Characterization of the Surface Properties of Wheat Spikelet Components Grown under Different Regimens and the Biocontrol Yeast Cryptococcus flavescens

Surface properties play an important role in plant–microbe interactions and determine if microbial propagules adhere to the surface of a plant. Fusarium head blight is an important disease of wheat that is initiated by the pathogen colonizing the wheat head. To better understand how surface properties of wheat may affect disease development and spray applications, the surface properties of wheat (Triticum aestivum L.) spikelet components were characterized under different environmental growing regimes. In addition, the surface properties of the biocontrol yeast Cryptococcus flavescens OH 182.9, which has been shown to effective in managing Fusarium head blight, were characterized. Wheat samples grown in a greenhouse environment were compared with samples produced in the field for two wheat cultivars. The results show changes occurring in the surface energy parameters and estimates of roughness during this period between the two cultivars. In general, the greenhouse samples were more hydrophobic than those grown in the field. The surface properties of the biocontrol yeast C. flavescens OH 182.9 were determined from contact angles on microbial lawns and revealed the cells were hydrophobic with a free energy of aggregation of −86.3 mJ/m2 in water.