Stress responses of Kentucky bluegrass varieties in monostands and blends.

摘要

Traditional recommendations for athletic field construction have included the blending of turfgrass varieties; however, due to recent advancements in breeding technology, single cultivars bred for generalized disease resistance, aggressive tillering, and herbicide resistance may be used in place of a blend, which was previously necessary to provide all of these characteristics. Four separate studies were initiated in East Lansing, MI on 25 September 2009 to measure the validity of using monostands instead of blends. Two studies were subjected to twelve traffic events (ten passes per week) with the Brinkman traffic simulator beginning 3 August 2010 and evaluated for various response variables. One of the studies, established on native soil, showed that the blends did not out perform all of their constituent varieties in quality, cover, and surface strength characteristics during traffic applications. In addition to these findings, a comparable experiment established on native soil but receiving 2.4 cm of high sand-based topdressing prior to traffic applications, provided similar results over the two years of data collection. Two additional studies focused on blends and monostands under Sclerotinia homoeocarpa (Dollar Spot) and Bispyribac-sodium (Velocity) stress. Two resistant and two susceptible varieties were chosen for blend construction. Two-year results from the dollar spot study consistently showed the resistant varieties and the blend of the two resistant varieties having fewer dollar spot infection centers and higher overall quality. Similarly, in the two-year duration, blends of the Velocity study showed tendencies of intermediate results in Normalized Difference Vegetation Index (NDVI), quality, and percent blighted tissue when compared to the resistant and sensitive varieties.