Fusarium graminearum fungal pathogens pose significant food safety concerns because they infect cereal crops and contaminate grain with harmful mycotoxins. Most F. graminearum strains in the U.S. produce the FDA regulated mycotoxin deoxynivalenol (DON), but an emerging NA3 population of F. graminearum produces the mycotoxin called NX with a slightly different chemical structure. Since little was known about the aggressiveness of NA3 strains and the function of NX during plant disease, ARS researchers in the Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, Illinois, compared disease development of the NA3 population to other North American F. graminearum populations. While NA3 strains typically spread more slowly in wheat, during initial infection they produced more mycotoxins in comparison to other populations. Furthermore, both NX and DON promote disease spread, but NX also has a unique function in enhancing pathogen initial infection. This work provides insights into the potential threat of emerging pathogen populations and mycotoxin types, but also identifies potential population specific control strategies.