The red stele pathogen, Phytophthora fragariae, was detected by a "root-tip bait" test in certified commercial stock strawberry plants, supposedly free of the disease. Susceptible bait plants (alpine strawberry cv. Baron Solemacher seedlings) were grown in a mixture of compost and root tips cut from runner plants under test. When root-tip samples were prepared with 1:99 infected/uninfected runner plants, the test gave positive results in all 10 trials.