Seed, my phrasing is horrible, isn't it? Sorry ... you mentioned that last year without added Milorganite-nitrogen you experienced thorough rust, and that this year after adding Milorganite-nitrogen you are experiencing no rust. As a statement, that seemed to define a general condition that, without a larger picture about weather to put it into, might seem to call into question the research findings that higher levels of nitrogren may increase susceptibility to rust? (Like, you had no extra nitrogen and got bad rust last year, then added extra nitrogen and didn't get rust this year, so how could nitrogen be linked with increased susceptibility to rust?) I appreciate the qualifications you made, and I like to think of data collected in research as at least a good starting point for exploration by us home gardeners when it may help point to things we cannot see or observe directly (such as this, rust dormancy, ploidy, etc.). Sue's note that the Milorganite concentration of nitrogen would be low when used at recommended dosage also speaks to it not likely to have increased a susceptibility to rust.
So, my question only sought to look at the flip-side to Sue's question about possible colder winter weather. If your spring 2014 temps stayed more in a range where rust is likely to develop (below 86) after you added nitrogen this year, and no rust developed after adding nitrogen, I could better understand your statement (temperature conditions would have been optimal, and even after adding nitrogen of any small level, no rust appeared). But if temps were high, then any small or large level of added nitrogen might still have increased general susceptibility for rust, even though heat might have suppressed it (just like sprays and colder winter weather might do, too, as was mentioned).
The 86 degrees is just from a University of Georgia inoculation of daylilies at a few different temperatures that found that those incubated around 86 Fahrenheit had significantly less disease observed over 15 days. The drop-off was steep, both below 50 and above 86 degrees. But, 86 or 92, its still a pretty tight range where researchers seem to have found some temperatures that, all by themselves, could put rust into dormancy until lower temperatures bring it back to the surface where it can be seen. I don't see it as a hard and fast "on or off switch" point, but just as a possible range where research found rust dormancy occurring.
I know its pretty hard to remember past climate, so I looked at historical data (I use it to check on my own garden each year), and it seemed that temps in your area during spring 2013 looked mostly below 80 (April 2013), with much more temperate weather for the first week of May (upper 60s) and not nearing 86 for highs until the last ten days of May 2013. That sounds like ideal temperatures for rust. But, for spring 2014, temps looked pretty close to the 86 degree mark for about half of April, and at or above 90 from May onward. So, maybe it is possible that this year's weather alone might suppress rust in your area, even if general susceptibility were slightly increased with a higher level of nitrogen? I'm not saying that is the case ... just that information on temperature might add to the overall context, and that is why I asked. Climate also looked similar for your weather in FL, Becky ... temps below 85 all the way through May 2013 with three times more rain than this year (ripe for rust?), but 90 and above with much less rain by early June 2014 (more likely for weather to cause rust dormancy?). Like we all have said, it is hard to know what conditions, practices, and yearly soil and weather conditions might increase or decrease the visible appearance of rust. So, it is even more applaudable that people who have rust this year might donate samples, by arranging to send infected leaves to Sue (if she is still collecting them), in order for her to supply a current research effort with a collection from different areas of the country.
Regarding rebloom, I too am amazed at it occurring here! We've have four waves of 100+ degree weather, and this last week averaged about 102 each day, but here come some buds from deep in my blast furnace garden! I have watered a bit more during the heat waves than I did last year, and more regularly every day or every other day depending on whether it is 95 or 105. It may have helped. I can't wait to see if it might have made it possible for a real full-garden re-bloom season once temps drop. If not, it might mean cooler weather comes just too late in the summer for an all-garden re-bloom anyway, and then I should likely go back to less water next year (hard to justify the extra water when we are in drought and can be fined $500 for even the tiniest run-off). Eeeks. So, I'm enjoying it immensely while it lasts!
