Today, Aug 26 2021, we pod blasted a few peanut cultivars grown at the Tidewater AREC in large plots to observe pod maturity at this time. While the peanuts planted in the first week of May might be ready in 20-25 days from now, those planted in late May are approximately 30 days from the optimum maturity. Keep in mind that weather is also a decisive factor; therefore, sampling for maturity again in 10-14 days from now will allow to pinpoint more accurately the day when peanuts are ready for digging.
In the past weeks, a few strawberry growers have expressed their concern about the possibility of cyclamen mite infestations. After visiting some strawberry farms in the Chesapeake area this week, I found symptoms of cyclamen mite damage in a few fields. Because of the small size of the mites, I took leaf samples from the symptomatic plants and confirmed the presence of the mites in the laboratory.
The cyclamen mite is a serious pest of strawberries. It has been reported in most strawberry-producing states. Cyclamen mites are tiny mites (0.001 in long) that feed on the tissue of nonexpanded and newly unfolded leaves in the strawberry plants. Adults and immatures of the cyclamen mite are considerably smaller than two-spotted spider mites and cannot be easily seen with the naked or a hand lens. Symptoms of cyclamen mite infestation include severely crumpled and crinkled leaves, as well as stunted plants.
The presence of cyclamen mites was confirmed mostly on ‘Ruby June’ strawberries, but they can infest any strawberry cultivar. Strawberry growers in the Virginia Beach metropolitan area and the eastern shore should beware of the presence of this pest mite in their field. There are very few miticides available for the control of cyclamen mites. Unfortunately, the same products used for the control of two-spotted spider mites do not always provide control for cyclamen mites. The best performing product against this pest is Portal (fenpyroximate). Agri-mek (abamectin), is also labeled for cyclamen mites. Despite being miticides, Acramite and Magister are not labeled for control of cyclamen mite and may not provide enough protection against it.
Dr. Lorena Lopez
Department of Entomology
Virginia Tech | Eastern Shore Agricultural Research and Extension Center (ESAREC)
(954) 529 9042 | email@example.com
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.
I know I missed a week of updates, but it was not much change in peanut maturity since recently. On Sep 28, however, some fields started looking close to digging. While some fields in theory still need three weeks to mature, others can be dug soon (see picture below showing samples of ‘Sullivan’ peanut planted at about the same time but in different fields with different conditions through the summer).
Maturity of peanut in Isle of Weight County, VA, on Sep 28, 2020. Samples are from different fields planted with Sullivan in mid-May.
Similarly, cultivar ‘Bailey’ showed variable maturities depending on the soil type, growth conditions, and irrigation. But in majority of approximately 35 samples looked at on Sep 28, Bailey seemed ready to dig starting within the first week of October.
With the exception of Bailey, peanut cultivars currently grown in Virginia have the high oleic oil chemistry. Thus, it is important to realize that cooler temperatures at this time of completing maturity may affect the high oleic oil chemistry. Research showed that temperatures in the range of 85 to 90 F during pod filling to harvest increased the oleic fatty acid content, which makes peanut a high oleic peanut; while lower temperatures promoted the linoleic fatty acid. I hope not, but if research proves right for our late maturing peanut this fall, when temperatures dropped in high 60’s or at the most 70’s for the past 3-4 weeks, this determination should be made as soon as first peanuts are picked and measures taken. This is particularly important for Virginian growers that primarily grow peanut for certified seed production.
Sample of ‘Bailey’ peanut in Isle of Weight County, VA, on Sep 28, 2020.
Frank Bryant pod blasting the peanut pods (left) and growers commenting on the pod samples (right).
Monday, Sep 14 2020, Extension Agent Livvy Preisser organized a pod blasting clinic in Windsor, VA, at the Indika Farms Inc.
As every year my technician, Frank Bryant, assisted the Agent with this activity. Keeping the distance, several growers brought over 25 peanut samples from almost 2000 acres from the neighboring fields.
In average, peanut still needs 3 weeks or longer to complete physiological maturity, regardless if the fields were or not irrigated. From all, only one sample of non-irrigated Sullivan was 2 weeks closer to digging. This agrees with what we have observed in the research plots this week.
Maturity of peanut in Isle of Wight County, VA, on Sep 14, 2020. Samples are from different fields, Bailey (upper left and center), Bailey II (upper right), and Sullivan (below).
Additional pod blasting clinics will take place on Sep 16 at Carolina Easter, Courtland, VA; Sep 18 at Meherrin Ag. & Chemical, Capron, VA; Sep 22 at TAREC, Suffolk, VA; Sep 23 at Carolina Eastern, Courtland, VA; Sep 25 at Meherrin Ag. & Chemical, Newsoms, VA; and Sep 28, at Indika Farms Inc, Windsor, VA. They are organized by Extension Agents Livvy Preisser, Elisabeth Pittman, and Josh Holland.
Because temperatures of the past 3 weeks seem to decrease in the next 3 weeks and into the Fall by 15 to 20 F daily, from high 80s and on some days mid-90s to only mid-70s, the rate of pod development from immature (white mesocarp color) to mature (brown and black color) will decrease as well. Therefore, patience is needed with peanut crop this Fall for harvesting high yields and SMK in Virginia.
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.
Bailey planted May 14, 2020 and pod blasted on Aug 25 (left) and Sep 8 (right), 2020.
Emery (left) and Sullivan (right) planted on May 14 and pod blasted on Sep 8, 2020.
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.