Assessment of Visual Evaluation Techniques
1984
Horst, G. L. | Engelke, M. C. | Meyers, W.
Visual evaluation parameters are routinely used to assess performance characteristics of turfgrass cultivars in field plantings. Rating systems are commonly employed to evaluate phenotypic variations in color, density, and uniformity of turfgrass stands during the year. In the present study, visual assessment data for quality and density ratings of cultivars of Kentucky bluegrass (Poa pratensis L.) and tall fescue (Festuca arundinacea Schreb.) from 10 turfgrass researchers were statistically analyzed to determine data conformity, consistency, and uniformity. Analysis of simultaneous data gathering by 10 investigators indicated the following: 1) Visual assessment scales were significantly different among evaluators, 2) Visual criteria used for data collection allowed a wide latitude of perception in quality and density characteristics, 3) Relative rank performance of cultivars differed among evaluators, and 4) Presently accepted techniques for visually assessing turfgrass quality and density are inadequate. Results of national and regional turfgrass cultivar evaluation trials should be considered with caution as most performance variables are based on the use of conventional evaluation schemes. This study emphasizes the need for a coordinated development of qualitative evaluation techniques based on substantiated, biologically definable, growth responses rather than visual perception.
显示更多 [+] 显示较少 [-]