sentence: The bacterial inoculum for plant infection was prepared by mixing thoroughly together all S. scabiei cultures grown in vermiculite.For infection trials , Magenta vessel GA-7 boxes containing 3 - to 4-week-old potato plantlets were transferred with the lid ajar to a Conviron growth chamber for 3 to 4 days at 21 ° C. Plants were then transferred to pots containing autoclaved sand and vermiculite ( 2:1 ) without bacteria ( control ) or thoroughly mixed with the bacteria inoculum ( 1:20 ) .