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.
Bailey planted May 14, 2020 and pod blasted on Aug 25, 2020Bailey planted May 3, 2019 and pod blasted Aug 27, 2019Bailey pegs and pods on July 20, 2020.Bailey pods with Southern Corn Rootworm and other damage
This article was co-authored by Virginia Tech Entomology Ph.D. student, Kadie Britt.
Here are the corn earworm moth catch numbers from a handful of pheromone traps that we have set up in hemp fields and one sweet corn field around Blacksburg, VA. Trap catch appeared to peak around mid-August with moths emerging from cornfields and has subsided a little toward the end of August. Crops such as soybeans, hemp, tomatoes, and sweet corn are still at risk to this important pest.
Corn earworm moth catch in Heliothis traps baited with corn earworm Hercon sex pheromone lures.
We have already started to see worms feeding on hemp throughout Virginia. CEW feeding on hemp causes mechanical damage to buds, allowing environmental pathogens to enter crop material, ultimately leading to bud rot. Bud rot is visible and present in hemp crops right now but is not prevalent just yet. Managing populations early on will be key to reducing crop injury this season.
Corn earworm larva on hemp plant in Virginia. Photo by Kadie Britt.
Strict regulations on pesticide applications to hemp prevent
the use of many available insecticides. We have conducted a laboratory
experiment to evaluate the efficacy of some products that are currently allowed
for use in hemp in Virginia as well as Pyganic, which is not labeled on hemp,
but is a widely used organic insecticide.
Treatments included in the August 19, 2020 bioassay
included:
To conduct this bioassay, corn earworm larvae (3rd to 5th instars) were collected from untreated sweet corn grown at Kentland Research Farm in Whitethorne, VA. Untreated hemp seed heads were collected from grain hemp, variety ‘Joey’, grown at the Urban Horticulture Center farm in Blacksburg, VA. Seed heads were dipped in spray tank concentrations of each insecticide at the high labeled rate and placed into 1 oz. diet cups. Larval corn earworms were placed directly on top of treated material. Mortality was evaluated at 1, 2, 3, and 4 days after the experiment was set up (Figure 3). PyGanic + PBO provided significantly greater efficacy against CEW than all other products tested with only 6.5% of worms surviving after 4 days. The addition of the synergist is needed for effective control with Pyganic due to pyrethroid resistance development in this pest. Unfortunately, Pyganic is not currently labeled for use on hemp in Virginia. Agree, XenTari, and PyGanic without PBO all performed similarly with 50.3%, 53.5%, and 59.9% of worms surviving after 4 days, respectively.
Survival after 4 days of field-collected corn earworm larvae placed on hemp seed heads that were dipped in spray tank concentrations of various organic insecticides. All products except Pyganic are permitted for use on hemp in Virginia.
Looking ahead this season, insecticide research trials in
CBD hemp will be conducted in Blackstone with all of the aforementioned
products plus many more. We will continue doing lab bioassays with CEW and
other insecticides that are allowed for use in hemp at this time. Results will
be shared as they become available.
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.
Average nightly corn earworm/bollworm moth black light trap captures for this week were: Dinwiddie=51; Greensville=9; Hanover=3 (first week with more than 0.5 per night); Prince George-Templeton=12; Prince George-Disputanta=3; Southampton=5; Suffolk=17. Here is the Table. At just over 200 vial tests conducted, corn earworm moth survival is 39%.
Please find the 2020 Virginia Tech Eastern Shore Agricultural Research and Extension Center Virtual Field Day available via YouTube. Pre-recorded sessions can be viewed in one playlist or you can pick and choose individual topics using the hyperlinks in the attached program.
As always, contact us with questions vis email, YouTube comments, or Facebook. Please let us know of any further research or Extension questions that you may have. We hope to see everyone again at our Painter, VA location in person in Summer 2021!
Stay healthy and take care!
Virginia Tech Eastern Shore AREC research plots. Photos by At Altitude Gallery, Cape Charles, VA ( https://ataltitudegallery.com/ ).
Average nightly corn earworm/bollworm moth black light trap captures for this week were: Dinwiddie = 26; Greensville =4; Prince George-Templeton = 9; Prince George-Disputanta = 6; Southampton = 8; Suffolk = 23. Thanks to our Agents and Growers for their efforts. Here is the data table
Sally Taylor and her entomology program sampled a Cotton Incorporated sponsored planting date experiment today at the Tidewater AREC in Suffolk, VA. We found 2 to 6.5% bollworm-injured bolls in conventional (non-genetically protected against bollworm) cotton. In our Virginia Soybean Board experiment with maturity groups 4 and 5 full-season soybean (beginning pod growth stage), we had 2.3 to 5 corn earworm larvae and up to 3 soybean looper larvae per 15 sweeps.
Over the past couple of weeks our fruiting vegetable crops at Kentland Farm in Whitethorne, Virginia have been invaded by abundant numbers of leaf-footed bugs (Leptoglossus spp.). These bugs that are in the same bug family Coreidae as the squash bug Anasa tristus. They are piercing sucking feeders that have killed entire cucumber and zucchini plants from their feeding on stems and leaves or have caused numerous puncture wounds on fruit, which result in a little fluid oozing from the fruit.
Leaf-footed bug adults and nymphs on zucchini. Photo by Courtney Walls, Virginia Tech Entomology Graduate Student.
These insect pests can be controlled using the same insecticides that are labeled for use on stink bugs and squash bugs, namely, pyrethroids or neonicotinoids for conventional growers. Organic growers can achieve some suppression of bugs with the use of products containing pyrethrins such as Pyganic or Azera, or with the use of Surround (kaolin clay powder), which also works to prevent sunscald on fruit.
Since early July, we have been monitoring Heliothis traps baited with corn earworm pheromone at on 4 hemp fields and one sweet corn field in and around Montgomery, Co., Virginia. Below are the trap catch results. After a week or two of low catch, the moth activity has picked up especially at the Wall sweet corn.
Average nightly moth captures for this week were: Greensville =10; Prince George-Templeton = 3; Prince George-Disputanta = 7; Suffolk = 21. Here is the data table
