Abstract
Responses of maize inbreds A239, A375, B14, CG1, CI.44, Ky61:2335, Ky66:2500, Oh28, M14, Pa32, Pa405, and Va35 to inoculation protocols with maize dwarf mosaic virus (MDMV) strains A and B were determined. Protocols included age of test plant at inoculation, number of repeated inoculations per plant, number of rubs per inoculation, and inoculum dilutions. Tests involving four inoculations with two rubs at 4-day intervals resulted in the greatest number of infected plants in all inbreds. Except for the number of repeated rub inoculations per plant with MDMV-A, cluster analysis of area under the disease progress curve separated inbreds into more groupings than did cluster analysis of final readings. MDMV-B was generally not more virulent than MDMV-A except in the number of repeated rub-inoculation tests involving inbreds A239, B14, M14, and Va35. Inbred Pa405 was most resistant to both strains. The significance of variation in host response to different inoculation protocols in studies of disease resistance evaluation is discussed.