look at the late-4’s reveal that the yield potential is still pretty good (see photos below; we did not harvest these due to a few varieties not yet being fully mature). Although we had a few aborted and small seed, most were intact. Keep in mind that this is a very good soil (Davidson clay) and the area did pick up a few rains that other parts of Virginia did not.

But what about our group 5 soybean? They don’t look nearly as good. Although pod abortion was not too bad, we had a good deal of flat pods and seed abortion within pods that were not completely flat where all seed were aborted. Don’t confuse the flat seed remaining in the pod with stink bug damage. Sting bug damage will usually result in discolored seed (there is one seed below that shows this); the small/flat seed due to drought-stress are usually not discolored. There was a pretty striking difference between the late-4’s and mid- to late-5’s; in general, the later maturity the more seed abortion.

Although I’m not seeing another concern, I think that it’s worth mentioning. A few years ago we observed drought-related green seed. These were not from late-maturing green stems or scattered plants. They were from the plant dying before the crop matured. This is only the case where we have extreme drought conditions and usually on a very low water-holding-capacity soil. But, I am seeing some dead leaves sticking to the stem, an indication of early plant death (see photo below) on some of our later-maturing varieties. While I hope this is not and issue this year, I did want to bring it to your attention. Too much green seed in a load will result in a reduced price for the crop.

Finally a note about green stems and branches. Anytime that we have a high amount of pod and/or seed abortion we can end up with some green stems. In some cases, we’ll even have green leaves on the plant although the seed are dry. This sometimes occur with high infestations of brown marmorated stink bug along the edge of a field or with certain viruses. But, drought can also cause this.

In addition to green stems, I’m getting reports of dry seed on the main stem (basically a mature plant), but the plant contains many green stems with immature seed. We have seen this in past years in low areas of the field where an overabundance of rainfall occurred early in the vegetative stages followed by a short intense drought (which I think stopped main stem growth) and by low light conditions. Once the drought was over, branch growth then took over. Branches are always behind the rest of the crop in maturity and the branches basically behave indeterminately (lower pods are more mature than upper pods), resulting in many immature seed at harvest. the last two pictures below are from late-May planted soybean in Mecklenburg County this year. At that location, about 10-12 inches of rain fell in the early vegetative stages and the soybean did not grow for the next 3-4 weeks, even with all this moisture. There was also lots of deer feeding. This was of course followed with the drought in Aug and September. While that situation was not exactly the same as the one I described previously, the problem is similar.

Regardless, one has to decide whether to harvest now and get the bulk of the crop before it shatters or wait until the rest of the seed to dry down. You definitely don’t want a lot of “butterbeans” in the load, but neither do you want lots of high-moisture seed that will affect overall moisture and storability. Shattering in today’s varieties are not as bad as in the past, so I’d wait a few days.

EVAREC Soybean Field Day is This Tuesday

The Eastern Virginia Agricultural Research and Extension Center (EVAREC) Soybean Field Day is this Tuesday, Sept. 24. The field day begins at 8:45 am and tours will begin promptly at 9:00 am. There are a number of different topics to be discussed, all supported by the Virginia Soybean Checkoff. The 2019 full-season soybean variety test will also be available for viewing. Lunch will be served by Nixon’s Catering. We look forward to seeing you there.

The EVARE is located at 2229 Menokin Road, Warsaw, VA 22572. For more information, contact Dr. Joseph Oakes, EVAREC Superintendent at 804-333-3485.

Group 1 Field Tour Schedule

  • 8:45 – Welcome & Introductions; Load Trailers to ACR 2
  • 9:00-9:20 – Integrated Pest Management Approach for Soybean
  • Dr. Sally Taylor
  • 9:25-9:45 – Food Grade Soybean Breeding
    • Mr. Nick Lord
  • 9:45 – Load Trailers to Y1
  • 9:55-10:15 – The Best Maturity Group for Your Farm
    • Dr. David Holshouser
  • 10:15-10:30 – The Use of UAV in Crop Research and Production
    • Dr. Joseph Oakes
  • 10:35-10:55 – Roundup-Ready and Conventional Soybean Breeding
    • Dr. Bo Zhang
  • 11:00-11:20 – Weed Management in Soybean
    • Dr. Michael Flessner
  • 11:20 – Walk to Seed Lab

Program & Speakers in the Seed Lab

  • 11:40 – Begin Indoor Program
    • Dr. John Fike: VT Forage Extension Specialist – Hemp Production
    • Dr. Mike Evans: VT School of Plant and Environmental Sciences
  • 12:00 – Lunch is Served: Nixon’s Catering

Thank You to Our Field Day Sponsors!

Crabbe Aviation                       Ryan Ellis

Frazier Quarries                      UniSouth Genetics

James River Equipment            Virginia Crop Improv. Assoc.

Montague Farms