Aerial Application of Fungicide Peanut Notes No. 190 2024

(Updated: Aug. 11, 2024, 1:31 p.m.)

*As you read the following response, note that application in much lower spray volumes is off label, and companies will not stand behind performance issues if products are not applied based on the label. As I have thought about it, I do have some concern about some products applied in low volumes that result in a high concentration of fungicide and other components of the formulated product in the spray solution. One product that comes to mind is Provost Silver. Over the years, even at traditional spray volumes, we have had some leaf burn. It is not caused by the active ingredients but elements of the formulation. Check with the manufacturer before you apply any fungicide by air at low volumes that have high concentrations of product. I suspect that a highly concentrated spray droplet could cause more burn (spots) than the same product applied at a higher spray volume that creates drops that are less concentrated.

Question:

I have had some questions about flying on peanut fungicides next week due to extremely wet conditions. We have full vine growth now and most growers have applied at least 1 shot of Apogee due to the vine growth.  1-3 gallons/acre is the volume planned with aircraft.  I feel this is not nearly enough for effective leafspot or southern stem rot control-- especially the southern Stem Rot.  What are your thoughts?

Jordan:

Fungicides do not perform well applied by air into a peanut canopy, especially for stem rot and Sclerotinia blight but also in the canopy where leaf spot begins. I would normally say there is no value in spraying by air. But we are in a very unique place. Conditions have been ideal for leaf spot for a while now and there is some rain in the forecast for next week. I don’t know when fields will dry for ground applications. Application by air could protect the top half of the canopy and that could prove beneficial. This is new territory but the top of the canopy needs to be protected as well as possible as epidemics develop. If you get to next week and it looks like dry weather is not eminent, an application by air might be helpful. I would use something with systemic activity with as much curative activity as possible.

Follow up:

Which Fungicide would offer the most systemic activity for this aerial application?  Would it need to be targeting only leafspot type diseases as it will not penetrate the canopy deep enough to aid with southern stem rot control.

Jordan:

Provost Silver, Priaxor and Revytek might have the most curative activity if you are behind already. I think sprays like this will only help the top half for leaf spot.