Experimental design and simulated
aphid infection in the field. The field
experiment was arranged and designed in
randomized complete blocks with five
replications of six different treatments for
melons and peppers. The experiment was
performed at the United States Department
of Agriculture farm, Agriculture Research
Service, BARC-West, Beltsville, Maryland.
For each treatment, 428 pepper plants or
128 melon plants were transplanted into
the field 3 weeks after preinoculation. Two
different challenge strains, CMV-D and
CMV-16, were used in the pepper experiment. The melon experiment was challenged with CMV-16, and the challenge
was applied either mechanically just before
transplanting to the field or in a simulated
natural challenge using viruliferous green
peach aphids. For mechanical challenge
inoculations, crude sap proved to be more
efficient in achieving infection and allowed
the preparation of larger volumes of
inoculum needed to inoculate the larger
plant leaves at this stage of the experiments