Monday, November 5, 2007
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Drought Avoidance Characteristics of Hybrid Bluegrass and Tall Fescue Cultivars.

Leonard Githinji, Jacob H. Dane, Robert H. Walker, and Edzard Van Santen. Auburn University, Auburn University, 285 Funchess Hall, Auburn, AL 36849-5412

Evaluation of relative drought avoidance characteristics is important for selecting turfgrasses that persist during drought periods. The objective of this experiment was to examine how irrigation amounts affect turf quality, root-length density and root dry mass. A 2-yr field study included the hybrid bluegrasses [Texas bluegrass (P. arachnifera Torr.) x Kentucky bluegrass (Poa pratensis L.)], HB 129 (Thermal Blue), HB 130, HB 328 and HB 329 (Dura Blue) and the tall fescue (Festuca arundinacea Schreb.), Green Keeper and Kentucky 31cultivars. These grasses were seeded during autumn 2004, at the Turfgrass Research Facility, Auburn, AL. The experimental design was a 6 by 6 Latin square within each of 3 irrigation blocks. These blocks were, respectively, irrigated at a rate of 100, 80 and 60 % of potential evapotranspiration. Turf quality values were determined using digital images collected once a week, while root-length density and root dry mass values were determined from samples collected in July and September of 2005 and 2006. Results of the ANOVA test showed that irrigation treatments did not significantly (P > 0.50) affect any of the response variables. The hybrid bluegrasses showed higher root-length density and turf quality values compared to the tall fescue cultivars. Rankings based on root-length density and turf quality were: HB 329 (Dura Blue) [best performance] > HB 130 > HB 328 > HB 129 (Thermal Blue) > Kentucky 31 > Green Keeper [least performance].