Pepper plants were then selected at the
first true leaf stage (4 weeks after seeding)
and melons at the cotyledonary stage (12
days after seeding) for further preliminary
tests in the greenhouse. Plants were divided into 10 groups. Control group 1 was
mock-inoculated with buffer. Control
groups 2 and 3 were inoculated with CMVD and CMV-16, respectively. The remaining
seven groups were inoculated with CMV-S
+ S-CARNA 5 (the vaccine). One of these
groups was kept without challenge inoculation as the vaccinated control. The other six
groups were mechanically challenged with
the severe virus strains CMV-D and CMV-16 at 1, 2, and 3 weeks after vaccination to
determine the optimum timing for challenge
of these particular cultivars.