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  • Author or Editor: Timothy S. Johnson x
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For the past century, daylily (Hemerocallis) hybridization focused almost exclusively on enhancing the diversity of flower forms, colors, and color patterns. This focus on the visual characteristics of daylilies resulted in the development of thousands of hybrids that come in a fantastic array of colors and color patterns. However, these modern daylilies exhibit little to none of the floral fragrance possessed by some of the daylily progenitor species. Because little work has been done on daylily floral volatiles, the objective of this research was to evaluate the floral volatile profiles of a variety of daylily species and hybrids and assess the state of fragrance among modern hybrids. Using a field collection system and gas chromatography–mass spectrometry (GS-MS), this study evaluated the fragrance profiles of 147 daylily genotypes. Eighteen volatile organic compounds, primarily terpenoids, were identified and their variations among the genotypes were investigated. Results suggest that fragrance could be a trait pursued in a breeding program to enhance the sensory phenotypes of new daylily cultivars.

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The purpose of this study was to evaluate the U.S.-Canadian Greenhouse Certification Program (USGCP) that was initiated in 1998. A survey consisting of 34 questions was designed and 43 out of ≈48 nurseries in Florida participating in the USGCP were visited. Based on the answers to the questionnaire, most of the nurseries were in compliance with the majority of USGCP requirements, growers were satisfied with the program, and there was an economic benefit to participating in the program. The main problems identified were the ambiguous wording of some of the requirements and the impracticality of keeping imported and domestic plants completely segregated. Moreover, many of the respondents did not have a written description of a pest management plan. Chi square statistical analysis showed that there was almost no difference between nursery groups in their responses to the majority of the survey questions, indicating that the USGCP is a successful program for both large and small nurseries. This quantitative assessment of the USGCP is the first assessment conducted for this program and discussed in a peer-reviewed publication.

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