Improved method for injecting fungal inoculum into corn ears

Corn (Zea mays L.) ear rot pathogens reduce yield and grain quality annually, and research on these pathogens and their interactions with the host can require inoculation of fungal material into the ears. A new system of mechanically inoculating corn ears was designed using a hydration backpack and auto-filling vaccinator with a needle attached. The efficiency of the new system was compared to a previously established inoculation method using a manual syringe method with an 18-gauge blunt end needle attached to a 60-ml syringe, with inoculum carried in a plastic beaker. Inoculation methods were tested by comparing the time to inoculate 100 corn ears with separate conidial suspensions of Fusarium verticillioides and F. graminearum in a replicated field trial. The new mechanical inoculation system reduced inoculation time by 42% (P = 0.0015) when compared to the manual syringe and needle method. Additional benefits of the new method include reduced risk of inoculum contamination, consistent inoculum volume per ear, and increased safety for personnel doing the inoculations.