The only comment I would make on the linkage to glyphosate--this is a scientific question, so it's a territory that's a little dangerous for me to tread--is that the introduction of glyphosate has certainly encouraged greater minimum tillage practices, which means a lot more crop residue straw left on the fields. Since this is a soil- and residue-based pathogen, the mere fact that farmers are now using glyphosate has certainly led to much better weed control and minimum tillage practices so we don't have the fuel costs of tillage. There are fewer passes over the field and less pesticide use. There have been tremendous advantages from using glyphosate. I think it is possible there would be a link to increased incidence of fusarium due to the increased trash left on the field.
Again, this is an area I'm not familiar with, so that's more speculative on my part than anything based on scientific study.