I keep looking for rust resistant plants for my garden, and I did a search of
rust resistant plants for 2015. I pulled up 39...all Gossard plants. Yes, the one I really wanted 'Stop The Car' is $150.00, so I won't be getting it for about ten more years.
Anyhow my question is where did the rust resistant rating come from?
Is the simple rating of "rust resistant" left up to the hybridizer to fill in when registering the plant, and the more precise numerical rust rating of 1-5 or such, assigned by University studies?
I thought it odd that all of a sudden for 2015 39 entries from one breeder were listed as rust resistant, what has changed?

I haven't been on ATP as long as many of you and the only thing I recall is that the original rust ratings were entered from these sources, according to an earlier thread:

http://garden.org/barn/notes/r...

I assume anyone who is an ATP member can enter rust data. It has nothing to do with AHS registration, the AHS does not do rust ratings, this is strictly an ATP thing. There was an AHS associated rust resistance/susceptibility survey (which is quoted in the ATP link above) but due to technical difficulties it is no longer functioning although the results appear to be included in the ATP ratings. It was for people to enter their garden observations but a cultivar would not appear on its public listing until it had at least three ratings because one observation from one garden is insufficient to make a determination, especially if it is a rating of resistance as opposed to susceptibility.

The ATP rating is based on the University Studies, not on member entries. Membembers could add a comment in the comments section, and that is all I know of. It doesn't have any effect on the actual rating in the search boxes. So if AHS did not do it, where did it come from? Anybody have a clue?

Larry - A very good question. I asked that question too and the answer I got was the university studies.

I often check several sources online before making a choice about a rust resistant cultivar. I have read comments from others that one listed as high rust resistance was not. So now I question those ratings. But I am also looking for specific pretty faces, so am willing to take a chance on one that is unknown or iffy if I really like what it has to offer in the bloom. Mostly I go with the ones that are truly showing rust resistance. I doubt very few will ever be completely rust resistant, but they may not get a severe attack of rust. Those are the genes I want in my hybridizing program. I also keep reading about Ted Petit's "Enjoy 24/7" daylilies for landscaping are quite rust resistant. Apparently he bred for Rust Resistance over the past few years once rust became an issue here in the USA and especially the south.

I think I will ask this over on the Site Talk forum and see if anyone knows how that info got into the database.

I looked for rust resistant rated cultivars for 2010 and 2011 (Edit: Ditto for 2012, 2013 and 2014) and got some results (not Gossards) and these would have presumably not have been included in the university studies either. So if ATP members can't add the ratings this is a good question!

Well my message has been posted in the database forum, so maybe we will find out soon.

Link? Thanks for doing that, Larry!

Link:
The thread "2015 Rust Resistant rating for 39 daylilies by Gossard" in Plant Database forum

This link may answer a few of your questions.....
The thread "Updating Daylily Rust Suseptibilty Dropdown - Problem and Question" in Plant Database forum

Char, no all that was old back in the days when the info was first being added. I think Dave worked out the kinks with that long ago. Where the new information is coming from is the question? Looks like some people did a lot of work entering that info back then. I certainly do appreciate all that work for the rest of us.

Ok, got it. You are asking specifically about the Gossard 2015 plants. If you go to his website and read the introduction information you will see a comment about rust resistance.
http://www.daylilynet.com/
My best guess is that when someone edited the data for those plants they put the rust rating in the database as well. Anyone can change the rust rating of a plant in the ATP database by using the pull down box wen editing data. How accurate this makes any of the rust ratings in the database is debatable. Someone must have entered the data from his website, the AHS registration info is not allowed to be posted until the 2015 checklist is printed.

Oh, then I am sorry for misleading people on that issue. I thought that was tied in with the rust decibel score, from the University Studies. So if I have a plant in my garden that gets rust badly, but it is showing as rust resistant in the database, then I could change the rust resistance to Shows Susceptibility? Seems odd, but if that is how it works...that is how works. Does the change have to be approved? Did all those Shows Resistance and Shows Susceptibility ratings come from members gardens, from web sites, studies? Any Ideas on that?

Seedfork said: So if I have a plant in my garden that gets rust badly, but it is showing as rust resistant in the database, then I could change the rust resistance to Shows Susceptibility?

That way around is more appropriate than being able to change susceptible to resistant, which shouldn't be able to happen IMHO. That's all inasmuch as it is useful for any one person to determine a rating from one garden in any case, which it really isn't.

Are any studies of daylily rust currently being conducted? Has any University done any studies in the past few years checking for rust resistant cultivars? Have they given up on it as a hopeless task? Do they feel rust is pretty much under control? Do they feel chemicals are the answer?
I don't know the answer to any of the above questions there seems so much still to learn, but maybe there is just no money set aside for research.
If a plant (this is all hypothetical) showed no rust, yet all plants around it did in my garden, and that plant was rated as "Shows Susceptibility" in other gardens, why would I not be just as justified in changing that to "Shows Resistance", as opposed to the other way around?
I agree one garden is not a reliable source either way, and it looks like to me this rating done in this manner just toggles from the rating of one garden to another instead of taking all the ratings for one plant from all the gardens and using that to develop a rating. Yet, I do wonder how many times this has actually happened that the ratings were switched?

Seedfork said:Are any studies of daylily rust currently being conducted?

Yes.

Seedfork said:Has any University done any studies in the past few years checking for rust resistant cultivars?

Yes. But consider that there are almost 80,000 registered daylilies, although not all are still around. Are they all going to get formally and scientifically tested? Just not going to happen.

Seedfork said:Have they given up on it as a hopeless task?

No.

Seedfork said:Do they feel rust is pretty much under control? Do they feel chemicals are the answer?

Can't answer for them but I doubt it on both counts. Usually with plant diseases the preferred option is to breed/grow resistant cultivars.

Seedfork said:I don't know the answer to any of the above questions there seems so much still to learn, but maybe there is just no money set aside for research.

The AHS still funds research. There may be other research going on that we won't know about until the results are published. Remember, prior to fifteen years ago there was no daylily rust in North America and it takes time to get funding, get the plants, thoroughly set up and conduct the study, figure out the results, get publication accepted, get published.

Seedfork said: If a plant (this is all hypothetical) showed no rust, yet all plants around it did in my garden, and that plant was rated as "Shows Susceptibility" in other gardens, why would I not be just as justified in changing that to "Shows Resistance", as opposed to the other way around?

Because even though other daylilies around it are affected and it isn't doesn't mean it isn't in some kind of microclimate and therefore not getting the right environmental conditions (for example it may be in better air circulation on the corner of a bed), or is slow to show rust (unless you count that as being resistant). It's possible for one's rating to change during the season for an individual cultivar.

Seedfork said: Yet, I do wonder how many times this has actually happened that the ratings were switched?

I've no idea either but it means that the rating that appears when you look up a plant is potentially only one person's experience and I would therefore give more credence to a rating of susceptible than a rating of resistant. Having said that, there is also the potential issue of misdiagnosis.

Sue - Thank you! You answered many of the questions I've been wondering about!

Larry - Thank you for ASKING those questions!!!