Wax Partitioned Soil Columns to Study the Influence of Soil Moisture Potential on the Infection of Wheat byFusarium graminearumGroup 1

Abstract

The influence of soil moisture potential on the infection of wheat [triticum aestivum] seedling by Fusarium graminearum Group 1 was examined using a new technique that enables accurate control of the moisture potential of infested soil surrounding the coleoptile. The coleoptile emerged through infested soil sandwiched between two wax layers. The moisture potential of the soil between the wax layers was adjusted by isopiestic or pressure membrane equilibration. The seminal roots grew in a lower soil layer maintained at a constant-105 cm hydrostatic suction. Infection of the coleoptile occurred between saturation and -2.15 MPa soil moisture potential, and maximum infection occurred at -0.5 MPa.