Comparing Inoculation Methods of Clavibacter nebraskensis on Corn (Zea mays) Under Greenhouse Conditions

Goss’s bacterial wilt and leaf blight of corn (Zea mays L.), caused by Clavibacter nebraskensis, is one of the top yield-reducing corn diseases in the Northern Great Plains. The use of efficient and repeatable inoculation methods in the greenhouse are needed to further understand disease development and host resistance. Although several inoculation methods have been reported, a direct comparison among them in the greenhouse has not been conducted. A greenhouse study was conducted to compare established methods for time to inoculate, disease incidence, and lesion development. Methods evaluated included creating wounds with scissors, pin-prick tools, sandpaper, or carborundum, or introducing bacteria by spraying, immersion, sponge, or syringe. Removing leaf tips with scissors and dipping newly injured leaf in bacterial suspension resulted in the fastest inoculation time (24 seconds), highest disease incidence (>80%), and fastest lesion development among methods tested. Most other methods had similar disease development, but varied on their success rate (incidence). These results can aid researchers on selecting inoculation methods to address research objectives on Goss’s wilt in the greenhouse.