So, two years later, what are the cultivars that have consistently been rust resistant? It's true that there may be more than one strain of the fungus, which would cause different levels of susceptibility in the literature. I think another possibility is the misnaming of cultivars that appear to be the same. One source says there are 10,000 named cultivars; surely some look identical but are not genetically identical with respect to pathogen susceptibility. How can one really know if a cultivar is from the original named source? And over time sports can develop from the original with new traits, which get passed along as the original named cultivar. Not to mention differing environments that may or may not promote susceptibility. 90% of the plants I buy, which are labeled somewhere as being resistant become infected here in Miami. Buttered Popcorn and Chinese Scholar are two new purchases this year that have become infected this early in our season.
