Lowndes – Echols Ag News

Valor on Peanuts

Valor Mishaps (Prostko)

In the heat of the battle to get crops planted on time, it is not uncommon for some herbicide misapplications to occur.  The unintentional application of higher than labeled rates is a not a good thing because money is wasted, crop injury potential is increased, and rotational crop intervals are jeopardized.  

Over the last few days, I have received several inquires about how peanuts might respond to Valor applied at rates higher than 3.0 oz/A due to sprayer calibration errors.  Keep in mind that when an herbicide is developed, application rates are based upon a ton of data.  The lowest use rate possible that will provide the most consistent weed control over a wide range of environments in carefully selected.  Additionally, most herbicide use rates have a “safety” margin built into the rate just in case of application errors.  

I looked back at some of my older Valor data and can tell you this regarding the response of peanuts to 6 oz/A of Valor:

1) In 6 field trials, there was no significant difference in peanut yield between 3 oz/A and 6 oz/A.

2) In 1 field trial, 6 oz/A of Valor resulted in a 7% yield loss when compared to 3 oz/A (Figure 1).

3) In 1 field trial, 6 oz/A of Valor resulted in a 15% yield loss when compared to a non-treated check.

Figure 1.  Peanut injury caused by Valor SX 51WG @ 6 oz/A which 
resulted in a 7% yield loss, Attapulgus, GA 2018.  


If a grower accidentally applied the wrong rate of Valor at planting, there is a good chance that nothing disastrous will happen.  With any application of Valor and regardless of rate, heavy rainfalls during the period of emergence until about 2-3 weeks after will result in significant visual injury.  I strongly encourage all growers to regularly calibrate their sprayers in order to prevent herbicide application mishaps!  Growers should not put all their faith in last year’s sprayer settings or sophisticated on-board computers.  

For the record, both UGA and the current Valor label recommend that ONLY 3 oz/A of Valor be applied within 2 days after peanut planting (I do not want anyone reading this blog to think that its OK to apply 6 oz/A!!!!!!!!!  That is not the purpose of this blog!!!!!!!).  V

Strongarm/Peanut Questions

Strongarm/Peanut Questions (Prostko)

Had a few questions about Strongarm (diclosulam) use in peanuts yesterday that I thought might be interesting to all:

1) In general, what application method is more effective for weed control in peanut (PPI or PRE)?

When averaged over 7 weed species, there was little difference in weed control between PPI and PRE applications of Strongarm (Table 1).  However, in dryland production fields with minimal future rain predictions, PPI applications would be preferred.

Table 1. Application Method Effects on Residual Weed Control with Strongarm 84WG @ 0.45 oz/A in Peanut.1

Weed Control (%)
Application Method
PPI2 PRE3
sicklepod 54 44
Florida beggarweed 78 87
bristly starbur 94 97
purple nutsedge 59 73
yellow nutsedge 78 78
morningglory sp. (Ipomoea sp.) 89 99
smallflower morningglory 94 96
All (average) 78 82

1Source: Grey et al.  2003.  Peanut Science 30:27-34.

2PPI = preplant incorporated.

3PRE = preemergence.

Also very important to remember that Strongarm provides a much broader spectrum of weed control when applied PPI or PRE when compared to POST applications.  However, the following 7 weeds are sensitive to Strongarm when applied POST: tropical spiderwort/Benghal dayflower; common cocklebur; common ragweed; bristly starbur; horseweed/marestail; morningglory sp.; and eclipta.

2) What application method is more effective for the control of tropical spiderwort/Benghal dayflower?

Data collected a few years ago in Grady Co. indicated that POST applications were more effective than PRE applications for the control of tropical spiderwort/Benghal dayflower (Table 2).

Table 2. Application Method Effects of Strongarm 84WG @ 0.45 oz/A on Benghal Dayflower/Tropical Spiderwort Control in Peanut.1

Application

Method

Control (%)2
46 DAP3 69 DAP 114 DAP
PRE4 75 cd 68 b 11 e
EPOST5 97 a 90 a 75 abc
LPOST6 88 ab 78 ab 60 c

1Source: E.P. Prostko and J.T. Flanders, 2003, PE-24-03, Unpublished data.

2Means in the same column with the same letter are not significantly different according to DMRT (P=0.05).

3DAP = days after planting.

4PRE = preemergence.

5EPOST = early-postemergence, 17 days after planting (2’’ tall, 3 leaf stage).

6LPOST = late-postemergence, 31 days after planting (6” tall).

Georgia Peanut Farm Show and Conference

Georgia Peanut Farm Show and Conference set for Thursday, Jan. 17

Kelley Manufacturing Co. sponsors the Grand Door Prize

 

 

TIFTON, Ga.  — Producers can improve the bottom-line of their farming operation with knowledge, connections and information gained at the 43rd annual Georgia Peanut Farm Show and Conference, held at the University of Georgia Tifton Campus Conference Center, Jan. 17, 2019, from 8:30 a.m. to 2:30 p.m. Peanut farmers and those involved in the peanut industry will be able to learn more about the latest products, services and peanut research at the show, which is sponsored by the Georgia Peanut Commission.

The one-day show offers farmers a full day to view the products and services of more than 100 exhibitors and a day of education. A free luncheon begins at noon for all peanut farmers in attendance. The Georgia Peanut Commission will present a short program beginning at 12:15 p.m. that will cover award presentations and an update from the National Peanut Board and Washington. The Georgia Peanut Commission, in cooperation with the OneBlood, will host a blood drive from 8:30 a.m. to 2:30 p.m. during the show.

The University of Georgia Peanut Team will present an educational peanut production seminar from 9:00 until 10:30 a.m. Team members will provide information on peanut production tips and have a question and answer session with team members specializing in irrigation management, insects, disease and nematodes, weed management and economics. Farmers will also have the opportunity to earn private or commercial pesticide applicator certification.

An Industry Seed Seminar will also be held from 10:35 to 11:35 a.m. during the show. This event is sponsored by the American Peanut Shellers Association Committee on Variety & Seed Development, Southern Peanut Farmers Federation and the Georgia Peanut Commission. Growers will be able to learn about peanut varieties available for 2019 and varieties on the horizon.

During this year’s show, Kelley Manufacturing Co. is providing the Grand Door Prize Package of one season’s use of a new peanut combine (choice of four-row, six-row or combine with Unload-On-The-Go option). At the end of the 2019 season, the winner has the option of purchasing the combine from an authorized KMC dealer with $15,000 off the list price. Also, KMC is providing a second drawing for one season’s use of a new Digger Shaker Inverter (choice of rigid or flex model in a two-row, four-row or six-row) or the use of a new KMC Dump Cart. At the end of the 2019 season, the winner has the option of purchasing the digger or dump cart from an authorized KMC dealer with 10 percent off the list price.

Additionally, farmers can register to win the Grower Prize, donated by Amadas Industries. This prize includes a certificate good for the amount of $10,000.00 towards the purchase of any new Amadas self-propelled combine or $5,000 towards the purchase of a new four-row or six-row Amadas pull-type combine or $1,000 towards the purchase of a new Amadas peanut dump cart. Amadas is also offering a customized Grizzly cooler which will contain a certificate good for a parts credit of $1,000 for Amadas parts through a local authorized Amadas dealer.

The winners of the Grand Door Prize and the Grower Prize must be certified peanut farmers with an FSA farm number and present to win.

For more information on the show, contact GPC at 229-386-3470 or online at www.gapeanuts.com.

Row Crop Disease Update Before Hurricane

By Dr. Bob Kemerait  Like they say, “no rest for the weary.”  It looked like we were going to be able to get out of this with fairly dry weather and then here comes the potential for a tropical storm.  If the path of the storm continues, it should hit sometime late on Wednesday and affect us through Thursday with wind and rain and, depending on how much rain we get, could keep growers out of the field for some period of a day or so to longer.

There is the obvious damage that wind and rain will bring, especially to the cotton crop- lodging cotton and putting lint on the ground.  For cotton not yet ready to pick, the weather could increase boll rot, though there is really nothing we can do about that.

For peanuts, the question is timing of digging.  It is my opinion that if the vines and pegs are healthy and not too much defoliation from leaf spot or damage from white mold is present, then it is better to leave the peanuts in the ground and to dig them after the storm passes.

If the peanuts are severely affected by leaf spot disease (significant defoliation) or disease (white mold) and the potential for yield loss is severe if they must stay in the ground into next week, then I would consider digging them.

If the crop is already behind in being dug (past harvest maturity) or the soil is “heavy” and digging may be delayed considerably, then I would also think about digging them.

Where peanuts are two or more weeks away from projected digging date, growers should consider whether a final fungicide application for management of leaf spot is needed.

Peanut Maturity Testing 2018

It won’t be long before peanut harvesting will begin. Our office will be providing peanut hull scraping for any peanut grower.  When picking samples, take 5 or 6 adjacent plants from two or three spots in the field.  If the field changes soil types or has some dry land spots, then separate samples should be taken. A sample needs to have 200 pods to show a good representation. Call the office if you have any questions.

pnutmaturity board

Row Crop Disease Update August 27

Dr. Bob  Kemerait gives a row crop disease update

  1. Soybeans: Asian soybean rust is still lightly scattered from Decatur County to Appling County, but has only been found so far in KUDZU.  Soybean rust is certainly not a major problem at the moment; however it could become so.  Management options are to protect the crop with a fungicide sometime between the R1 (early bloom) and R3 (early pod set) stages.  Such timings may correspond well with other disease and insect control measures.  Some “Cercospora leaf blight” is being reported; this disease causes much of the upper foliage to take on a “bronzed” cast and then leaves drop prematurely leaving the “bony” petioles like skeleton fingers to the sky.  Cercospora leaf blight also causes purple seed stain.  Fungicide applications at pod set (R3) can help manage this disease.
  2. Late-planted corn: Southern corn rust is now commonly observed on older corn across the Coastal Plain, corn that is too late for it to matter.  However, southern corn rust does pose a threat to younger corn and preventative protection with a fungicide is something to consider, especially as the crop approaches the tassel growth stage.  Also, I am receiving numerous reports of young corn affected by northern corn leaf spot (Bipolaris zeicola) which produces numerous, small-to-medium sized red/brown spots, sometimes with appearance of concentric rings.  Typically, corn is most severely affected by northern corn leaf spot early in the season and then grows out of it; however I cannot be sure that this will always be the case.  I have no data on fungicides for management of northern corn leaf spot, but as it is closely related to northern and southern corn leaf blights, I am confident that mixed mode of action products we already use will be helpful for the “spot” disease.  If a grower does spray, applications as early as V6-V8 would be appropriate. But again, I just don’t know if it matters.
  3. Cotton: I hear you.  And I feel your frustration.  We have three diseases of significant importance in the field right now.    Boll rot.  The rain and heavy vegetative growth we have seen this year has created perfect conditions for fungal boll rot.  We are seeing a lot of it.  We are not seeing a lot of bacterial boll rot, though some is certainly there.  Fungal boll rot is most severe in lower bolls deep in the canopy or where insect damage also occurs.  Fungicides are not an effective treatment; only opening the canopy up to increase airflow and reduce humidity can help reduce boll rot.  2.  Areolate Mildew.  First, Andrew S. and others, I didn’t make the name up.  Second, I know that there is great concern and I have heard growers complaining that there fungicide applications did not stop the disease.  Here are some thoughts.  For the second year in a row, Areolate mildew is early and widespread.  Areolate mildew can cause significant premature defoliation.  I do know that fungicides like Headline and Quadris and certainly Priaxor can slow the spread of the disease, though not necessarily stop it, especially when it is well established in a field.  It is not clear how much yield is at risk or that can be protected; but it is believed that significant premature defoliation is not a good thing, unless one is trying to open the canopy up to slow boll rot.  Here are my recommendations, though they have not been proven with any hard data.  If a grower is within 4 weeks of defoliating the crop anyway, save the money and don’t spray.  If the grower is more than 4 weeks of defoliating and the areolate mildew is not too severe (i.e. already causing significant leaf drop) then there may be a benefit to treating with a fungicide.  This may not stop the disease but will slow its development.  3.  Target Spot.  Target spot has been severe and widespread in this rainy season.  I believe well-timed fungicides have been helpful this year.  I don’t believe there is any benefit to a fungicide application after the 6th week of bloom.  Either there is too much disease already to stop it or there is not enough time for disease to develop.  In this season, a second fungicide application 2-3 weeks after the first application is something to consider.
  4. PEANUTS: Getting lots of questions these days about late-season peanut disease problems.  Just a few thoughts.    Three weeks to go until you dig the peanuts and little-or-no disease in the field?  I wouldn’t put out any more fungicides unless there is threat of a hurricane or tropical storm.  If three of more weeks out and on your last spray and you are seeing some leaf spot develop, applying a pint of chlorothalonil tank-mixed with 7.2 fl oz of  tebuconazole or 5.5 fl oz of Alto or 5 fl oz of Topsin or 2.5 fl oz of Domark.  If time for your last spray and very little leaf spot is present, then 1.5 pints of chlorothalonil may be all you need.

If white mold is popping up in your field late in the season and is confined to individual plants scattered across the field, then you may want to mix tebuconazole with your last leaf spot spray.  If the disease is more severe, or you are really worried about it, then you might consider using 16  fl oz or Convoy rather than tebuconazole.

It is generally advisable to wait to dig the peanuts until they are “ready” based upon the hull-scrape test.  This is true even if there is significant tomato spotted wilt in the field or some white mold.  HOWEVER:  if there is significant defoliation from leaf spot or significant white mold in the field, it often best to dig the peanuts earlier than planned to avoid excessive digging losses.

UGA Cotton and Peanut Research Field Day

Cotton & Peanut Folks,

 

On Wednesday September 5th 2018 in Tifton, GA the UGA Cotton and Peanut Teams will be hosting 2018’s UGA Cotton & Peanut Research Field Day.  This annual event provides an excellent opportunity for anyone who is interested in learning more about our two most widely planted row crops here in Georgia.

 

We have planned a day which we hope will be both interesting and informative while allowing plenty of opportunities for the fellowship and fun we come to expect at a UGA Field Day in Tifton.

 

There is no cost to attend, we only ask that you RSVP if you plan to attend (just for a lunch headcount – call Mrs. Jeannie Evans at 229-386-3006 or email her at jevans12@uga.edu ).  The Georgia Cotton Commission and the Georgia Peanut Commission have graciously sponsored the field day’s lunch, in addition to continually providing the funding needed to support UGA’s research and education efforts.

 

For more details on speakers, locations and specific times be sure to take a look at the agenda (see attached).  The agenda, as well as maps for traveling to and from the research farms we’ll visit, can also be found at www.ugacotton.com .

 

In summary, the field day will start at the Tifton Campus Conference Center (TCCC) in the North Parking Lot at 8 AM.  After a brief welcome, the trams will leave for the RDC Pivot at 8:15 AM.  After four stops around the RDC Pivot, we will drive to the UGA Ponder Farm to tour several trials and hear from more of our speakers.  We will finish up the outdoor program prior to lunch (which will be at the TCCC) and hear from our economists inside as well as representatives of UGA’s administration and the Georgia Cotton & Peanut Commissions.

 

We look forward to seeing you there.  Please feel free to share this email and invite anyone who may enjoy learning more about cotton and peanut production in Georgia.

 

See you Wednesday, September 5th in Tifton!

 

Jared Whitaker & Scott Monfort

(UGA Extension Cotton & Peanut Agronomists, respectively)

 

 

 

Jared Whitaker, Ph.D.

The University of Georgia

Cotton Extension Agronomist
2360 Rainwater Rd.

Tifton, GA 31793

 

229-938-2448

jared@uga.edu

 

Weed Science Update – August 21 (Prostko)

A couple of things you might find of interest:

1) A local crop consultant recently sent me this picture of prostrate globe amaranth (Gomphrena celosioides).  I have never seen this plant before and for the record, Dr. Mark “The Czar” Czarnota (UGA-Griffin Campus) identified it for me.  It is a member of the Amaranthaceae (pigweed) plant family.  For more general information about this weed, please refer to the following link: http://wssa.net/wp-content/uploads/Gomphrena-celosioides.pdf

2) Had a peanut grower ask me if 2,4-DB applied to large sicklepod plants would have any effect on seed production.  A quick review of the literature would suggest that 2,4-DB applications made at the initial flower to peak flower stages of growth will cause significant reductions in the number of sicklepod seed produced.  However, applications before or after that time have no effect on seed production (only initial flower and peak flower seed numbers were statisicially different than the NTC-none).

Reductions in Grass Control in 2018? (Prostko)

Getting plenty of calls about perceived reductions in grass control after applications of ACC-ase inhibiting herbicides, such as Select (clethodim) or Poast (sethoxydim), have been applied.  Some folks first reaction to this “lack” of control is that we suddenly have widespread ACC-ase resistance.  When its comes to the issue of resistance, I will never say never.  But, before traveling down that bumpy road, I would like for you and your growers to consider the following:

1) Currently, only 2 grass species have been “officially” confirmed to have evolved ACC-ase resistance in Georgia including large crabgrass and Italian ryegrass. Scientific confirmation of herbicide resistance takes lots of time, manpower, and greenhouse space.

2) Labeled heights for optimum control of various common grasses with Select, including crabgrass, Texas panicum crowfootgrass, and goosegrass, are 2″- 6″.  

3) The following is some data illustrating the effect of Select rate and timing on the control of goosegrass.  Please note that goosegrass control was reduced by 16-23%, depending upon rate, when applied at the 4-6 tiller stage of growth.

Figure 1.  Goosegrass control with Select applied at different rates and timings.

4) If Cadre (imazapic) was applied prior to the grass herbicide application, it is very likely that grass control will be reduced.   Research has shown that Cadre can reduce the photosynthetic rate of goosegrass which then reduces the sensitivity of the ACC-ase enzyme to clethodim (Burke and Wilcut.  2003.  Physiological basis for antagonism of clethodim by imazapic on goosegrass.  Pesticide Biochemistry & Physiology) 

5) At this time of the year, peanut plants are kinda tall (> 12″).  Thus, any grass plants peaking out of the top of the peanut canopy are not likely to be adequately controlled due to size and coverage issues.

6) Before dropping the R-bomb, please double-check use rates, stages of growth, adjuvants, rain-free periods, and field history.  The threat of herbicide resistance is definitely real but it does not happen in one night.

Row Crop Disease Update August 10, 2018

Dr. Bob Kemerait gives row crop disease update:

DISEASES of PEANUT:  White mold and leaf spot aren’t breaking lose in every peanut field in Georgia, BUT hot temperatures, high humidity and frequent rains have created near-perfect conditions for the development, spread and, sometimes, explosion of these diseases.  Growers need to stay on a good fungicide program, tightening spray intervals where disease is becoming problematic and/or where there is concern if the crops have received enough drying time after a fungicide was applied.

FOUR COTTON DISEASES:  Target spot, areolate mildew, Stemphylium leaf spot, and bacterial blight.

What a season it has become when target spot and areolate mildew are causing greater angst than bacterial blight.

 

EASY STUFF:

 

  1.  Bacterial blight is present and is affecting yield in some fields.  Susceptible varieties will get this disease and losses may occur.  THERE IS NOTHING TO BE DONE ABOUT IT NOW. However, growers should note the varieties where they find it and determine at the end of the season if the disease became severe enough to avoid planting those varieties again.
  2. Stemphylium leaf spot is present as well.  Stemphylium leaf spot is caused by a deficiency in potassium in the plant.  Dr. Glen Harris is our soil fertility expert; I believe he would agree that excessive rains could have leached potassium this year.  Fungicides ARE NOT a solution for Stemphylium leaf spot; Dr. Harris has the best information about managing potassium.

 

HARD STUFF:

 

  1.  Target spot and areolate mildew are present in a number of fields this year.
  2. At times, target spot and areaolate mildew appear late enough in the season that the defoliation resulting from these diseases does not affect yield and use of fungicides is not needed.
  3. The question for both diseases is not, “Can we protect the cotton in this field with a fungicides?” but rather, “Should we protect the cotton in this field with a fungicide?”
  4. We have very very little data on areolate mildew, but from what I do have, I am confident that we can easily control this disease using strobilurin products like Headline or Quadris, or mixed products like Priaxor or Elatus.  Proline may work as well but I don’t have data.
  5. Though we can control areaolate mildew, does it make us any more yield than if we didn’t control it?  When conditions are favorable, areolate mildew can rapidly defoliate a cotton crop.  If a grower is withing 3-to-4 weeks of defoliating anyway, I would NOT use a fungicide.  If the crop still had 4 or more weeks to go, I would consider weather, yield potential, how much disease is in the field and then decide to spray or not.
  6. If areolate mildew, or target spot, is already well-established in the field (i.e. causing significant defoliation, then there is little hope that a fungicide will help.
  7. Target spot is a significant concern this year and is widespread.  Not every cotton grower in the state needed to spray a fungicide for target spot, but I encourage growers to carefully consider their options.
  8. Target spot is of particular concern this year because a) the wet and warm conditions are perfect for an explosion of the disease, b) the disease has been found early in many fields, and c) the price of cotton makes protection 100-250 lbs lint/acre attractive.
  9. I believe the best window of opportunity for managing target spot is from the first week of bloom to the sixth week of bloom.
  10. A little target spot in a crop (meaning scattered spots on lower leaves and no defoliation) during the first week of bloom and favorable weather IS a concern, as it would be at the third week as well.  A “little target spot” at the 4th-6th week of bloom is much less of a concern.
  11. When a fungicide program begins as early as the first week of bloom because of the disease situation; a second application may be beneficial two-to three weeks later.  I don’t envision an application, follow-up or otherwise, after the 6th week.
  12. It will be quite difficult to control (impossible?) target spot if there is already significant defoliation in the field before an application is made.  If 25-30% of the leaves are already gone, a fungicide likely won’t work.
  13. THE  THREE MOST IMPORTANT POINTS TO MANAGE TARGET SPOT, in order of importance, are 1.  TIMING  2.  COVERAGE  3.  SELECTION of FUNGICIDE.