Question:

Attached is a fungicide program recommended by someone. What do you think?

*I’m not including the specifics of the program with my posted answer. I’m giving my thoughts on how to approach disease control in general based on general ideas about the recommendation

Jordan:

Nothing wrong with the program you sent. But here are a couple of things to consider.

The start was early by 2 weeks (June 15 start).

Lots of things added to the mixes that may not bring value. Look at a recent post about boron and manganese products on rates and what products deliver. Here’s my standard program:

Chlorothalonil 24 oz now

Provost Silver 13 oz 2 weeks later

Miravis/Elatus 2 weeks later

Chlorothalonil plus Tebuconazole 3 weeks later

Chlorothalonil 2 weeks later

Something for stem rot is needed from mid-July through first week of September. Miravis plus Elatus has activity against Sclerotinia blight, leaf spot, and stem rot. Of course, there are numerous other options for sprays 2, 3, and 4. They only give 2 weeks of control. Let’s say you drop Miravis/Elatus. Priaxor, Lucento, and Revytec are good options in that block.

At least right now, Provost Silver has proven curative activity. Some others might too, but I don’t think we have documented that. Chlorothalonil and Miravis have NO curative activity, so if the spray before these gets stretched out longer than ideal, you might switch to Provost Silver and then get Miravis/Elatus and chlorothalonil back in later.

I am not trying to sell Miravis and Elatus. However, the value it brings to Sclerotinia blight suppression should not be overlooked.

The program outlined ends on August 23. I think that is too soon. We often need to spray well into September. That’s a year-by-year decision.

I lean toward spraying dry manganese and dry boron products just once. They have adequate amounts to solve a problem if it occurs. You can add some of the liquids to each application as listed in the recommended program. Not sure how that pencils out economically.

Not sure what the sulfur brings to the table as well as what I assume are a micronutrient mix. I have not looked at these but over the years products like them. If sulfur is a micronized sulfur, it could bring some suppression of the pathogen causing leaf spot disease. But it must be micronized (very small particles for coverage.)