Seminole Crop E News

Agricultural News for Farmers and Agribusiness in SW Georgia

Archive for April, 2013

Paraquat Mixing Issues

Posted by romeethredge on April 30, 2013

Avoiding Mixing Issues with Paraquat!

Drs. Culpepper, York, Mclean, Faircloth

During 2012, numerous tank compatibility issues occurred when mixing paraquat (Gramoxone SL 2.0 and others) with commonly used burndown or preemergence herbicides for cotton. Efforts over the winter have shown that each major supplier of adjuvants (non-ionic surfactants, AMS, crop oils, etc…) has products that are effective in avoiding compatibility issues.

Two themes are clear from these tests:

1) use higher GPA’s such as 15 when possible, and

2) slow down and remember proper pesticide mixing procedures; such as adding half the water to the tank before adding ANY pesticide or adjuvant to the spray tank. Due to the numerous adjuvants available, differing water sources, and spray volumes, the best approach is for each grower to conduct compatibility tests prior to mixing herbicides in their spray tank.

Methods to conduct compatibility tests when applying paraquat mixtures at 15 GPA:

1. Place 1 quart of water in an approved clear container for pesticides.

2. Add adjuvants: 4.7 mls or 1 teaspoon equals 0.5% v/v as recommended. Invert 10 times and evaluate. Invert EACH time you add an adjuvant or pesticide to the container.

3. Add 7.9 mls of Reflex, or 1.5 teaspoons (this equals 1 pt/A).

4. Now each grower would have to decide which Reflex tank mix partner will be used such as Warrant, Direx, or Prowl. For Warrant add 24 mls or 5 teaspoons (equal to 3 pt/A), Direx add 12 ml or 2.5 teaspoons (equal to 1.5 pt/A) or Prowl add 16 mls or 3 teaspoons (equal to 1 qt/A).

5. Add 16 mls or 3 teaspoons of paraquat (this equals 1 qt/A). 6. After placing products in container, place lid on container and tighten. Invert at least 10 times and evaluate.

7. If incompatibility is apparent, repeat the test with the addition of a compatibility agent at the appropriate rate BEFORE adding a non-ionic surfactant. AMS-containing adjuvants have been effective in some cases. 8. After compatibility testing is complete, dispose of any pesticides and containers in accordance with the Storage and Disposal section of the labels for the herbicides used.

Spray Tank Mixing Order When Applying Paraquat:

1. Fill spray tank ½ full with clean water.

2. Begin tank agitation and continue agitation until the tank is empty after application.

3. High quality adjuvant(s).

4. Dry Formulations (WP, DF, etc.) 5. Liquid Formulations (SC, EC, L, etc.)

6. Paraquat

7. Fill remainder of spray tank

Additional Thoughts: 1. Using at least 15 GPA carrier volume will lesson compatibility issues; thus, the example above used 15 GPA, but if applying other volumes make appropriate changes above. 2. Each water source should be tested as it can greatly impact compatibility. 3. Test each adjuvant; test 2012 product and 2013 product even if it is the same name brand. 4. Warm water will lessen compatibility issues. 5. If compatibility problems do occur in the tank, a commercial degreaser (such as Purple Power) has been shown to be an effective cleaning agent. Avoid exposure to pesticides while cleaning tanks. 6. The example above uses general herbicide rates; adjust rates according to those being applied. 7. Pesticide mixing containers can be purchased: http://www.co2sprayers.com/results.cfm?Category=56&subcat=ALL 8. Syringes, marked in ml, can be purchased at: http://www.fishersci.com (just search syringes). 9. Joint efforts are underway between Syngenta and UGA to develop and distribute an inexpensive test kit that is simple to use for 2014.

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Posted in Cotton, Weeds | Tagged: , | Leave a Comment »

Crop Disease Update

Posted by romeethredge on April 27, 2013

UGA Extension Plant Pathologist, Bob Kemerait, gives us the following plant disease update.

Fungicides and Corn:

My graduate student Suzette Arcibal has spent much of last season assessing the impact southern corn rust, northern corn leaf blight and southern corn leaf blight.  Her graduate studies have been sponsored by BASF and I am grateful for their support.  Based upon her findings, here are my comments for use of fungicides on corn:

1.  For management of foliar diseases on corn planted in March and April:

a.  Watch sentinel plot reports for detection of southern corn rust.

b.  Control of southern corn rust:  In most situations I believe that a fungicide application made at first tassel (VT) will be sufficient to lay a good foundation to rust control and may be all that is needed for the season; however depending on the pressure, growers may be advised to make a second application within 3 weeks of the first.

i.  Triazole and strobiluirn fungicides are effective against rust; the combination of both will have a longer protective window and broader activity against other pathogens.

c.  Control of northern corn leaf blight (NCLB):  Unlike southern corn rust which must be reintroduced into Georgia in 2013, the northern corn rust pathogen is already here surviving in last year’s crop debris.

i.  Northern corn leaf blight will not be a problem in every field, but in fields where it is a problem, timely use of fungicide program can protect yield.

ii.  From Suzette’s data, northern corn leaf blight is most effectively managed by a combination of an early application (for example the 5th true leaf stage) and a follow-up application at late tassel-early silking stage.

iii.  The spores of the NCLB fungal pathogen can be spread between fields; however the earliest infections will likely occur as rain and irrigation splash the spores from the crop debris and soil to the lower leaves of the corn plants.

iv.  I recommend that as the corn crop approaches the 5th-true-leaf stage, growers should scout to determine if northern corn leaf blight is developing.  Again, not all corn fields need to be treated with a fungicide for management of northern corn leaf blight; however it is important note if the disease is likely to be severe.

v.   I believe that northern corn leaf blight is more difficult to control than is southern rust (assuming you are on time with applications) and that a combination of strobilurin and triazole fungicides is an important consideration.

2.  For management of foliar diseases on corn planted after April:

a.  The threat from southern rust becomes more severe.

b.  The threat from southern corn leaf blight increases.

c.  The threat from northern corn leaf blight remains important.

d.  The potential benefit to beginning a fungicide program 

e.  The potential yield benefits from use of a fungicide becomes even greater as a percentage of potential yield for late-planted corn.

f.  The benefit of planting a rust-resistant hybrid becomes more important with late-planted corn.

Two web sites to note:

www.sbrusa.net (National site to follow the progress of Asian soybean rust)  We have not found any soybean rust on NEW GROWTH kudzu but did find some on OLD GROWTH kudzu in Miller County.  Those old leaves have been destroyed.  Soybean rust is present in northern Florida, Alabama, and Louisiana.

scr.ipmpipe.org  Sentinel plot site for southern corn rust.  Southern corn rust has not been found in Georgia yet in 2013.

Posted in Corn, Crops, Soybeans | Tagged: , | Leave a Comment »

Modified Trap Shotgun

Posted by romeethredge on April 27, 2013

This week a regional 4-H shotgun event was held that we participated in. We have 24 members on our Seminole county team this year and many coaches and volunteers that make it happen. It was a good day and we had many of our shooters qualify for state competition coming up in a few weeks, and all of them learned more about proper gun use and gun safety.

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Poultry Judging

Posted by romeethredge on April 27, 2013

_DSC4966Our Seminole county 4-H Senior Poultry Judging team did so well at regionals that we were invited to the State event held this week. It was a tough contest but our youth represented us well.

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Question of the Week – Phosphorus and Anthocyanins

Posted by romeethredge on April 27, 2013

Last week I had a photo of purple corn beside some normal looking corn. In this field the grower did not use pop up fertilizer ( fertilizer put close to the young plants that usually contains Phosphorus). He did use a good dose of preplant Phosphorus. At this spot in the field he changed corn hybrids and that is what we see here. One row is one variety and the other one is another variety. We ran a tissue analysis and a soil test here and the nutrients in the soil, including P were at sufficient levels. However the plant tissue was deficient in Phosphorus. We know that cool temperatures like we were having makes it difficult for plants to take up phosphorus. We also know that different corn hybrids sometimes respond differently to low nutrients in the tissue.

Another kink here is that the seed company says that the corn hybrid here that is purple sometimes has a buildup of anthocyanins, causing changes in plant color, with warm weather followed by cold rain and weather.  Since the tissue came back low we can say here the color was likely caused by low P due to cool conditions and the hybrid response to it.

Here’s a photo with the purple corn in the foreground and the green corn in the background.

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Posted in Corn, Fertilization, vegetables | Tagged: , , | 1 Comment »

Crop Oil with Corn Herbicides

Posted by romeethredge on April 22, 2013

Dr. Eric Prostko, UGA Extension Weed Scientist says that this is one of the most common questions asked this time of year….Should crop oil be added to Glyphosate + Atrazine tank-mixes in field corn? _DSC4457

Generally, his response is that if you are using a “loaded” formulation (i.e. already has adjuvants included) then there is no need for an additional adjuvant.

Which formulations of glyphosate are loaded or unloaded? Rather than reinvent the wheel, check out the links below for additional information about the various formulations of glyphosate:

http://www.ag.ndsu.edu/weeds/sugarbeet-files/Glyt%20RRbeets.pdf

http://extension.psu.edu/agronomy-guide/pm/tables/table-2-4-1a

http://www.agronomy.ksu.edu/extension/doc2053.ashx

http://www.lsuagcenter.com/NR/rdonlyres/668FD70D-CD74-4553-99AE-55B943F6B557/89884/13Z2GlyphosateAPPENDIXA.pdf

http://www.msuweeds.com/assets/2013WeedGuide/2013WGTable10.pdf

Posted in Agriculture, Corn, Weeds | Tagged: , | Leave a Comment »

Question of the Week – Tri Colored Heron

Posted by romeethredge on April 18, 2013

Last week I had a bird for you to indentify and it was the Tri Colored Heron.

This week I have a photo of some corn and some of it looks different. Why is one row a different color and why?

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Posted in Corn, Wildlife | Tagged: | 4 Comments »

Corn Straightening Out

Posted by romeethredge on April 18, 2013

Corn is finally straightening out.  We’ve had some good weather right here recently. Some corn we checked today is in the V5 stage and is getting tall. Weeds are growing well too and palmer amaranth is emerging. Lots of corn sidedressing is going on and some fields that haven’t had it are looking somewhat deficient.  Weed controls are going out as well when the wind permits. _DSC4843

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Soybeans for 2013

Posted by romeethredge on April 16, 2013

Here’s some information concerning planting dates for soybeans. Fullscreen capture 4162013 75511 PM

The optimum period for planting soybeans in Georgia is from May 10 to June 10.

Planting can begin as early as May 1 if soils are warm (>70°F) and tall-growing MG V or VI varieties are used. Planting before May 1 usually causes premature flowering, plant stunting and reduced seed quality, especially in MG VII or later varieties. Very early-maturing soybean varieties tend to have a more narrow range of favorable planting dates than do late-maturing varieties. This occurs because at southern latitudes the photoperiod response induces early varieties to flower before obtaining adequate growth necessary for optimum yields.

Planting after June 10 reduces plant growth, auxiliary limb branching, root nodulation and nitrogen fixation, and yield.

However, the planting period can be extended as late as June 30 if adapted tall growing late maturing varieties are used.

These varieties should be used in conjunction with approved late-planting practices of higher plant populations and close rows when planting cannot be made during the optimum period. Typically, all planting should be completed before July 1. Growth and yield, even with the best of efforts, may not be economicalafter this time.

Expect soybean yield with good varieties and management to decline about ½ to ¾ bushel/A for every day planting is delayed after June 10.

Planting date guidelines above can be modified slightly for the Early Soybean Production System which uses MG IV or early MG V indeterminate soybeans and the Ultra-Late Soybean Production System which consists of planting soybean following corn harvest. See the section in the soybean production guide “Early and Ultra-late Soybean Production Systems in Georgiafor more details.

Here’s a link to the newly revised Soybean Production Guide for 2013.

http://www.caes.uga.edu/commodities/fieldcrops/soybeans/documents/2013GeorgiaSoybeanProductionGuide.pdf

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Sicklepod (Coffeeweed) Control in Peanut

Posted by romeethredge on April 16, 2013

Sicklepod and Peanut according to Dr. Eric Prostko. UGA Extension Scientist

Despite the fact that Palmer amaranth has been Public Enemy #1 for the last several years, We continue to receive inquiries about the management of sicklepod (a.k.a. roundleaf coffeeweed) in peanut.  Here are a few things to consider:

  1. A single sicklepod plant can produce 25,000 seeds.

  2. Sicklepod seed can remain viable in the soil for at least 5 years.

  3. Sicklepod emergence is greatest from soil depths ranging between 0-1”.  However, emergence can occur from as deep as 4-5”.

  4. Sicklepod seed does not require light for germination.

  5. The minimum amount of time that peanut must remain sicklepod-free in order to prevent yield loss is 4 weeks after peanut emergence.

  6. The maximum amount of time that peanut can tolerate interference from sicklepod without influencing yield is 10 weeks after peanut emergence.

  7. Research in NC has shown that sicklepod control was 9% higher when planted in twin-rows compared to single rows.

  8. Some research has suggested that cereal rye mulches can reduce sicklepod plant height and biomass.

  9. There is no herbicide labeled for use in peanut that provides acceptable residual control of sicklepod.  In wetter years, when crop injury is potentially greater, I have observed some sicklepod control with Valor but not enough to get excited about.

  10.  Historically, Cadre has been the most effective POST herbicide for the control of sicklepod in peanut.  However, the maximum labeled height for sicklepod control with Cadre is only 3”.

  11.  Multiple POST applications of 2,4-DB will provide sicklepod suppression but not control.

  12.  Results from research in GA and FL, conducted in 1994/1995, showed that late-season populations of sicklepod could be controlled > 85% with a 50% solution of paraquat applied in a wick-bar. 

  13.  At this point in time, there have been no cases of herbicide-resistant sicklepod reported in the world.

Posted in Peanuts, Weeds | Tagged: , | Leave a Comment »

 
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