Hunt Sanders
Peanut inversion has begun. Seems like most of these varieties are right on time (140-145 DAP) depending on the field.
Leaf Spot Has Exploded — But Why?
Leaf spot has been a hot topic lately, and over the last week, it has EXPLODED in some fields. Defoliation is becoming rampant.
The question I keep hearing is: “How can I have this much leaf spot when I have been using premium fungicides?”
There is no single answer.
I believe several factors are coming together to create the late-season leaf spot we are seeing right now.
I have heard growers say:
“My TifNVs are loaded up with leaf spot.”
Another says:
“My DynaGrows are defoliating.”
And another:
“My 06Gs have the most leaf spot I have ever seen.”
This is why I do not believe we can simply point to one variety and say, “That variety has leaf spot.”
Variety certainly plays a role in a peanut’s susceptibility to leaf spot, but the environment and management history of the individual field can have a tremendous impact on how that disease develops.
So why are we seeing it explode now?
Think about what has happened over the course of the season.
We have a peanut canopy that is now mature and dense. We have had periods of favorable moisture and humidity. We have fields with different rotation histories. We have had weather that has made timely applications difficult in some situations. And we have peanuts that are simply older and have been exposed to disease pressure for a longer period of time.
Put all of those factors together, and disease can go from something you barely notice to significant defoliation in a very short period of time.
Once significant defoliation is occurring, we are no longer talking about preventing a problem—we are trying to protect what yield and peg strength remain.
significant late-season defoliation can weaken peg strength and increase digging losses. If defoliation becomes severe, the disease itself can become a factor in deciding whether peanuts can safely remain in the ground until the originally projected digging date.
The biggest takeaway: Don’t judge your leaf spot situation solely by the variety planted or the price of the fungicide used.
Look at the whole field history.
Variety matters.
Fungicide selection matters.
Timeliness matters.
Rotation matters.
Weather matters
The only variety that I have seen go past 145 days is the 12Y so far this year.
Remember to keep an eye on the 21GRs, they will begin to drop pods. I would rather yield 2.5 tons and grade a 72 than yield 1.75 tons and grade a 77. That’s just me.
Consider the weather coming up. If you have weakening pegs and rain chances are high, I would consider getting those nuts out of the ground before the dirt get heavier.
The new variety FloRun 725 seems to be maturing a little early. Instead of the 140-145, seems to be going around 135-140.
Peanut variety trial update
1: Georgia 23RKN 2: Georgia 06g 3: DynaGrow 913 4: FloRun 725 5: Tif NV HG 6: Georgia 24 NHO 7: FloRun 52N 8: Arnie
Some interesting data was taken yesterday at the peanut trial, peanuts are 135 DAP today. We will try to dig them NEXT Friday, putting them at 142 DAP. Below is a PDF with the maturity boards of each variety.
Remember that when it comes to using harvest aids for peanuts, AIM is our best option. This doesn’t mean that AIM is going to make them disappear, it simply means that it will make the morning-glory brittle to where it will not wrap.
Spray 7 days before digging: 1-2 oz/A: 6-8 hours rain free period
AIM is less effective on small flower morning-glory.
Use at least 15 GPA for optimum results
DO NOT GRAZE or FEED PEANUT HAY to LIVESTOCK
There are several resources your county agent has access to for assisting the public:
- SpotOn Digital Sprayer Calibrator & nozzle cleaner tool – Accurate flow rate checking of individual sprayer nozzles.
- Fertilizer Spinner-Disc Spreader Calibration – spread pattern testing of fertilizer spreaders.
- Hay Moisture Tester – Evaluation and assessment of hay to bale at optimum moisture content – decrease mold growth and increase feed value. Test baled or unbaled (in field)
- Forced Motor Planter Calibration – at-plant insecticide hopper box calibrations. Potential benefits: increase insecticide application efficacy with the appropriate and effective application of product label and recommended control rate. Decrease
- Mobile Irrigation Lab – Pivot efficiency evaluation/Irrigation audits to support water conservation and decrease irrigation costs.
- Harvest Moisture Testing – Corn and soybean moisture testing to decrease drying time and fuel costs.
- Enviroscape Watershed Model – Environmental education programming tool. Interactive demonstration of the sources and effects of water pollution. Present and illustrate watershed/stormwater concept.
- Rainfall Simulator Tabletop Educational Program tool –
- Digital wind meter educational tool – Anemometer measures wind speed to support safe pesticide applications and reduce drift.
- Pivot Calibrations
- Drone imagery/scouting