Category Archives: Cotton

Peanut-Cotton Infonet Update

The Peanut-Cotton Infonet is up and running for the 2018 growing season. As in previous years, the website will provide:

  • Maximum, minimum, and average air temperatures
  • Average soil temperature at a 4 inch depth
  • Daily and accumulated (from May 1) peanut heat units
  • Daily and accumulated (from May 1) cotton degree-days
  • Daily and total seasonal (from May 1) rainfall
  • Last effective spray date for peanut leaf spot
  • Sclerotinia blight risk
  • Frost advisory (from September 25th to completion of harvest)

The web address has changed slightly and the website can be found here.

Soil temperatures in southeastern Virginia have been cool over the past couple of weeks (average less than 60 °F), and cool, wet conditions in some fields will favor seedling diseases in early planted crops. A warming trend over the next week will hopefully result in more favorable planting conditions towards the beginning of May.

For questions or concerns regarding the Peanut-Cotton Infonet throughout the growing season, contact Dr. Hillary Mehl (hlmehl@vt.edu).

Another Online Dicamba Training Option

Earlier this week I posted links to BASF’s online dicamba training module.  Here is another online training option from Monsanto.  Again, Michael and myself encourage applicators to attend face-to-face trainings, but know that extenuating circumstance exist.  You can access the training at the link below.

 

http://www.roundupreadyxtend.com/stewardship/education

 

As always, feel free to contact us with any questions or concerns.

Online Dicamba Training

BASF’s dicamba training module is now live! To access the training visit engeniastewardship.com and click on the training tab.

This online training module satisfies the US EPA requirement for mandatory dicamba training. It should be utilized as an alternative training opportunity for individuals who are unable to attend in-person trainings. BASF and Virginia Cooperative Extension strongly encourages in person training because it offers opportunities for dialogue and questions. Individuals can request in person trainings on engeniastewardship.com.

This online training module will NOT fulfill the Engenia® herbicide label requirement for training in the following states:

  • Alabama, Arkansas, Georgia, Indiana, Mississippi, Missouri, and North Carolina: state university / extension training only
  • Kentucky and Louisiana: in-person training only
  • Florida, Illinois, Iowa, Minnesota, North Dakota, Oklahoma: Currently in-person training only

Time to start planning for horseweed/marestail

Charlie Cahoon and Michael Flessner, Extension Weed Specialists at Virginia Tech

Horseweed or Marestail

Horseweed is a winter or summer annual and a member of the asteraceae family.  In the winter annual cycle, horseweed germinates in the fall and overwinters as a basal rosette. The following spring, the rosette bolts, reaching 1.5 to 6 feet in height.  While most populations of horseweed in the region emerge in the fall, significant spring emergence can occur under certain conditions.  Spring germinating horseweed does not form a rosette.  Leaves are alternate, simple, linear to oblanceolate in shape, and lack petioles.  Leaf margins are either entire or toothed.  Flowers consist of numerous small heads arranged in a panicle with many white ray flowers and 20 to 40 yellow disk flowers.  Seed are small and have a pappus of tan to white bristles (resemble dandelion seed).  Seed are easily dispersed by the wind, allowing it to quickly spread to nearby fields and within fields.

Bolted horseweed. Virginia Tech Weed ID Guide.

Herbicide resistance:  Regionally, glyphosate- and ALS-resistant horseweed are widespread.  If you are unsure of the resistance status in your fields, assume resistance to glyphosate and ALS herbicides. Resistance to Gramoxone (PS I-inhibitor) has been reported in Delaware.

Management:  Horseweed is more prevalent in no-till fields compared to fields prepared conventionally.  Tillage can be useful in the long-term management of horseweed.  Chemical control of horseweed is more consistent when the weed is in the seedling or rosette stage compared to bolting plants.  Traditionally, glyphosate and ALS-inhibiting herbicides effectively controlled horseweed, however, biotypes resistant to these herbicides are wide-spread.  Chemical control of glyphosate- and ALS-resistant horseweed requires a postemergence herbicide to control emerged horseweed and depending on application timing a residual herbicide for horseweed yet to emerge.  Due to the prolonged germination period, horseweed seedlings can emerge 5 to 6 weeks after residual herbicide application, thus fall applications of residual herbicides often have limited effectiveness for spring emergence.

Herbicides used for emerged plants include 2,4-D (1 pt in the fall or 1 qt in the spring), dicamba, Liberty, Sharpen, or Gramoxone plus a triazine herbicide (atrazine or metribuzin).   Preliminary research from Virginia and North Carolina suggest Elevore (a new auxin herbicide from Dow) also controls horseweed well.  Fourteen days are required between Elevore application and corn or soybean planting and 30 days prior to cotton planting.  Herbicides providing residual control include Valor SX, triazine herbicides (atrazine, simazine, and metribuzin), and ALS-inhibiting herbicides (if horseweed is not ALS-resistant).

Horseweed seedlings do not tolerate shade.  Thus a well-established cover crop, or dense crop canopy can be very effective to manage horseweed infested fields.

Horseweed rosette. Virginia Tech Weed ID Guide.

Soybeans: The key to managing horseweed in in soybeans is to control it prior to planting. Horseweed needs to be controlled prior to bolting (grow upright); this may require an application weeks prior to planting.  Glyphosate plus 2,4-D (1 qt/A), glyphosate plus dicamba or glyphosate plus Sharpen will effectively control glyphosate- and ALS-resistant horseweed when they are small.  Pay attention to rotational restrictions of preplant burndown herbicides when planning burndown applications and planting.  If horseweed are susceptible to the ALS-inhibiting herbicides, Classic-containing herbicides (i.e. Canopy, Valor XLT, Envive, Surveil) are effective.  If applications are made early pre-plant, herbicides containing Valor SX or metribuzin or the Authority products can be included to provide residual control, or a second application of a non-selective herbicide may be needed at planting. Liberty or Gramoxone also control small horseweed and can be used as a part of the burndown application.  If horseweed is present at planting, Gramoxone plus a residual product (Valor SX, Authority products, metribuzin, or Sharpen) is suggested in regions with later emerging horseweed.    Foliar applied PPO-inhibiting herbicides (Blazer, Reflex or Flextar, Resource, and Cobra) DO NOT control emerged horseweed.  For Liberty Link varieties, Liberty applied postemergence controls small horseweed.   Classic and FirstRate are postemergence options where horseweed are susceptible to the ALS-inhibiting herbicides and are small.

Cotton:  Like soybean, horseweed needs to be controlled prior to cotton planting.  Burndown combinations of glyphosate plus 2,4-D/dicamba plus Valor SX is normally in order.  Again, pay attention to plant-back restrictions when timing burndown applications.  Glyphosate plus Sharpen is also effective, but requires a long waiting period between application and cotton planting.

Corn:  In no-till corn, Gramoxone plus triazine, glyphosate plus atrazine plus 2,4-D or dicamba, and Liberty plus atrazine applied burndown of emerged seedlings and residual control of glyphosate- and ALS-resistant horseweed.   Consult labels for waiting interval prior to planting corn.  Atrazine alone will provide good residual control of horseweed.  Dicamba and 2,4-D are the most effective postemergence herbicides.  For small emerged horseweed, foliar applied HPPD-inhibitors or Liberty plus atrazine are effective.

Sorghum:  Glyphosate plus Sharpen or Gramoxone plus a triazine applied burndown.  Atrazine alone or in combination with Gramoxone applied preemergence for residual control and control of small emerged horseweed.  Atrazine can be used postemergence for control of small horseweed.  However, similar to corn, 2,4-D and dicamba are the most effective postemergence options.

Small grains:  2,4-D, dicamba, Quelex, or Huskie will provide effective postemergence control of horseweed in small grains.  Harmony Extra is also very effective on small horseweed that is susceptible to ALS-inhibiting herbicides.

Fall fallow application:  In fields with a history of horseweed, fall applied herbicides can be helpful in managing the weed.  However, a fall herbicide application will not substitute for a spring burndown application.  Target applications for emerged horseweed plants in the late fall after one to two killing frosts.  2,4-D or dicamba should serve as the base for these applications.  Glyphosate is often suggested in combination with 2,4-D and dicamba to control other winter annual weeds.

To see similar information on other problematic weeds consult the Virginia Pest Management Guide: Field Crops at http://pubs.ext.vt.edu/456/456-016/456-016.html or the Mid-Atlantic Field Crop Weed Management Guide at https://extension.psu.edu/mid-atlantic-field-crop-weed-management-guide.

As always, don’t hesitate to contact Michael or myself with any questions or concerns.

 

Dicamba Training: Tuesday February 6, 2018 Paul D. Camp CC

For those of you near Franklin, VA, I wanted to let you know of another dicamba training scheduled.  BASF will be holding a dicamba training on Tuesday February 6th, 2018 at 4:15pm at the Paul D. Camp Community College Regional Workforce Development Center ( 100 North College Drive Franklin, VA 23851).  The training should last about 1 hour.
Just to be clear, this training has been scheduled immediately after the 2018 Virginia Cotton Production Meeting, however, it is not associated with the Virginia Cotton Producers Association nor Virginia Cooperative Extension.
As always, feel free to reach out to Michael or myself with any questions or concerns.

Dicamba Training Announcement

The federal labels for XtendiMax® herbicide with VaporGrip® Technology (Monsanto), Dow DuPont ® FeXapan® herbicide Plus VaporGrip® Technology, and Engenia® Herbicide (BASF) now require additional training beyond a Pesticide Applicator’s License prior to use of these products “over the top” of dicamba-tolerant soybean or cotton.  Training for 2018 will be provided by the registrants of the products (BASF, Monsanto, and Dow DuPont).

Agents/dealers interested in scheduling a training in their area or having a company representative deliver the training at an already scheduled meeting should contact the following company representatives:

Company

Area

Name

Email

Phone

BASF

Eastern Shore

Gar Thomas

garfield.thomas@basf.com

NA

BASF

Rest of Virginia

Kelly Liberator

kelly.liberator@basf.com

NA

Monsanto

Virginia

Jeff Phillips

Jeffrey.i.phillips@monsanto.com

330-402-2591

Monsanto

Southeast Virginia

Ken Lampkin

kenneth.c.lampkin@monsanto.com

919-709-6049

If you schedule a training with either BASF, Dow DuPont, or Monsanto, I would encourage you to make the other companies aware of the training planned in your area.  That way, the companies can better coordinate their efforts to reach as many applicators as possible.  Also, training by any of the three registrants will cover all dicamba products labeled for in-crop use to dicamba-tolerant soybean or cotton (applicators do not need to take training from the registrant of the specific dicamba product they intend to use).

In lieu of the face-to-face trainings, the companies also plan to have a web-based training that will satisfy applicator training requirements.  Michael and I feel the face-to-face training will better prepare the applicators for the off-target challenges of dicamba.  Web-based training can be used as a last resort if a grower is unable to attend face-to-face training.  The following websites offer more information on web-based training:

https://www.roundupreadyxtend.com/Pages/default.aspx

http://www.dupont.com/products-and-services/crop-protection/soybean-protection/articles/fexapan-application.html

There are a few trainings scheduled for the area.  See the  link below for an announcement from Monsanto for two training sessions in Suffolk, VA on Wednesday January 31st.  BASF will be training applicators at the Virginia Grains & Soybean Conference (http://www.virginiagrains.com/annualconference/).  The BASF training for this meeting is schedule for Wednesday February 21st at 12:00pm.  I anticipate both companies to have other training;  Michael and I will keep you updated as we receive word.  Please help spread the word on these trainings, as many growers still do not know that training is required.  Also,I would encourage you and your applicators to pre-register for the events so folks can plan accordingly.

With that said, feel free to reach out to Michael or me if you have any questions or concerns.

Monsanto Dicamba Training Announcement

Eastern Shore AREC Field Day CANCELED!

Due to impending rain Tuesday and Wednesday and already saturated soils, the Eastern Shore AREC field day scheduled for Wednesday, September 13, 2017 has been canceled. Let’s hope Hurricane Irma keeps tracking further west. We certainly do not need any more rain!

Eastern Shore AREC Field DAY: September 13th, 2017

Please join us for Virginia Tech’s Eastern Shore Agricultural Research and Extension Center (ESAREC) 2017 Research Field Day on Wednesday, September 13th. Registration is free, open to the public and will begin at 8:00 AM at the ESAREC complex located at 33446 Research Drive, Painter, Virginia 23420. The field tour will begin at 9:00 AM and conclude with lunch at 12:30 PM.  See the attached flyer for specific projects to be highlighted and more information.

If you would like more information or are interested in sponsoring this event, please contact Lauren Seltzer at 757-414-0724 ext. 11 or email at mlpeyton@vt.edu.

2017 ESAREC Field Day Announcement

Plant Bug Update – 4 August 2017

Twenty-three representative cotton fields in eight Virginia counties were scouted weekly for mean plant bug density. Data for the July 17th to August 3rd sampling period is represented in the distribution map below (follow link to view). Red dots on the map represent fields that have averaged at or above the spray threshold for plant bug during the sampling period. Plant bug densities for multiple fields has increased substantially since the last update in mid-July. Nineteen of the 23 sampled fields have reached the spray threshold at least once this season since sampling began in late-June. Plant bugs are present in every county sampled and are likely present in at least low numbers in all cotton growing counties in the state. Therefore, we recommend scouting your cotton fields regularly for plant bug.

The spray threshold for plant bug in Mid-Atlantic cotton is eight plant bugs (i.e., adults and nymphs) per 100 sweeps in addition to square retention below 80 percent. We recommend conducting four to eight random 25-sweep samples throughout each field. Once flowering begins, we recommend continuing sweep net sampling and also looking for dirty blooms (pictured below) or sample dime to quarter size-bolls from 25 random plants for internal feeding damage (e.g., warts, stained lint, punctures). Spray treatment may be warranted if dirty blooms and or internal damage exceeds 15 percent and plant bugs are also active in the field. Please refer to the Virginia Cotton Production Guide (pg. 23)  or Pest Management Guide (sect. 4, pg. 88) for spray recommendations if spray threshold is reached.

“Dirty bloom” indicative of plant bug feeding.

When viewing the distribution map in full-screen mode, click on the left arrow icon to view map legend. Click on individual fields represented by colored dots on the map to view mean plant bug density for the sampling period as well as total mean density for the season. Mean plant bug densities were calculated by sampling four sweet net samples (25 sweeps per sample) and four drop cloth samples across each field. Total adults and nymphs in a single visit were totaled and averaged for each visit within the sampling period.

View full-screen distribution map

Plant bug distribution map for the July 17th to August 3rd sampling period.

 

Plant Bug Distribution Map

Twenty-three representative cotton fields in eight Virginia counties were scouted weekly for plant bug abundance and square retention. Data for the June 28th through July 13th sampling period is represented in the distribution map below (follow link to view). We will continue to post updates to the map through peak plant bug abundance in cotton. Sweep net and drop cloth samples were taken for each field to account for sampling bias associated with sweep net sampling towards adult captures and drop cloth sampling towards nymphal captures. When sampling cotton fields for plant bugs, look carefully for nymphs (pictured below). Since nymphs are flightless, they may spend more time feeding in an isolated area and cause more damage than adults because their movement in and out of fields is limited. The action threshold for plant bug in Mid-Atlantic cotton is generally eight plant bugs (i.e., adults and nymphs) per 100 sweeps in addition to square retention below 80 percent.

Plant bug nymph feeding on weedy host, buckhorn plantain (Plantago lanceolata).

When viewing the distribution map in full-screen mode, click on the left arrow icon to view map legend. Click on sampling labels on the map to view square retention and number of samples taken from each site. Mean plant bug densities were calculated by sampling four sweet net samples (25 sweeps per sample) and four drop cloth samples across each field. Total adults and nymphs in a single visit were totaled and averaged for each visit within the sampling period.

Click here to view full-screen distribution map

Plant bug distribution map in Virginia cotton sampled from 28 June to 13 July 2017.