Dissemination of Goss’s Wilt of Corn and Epiphytic Clavibacter michiganensis subsp. nebraskensis from Inoculum Point Sources

摘要: Goss's wilt of corn, caused by Clavibacter michiganensis subsp. nebraskensis, has reemerged since 2006 as an economically important disease corn in the Midwestern United States. In 2012 and 2013, field plot studies were conducted with a pathogenic, rifampicin-resistant C. nebraskensis isolate wilt-susceptible hybrid to monitor epiphytic population densities temporal spatial spread incidence originating from inoculum point sources. The randomized complete block trial included three treatments: noninoculated control, sources established wound inoculation, consisting nebraskensis-infested residue. Epiphytic was detected on asymptomatic leaves collected up 2.5 m away at 15 days after inoculation both years. percentage leaf samples which increased until mid-August years, reached 90, 55, 35% wound-, residue-, plots, respectively, 2012; 50, 11, 2%, 2013. Although growing seasons drier than normal, over time space all Plots infested residue had final 7.5 1.8% respectively; plots wound-inoculated source 16.6 14.0% respectively. Our findings suggest that relatively recent outbreaks new regions States may be result gradual, nondetected buildup fields.