In the past two weeks, peanut progressed nicely towards harvest maturity. The pictures below show maturity of Bailey on Aug 25 and Sep 8, 2020; and maturity of Sullivan and Emery on Sep 8, in fields at the Tidewater AREC, Suffolk, VA. Recent good soil moisture and high temperatures, not many exceeding 95 F, seem to close the gap between last and this year’s harvest time. It is, still, very improbable to have an early digging, like we have had in the past two years when peanut was complete dug by end of Sep in Virginia. Maybe by the end of Sep, 2020, we will start digging some early planted fields. I will provide weekly updates.
This year, peanut is nowhere near where it was last year, from the pod maturity point of view. The pictures below show 100% white (immature) pods from Bailey planted on May 14, 2020, and collected on Aug 25. Last year, on Aug 27, pods of Bailey planted on May 3, 2019, ranged from 10% white to 25% brown and black (fully mature), with the majority in yellow and orange mesocarp color denoting substantial progress towards physiological maturity. Indeed, in 2019, peanut was planted earlier than this year, but this only explains part of the reason why this year peanuts are maturing later than in 2019. The other part comes from the dry and hot July, when pollination, and growth of pegs and pods were slowed down. Tropical storm and other rain events at the end of July benefitted pod development, but maturity is still delayed from the last season. I am showing pictures only from Bailey, as the main cultivar grown on 50% of the peanut acreage this year; but we looked at Sullivan, Emery and Wynne as well and they look similar with Bailey. This year, we also noticed on all these cultivars a fair amount of Southern corn rootworm and other pod damage, regardless the soil where pod samples were collected at the Tidewater AREC. I will continue updates on peanut maturity every other week.
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.
Observations from the field this week indicate that there are spider mite infestations at some level in most, if not all, peanut, cotton, and soybean fields in the drought-stressed Virginia regions. Drying of corn and weeds is contributing to this problem. Let’s all hope we get the rain we need to make a good crop this season. Rainy, humid weather will favor fugus that kills mites, but its effect may be mitigated by extremely hot conditions. Just in case, and since our last bad mite year was 2011, see below for a refresh about spider mites and how to treat them in each crop…
Concentrate on the field borders and look for the early signs of white stippling at the bases of the leaves. Do not confuse mite damage with dry weather injury, mineral deficiencies, and herbicide injury. Mite infestations will have some pattern, usually originating from field margins. Consider applying a miticide if more than 50 percent of the plants show stippling, yellowing, or defoliation over more than one-third of the leaves. Recommended products include Zeal and Agri-mek (other abamectin products are available, but not labeled for soybean). Lorsban and dimethoate are labeled and may require a second application. Bifenthrin will offer some suppression, but mite infestations will come back stronger.
Heavy infestations usually occur first around the borders of peanut fields; then they spread inward throughout the fields. Avoid harvesting spider mite infested cornfields or mowing weedy areas next to peanut fields until peanuts are harvested. Spider mites will readily move into peanuts when corn dries down or is harvested. Be prepared to treat peanuts if adjacent corn is infested. Use adequate pressure and GPA to ensure penetration of the canopy. Comite is our only registered product that works. See graph below from Dr. Mark Abney at UGA.
Mite damage first appears as a slight yellowing of the leaves, which later changes to a purplish or bronze color and is usually associated with webbing. Damage occurs especially in spots or on field edges but widespread defoliation is not uncommon if favorable conditions persist. I recommend abamectin (10 oz/A rate is usually sufficient) or Zeal for control. Bifenthrin, other pyrethoids, and especially acephate, will flair mites. If you are treating for plant bugs, I recommend Transform at 2-2.25 oz/A until wetter conditions prevail. Be mindful of the bollworm flight next week and do not make automatic sprays for worms until you confirm a problem in your field. Worm specific products (Prevathon, Intrepid Edge, Blackhawk) are better options than broad-spectrum insecticides (pyrethroids).
Our annual post-bloom survey starts next week. If you need help learning how to scout insect pests, call or text me on my mobile (919) 801-5366.
The 2020 VA Ag Expo has been cancelled. The Ag Expo committee with guidance from the Virginia Soybean Association and Virginia Grain Growers Association have made this difficult decision to ensure the health and safety of exhibitors and guests as a result of the COVID-19 pandemic. We will be reaching out to each exhibitor and sponsor to discuss our next steps. We appreciate your support and look forward to 2021!
Before I get into tips for soybean, I must emphasize one must focus on the entire double-crop wheat-soybean system. Both crops must contribute to profit; one crop cannot carry the other. You will may save some input costs such as lime, fertilizer, and rent (making those seasonal cost spread over two crops) with the double-crop system, but certain costs such as soybean seeding rate will increase. In the end, these inputs roughly equal out with the exception of land rent that can vary greatly over Virginia.
With that said, the most important thing to insure a profitable double-crop system is yield, yield of both crops. Without a minimum of 80+ bushel/acre wheat and 33-35+ bushel soybean, the system will not likely be as profitable as the full-season soybean system, especially with today’s low prices.
Assuming that you will intensely manage both crops during the growing season (note that intensely managing does necessarily not equate to greater input costs, but instead greater attention), the most important thing that anyone can do right now for greater yields is to harvest the wheat crop as soon as possible, and then immediately plant the soybean. Our 3-year, 5-state (PA, MD, DE, VA, NC) project conducted just a few years ago clearly confirmed that this is one of, if not the most important decision that a double-crop farmer can make. In that project, we generally showed a rapid decrease in both wheat and soybean yield with delayed harvest and planting after mid-June. Wheat yield declined anywhere from 0.5% to 2.5% per day, depending on location and year, versus wheat that was harvested at 18-20% moisture. This was largely due to rapidly declining test weights afterwards. And we also noted that quality decreased in many test locations. Note that if wheat is harvested this wet, then it will need to be dried almost immediately. I don’t recommend this unless you have a continuous-flow drier or have a buyer willing to take the high-moisture wheat without severe price dockage.
Although we found a benefit to the wheat crop, probably the bigger benefit however to harvesting wheat at high moisture is earlier planting of the soybean. On average the soybean yield began to decrease about ½ bushel/acre per day by mid-June, but this increased to 1-2 bushels per day once we got into late-June (more northerly Mid-Atlantic states) and early-July (more southerly Mid-Atlantic states). This resulted in a major income difference.
Just to re-emphasize this most important point, harvesting the wheat and planting the soybean ASAP is the most important thing a farmer can do to make this system as or more profitable than a full-season soybean system. The current weather is not helping with this (we could have harvested much of our wheat this week), but hopefully next week will bring drier weather.
Here are some other tips that are very important when planting double-crop soybean.
Variety Selection. Select the latest maturing varieties that will mature before the frost. This will assist with growing as much leaf area and having as many reproductive nodes as possible. Plant the earlier maturing varieties in this maturity range on your best soils and the later relative maturities on the poorer-yielding land.
Always Plant in Narrow Rows. I prefer 15 to 20 inch rows seeded with a planter that singulates the seed. Seed singulation insures uniform seed placement within the row and no big gaps between plants. The other option is to plant with a drill, which achieves the narrow rows but results in what many refer to today as a “controlled spill”. This results in many gaps, 2 or 3 seed planted in the same place, and generally lower yields (we proved this in some on-farm double-crop studies in the early 2000s). Still, a drill is better than 30-inch (or wider) rows at such a late planting date.
Seeding Rate. Beginning next week in Virginia, plant 140,000 to 160,000 seed/acre and increase that rate by 20,000 seed/acre with each successive week. This will of course put the seeding rate up to 200,000 to 220,00 plants by the first full week of July, sharply decreasing your profit with greater seed costs and lower yields. Again, this is to insure maximum leaf area and node development. Note that as one moves north and west, greater seeding rates may be needed due to the shorter growing season (e.g., northwest Virginia may require a greater seeding rate than southeast Virginia, or North Carolina). If using a drill, I suggest increasing these rates by 10%.
Insure Good Soil-to-Seed Contact. First, adequately spread the wheat residue. No planter will uniformly plant through inches of matted residue. Then make sure the planter is properly set to 1) cut the residue, 2) penetrate the soil to the proper seeding depth, and 3) ensure good soil-to-seed contact. These steps must take place in order. And they affect each other; a mistake in accomplishing one of the steps can result in mistakes in the other two. I suggest waiting until late morning to begin planting to insure that the small grain residue to dry – unless the residue is dry, cutting through it will be a problem, resulting in hair-pinning of the residue and prohibiting proper soil-to-seed contact.
Plant into soil moisture. If there is plenty of moisture, you can plant as shallow as ¾ inch and get good and rapid emergence. If a little dry on top, you can plant as deep as 1.5 inches. With warm soil temperatures, soybean will generally emerge well from this depth and may even emerge from even deeper depths (but I don’t recommend). Unless you farm in wet, poorly drained soils or are growing continuous soybean, I don’t usually recommend a fungicide seed treatment during June and July due to warm soils. Double-crop soybean usually emerge quickly if planted into soil moisture and will “out-grow” any seedling disease.
Insure Nitrogen Fixation. If soybean have not been grown in a field for the past 3 years, then be sure to apply inoculate to the seed with the proper bacteria. This will insure adequate nitrogen fixation by the soybean plant. There is no need to apply nitrogen; definitely don’t apply more than 25-30 pounds/acre or you will inhibit this vital biological process. As a side note, we did find a fairly consistent 1 bushel yield increase with starter N at 25 lbs/acre due to slightly better early-season growth; but this did not pay for the cost of the N – so I don’t recommend.
Fertility (P, K, S, etc.). Keep in mind that the straw contains quite a bit of nutrients. If the straw is harvested, make sure that you are replacing those nutrients that are leaving the field. For more information, see our VCE publication, The Nutrient Value of Straw. And make sure that you are being paid more for the straw than these nutrients and organic matter is worth!
Although it appears that we can use existing stock of labeled dicamba products (XtendiMax with Vaporgrip Technology, FeXapan, and Engenia) for Xtend soybean varieties, some may want to switch to or use Enlist varieties to control resistant or hard-to-kill weeds in their double-crop system.
Therefore, I’m listing this past year’s results of the performance of Enlist varieties from our variety tests. Note that most of maturity group (MG) 4 varieties. I tested no late-5 or 6 varieties.
Again, the varieties that you have already selected are likely the best-performing ones for your fields; therefore, I do not recommend changing unless you need the Enlist system to control weeds in certain fields.
The Virginia Grain Producers Association has announced the rules and entry forms for the small grains yield contests. This is a great way to promote good small grain management and for top producers to be recognized.
The court ruling yesterday has given a devastating blow to farmers that are depending on the Roundup Ready 2 Xtend herbicide program for their soybean. There seems to be much discussion regarding clarification of this ruling, including when the ruling can take effect and a possible “existing stocks” provision.
Until the ambiguity around the decision is clarified, it’s worth thinking about seed choice. Assuming there is little that can be done about soybean already planted and growing other than alter your postemergence tank-mixes, you may have an opportunity to switch varieties for the upcoming double-crop soybean planting.
First and most important, do not change your variety selection if you have weeds that can be controlled without the addition of labeled dicamba products (Enginia, FeXapan, Xtendimax) to your herbicide program. The varieties that your have already selected are most likely to be best for your farm and will maximize your yield.
However, if you must add dicamba to your glyphosate to kill glyphosate-resistant marestail (hopefully you’ll take care of this weed before you plant), Palmer amaranth, or common ragweed, then you have some options with Liberty-Link, Enlist, Liberty-Link GT27, or a few other varieties that have stacked the GT and LL traits.
Like all herbicide-resistant traits, there are good varieties and there are some that don’t yield so well. I suggest that you refer to our Virginia Soybean Performance Tests 2019 or other good private and public resources to see how these have performed.