Effects of sericea lespedeza residues on selected tallgrass prairie grasses

Sericea lespedeza (Lespedeza cuneata [Dumont] G. Don) has shown allelopathic properties in tame pastures but no studies have been done on its allelochemical effects on grasses in eastern Kansas rangelands where it is currently invading. Big bluestem (Andropogon gerardii Vitman), little bluestem (Andropogon scoparious Michx.), indiangrass (Sorghastrum nutans (L.) Nash), and Kentucky bluegrass (Poa pratensis L.) were exposed to sericea lespedeza stem and leaf residues and their germination and growth responses studied. Compared to the checks, germination rates were reduced for big bluestem (15 to 27%), indiangrass (25 to 39%), and Kentucky bluegrass (47 to 60%). These grasses also exhibited shorter radicle lengths and shorter coleoptile lengths. However, none of these grasses had any growth reductions. Little bluestem was not affected in any way.