Hello Jon, Yes, I have used these fungicides mixed together. The reason for this is to kill all that you contact with the contact fungicide and kill the remaining spores with the systemic. Unfortunately, that does not happen and some spores seem to get by and repopulate. You can also use chlorthalonil as a contact fungicide if you can't find Mancozeb.
In case you are not aware, fungicide resistance is a continuing problem with systemic fungicides, and certain fungicides are more susceptible than others. There is a group called FRAC (Fungicide Resistance Action Committee) that publishes a list of fungicides divided into groups by their FRAC code. Each FRAC grouping specifies the mode of action by which the fungicide works and FRAC recommends that no systemic fungicide is used spraying-after-spraying. Instead, they recommend that the mode of action of the systemic fungicide be changed every spraying to minimize fungicide resistance.
You can find a FRAC code list by searching for it on the internet. A new one is put out each year. You can also find items that explaining it better than I have.
For your immediate needs: Mancozeb if Group M5 Chlorthalonil is Group M3
Propiconazole is Group 3 Myclobutanil is another systemic from Group 3 that is available is most big box stores and has activity against daylily rust. However, you cannot rotate it with Propiconazole since it is in the same group
One option is Thiophanate-methly which is in Group 1. Its not cheap, but its not awful. The branded product in Cleary 3336, but there are generics if you look for them.
Only one other group comes to mind that has action against daylily rust and that is Group 11 which includes several "strobulin" or "strobin" chemicals. There are two that seem to work best against daylily rust - Azoxystrobin and Pyraoclostrobin. All of the chemicals in this group are extremely expensive and they are also highly risky for developing resistance. Let's hope that you do not have to resort to them!
There is a lot of information on the internet about daylily rust if you are willing to sift through it all. There is a lot of old material from the early 2000's, some of which has been expanded on. you might wish to look at the Daylily Rust Pages which you can find at:
http://www.ncf.ca/~ah748/rust....
Sue Bergeron (a member here at ATP) has compiled a lot of information there which cuts out most of the duplication you will find on the internet.
Good luck!
Larry
