Cause And Control Of New Lettuce Diseases
Black root rot of lettuce caused by the fungus Chalara elegans was found in crops on the eastern Darling Downs, Granite Belt, Brisbane metropolitan region and Bundaberg but not the Lockyer Valley. In addition, it caused problems in hydroponically grown crops at Gatton and Mareeba. Corky root caused by the bacterium Rhizomonas suberifaciens was found in crops on the Eastern Darling Downs and the Lockyer Valley. A soil sampling technique and bioassay was developed which indicated probable disease severity. Field experiments showed disease severity could be reduced by using transplants rather than direct seeding.