First, I would like to introduce myself. I am Tim Bryant, the new assistant professor of entomology and extension specialist at the Tidewater AREC, in Suffolk, VA. I did my master’s degree here at the TAREC under Dr. Sally Taylor, and I am excited and grateful for the opportunity to come back and work with the farming community in Virginia. I am also looking forward to continuing to provide updates on this platform as regularly as we have updates to provide. Now, on to a quick update from my first few weeks on the job…
Soybean aphids have been reported in Mecklenburg and Prince George counties (First reports 8/28). Aphids can reproduce asexually, and are capable of rapid population growth under the right conditions, so close monitoring is important. Our threshold for managing soybean aphids is 250 per plant at R4 (full pod) or prior, and 1000+ at R5 (beginning seed) and beyond. The below image shows 300 aphids on a single leaflet as a point of reference (Photo credit: Roger Schmidt, University of Wisconsin-Madison, Bugwood.org). There is likely to be multiple developmental stages of aphids present at one time, and early stages are very small.
There are a couple key considerations for managing aphids; 1) they are highly susceptible to population crashes from natural enemies or weather events, and 2) broad-spectrum insecticide applications (i.e. pyrethroids) may kill aphids, but also the afore-mentioned beneficial insects. Eliminating beneficials can potentially flare up spider mites or other pests later on. If you think you may have an aphid problem, scout several areas of the field to estimate the number of aphids per plant and pay close attention to the number of beneficial insects present. Where we scouted for aphids, there were also large numbers of lady beetle adults and larvae, which are excellent aphid predators. If you reach the aphid threshold, sample again in 5-7 days to ensure the population has not crashed. Narrower spectrum insecticides (e.g. sivanto) may preserve some beneficial insects if an application for aphids is made. See our pest management guide (beginning on page “4-62”) for more details on labeled products, application rates, etc.
The below image shows a lady beetle larvae, which were found in abundance along with the aphids we are reporting on here, feeding on an aphid (Photo credit: Winston Beck, Iowa State University, Bugwood.org).
Location: Southern Piedmont AREC. We will not be at the main station, but park directly in the field. Look for signs between Blackstone and the main station on Hwy 40/Darvills Road.
Google Maps link to field entrance: https://goo.gl/maps/iKZmYnjx7wM2
Field entrance near: 1200 Darvills Road, Blackstone, VA 23824. GPS is not always accurate. Field entrance between Nottoway Lanes and Military Road.
Continuing Education Credits Approved:
NRCS Conservation Planner: 2.0
DCR Conservation Planner: 2.0
DCR Nutrient Mgmt Planner: 1.0
Certified Crop Advisor: 2.0 (Pest Mgmt)
Please register by texting 540-315-2954 or emailing flessner@vt.edu
Highlights:
View over 100 herbicide plots
Learn about herbicide resistant Palmer amaranth and common ragweed control options
Cover crops for weed control
Harvest weed seed control:
Chaff lining
Redekop Seed Control Unit
Pasture herbicide plots
If you are a person with a disability and desire any assistive devices, services or other accommodations to participate in this activity, please contact Michael Flessner at (540-315-2954) during business hours of 8:00 a.m. and 5:00 p.m. to discuss accommodations 5 days prior to the event. *TDD number is (800) 828-1120.
Virginia Cooperative Extension is a partnership of Virginia Tech, Virginia State University, the U.S. Department of Agriculture, and local governments. Its programs and employment are open to all, regardless of age, color, disability, gender, gender identity, gender expression, national origin, political affiliation, race, religion, sexual orientation, genetic information, military status, or any other basis protected by law.
The upcoming weekend rainfall (our meteorologists seem assured that it’ll be widespread) should greatly help parts of Virginia that are short on or getting short of topsoil moisture and position us perfectly for a good start to the soybean growing season.
However, with the rainfall comes cooler soil temperatures. Below are predictions for 4-inch soil moisture and soil temperature over the next 10 days from Orange (one of the coolest parts of Virginia) and Suffolk (one of the warmest parts). As you see, soil temperatures will plummet from relatively warm (>60o) to nearly 50o or less over the weekend. While soybean seed will germinate and emerge in a reasonable amount of time at 60O, germination and emergence will be very slow when temperatures dip below this.
Therefore, heed my suggestion and make sure that you have a good fungicide seed treatment on anything that you are planting now or early next week.
Below is the fungicide efficacy chart from our Pest Management Guide. The main diseases that we need to concern ourselves with are Rhizoctonia and Fusarium sp. If in wet soils, Pythium and Phytophtora sp. could also be a problem with slow-emerging soybean. Be sure to protect a slow-emerging crop with a fungicide containing the active ingredients that provide good to excellent control of the appropriate disease.
Many may have already planted. Some have stopped planting other crops such and peanut and cotton due to cool soils and started planting soybean instead. Regardless, an advantage of soybean is that it tolerates a wide range of planting dates. I’ve found no advantage to planting soybean before May and have seen little yield penalty from planting as late as the first week of June, under most conditions. There are advantages to planting early and planting late, but that is not the subject of this post. Contact me for more detailed discussion on this matter-it will take more that a few comments.
With that said, I’ve always preferred May planting due to less risk of frost damage and slow emergence that is common with earlier planting. Still there are big differences in management when planting in early- versus late-May. Here I’ll review a few of these.
Plant earliest maturing varieties first, then move to later maturing varieties. This will spread risk and harvest dates. We have however observed that early-planting and/or early-maturing varieties work better under productive soils/fields. If planting on poor soils/unproductive fields, later-maturing varieties will extend the growing season and push the critical pod- and seed-filling stages to less stressful times of the year.
Always plant into moisture. But don’t plant more than 1 inch deep when soils are cool or emergence will be delayed substantially. One-half to 3/4 of an inch is adequate. For later planting dates when soils are warm, one can plant as deep as 1.5 inches and get rapid emergence.
If planting into cool soils (usually before mid-May), use a good fungicide seed treatment. It could take 10 days or more for the soybean to emerge; plenty of time for soil-born seedling diseases to attack.
A final plant population of 70 to 100 thousand plants per acre is usually adequate for full-season plantings. This means that 95 to 130 thousand seed per acre is enough, depending on expected emergence. Our research and in other states have observed that less seed is needed with low-yielding fields and greater seeding rates are needed with high-yielding fields. The problem is knowing how much the field will yield.
As always, contact me for more details regarding these tips or discuss other early-season soybean issues.
Which soybean variety is best suited to my region? State variety testing programs provide critical research to help answer that question by evaluating hundreds of soybean varieties every year across multiple locations within a state. But what if we think beyond the bounds of our state borders when it comes to variety evaluation?
While a single state alone provides valuable data, our growing regions often cross state lines. A location in southeastern Virginia may share more similarities to sites in eastern North Carolina than it does to the Northern Piedmont of Virginia. Furthermore, by combining variety testing data across multiple states, we can create a more robust dataset that allows us to better predict which varieties are best suited to specific regions and growing conditions.
Pulling and combining data from select locations within multiple state variety testing programs can be a daunting task. Over the past year, a team of variety testing coordinators from Tennessee, Arkansas, Kentucky, North Carolina, and Virginia have been working to make that process a lot easier. Through funding from the United Soybean Board and in collaboration with Centrec Consulting Group, LLC, we created a tool that will allow users of variety test data to combine and visualize soybean variety testing data across multiple states in the Mid-South. This new tool is available at https://marketviewdb.centrec.com/?bi=MidSouthVarietyTrials.
In addition to choosing locations, another key component of this database is the ability to filter the results to include only the relative maturities, brands, and herbicide tolerances that you want. It can also let you chose whether to include irrigated and/or non-irrigated, or full-season and/or double-crop sites. You can also chose the soil textures that you are interested in.
I won’t go into the details of how to use the site in this blog. But, try it out. Contact me with questions or comments.
The database currently contains 2018 – 2020 data but will be updated as 2021 soybean variety trial data becomes available. We hope that you find this tool useful. We would value your feedback/suggestions as we continue to refine this product to better meet stakeholder needs. A brief survey can be found at https://utk.co1.qualtrics.com/jfe/form/SV_6u5lHEwEOXnXODA.
The database described in this article was developed with support from the United Soybean Board.
In an effort to better recognize Virginia’s soybean producers, Virginia Soybean Association is completely revamping the 2021 Soybean Yield Contest! Through a combination of checkoff dollars and sponsorship support, we’re happy to announce the a new and improved soybean yield contest.
There will be two categories: full-season and double-crop. There is no restrictions on irrigation (irrigated fields are accepted). Most of all the awards for the top 3 winners in each category has increased substantially due to our sponsors (see below).
1st Place – $2,500
2nd Place – $1,000
3rd Place – $500
This has already garnered a lot of interest. We look forward to receiving your entries.
Until these big high-pressure systems sitting in the eastern part of the country move east, it looks as if we are in for another week or so of dry weather. This is not good for soybean planting, any way you look at it. So, what should we do?
There are basically three options:
Plant shallow in dry soil and hope for enough rain to get the seed out of the ground. If you decide to take this approach, you want to ensure you achieve uniform seed depth and that you are not allowing the seed access to moisture below the seed that could lead to variable emergence. This approach would be less risky in clean-tilled situation where you are more confident that you have dried the soil out at shallow depths. Soybean seed will sit in the ground for several weeks and still emerge well when rainfall occurs. Some worry about “cooking” the seed during this period. Although it is true that the seed will continue to respire and its ability to germinate will decline, the bigger risk is that you catch a small rain that allows the soybean seed to imbibe water but not enough to get it out of the ground.
Caution must be exercised in no-till systems. With no-till the soil has not been uniformly dried out with tillage; therefore, there is non-uniform moisture distribution across the field. This leads to uneven access to moisture and ultimately emergence variability. Parts of the field will have adequate moisture to get the soybeans out of the ground, other parts will be completely dry as in tilled conditions, and much of the field will be in between. Those in-between areas are likely to have enough moisture to swell the seed and/or initiate germination but not have enough moisture to allow the seedling to emerge. This is my least favorite option.
Plant deep to the moisture. Under most conditions, soybeans may be planted 0.75 to 1.5 inches deep. But I don’t usually like to go much over 1 inch deep, especially in May. I want soybean to come out of the ground as fast as possible. With that said, we planted some at 1.5 inches last week. Soil temperatures are generally high enough right now for the seed to germinate and plants emerge relatively quickly. Soybeans should not be planted deeper than 2 inches. Many are not finding soil moisture at less than 2 inches. Even if there is moisture 1.5 inches down, exercise caution using this approach, especially your soils are prone to crusting, because a heavy rainfall could seal the soil before the soybeans emerge. In tilled conditions, the planter can push the soil down a little, creating a ridge of fluffy soil on each side. A heavy rain will cause this soil to move into that furrow and possibly add another ½ to 1 inches of soil to your depth. If you are going to go this route, check the emergence score on the variety.
Keep the seed in the bag until the next time we catch rain. This is the safest approach and the one that I am leaning to now. Based on historical data, we have another couple of weeks before we start seeing yield declines from delayed planting. Data from recent research throughout the Mid-Atlantic shows that each day delay in planting past mid-June can result in a ½ bu/A or more yield loss and in general these yield declines begin in the second or third week of June. We still have some time before we get to that point. The optimum planting date range for soybeans is late-April through mid-June, although it will vary from year-to-year and field-to-field based on rainfall, soil water holding capacity, and soybean maturity, but the goal is to get the soybean plants to lap the middles before reproductive growth begins. We still have still have time to do this in most cases.
Waiting to plant
is more of a concern for those who still have early-maturing varieties to plant
(MG 3 and early-4), as these varieties will have less time for vegetative
growth. I do suggest planting your earliest maturity groups first, whichever strategy
you choose to employ. Later maturity
groups have more time for adequate growth when planting is delayed.
What about
fungicide seed treatments? You have likely already decided on this and cannot
change. But fungicidal seed treatments
are less likely needed in this situation where soils are warm. It looks as if
temperatures will be warming all week, so I don’t see cold soils as a problem.
Whatever decision
a grower makes, uniform seed placement in critical to achieve uniform emergence
and ensure each seed has as equal of access to water as possible. I don’t get too concerned if some
plants emerge just a few days apart, but we don’t need them emerging a week
apart. Dr.
Rachel Vann of N.C. State discussed the importance of uneven and delayed emergence
in soybeans – How
Important Is Uniform Emergence in Soybeans? Still, keep
in mind that although earlier emerging plants will usually yield more, the late
emerging plant will still contribute to yield.
Due to soybean’s compensatory ability, the yield on the whole will
differ little from only a few days difference in soybean emergence within the
row. If you know me, you know that I’m
not a fan of planting with drills due to lack of equal spacing within the row. This lack of even spacing will become
increasingly important if plant emergence is not good.
In conclusion,
there are advantages and disadvantages to each planting option discussed, but
we still have time to plant soybeans in our region before we see drastic yield
declines. All options discussed will likely result in delayed emergence due to
environmental conditions.
Fire ant mound around brace roots of corn plant, Suffolk, VA.
We have high numbers of fire ant mounds in our crop fields and around our farms this year. There have been some unfortunate encounters and this message is to make you aware of what these mounds look like and the potential for injury. Mounds look like large piles of loose dirt (keep in mind they have to start small at some point). They are often found around fence posts and mailboxes, but many are located in fields, pastures, and lawns. Field borders and paths are frequently infested. Fire ants sting, just like wasps and bees, and some people will be allergic and require medical interventions. People that are not allergic will have itchy, painful welts that often fill with fluid and may take days or a week or more to heal. Usually, you will have dozens or even hundreds of stings. This is because the swarm very fast and wait to sting all at once. Keep in mind that I have lived around them most of my adult life in North Carolina and we have come to accept them as part of our environment and have learned caution and awareness. I have been stung multiple times, usually once every few years, and usually when I am scouting crops. Be aware of where your feet are standing. Walk quickly when crossing a field because you can disturb them and get away without injury. Treatment options are below for mounds located near homes and barns. You do not want children or young animals near these things.
Fire ant mound around edge of soybean field, Suffolk, VA.
I would not attempt to clear your crop fields. A single acre can contain hundreds of mounds and millions of fire ants. Fire ants are predators and will eat caterpillars and other insect pests. They will not eat seeds and plants. Large mounds can damage equipment in rare cases. Products exist that can be applied to turf and lawns with year-long residuals (e.g., TopChoice). These products require a pesticide applicator license to purchase. Baits (e.g., Advion) are an alternative if you are not licensed to apply insecticides. These can be purchased online, many local retailers do not carry them yet. Surface treatments do not work because the colony can live very deep underground. Do not attempt to treat once the weather turns cold because it will not work. Wait until spring. Pray for a cold winter.
Be safe y’all and stay healthy. As always, reach out to me if you have questions or concerns. Keep in mind that I am NOT an urban or ornamental entomologist and I am NOT trying to sell you any specific product. FOLLOW THE LABEL WITH ANY INSECTICIDE.
Although it’s hard to accurately
estimate soybean yields until maturity, doing so can give you an idea of your
crops potential this year or differences between fields or soil types.
Maybe you’re considering entering the soybean yield contest or maybe you
just want some peace of mind.
Here are some general guidelines
for estimating soybean yield. Again,
estimating soybean yield is inaccurate unless detailed sampling is done late in
the growing season. Estimates are
usually not very good until the soybean approaches physiological maturity (R7).
Only about 50% of the total seed dry
matter has accumulated by the R6 development stage. Stresses during the R6 to R6.5 stages can
result in large yield losses mostly by reduced seed size, but also by reduced
pods or beans per pod. After R6.5,
stresses will cause a much smaller loss.
To estimate yields, follow the steps below. Be sure to sample in 5 to 7 different areas of the field.
1. Determine the number of row feet needed to make 1/1000th of an acre from the table below. In narrow rows, one may use 3 or 4 side-by-side rows instead of one long row
2.
Determine the plant population per acre.
Count the
number of plants for the row feet determined above in 5 to 10 randomly chosen
area of the field. Multiply this number
by 1000. Average the number of sampling
areas. Note that the more areas of the
field that you sample, the more accurate are your estimates.
3.
Determine the number of pods per plant. As you
are making your stand counts, pull up 5 consecutive plants in the row you
counting. These 5 plants should be
growing next to each other. This will
insure that you don’t just pull the best looking plants in the row. Also, try to avoid gaps in the row as the
plant next to the gap will have more pods than the average plant. Count the number of pods on these
plants within the sample area and average.
4.
Determine the pods per acre. Multiply the plant population (step
2) by the pod average (step 3).
5.
Determine the number of seeds per acre. Multiply the number of pods (step
4) by 2.5 seed per pod. This is an
average number of seed per pod for most varieties. Some varieties may have more, some less.
6.
Determine pounds of seed per acre. Divide the seeds per acre (step 5) by 3000
seeds per pound. This number can vary
from 2500 to 3500. Higher numbers
represent smaller seed that are more likely during late-season drought. Smaller numbers represent seed that form with
abundant August/September rainfall. You
may want to obtain a low, medium, and high estimate.
7. Determine the yield estimate. Divide the pounds per acre (step 6) by 60 pounds per bushel.
As an alternative to calculating your numbers, you can use the chart below to determine how many pods or seed per pod you would need at three different plant populations to obtain a certain yield.
Each year, the Virginia Soybean Association in cooperation with Virginia Cooperative Extension sponsors a 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.
There are three Soybean Yield Contest categories: 1) Full-Season, Non-irrigated; 2) Double-Crop, Non-irrigated; and 3) Irrigated (Full-Season or Double-Crop).
Any grower (owner-operator, tenant, or tenant-landlord team) who is a member of the Virginia Soybean Association and produces 10 acres or more of soybeans within Virginia’s boundaries is eligible. Participants may enter one, two, or all contests.
Details of the contest can be found at the Soybean Extension & Research webpage. Please contact your local Virginia Cooperative Extension office if you wish to enter the contest, preferably at least 5 days before harvest.
