Reflex Labeled for Georgia Watermelon, Squash, and Pumpkin (Culpepper)

These new herbicidal tools are a result of cooperative efforts involving The University of Georgia, Syngenta, IR-4, The Georgia Department of Agriculture, The Georgia Agricultural Commission for Vegetables, and Industry.  It is critical that agent’s help growers understand that their specific production practices may alter weed and crop responses to recommended herbicides. 

Important Points to Remember:

1.  Growers must have a label in hand when using Reflex in these crops.  These labels are written by Culpepper and Syngenta so if there is any confusion let me know.

2.  Agents MUST NOT give growers any indemnified label.  Growers must follow the steps below to obtain their own label.  The process of growers obtaining labels is actually the method being used to indemnify the use of Reflex in these crops.  If an agent was to provide a grower the label, it may make the agent or even UGA liable if issues were to occur. 

3.  Growers must evaluate these programs on limited acres until gaining experience.  Keep in mind these labels are developed from 10 to 15 studies conducted primarily by my research here in Georgia; most other pesticide labels are developed from over 200 replicated trials conducted by dozens of scientists across the country.

  

4.  I have created a watermelon circular, similar in format to the cotton circular.  The circular should be up on our website at www.gaweed.com by March 12, 2014.  If you would like laminated copies for your growers, e-mail me the number of copies that you would need and a shipping address.

5.  Support Syngenta and use Reflex; no generic company has shown any desire to support such challenging label development!!!!!!!!!!!!

Obtaining the label:

1.  Go to www.farmassist.com

2.  Select products along top bar.

3.  Select indemnified labels (4^th one down).

4.  Login (first time users create login and password).

5.  For state, select Georgia and for product, select Reflex in this scenario (play around and see

our other labels) and then submit.

7.  Select the Reflex label and crop of interest and submit.

8.  Accept waiver; this is the process making the label an indemnified label.

9.  Print label and have present during application.

Brake F2 Labeled for Georgia Cotton (Culpepper)

The Section 18 Emergency Use Exemption for Brake F2 in cotton has been approved by the EPA and GDA.  Thus, the product is labeled for use during 2014.  

Important Things to Remember:

1.  Apply preemergence behind the press wheel at 16 oz/A; do not apply over cotton.  It is also labeled preplant but Valor and/or diuron are better options.

2.  Brake F2 is a mixture of fluridone and fomesafen; the fluridone will require at least 0.6” of rainfall or irrigation for activation.  Both active ingredients are effective on pigweed.

3.  Suggest rotating only to cotton or peanut in 2015.  If the crop is lost, must replant back to cotton.

4.  The product is quite pricey.

5. A Brake F2 system should provide control similar to that achieved with current recommended programs; although, less injury from Brake F2 may be noted when compared to alternative preemergence herbicide options.

6.  Slides that I used this winter should be up on our UGA Weed Science web site by March 10, 2014 (www.gaweed.com).

7.  Brake F2 Label was attached to the original e-mail that was sent to you.

Warrant Receives Peanut Label (Prostko)

Warrant recently received both federal (January) and state (February) approvals for use on peanuts in Georgia. Here are a few of my thoughts regarding its potential use in 2014:

1) The current supplemental label only permits PRE and/or EPOST applications (before flowering).  

2) Of these 2 timings, I would prefer to see EPOST applications of Warrant tank-mixed with Gramoxone + Storm + NIS.  

3) At this point in time, I have NOT observed any real differences in weed control between Dual Magnum and Warrant based peanut weed control programs (Figure 1).  However, there is some data that suggests that Warrant might be a better choice for non-irrigated fields.

Figure 1.  Dual Magnum vs. Warrant Based Weed Control Programs

4)  A copy of the current supplemental Warrant peanut label can be viewed at the following location:

http://www.cdms.net/LDat/ld9KA011.pdf

5)  I have made some suggestions to Monsanto that hopefully will result in a better and more usable label in the near future.

Peanut Yields and Cobra + 2,4-DB (Prostko)

Frequently, peanut growers get concerned when they make herbicide applications that "burn" their crop.  One of the herbicides that can cause this type of injury is Cobra (Figure 1).   Recent results from tests conducted in Florida reconfirm that the injury caused by Cobra or Cobra + 2,4-DB is cosmetic in nature and does not negatively impact peanut yields (Figure 2).  In these tests, Cobra or Cobra + 2,4-DB treated plots yielded 97-105% of the non-treated check plots. Cobra or Ultra Blazer + 2,4-DB is recommended for the control of Palmer amaranth in peanut fields when Cadre is not a viable option due to ALS-resistance or crop rotation concerns (page 460 of 2014 UGA Pest Control Handbook). 

Figure 1.  Peanut leaf burn caused by Cobra.  

Berrien County Atrazine Resistance - Part 2 (Prostko)

In my last blog, I informed you of the recent discovery of atrazine-resistant (AR) Palmer amaranth in Berrien County.  After a more thorough investigation by Berrien County Agent Fast Eddie Beasley, it was discovered that the corn rotation in this field was shorter than expected (Figure 1).  Because this rotation is different from the fields where AR-Palmer was first confirmed in Georgia, there is some concern about how the resistance occurred.  Here are a few things that you might want to consider before thinking that the sky has fallen:

1) AR is not a brand new phenomenon.  The first (ever) reported case of herbicide resistance was AR-groundsel (Senecio vulgaris) way back in 1970 in the Pacific Northwest.

2) AR-Palmer was confirmed in Georgia in 2008 (Macon County).  Thus, the UGA Weed Group has had 6 years to work on this problem.  As indicated in the previous blog, numerous other herbicides are available for use in field corn that will provide outstanding pigweed control (page 155 of 2014 UGA Pest Control Handbook). However, atrazine is still very much needed in our corn weed control programs for troublesome weeds such as sicklepod and morningglory.

3) It is possible that AR-Palmer evolved in this field via pollen movement or physical seed movement (birds, equipment, animals, gnomes, etc.).

4) It might also be possible that AR-Palmer evolved in this field due to the fact that the resistance is metabolism-based rather than target-site based.  It has been documented in other weeds species with metabolism-based resistance that cross-resistance can occur in the absence of selection pressure.  This has been confirmed in some ACC-ase resistant Rigid ryegrass (Lolium rigidum) populations that were also cross-resistant to ALS herbicides that were never used in the field.  Mother Nature at its finest (i.e. genetics and evolution)!!!!

5) Herbicide resistance is a complicated issue for sure.  Consequently,  it is very important for our growers to be proactive and make every effort to delay the evolution of herbicide resistance in all of our crop production systems (tillage, cover crops, crop rotations, mode of action rotations, hand-weeding, soil seed-bank management, etc.).

Atrazine-Resistant Palmer Amaranth Confirmed in Berrien County (Prostko and Vencill)

Plants from a recently collected Palmer amaranth seed sample, submitted by Berrien County Extension Agent Eddie Beasley, have been confirmed to be resistant to atrazine (Figure 1). This population was also resistant to glyphosate but not Staple (pyrithiobac).  The discovery of atrazine-resistance (AR) in Berrien County is potentially very important since this seed sample was collected from a row-crop production region (i.e. not a dairy production region).  As far as we can tell at this point, the field in question was continuous corn for at least 10 years.  This would suggest that the AR evolved via selection pressure rather than pollen flow or physical seed movement.  

There are a couple of positives here.  Firstly, 5 lbs/A of atrazine controlled these plants which would indicate that the level of resistance is low (2X) in comparison to what we have observed with glyphosate (6-8X).  Secondly, this population was controlled with Evik (ametryn), another member of the triazine herbicide family.  This confirms results from our previous research which suggested that AR in Georgia is metabolism based rather than target-site based.   

How do we plan to address this issue?  In 2013, Dr. Vencill and several County Extension Agents collected various weed seeds from numerous locations across Georgia (Figure 2). These weeds are now being screened for resistance to multiple herbicides, including atrazine. Also, we are planning to collect additional Palmer amaranth seed this summer in the major corn growing counties.  The plants grown from these seed samples will be screened by Dr. Vencill for resistance to atrazine.     

Although this recent discovery is alarming, we do not think that it necessarily means that AR is widespread.  Results from the above mentioned surveys will answer this question.  At this point in time, growers using normal crop rotations likely need not worry about AR.  Fortunately, numerous other herbicides can be used in field corn to effectively control Palmer amaranth (Armezon, Callisto, Capreno, Dual Magnum, Impact, Laudis, Liberty, Realm Q, Status, Warrant, and Zidua).   Refer to page 155 of the 2014 UGA Pest Control Handbook for specific recommendations regarding the control of GR-ALS-AR-Palmer amaranth in Georgia field corn (http://www.ent.uga.edu/pmh/Comm-Field-Corn.pdf).

Figure 1.  2013 Berrien County Palmer Amaranth Population Treated with 1, 2, and 5 lbs ai/A of Atrazine.

Figure 2.  2013 Herbicide-Resistant Weed Survey (Dr. Bill Vencill).

Liberty-Link Soybean Varieties (Prostko)

Growers searching for Liberty-Link (LL) soybeans varieties that perform well in Georgia may find that this list is rather short at this time.  This is typical for new technologies as varieties tend to get better as the technology becomes more widely adopted over time and space.  Just think back to the 1st generation of RR soybean varieties.  These early RR varieties were not the racehorses of today.  The chart listed below is a summary of the rankings for LL soybean varieties grown in the official 2013 UGA OVT tests (irrigated).

You will note that only 3 LL soybean varieties were ranked in the top 10 (yield) at 3 of 6 locations.  These include HBK LL4950 (indeterminate), HBK LL5350, and Halo 5:45.  Our recently hired UGA soybean breeder, Dr. Zenglu Li, is also incorporating the LL technology into his breeding program.  Thus, it is very likely that Georgia-bred LL varieties will be available in the near future.