The level of deoxynivalenol (DON) in Fusarium head blight (FHB) infected barley grains is a key outcome of FHB resistance breeding because DON diminishes quality. However, the financial and resources required for DON measurements limits most early breeding programs to rely on visual severity score for selection. Because visual disease severity scores may not correlate well with DON levels post-harvest and only one cycle can occur in a field season, breeders would benefit from a greenhouse screening method. A dip inoculation method was developed as a high-throughput assay that would estimate FHB response under controlled conditions. This method is an attempt to create an evaluation of FHB resistance in the greenhouse with better correlation to DON than field severity. The objectives of this study were to 1. examine the sources of variation within this controlled environment assay, 2. determine the correlation between severity and DON, and 3. determine the correlation between fungal biomass estimates and DON. In this study, 6 two-row barley cultivars from the Aberdeen ID training population were evaluated after inoculation with the FHB isolate PH1 at two concentrations (10⁵ and 2 x 10⁵ conidia per mL). Ten heads of each line were evaluated at each inoculum level for severity, fungal biomass, and DON (ppm). DON level was influenced by line(P=0.0054), but severity score and fungal biomass were not (P>0.05).  This suggests a role for the host in DON accumulation that may be independent of fungal growth. Inoculum concentration had no effect on DON, severity score, or fungal biomass in this study (p>0.05).  A strong correlation was observed between fungal biomass and DON (r=0.9, P<0001), while the correlation between severity score and DON was lower (r=0.4, P<0001). This suggests that fungal biomass may be a more accurate predictor of DON accumulation than a visual severity score, at least under controlled environmental conditions.