Update on peanut maturity, Aug 28

On Aug 26, a pod blasting clinic has been organized at the Indika Farms in Windsor, VA. A total of 24 samples (fields) representing 1056 acres were evaluated. Samples were from Isle of Wight, Suffolk, and a few from Southampton counties. Optimum digging for these samples was estimated to take place in 15 to 30 days from Aug 26, with the majority of the samples showing to be ready in 20 days. Dates for future pod blasting clinics are Sep 9 at Indika Farms (contact Livvy Preisser livvy16@vt.edu for details), Sep 4, 10 and 18 in Southampton (contact Joshua Holland cvfd262@vt.edu for details), and Sep 19 in Greensville (contact Sara Rutherford sriggan@vt.edu for details).

A few pictures from Aug 26 pod blasting clinic are shown below.

Bailey planted on May 8 in a sandy soil in Southampton Co., VA.
Bailey planted mid-May in IOW, VA.
Sullivan planted on May 8.
Emery planted on May 9.

Eastern Virginia AREC Soybean Field Day – Sept 24, 2019

Join us for the 2019 Eastern Virginia AREC Soybean Field Day in Warsaw on Sept. 24.

Field Tour Topics
• Roundup-Ready and conventional soybean breeding: Dr. Bo Zhang
• Food-grade soybean breeding: Dr. Bo Zhang
• The best maturity group for your farm: Dr. David Holshouser
• Weed management in soybean: Dr. Michael Flessner
• Integrated pest management approach for soybean: Dr. Sally Taylor
• Use of UAV in crop research and production: Dr. Joseph Oakes
• Industrial hemp production: Dr. John Fike

Registration begins at 8:00 a.m.
➢ Field research tours begin at 8:30 a.m.
➢ Lunch: 12:00 p.m.

Please register by emailing Joseph Oakes at jcoakes@vt.edu

Corn earworm pressure and recommendations for sweet corn in Virginia

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Corn earworm larva in mature sweet corn ear.

Corn earworm is the major pest attacking corn ears in the mid-Atlantic U.S. Moth activity has been high in some areas of Virginia such as the Eastern Shore based on pheromone trap catches and grower reports in fields. Sweet corn is one of the most preferred host plants for corn earworm, especially if fresh silks are available when female moths are ovipositing.

For control in sweet corn, it is recommended to begin treatment when the ear shanks emerge or the very first silks appear. Silk sprays should continue on a schedule based on pest pressure on the farm or area blacklight or pheromone trap counts, geographical location, and time of year. This time of year (August) it may be necessary to treat on a 2-3 day schedule.

Dr. Sally Taylor (Tidewater AREC) and I have seen increased levels of pyrethroid (insecticide class 3A) resistance in CEW populations throughout Virginia, and that these insecticides should be used with caution and rotated to other insecticide classes within a season.  See the list of recommended insecticides in the table.

During heavy populations and high temperatures, treatments will need to be made according to the legal “days to harvest” of the chemical. For best control during heavy infestations, maximize the gallonage of water per acre, use a wetting agent, and make applications during the early morning if possible. If irrigation or rains wash off the spray within 24 hrs after an application, repeat treatment as soon as the foliage dries.

 
Group Product Name Product Rate   Active Ingredient(s) (*=Restricted Use) PHI (d) REI (h) Bee TR
3A Lambda-Cy, LambdaT 1.92 to 3.84 fl oz/A lambda-cyhalothrin* 7 12 H
3A Mustang Maxx 2.24 to 4.0 fl oz/A zeta-cypermethrin* 1 12 H
3A Perm-UP 3.2EC 4.0 to 8.0 fl oz/A permethrin* 1 12 H
3A Tombstone 2EC 0.8 to 2.8 fl oz/A cyfluthrin* 0 12 H
3A Warrior II 1.28 to 1.92 fl oz/A lambda-cyhalothrin* 7 12 H
3A Asana XL 5.8 to 9.6 fl oz/A esfenvalerate* 3 12 H
3A Baythroid XL 0.8 to 2.8 fl oz/A beta-cyfluthrin* 0 12 H
3A Bifenture 2EC, Sniper 2.1 to 6.4 fl oz/A bifenthrin* 3 12 H
3A Hero EC 4.0 to 10.3 fl oz/A zeta-cypermethrin* + bifenthrin* 3 12 H
1A Lannate LV 1.0 to 1.5 pt/A methomyl* See label 48 H
5 Blackhawk 36WG 2.2 to 3.3 oz/A spinosad 1 4 M
5 Radiant SC 3.0 to 6.0 fl oz/A spinetoram 1 4 H
28 Coragen 1.67SC 3.5 to 7.5 fl oz/A chlorantraniliprole 1 4 L
Combo products containing a pyrethroid 3A          
Cobalt Advanced 11.0 to 42.0 fl oz/A lambda-cyhalothrin* + chlorpyrifos* (Group 1B) 21 24 H
Besiege 6.0 to 10.0 fl oz/A lambda-cyhalothrin*+chlorantraniliprole (Group 28) 7 12 H

Bt Transgenic Sweet Corn

Bacillus thuringiensis (Bt) sweet corn hybrids are available that express single or pyramided insecticidal proteins for protection against lepidopteran “worm” pests. Attribute® hybrids (Syngenta Seeds) expressing the cry1Ab protein (YieldGard trait) have been available since 1998, and these hybrids now express the Liberty Link herbicide tolerance trait. Performance Series™ hybrids (Seminis Seeds) expressing two Bt proteins (cry1A.105 and cy2Ab2) are also available and these have the RoundupReady gene as well. However, based on multiple years of field trials in Virginia and surrounding states, neither of these Bt traits/varieties provide effective control of CEW due to Bt resistance development to the Cry proteins.  Thus, fields planted in these Bt hybrids will need insecticide applications, depending on the insect pressure and level of resistance in the population. In addition, under moderate to high moth activity (early August-early September), many eggs are laid later in ear development after the expressed Bt protein has degraded in dead silk tissue. This loss of protein activity also is accelerated by hot, dry conditions, which cause rapid desiccation of the silk tissue. As a result, earworms and fall armyworms have a greater chance of surviving and invading the ear. Under high moth activity, up to 50% or more of the Attribute ears can become infested with larvae. In this situation, spray schedules of 3 or 4 applications starting 3-4 days after the first onset of silking and repeated 3-4 days apart may be required.

Attribute® II Bt corn hybrids (Syngenta Seeds) with pyramided genes expressing YieldGard and Viptera traits (Vip3A protein) and stacked with the Liberty Link trait are now available. This Bt pyramided gene technology currently provides outstanding nearly 100% control of all lepidopteran pests of sweet corn.

Soybean Fungicide Advisory – August 15, 2019

For soybean that is at or near the beginning pod (R3) stage, it is time to consider whether or not a fungicide application is needed to control foliar diseases and protect yield. Most of the soybean in Virginia is past the beginning pod (R3) stage, and fungicide applications are more likely to be profitable when applied at or near R3/R4. The Virginia soybean fungicide advisory indicates that disease risk is variable across the state. Fields with moderate risk should be scouted since foliar diseases will not be an issue in every field every year.  Keep in mind that other risk factors also contribute to disease severity and yield loss to fungal diseases. High risk fields include those where susceptible soybean varieties are planted, there is a recent history of soybean foliar diseases, and/or rotations out of soybean are short or soybean is planted continuously over several years. Foliar fungicides are ineffective for control of most stem and root diseases. If based on the soybean fungicide advisory or other factors you decide to apply a fungicide, applications are generally the most effective when applied between R3 and R4 stages (no later than R5). The most recent Soybean Fungicide Efficacy Table can be downloaded from the Crop Protection Network website. Instructions on how to use the Virginia soybean fungicide advisory can be found in the July 19 blog post. A summary of disease risk and spray recommendations for different locations in Virginia can be found below. If you have any questions, contact Dr. Hillary Mehl (hlmehl@vt.edu).

Region of VirginiaLocation of weather stationSoybean disease riskRecommendation
Eastern ShorePainterHighSpray
SoutheasternSuffolkModerateScout
SoutheasternVirginia BeachHighSpray
Northern NeckWarsawHighSpray
CentralBlackstone ModerateScout
NorthernMiddleburgModerateScout
NorthernShenandoahModerateScout
NorthernWinchesterLowDon’t spray
WesternCritzHighSpray
WesternBlacksburgHighSpray
WesternGlade SpringHighSpray

For detailed daily advisories, select the location closest to your field and download the corresponding file here:

Corn earworm/bollworm update for August 15, 2019

Moth numbers from reporting black light trap stations dipped somewhat from the highs of last week; please see the table below for more details. However, what this does mean for soybeans that are in the flowering stage or later is to scout for corn earworm larvae and use the online threshold calculator https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html with information specific to your fields. Please keep scouting in cotton, peanut, and other crops, too. Here is the black light table:

Peanut maturity in Suffolk, VA (planted on May 15 and dug on Aug 13)

According to the Peanut – Cotton Infonet (https://webipm.ento.vt.edu/cgi-bin/infonet1.cgi) online report system, peanut planted on May 1st in Suffolk, Capron, Greensville, and Waverley, VA, accumulated to the date around 2100 °F in all these locations.  It is good to remember that the Virginia-type cultivars grown in Virginia requires around 2600 °F to reach harvest maturity. With sustained daily temperatures at around 90 °F, physiological maturity could be reached in a week or two, then? It is incredible early for a “normal” year but nothing impossible, as the last year taught us.

Choosing when to dig is a big decision and no one should rush to it without checking the maturity first. If dug too early, yields will be significantly reduced from immature seeds (small sound mature kernel and extra-large kernel content on a farmer stock grading rating); this will substantially reduce the price per ton. Immature peanuts of the “high oleic” cultivars like Sullivan, Wynne, Emery, Bailey II, and Walton may not reach the threshold 75% oleic fatty acid content required for the high oleic seed to pass the high oleic standard; this may downgrade the certified seed to commercial status and, again, reduce the farmers pay per ton.  If waiting too long, over-mature kernels will drop off the vines before being picked by the combine, and yield and pay will be substantially reduced in this way.  For example, if only one pod per square foot is shed from over-maturation, the loss per acre could be 100 pounds per acre for Bailey and Sullivan, and even more for Wynne and Emery.  Usually, pod shedding can easily cause 25% yield reduction.

When to dig is, therefore, better to be a knowledge-based decision. This is now possible by the availability of peanut “maturity charts” and pod-blasting “clinics” organized by the Extension Agents and Specialists of the Virginia Coop. Ext. program; clinics will start by end of Aug and continue through end Sep in several counties in SE Virginia.  For example, Indika Farms will host one on Aug 26 starting at 8:00 AM in Windsor, VA.

To provide some guidance for when to start maturity evaluations, pod-blasting of three major cultivars was performed on Aug 13 and images are presented below. Pod samples are from one single field at the Tidewater AREC planted on May 15. As pictures show, the majority of the pods are yellow with less than 20% immature (white or green) and very few orange. Kernels are well developed inside the yellow pods and the orange pods have thin and darkened hulls inside, which is a clear indication that maturity has begun.  I will continue to update on the peanut maturity progress in Virginia in the coming weeks.

Maturity of ‘Emery’ peanut planted on May 15 and dug on Aug 13.
Maturity of ‘Sullivan’ peanut planted May 15 and dug Aug 13.
Maturity of ‘Wynne’ peanut planted May 15 and dug Aug 13.

Soybean Fungicide Advisory – August 8, 2019

For soybean that is at or near the beginning pod (R3) stage, it is time to consider whether or not a fungicide application is needed to control foliar diseases and protect yield. The Virginia soybean fungicide advisory indicates that disease risk is variable across the state. Fields with moderate risk should be scouted since foliar diseases will not be an issue in every field every year.  Keep in mind that other risk factors also contribute to disease severity and yield loss to fungal diseases. High risk fields include those where susceptible soybean varieties are planted, there is a recent history of soybean foliar diseases, and/or rotations out of soybean are short or soybean is planted continuously over several years. If based on the soybean fungicide advisory or other factors you decide to apply a fungicide, applications are generally the most effective when applied between R3 and R4 stages (no later than R5). The most recent Soybean Fungicide Efficacy Table can be downloaded from the Crop Protection Network website. Instructions on how to use the Virginia soybean fungicide advisory can be found in the July 19 blog post. A summary of disease risk and spray recommendations for different locations in Virginia can be found below.

Region of VirginiaLocation of weather stationSoybean disease riskRecommendation
Eastern ShorePainterHighSpray
SoutheasternSuffolkModerateScout
SoutheasternVirginia BeachModerate to highScout
Northern NeckWarsawModerate to highScout
CentralBlackstone ModerateScout
NorthernMiddleburgModerate to highScout
NorthernShenandoahHighSpray
NorthernWinchesterLowDon’t spray
WesternCritzHighSpray
WesternBlacksburgLowDon’t spray
WesternGlade SpringHighSpray

For detailed daily advisories, select the location closest to your field and download the corresponding file here:

Corn earworm update for August 8, 2019

Black light trap catches of H. zea (corn earworm/bollworm) moths increased at most locations this week. Please see the data table for more information.

We have tested 168 corn earworm moths in our cypermethrin vial tests so far this season, with a seasonal average of 39.5% survival. Here are the results by month (we’ll be conducting more tests throughout August):

We have updated our corn earworm survey of field corn (as a predictor of infestation risk in other crops such as soybean) to include Rockingham County’s 10.8% infested ears. Thanks to all cooperators for their efforts. Statewide average infested ears was 15.3% for 2019. The updated table and map are here:

Early Cutout in Cotton: Why?

The 2019 growing season in Virginia is one that has been marked by a good planting window in early May resulting in a sizable portion of Virginia cotton planted in the first two weeks, followed by spotty rainfall events across the growing region with most areas receiving adequate rainfall throughout the season. Couple the early planting date with light overall insect pressure early during the reproductive period resulting in higher than normal fruit retention across Virginia. Yes, there have been pockets of high pressure from tarnished plant bugs, but for the most of Virginia pressure as been light through June and July. Cotton was flowering by July 4th in 2019 with early planting and entering week 5 or 6 of bloom by the first week in August. Data in Virginia show that nutrient concentrations in leaves and petiole decrease rapidly from the 1st to 4th weeks of bloom, indicating the plant is beginning to shut down in terms of nutrient uptake. After the 4th week of bloom nutrient concentrations level off at lower concentrations. With dropping petiole and leaf nitrate-N, sulfur, and potassium, fields will begin to show signs of nutrient deficiencies and overall yellowing or reddening. These areas will be more pronounced in sandier areas first then spread into heavier textured soils.

First, producers and/or crop consultants should evaluate nodes above white flowers (NAWF) to determine if cotton has reached “cutout”. Cutout has been described as the point at which NAWF < 4 or 5. Cotton that has fallen below this threshold and exhibiting overall yellowing or reddening will be at “cutout”. These symptoms usually occur towards the latter part of August in Virginia, but given higher fruit retention in 2019 coupled with an early planted crop and high heat unit accumulation these symptoms will occur sooner in 2019.

One may worry if your crop has low boll retention, also commonly referred to as “missing positions” and is exhibiting the symptoms of cutout. . Insect damage and other environmental conditions resulting in low fruit retention typically will delay maturity thus cotton will stay greener longer and exhibit a high level of vegetative growth. In this case, review rainfall data and nutrient management strategies as some environmental condition may have increased nutrient loss thus reducing crop uptake resulting in premature cutout. An example may be a large rainfall event leached a significant portion of nitrogen/sulfur/potassium thus cotton is running out of nutrients. There is no management strategy that will “make up yield” in this situation at this point in the season, however nutrient management strategies could be tweaked in future years to hedge potential losses in the future.

Earlier than normal cutout does not signify the need for higher rates or additional applications of nutrients, especially if boll retention is high and heat unit accumulation is appropriate for that growth stage of the crop. This is the natural senescence (entering dormancy) for cotton and is a positive when discussing defoliation and harvest aid applications. For Virginia, the last effective bloom date is around Aug. 25-31, so even though cotton has reached cutout early this does not mean it is no longer susceptible to insect pressure. Continue to scout and follow Dr. Sally Taylor’s recommendations to protect later bolls, which can represent around 10% of lint yield.

For further questions or concerns feel free to contact me at whframe@vt.edu and/or 757-807-6539.