Evaluation of 125 Petunia Cultivars as Bedding Plants and Establishment of Class Standards

Abstract

Central Florida has a climate similar to many locations in the southeastern United States and parts of Asia, Europe, and Australia. Thus, Florida is an important testing ground for new bedding plant cultivars not only in the United States, but around the world. The authors evaluated 125 petunia (Petunia ×hybrida) cultivars in replicated class tests at Bradenton, Fla. (lat. 27º4′N, long. 82º5′W) in 2000–04 and at Balm, Fla. (lat. 27º8′N, long. 82º2′W) in 2005–06. In this report they establish petunia classes and cultivar standards for each class, and provide objective plant measurements of vegetative and floral characteristics, and subjective performance ratings. Petunia cultivars were grouped into 73 classes based on the distinguishing characteristics for petunia, which are plant type and height, and flower type, color, and color pattern. Comparisons were made within each class to determine performance and to select a cultivar as the standard for the class—a plant with the highest overall performance rating that can represent the class in future trials against new cultivars. During the initial trials, larger numbers of cultivars were evaluated and eliminated from future comparisons when each class standard was selected. Many flower colors and color combinations, as well as plant types and other distinctive characteristics have been developed for bedding plants. By creating class standards for each distinctive characteristic, better choices over a wider range of classes are available to growers and landscapers in this climate. Cultivars with an outstanding overall performance rating (combined foliage, flower, arthropod feeding symptom, and disease symptom ratings ≥5.5 points on a 1 to 7-point scale) for class standard selections were (floribunda, single mix class) ‘Madness Waterfall Mix’ and [single purple (dark), red-violet class] ‘Madness Magenta’; [grandiflora, single blue (dark) class] ‘Eagle Blue’, (single orange shades/tints class) ‘Ultra Salmon’, and [single purple (dark), red-violet class] ‘Storm Violet’; and [spreading, normal, orange (dark) shades/tints class] ‘Ramblin’ Salmon Capri’, [orange (light) shades/tints class] ‘Ramblin’ Peach Glo’, [pink (dark) class] ‘Wave Pink’, [purple (dark), blue-violet class] ‘Avalanche Lavender’, [purple (light) blue-violet class] ‘Ramblin’ Lavender’, (red class) ‘Avalanche Red Improved’, (rose class) ‘Avalanche Rose Improved’, (white class) ‘Plush White’, and [spreading, tall; blue (dark) class] ‘Wave Blue’. These cultivars would likely perform well in the southern United States or areas of the world with similar heat and cold hardiness zones.