sentences:  The occurrence of deoxynivalenol is associated primarily with "Fusarium graminearum" ("Gibberella zeae") and "F. culmorum", both of which are important plant pathogens which cause fusarium head blight in wheat and gibberella or fusarium ear blight in corn.The incidence of fusarium head blight is strongly associated with moisture at the time of flowering (anthesis), and the timing of rainfall, rather than the amount, is the most critical factor.However, increased amount of moisture towards harvest time has been associated with lower amount of vomitoxin in wheat grain due to leaching of toxins.