Seedfork said:I think I did change the susceptibility rating from resistant to susceptible once, but when I thought that was only one bad season I was not able to change it back. Seems I was told once it showed as being susceptible then it was. I used to put a lot of faith in the ratings but not so much any more, I still use them as a general guide.
The shows susceptibility or resistance section reflects only the opinion of the last person who changed it.
It is a difficult goal to plant only resistant daylilies.
If I do get a plant or seedling that gets attacked by rust, I will pitch it.
And I'll take that opinion. It's better than "no opinion" like on 95% of the daylilies listed.
How were these different scales combined? How were the effects of different test periods combined?
How would a change from susceptible to resistant be useful (assuming such a change is possible in the DB)? It would pretty much indicate that either someone has a mis-labeled plant, the environmental conditions where the plant is growing in their garden were not conducive to rust development, or.............. A daylily that is susceptible in one garden is genetically susceptible, that doesn't change.
Of course it's all a matter of degree, in plant pathology "resistant" does not mean immune and resistant plants can still get rust.
admmad said:...Further to Sue's comment that even daylilies identified as resistant or highly resistant get rust, 'Stella de Oro' is described as follows in one research paper on rust, "Prairie Blue Eyes, Going Bananas and Stella de Oro were resistant or highly resistant, and Mardi Gras Parade was highly resistant to the 16 isolates of P. hemerocallidis" meaning Stella was resistant or highly resistant to all 16 different rust lines. Yet two of those lines had been produced from rust infections present on different Stella plants in different locations.
sooby said: Rust on your hollyhocks, roses, grasses, or any other plant won't spread to your daylilies.
To breed for rust resistance you need rust to be more or less rampant in part of your breeding area to test for the resistance of seedlings - thus you need to grow susceptible daylilies.
That's what I thought, also. I know one breeder who brought in rust from Florida just to test against it.
In my daylily garden, when I first started, I got rust within a few weeks after I planted daylilies that were rust magnates. When I got them they came in clean from growers who spray.
bobjax said:I read that certain weeds harbor it and that it is the air.