Evaluation of turf-type bermudagrass cultivars and experimental genotypes for rooting characteristics and drought performance
Abstract
Bermudagrass (Cynodon spp.) is one of the most widely used warm-season turfgrasses in the southern and transition zone areas of the United States. Due to the scarcity of water for turfgrass irrigation, it is necessary to identify and use drought-resistant cultivars. The purpose of this research was to evaluate commercially available bermudagrass cultivars and experimental genotypes for rooting traits and drought resistance. Three separate greenhouse studies were conducted to evaluate different bermudagrass genotypes for rooting characteristics when grown in clear polyethylene growth tubes under non-limiting soil moisture conditions. Genotypes were examined for shoot dry weight and root traits [rate of root depth development (RRDD), total root length (TRL), root surface area (RSA), average root diameter (ARD), root volume (RV), root dry weight (RDW), root length density (RLD), and root to shoot ratio (R/S)]. Significant differences were observed among the genotypes for all of the parameters examined. This research will help in identifying genotypes with superior rooting traits and prescreening a large number of genotypes prior to field drought evaluation. Drought performance of ten bermudagrasses was also investigated in the greenhouse when grown in 120 cm deep pots. 'TifTuf' was the top performing genotype for drought resistance. The high correlation among drought response parameters turf quality (TQ), leaf firing (LF), and normalized difference vegetative index (NDVI) indicates their usefulness to assess relative drought resistance. A field study was conducted to characterize the turf performance of 19 experimental and 2 commercially available bermudagrasses TifTuf and 'Tahoma 31'. Genotypes varied significantly for the evaluated parameters such as percent establishment (PE), turf quality (TQ), seedhead prolificacy (SH), fall color retention (FCR), spring green up (SG), and winterkill (WK). TifTuf and OSU1876 had maximum FCR. Winterkill ranged from 5.3 to 97.3 percent among the genotypes. Tahoma 31 had a less winterkill than TifTuf and 80% of the experimental genotypes. The results indicate that significant differences are present in the turf performance of the new genotypes evaluated in this study.
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- OSU Theses [15752]