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South Carolina peanut growers at tank-mix decision timeSouth Carolina peanut growers at tank-mix decision time

• This might have been one of the longest planting seasons for South Carolina growers in several years with peanuts being planted from mid-April to mid-June.• A large portion of the peanut crop has reached 45 to 60 days old. With this in mind, there are a few important items to remember.

June 27, 2012

4 Min Read

The South Carolina peanut crop has improved dramatically over the last two weeks.

Some of the early planted peanuts are beginning to lap the middles and are blooming well. 

Although the majority of the South Carolina peanut crop is doing well so far, growers are still having germination/stand problems with a few of the late planted runner varieties. Some growers were able to replant, while others either could not get seed or have run out of time. 

This might have been one of the longest planting seasons for South Carolina growers in several years with peanuts being planted from mid-April to mid-June.

In addition to late-season planting issues, Mother Nature also played a hand in delaying early-season weed control and gypsum applications for many of our growers. Fortunately, improved conditions have allowed growers to get back in the fields and slowly catch up.  

I have really enjoyed getting out and visiting with growers throughout the state. Please call me if I can help in any way.

A large portion of the peanut crop has reached 45 to 60 days old. With this in mind, there are a few important items to remember:

• Fungicide programs should have been initiated for leafspot and soilborne disease control. Conditions for disease development and spread are favorable for both types of disease.

• For fields with known leafspot and moderate white mold problems, consider using one of the systemic leafspot fungicides in either the 45DAP (Tilt) or 60 DAP (Headline, Provost, Abound, etc). This will help get a start managing any leafspot disease that might develop as a result of the rainy conditions.

• Remember that some leafspot fungicides are not as effective on soilborne disease. You might need to add tebuconazole or Convoy. Please see page 47 of the 2012 Peanut Money Maker for more detailed information.

Try to finish your gypsum applications ASAP

Apply Boron (in first fungicide application) and Manganese (at 60 DAP & 75 DAP fungicide applications)

• Please see label to determine the correct rate as many products have different concentrations.

At 45-60 DAP, is when you can determine if you have an inoculant failure. An average of 15 large nodules per tap root at 45 DAP is considered good; less than 10 per taproot is marginal and less than 5 indicates poor inoculation.

Clean up grass and weed escapes

• Make sure to check labels for pre-harvest intervals.

To help answer questions received over the last few weeks regarding tank mixtures, I have added some information from a talk David Jordan, North Carolina State peanut specialist, gave at our state meeting. I hope this helps.

Tank mix questions, answers

Tank mixes — the wild cards

• Is formulation more important than active ingredient? Yes it can be.

• Does the adjuvant recommended for each component differ? Yes it does.

• Do water pH, softness and hardness affect control and mixing properties? Yes, but hard to predict.

• Do stress and pest size affect control? Bigger and stressed plants increase antagonism.

• Is the timing of application for all pests really the same? No.

• Peanut injury, pest control, mixing and settling issues are all a part of “compatibility.”

Tank mixes — answering questions

• The “label is the law” but labels can be ambiguous when it comes to tank mixtures (wise for the company but a challenge for recommendations).

• Paraquat injury greater when mixed with residual herbicides (Dual products, Outlook).

• Grass control lower when paraquat is mixed with Basagran, although Basagran reduces injury; most other weeds no major impact.

• Don’t apply paraquat if you have a lot of thrips damage.

• Mixing paraquat and Orthene okay, mostly.

• Injury from Basagran greater when applied after Thimet or Phorate.

• Grass control by clethodim (various products) and Poast often reduced by Cobra, Ultra Blazer, and Storm (10 to 40 percent) but not as much by Cadre and even less so by 2,4-DB or residual herbicides (Dual products, Outlook)

• Mixing Dual or Dual Magnum with Storm, Cadre, Ultra Blazer and Cobra will increase injury 10 to 20 percent over these herbicides alone.

• Broadleaf weed control (Cadre, Pursuit, Ultra Blazer, Cobra, 2,4-DB) control is generally not affected by fungicides, insecticides, or other herbicides (up or down 10 percent).

• Grass control is generally lower when clethodim (various products) or Poast are applied with chlorothalonil products, Headline, and Abound more so than Provost, with tebuconazole (various products) least affected.

• Disease control generally not affected by insecticides or herbicides.

• Insect control generally not affected by fungicides or herbicides.

• Most plant growth regulators do not affect pesticide performance.

• Boron and Manganese products generally do not affect pest control, but pesticide and adjuvant can affect absorption of micronutrients (concern with boron toxicity).

• When multiple products are combined, adverse effects on pest control are usually not “overly interactive” (one component generally stands out if there is a problem)?

(It’s not easy timing tank-mix applications in peanuts, but good information on that subject can be found by clicking here).


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