- The new 2019 Virginia Peanut Production Guide is available at this link https://pubs.ext.vt.edu/SPES/SPES-67/SPES-67.html
- This guide describes peanut production practices including cultivars, planting, management, and harvest. Under management, information is provided on the optimum time for nutrient and irrigation applications; describes rotations effect on yield; soil preparation, etc. It also identifies major pests for the region including weeds, insects and disease, and how those to be controlled.
- Archived Peanut Production Guides can be accessed from: http://www.sites.ext.vt.edu/newsletter-archive/peanut-production/index.html
Variety selection continues to be one of the most important decisions that we can make. It is also one of the first steps to take that insure success. It’s a hard choice because there are so many varieties available. Still, this choice is one that will affect your profitability throughout the year.
Soybean yields in our variety tests have increased by an average of 0.4 bushels per year over the last 30 years. Some of this increase is due to better varieties, some is due to better management. In those tests, the highest and lowest yielding varieties varied by 20% or more (8-10 bushels). It is therefore clear that making the wrong choice will seriously impact next year’s soybean crop. Unfortunately, environment (rainfall, temperature, soil type, field, etc.) affects yield variation more than variety – there is always lots of year-to-year and site-to-site variation. Still, each variety has specific strengths and weaknesses that make it more or less suited for any given situation.
Putting the Right Variety in the Right Field
With all this variation, it is very important that you place the right variety in the right field. This will be influenced by 1) planting full-season or double-crop; 2) maturity; 3)herbicide tolerance; 4) disease and/or nematode tolerance; and finally 5) yield potential. There are also a number of other factors that differentiate varieties such as shattering and lodging susceptibility, height, branching ability (thin vs. bushy), seed size, seeds/pod, protein and oil content, other specific traits, etc.), but these will rarely affect your bottom line. Although all of the top five things I listed are important, yield potential is clearly what is of most interest. However, if you do not pay attention to numbers 1 through 4 first, your yield potential can be low.
To cover all of the things that make variety selection important would take more words than this blog will allow, so we will first focus on the choosing the right maturity.
Relative Maturity Choice: Spreading Out Environmental Risk
First, I should say something about early planting of an early-maturing variety. I define this as planting in April or early May a variety that is about one full maturity group earlier than the maturity that is most adapted, based on historical data, for your area. First, early-planted early-maturing varieties will always have a greater risk of poor quality seed. The seed of these varieties are maturing during September and early October, when the weather is relatively warmer. Warm and wet weather are perfect conditions for seed decay. 2018 has been one of the worse years for this, primarily due to excessive rainfall and much warmer September temperatures. To the right is an example of a maturity group (MG) 3 soybean planted in April in Madison County (MG 4 is the most adapted maturity for this area). Clearly, you don’t want to end up with this. While early maturing varieties have their advantages, their associated risks should keep the percentage of acres planted to a minimum.
On the other hand, do not keeping all varieties in a tight maturity range. The performance of varieties within a certain maturity range will almost always depend the environment that they experience during pod and seed fill. If conditions are good (adequate rainfall, moderate temperatures, good soils) during that time, yields will be high. Unfortunately, the weather cannot be predicted in our humid southeastern U.S. environment. While late-July and early-August are generally our hottest and driest times of the year, we have just as good of a chance of going through a hot and dry period in June as well as July as well as August, and sometimes in September. Still, on average, certain relative maturity ranges yield more than others in the south central part of Virginia. Below are the average yield balance (no. of bushels/acre greater or less than average) of a range of soybean maturities tested in our full-season variety tests over the last 10 years, separated by location.
I’ll use our Southern Piedmont location (Blackstone) as an example of a location that shows the greatest yield gap between the earliest and latest varieties (nearly 15 bushels!). This is likely due that area typically experiencing the more stress (hot and dry) from late July through August than other regions.
Similar but on the opposite end of the spectrum, MG 3 and 4 varieties work best at the Northern Piedmont (Orange) location. Maturity group 5 varieties generally not as adapted in that northerly environment.
The northern and southern Coastal Plain sites (Warsaw and Suffolk) behave similarly to Blackstone – MG 5 outperform MG 4 varieties; but the yield gap between relative maturities is not as wide.
Our Eastern Shore location does not follow the same trend of MG 5’s being the highest average yielding varieties as one moves south and east.
Note that maturity group (MG) 5 varieties relatively better in the more eastern and southern locations of Virginia’s mainland, while MG 4 varieties tend to do better in our most northwestern location (Orange) and on the Eastern Shore (Painter). While MG 3’s don’t yield as well, the group 4’s are the highest yielding. Why? I attribute it to two things: yield potential and temperature. In general, this site has over time been one of our highest yielding sites. Although rainfall patterns are similar to other locations in Virginia, it is our coolest location (and there is usually a breeze) – both likely a water effect. Therefore, the site experiences less stress. So, pushing the critical pod- and seed-filling stages slightly earlier in the year are not as problematic.
So, should you stick only with maturities that perform best on average? Not necessarily. Using Blackstone as an example, note that although the late-group 4 varieties yield less than MG 5’s on average, they yield much better than earlier 4’s. And late-4’s yield just as well as 5’s in Orange and Suffolk. I stress that these are averages – 10-year averages of all varieties within those relative maturity ranges. Is it possible for the MG 4 varieties to yield more than the 5’s in Blackstone or Warsaw? Is it possible for MG 5’s to yield more in Painter? Yes! It just does not happen as often.
We took that same data and calculated the probabilities, not absolute yields, of obtaining similar or greater yields of all relative maturity groupings tested. The results are below.
Once again, to use the Blackstone data as an example, we can see that growing a late-MG 5 variety will yield at least as much as all of the other relative maturities 90% of the time (bar height). In addition, there is a 50 to 60% chance (height of the hatched portion of the bar) that the 5’s will yield significantly more than the 4’s. So, it seems that you will never go wrong with those varieties, correct? You’ll probably (~80% chance) not go wrong by growing a large percentage of those varieties, but should you should you only plant MG 5’s? I suggest that you do not grow only MG 5 varieties. There is still a 10 to 20% chance that the 5’s will yield less than the other maturities. Plus, there is a 60% chance that late MG 4 varieties will yield just as much as MG 5 varieties (and a 30% chance that they will yield more).
Painter is another good example. Although there is a yield gap between the 4’s and 5’s, there is a 50 to 70% chance that MG 5 will yield as well as MG 4 varieties. And there is a 30% chance that they will yield more! You can use the same thought process for the other locations.
- Plant 60 to 80% of your land to MG 5 varieties. We have also found that later maturities generally do better on our more droughty soils, so take that into consideration if possible.
- Plant 20 to 30 % to late-MG 4 varieties (4.7-4.9). If possible, plant these on your higher-yielding soils. We have found that this range of maturities have our greatest yield potential throughout Virginia if the weather cooperates.
- Plant 0 to 20 % to mid-MG 4 varieties. These are risky, especially on droughty soils or in double-crop settings. It is highly likely that these varieties will experience some (or a lot) of stress during the seed and pod fill stages. Plus, seed quality will almost always be poorer than other maturities. If you do grow these, harvest as soon as possible as seed quality will continue to degrade with time. Don’t plant these in April or early May. This places the most critical times of development (pod and seed fill) during late-July and August. And seed quality will be even worse since they will likely mature during the warmer part of the year. Still, yield potential can occasionally be quite high.
Southern Coastal Plain (same comments apply regarding droughty soils and seed quality)
- Plant 30 to 60% of your land to MG 5 varieties.
- Plant 30 to 50 % to late-MG 4 varieties (4.7-4.9).
- Plant 10 to 20 % to early- and mid-MG 4 varieties.
Northern Coastal Plain (same comments apply regarding droughty soils and seed quality)
- Plant 30 to 60% of your land to MG 5 varieties. In double-crop systems, reduce that percentage to 30 to 50%.
- Plant 30 to 50 % to MG 4 varieties (4.7-4.9). In double-crop systems, increase that to 50 to 70% late-4’s and plant 10-20% early-or mid-4’s.
- Plant 0 to 20 % to late-MG 3 varieties.
Eastern Shore (same comments apply regarding droughty soils and seed quality)
- Plant 20 to 40% of your land to MG 5 varieties.
- Plant 50 to 70 % to late-MG 4 varieties (4.7-4.9).
- Plant 10 to 20 % to early- and mid-MG 4 varieties. Plant 0-10% in double-crop.
- Plant 10 to 20% to late-MG 3 varieties.
Northern Piedmont (same comments apply regarding droughty soils and seed quality)
- Plant 0 to 20% of your land to MG 5 varieties. Don’t plant MG 5’s double-crop.
- Plant 60 to 80 % to MG 4 varieties (4.7-4.9).
- Plant 10 to 20 % to mid- or late-MG 3 varieties.
The proportion of MG 4 and 5 will ultimately depend on your risk tolerance. Note that as you move west and north, the risk of an early frost is greater; therefore, growing lots of late-maturing varieties may not be a great idea, especially double-crop, and the probability of slightly earlier maturities doing better is greater.
Hopefully, this will give you some guidance in choosing your maturities within the next few weeks.
IMPORTANT: Keep in mind that the yields and yield balances shown are an average of all varieties in those relative maturity groupings. This does not mean that every variety in those grouping perform in this manner on every field. Make sure that you first the variety that meets your match your field’s pest management needs; then, select a high-yielding variety within that relative maturity range.
David Holshouser, Soybean Agronomist & Hillary Mehl, Plant Pathologist
We appreciated the rainfall this year. It should lead to some very good yields in many parts of Virginia. However, the same weather conditions for high yields has led to some of the worst seed quality that we’ve ever experienced. This is in addition to the pod splitting and seed sprouting that we began observing last month.
We began seeing extremely poor seed quality in our May-planter maturity group (MG) 3 soybean in our Orange variety test last week. The early MG 4 soybean did not look much better, but they were not yet mature.
The photo on the left is the worst that has been called to my attention. These are April–planted early MG 3 soybean from Madison County. To use the farmer’s words, “A real kick in the stomach.” Soybean in this shape are pretty much a total loss. It is especially hard when the yield potential was outstanding.
Below are photos from Westmoreland and Dinwiddie counties showing similar results. We are not seeing the same problems in our May-planted MG 4 soybean in Suffolk, but are seeing quite a bit of purple seed stain in some varieties.
So, what caused this? From these photos, we are seeing signs of several diseases, including Phomosis/Diaporthe, Cercospora, and anthracnose just to name a few. However, we have not yet confirmed the diseases – samples are on the way to the Tidewater AREC’s disease lab.
But that is just the possible diseases. What caused the disease to be so bad?
I think that we can blame it largely on excessive rainfall (and many rainfall events) and a very warm September. Most of the seed diseases come on strong during maturation; hence, our early MG soybean, especially those planted in April and early-May experienced those conditions.
Below is a weather summary from the month of September in Orange County, showing 2018 and long term average temperatures and accumulated precipitation. Notice the high rainfall, especially during the latter part of the Month, when our MG 3 and early-4 soybean were maturing. Secondly, notice the temperatures during that same time period. This set up nearly perfect conditions for many seed diseases to form.
What can we do about it? Unfortunately, we cannot control the weather. And what we have done this year cannot be undone. But, here are a few pointers for that may help this and in future years.
- Harvest as soon as possible after soybean are mature. The diseases will only continue to grow and develop. If you have drying capability, harvest at a little higher moisture and dry it down to 13%.
- Plant varieties best adapted to your farm(s). While you have discovered (and heard me – David – say) that early-planted early-maturing varieties have very good yield potential if we have a cool and wet July and early-August (not the normal), there is always the risk of poor seed quality. Only if September is cooler than average and rainfall is not excessive will this system give us good quality seed. Year in and year out, May-planted late-MG 4 and MG 5 soybean are our best overall choice. Also, it is rare that double-crop soybean have poor seed quality.
- Select disease resistant varieties. Most companies do not list resistance to many of our seed diseases, but we have seen differences in varieties. Look over our final soybean variety test results for more information on seed quality scores and purple seed stain ratings.
- Select disease-free varieties. Next year, notice your seed quality. While most companies will not bag disease-ridden seed, some could sneak through. Seed treatments may be in order.
- Minimize insect damage to pods. Though not necessary for infection, insect damaged pods are more likely to be colonized by fungal pathogens.
- What about foliar fungicides? We have not found that foliar fungicides can overcome warm and wet conditions during seed maturation, especially when applied to the R3 stage. Will a later application help? That is hard to say. In some cases, applying a fungicide at R5 will improve seed quality, but this is not a sure thing and a yield is unlikely to be improved with later applications.
We are seeing immature soybean once again sprouting in the pods in Suffolk and Gloucester County, and I heard of this happening in other states. This seems to occur every 3-6 years somewhere. Although I don’t have a great explanation for why this occurs, it usually happens when there are good growing conditions early followed by 2-4 weeks of drought stress during pod formation, and then excellent conditions return for seed fill. Typically, it happens in big-canopied soybean (lots of leaf area) with lots of yield potential, but not enough pods (or big enough pods) to fulfill that potential. I think that the seeds enlarge so much that the pod splits.
Keep in mind that I’m talking about immature seeds and pods. This can also occur after the crop matures (R7 to R8) when we get excessive rainfall after the seed in question has dried down. But, I have not seen that yet this year.
There is little that you can do about it. Those sprouted seed will usually dry up on the plant and be blown out the back of the combine.
Although there has to be some yield loss, I’ve not seen it to be very great. And, I suspect that if you did not notice the sprouted seed, you probably would not know that you had a loss.
For more information, see previous blogs on this subject.
While this post is likely too late for corn, it does apply to other crops. If you have yet harvested all of your corn, it’s never too late to calibrate your yield monitor.
First, I am no expert in calibrating yield monitors. My experience with the process only involves showing up to the farm with an accurate weigh wagon (or we use their grain cart), riding with the combine operator as he harvests a known area of the field, weighing the load and obtaining a moisture from the load (with a calibrated moisture tester), then watch him do the calibration.
Still, I understand the need for calibration although it takes time and may mean looking in the manual to learn or refresh one’s memory on the process.
John Barker, Knox County Extension Educator (Ohio State Extension) wrote an excellent article, “It’s almost that time of year … Don’t forget to calibrate your yield monitor!”, which is a step-by-step checklist of how to do this. I highly encourage all to read it.
We do have several weigh wagons located around the state that Virginia Cooperative Extension uses for our on-farm research. If you want me or one of your County Agents to help with this process, let us know.
Friday, Sep 7th, a pod-blasting clinic was organized in Windsor, Isle of Wight County in Virginia. Farmers brought samples for maturity evaluation from 40 fields, in majority from the IOW but a few were from Suffolk and Southampton. Samples were taken from fields totaling a minimum of 3100 acres of peanut. Based on the mesocarp color, we identified that one sample was ready to dig, 12 in a week, 15 in a week and a half (10 days), 8 in two weeks, and 4 in three weeks or more. This indicated that two thirds of these fields were ready for digging after this week and after the hurricane Florence has passed.
Peanut varieties planted were in majority Bailey and Sullivan with only very few acres of Wynne and Emery, the last being a new cultivar just released in 2015. On these checked fields, farmers did not irrigate and only one farmer used Apogee, a growth regulator that could have affected maturity. Defoliation due to leaf spot was almost absent in all fields, as it was rootworm damage.
The earliest to be dug, in no more than a week, were fields planted during the first week of May and receiving constant rainfall in June, July, and August. Note that precipitation received in July and August exceeded by far this year the multi-annual average for most fields. Some fields planted in mid-May and constantly rained out, also showed digging approaching in 7-10 days (picture below). The only early May plantings a little behind, 10-14 days from digging, were fields with a dry June, regardless if for the rest of the summer they were wet; and the majority of fields planted in mid-May. Based on the color charts, the fields planted during the last week of May could wait three weeks or more before digging. Meanwhile, several other pod-blasting clinics will be organized to help farmers decide when and what fields to start digging with.
This result came to no surprise. It has been determined that Bailey requires about 2700 °F heat units (or GDD) to reach optimum maturity. The Cotton – Peanut Infonet online service provided by Virginia Tech here https://webipm.ento.vt.edu/cgi-bin/infonet1.cgi shows that by Sep 7th peanut planted on May 1st received 2649 °F in Suffolk, 2637 °F at Capron in Southampton, 2718 °F at Skippers in Greensville, and 2640 °F at Waverly in Sussex. Researchers at the University of Georgia determined that every event of rainfall and irrigation received by a crop at one inch or above has an effect equivalent with 10 °F heat units and can speed up peanut maturity. If so, 100 or 200 heat units are to be added to those measured by the thermometer. Indeed, under the conditions of this year early May planted peanuts are expected to be ready for digging 7 to 10 days sooner than last year.
In general, we’ve had a good, but not great year for soybean in Virginia. Although many areas were hit with a 3 to 4 week dry spell during July, August rains kept us in the game. However, we did not see the ample rains or cool temperatures that we experienced in August of 2017, which resulting in record yields. Below is a summary of August rainfall and temperature anomalies for the U.S.
As you’ll notice, we had about average or slightly below average precipitation and average to slightly above average temperatures for most of Virginia’s soybean growing areas.
So, I do not suspect that our yields will be as good as last year. Still, our earlier-maturing varieties planted in April or May should yield quite respectably considering that most have made over 50% of their yield – they have reached the R6 stage (see photo below). Yield of our later-maturing varieties, planted in May and early June, and our double-crop plantings are not quite there yet – much of our yield is yet to be determined – R5 soybean have only made roughly 25% of their yield at that time.
So, what do we need for good yields? Rain is obvious. Full-canopied plants with adequate soil moisture will draw about 0.25 inches of water/day from the soil. But, we also need cool temperatures – soybean do not generally like 90+ degree days, especially when forming seed.
Below is the 10 day rainfall and temperature forecast for the U.S., and it does not necessarily look good for us. Note that the rainfall is predicted accumulation and the temperature map shows anomaly. Although we should get some rain this weekend only (more in northern parts), temperatures are supposed to be above average. But, forecasts are only forecasts. The weather does change. I hope we will get the needed rainfall that they are predicting this weekend. But a big ridge appears to be setting up over the Mid-Atlantic states for next week. This usually means warm weather and only at the edges of ridges do we normally see rainfall – note the heavy rainfall predicted from Nebraska through Michigan.
I don’t mean to discourage, just to inform. We still have decent soil moisture, at least in the subsoil. With rain this weekend, we should get through next week without too much harm to the crop.
Our double-crop soybean (assuming late maturity group 4’s and group 5’s planted in late June to July) are just now in the R5 stage – it usually takes 80 to 100 days from planting to reach R6, depending on maturity and planting date. So some timely September rains will usually result in good double-crop soybean.
When will our yield be “made”? Below is table showing the number of days to soybean physiological maturity (R7; 95% of yield has made). When can we expect to be harvesting our soybean? Full maturity is reached about 2 weeks after R7 and harvest can proceed after the soybean have dried down to a harvestable moisture, usually within a week after R8.
The 2017 Virginia On-Farm Wheat Test Plots have been published and are now available on the Virginia Cooperative Extension website. For more information or a hard copy, contact Mike Broaddus, Extension Agent, at the Caroline County office.
he demonstration and research plot results discussed in this publication are a cooperative effort by seven Virginia Cooperative Extension agents, extension specialists from Virginia Tech, and a VCE summer intern. We are proud to present this year’s on-farm small grain plot work to you. We hope the information in this publication will help farmers produce a profitable crop in 2018.