Plant Madness was a classroom activity developed and implemented for the Landscape Plants II identification course at Kansas State University. The game was modeled after the National Collegiate Athletic Association college basketball March Madness tournament and Bracketology. One activity objective was to provide students an opportunity to learn new and recent cultivars and plant species not specifically covered in the class curriculum. The activity also provided students opportunities to practice public speaking skills, an avenue to be creative, and simply have fun in class. In Plant Madness, each student randomly drew a plant from a hat and then students were randomly assigned tournament seed rankings (preliminary rankings). On specified game days, one student played against another student, each having 2 minutes of play. Student play varied, and consisted of defining different plant attributes, landscape appeal, and interesting facts, for example; or identifying the opposing student’s plant’s faults through riddles, poems, games, songs, or simply recitation. Referees (e.g., guest faculty, graduate students) reviewed student play and awarded points, and the student with the highest score advanced to the next round through the single-elimination tournament. A postactivity survey was administered [Spring 2016 and 2017 (n = 44)] to obtain student feedback. When asked if the students liked the activity, it was nearly unanimous, 98% liked Plant Madness. Similarly, most students (93%) self-reported the activity increased their awareness of new or recent plant cultivars. When asked to rate the activity compared with other class approaches for learning different plants based on a scale of 1 (excellent) to 5 (poor), the average rating was 1.8. Students’ average rating for their ability to be creative for Plant Madness was 1.8 (1 = to a large extent, 5 = not at all). Ninety-five percent of the students recommended repeating the activity.
Chad T. Miller and Mark P. Bridgen
The dormancy mechanism in achimenes (Achimenes hybrids) has not been thoroughly characterized. Rhizomes of five recently developed achimenes cultivars were stored for 0, 4, 8, 12, or 16 weeks at 68 °F. Cultivar A09 demonstrated a strong decrease in the time to root after 4 weeks of storage, rooting after 13 weeks postplanting. The rooting response for cultivars A16, A21, and A22 was significantly less than cultivar A09; they developed roots between 2.6 and 7.6 weeks after 4 weeks of storage. Rhizomes stored longer than 8 weeks resulted in decreased rooting responses for all cultivars. Shoot emergence was delayed in all cultivars with cultivars without any storage period; cultivars A09, A16, and A23 exhibited a stronger delay than other cultivars. After 4 weeks of storage, the number of weeks to shoot development decreased for all cultivars and after each additional 4-week storage period, the number of weeks to shoot development decreased or remained the same. After 16 weeks of storage, shoots developed in less than 4 weeks for all cultivars. Pupation occurred in four of five cultivars on rhizomes given no storage or with only 4 weeks of storage. The results obtained suggest that the dormancy period of some newer achimenes cultivars is abbreviated in comparison with older cultivars.
Matthew S. Wilson and Chad T. Miller
Virtual plant maps were developed using a web-application for plant identification courses with the goal of providing an additional study resource to students. Each map plots the plants covered for the given weekly plant list, providing photographs of specimens, correct nomenclature, along with additional identification and cultural information. The virtual plant maps provide students an opportunity to review and revisit plants covered in lecture and laboratory sections on their own and at their convenience. An additional advantage of the virtual plant maps is that they can be easily created using a free web-application via any Internet browser, without the need for rigorous understanding of software and webpage design.
Chad T. Miller, Neil S. Mattson, and William B. Miller
Oxalis regnellii, the shamrock plant, and O. triangularis are niche ornamental greenhouse crops produced and marketed primarily for their foliage; thus, it is imperative to produce the fullest, most colorful, and blemish-free plants as possible. An experiment was conducted using O. regnellii, comparing two irrigation methods, overhead (drip) irrigation versus subirrigation, in addition to varying 20N–2.2P–16.6K fertilizer concentrations, 50, 100, 200, 300, and 500 mg·L−1 nitrogen (N). Overhead irrigation produced larger plants with increased root mass as compared with subirrigation. Low or high fertilizer concentration (50 mg·L−1 N and 500 mg·L−1 N, respectively) led to reductions in the fresh and dry weight of overhead-irrigated plants compared with intermediate fertilizer rates. At the highest fertilizer treatment, plant height was decreased. Chlorophyll index (based on SPAD readings) increased linearly and quadratically for subirrigated and overhead-irrigated plants, respectively. A second study analyzed the effects of seven different fertilizer formulations on growth of O. regnellii and O. triangularis. The fertilizers used in this study were Jack's LX All Purpose (21N–2.2P–16.6K), Peter's Professional (20N–8.8P–16.6K), Jacks Poinsettia FeED Ca-Mg (15N–1.7P–12.5K), Jack's Petunia FeED Mg (20N–1.3P–15.7K), Peter's Professional Peat-Lite Dark Weather Feed (15N–0P–12.5K), Peter's Excel Cal-Mag (15N–2.2P–12.5K), and the slow-release fertilizer Osmocote® (14N–4.2P–11.6K). Growth of both species was significantly reduced by fertilizers that contained little or no phosphorus (P). Current water-soluble fertilizer recommendations of 21N–2.2P–16.6K or slow-release granule fertilizer of 14N–4.2P–11.6K (Osmocote®) produced acceptable, marketable plants, whereas the best O. regnellii and O. triangularis plants were produced using 15N–2.2P–12.5K and 20N–1.3P–15.7K formulations, likely as a result of the additional calcium (Ca), magnesium (Mg), and iron (Fe) in the mixtures.
Matthew S. Wilson, Chad T. Miller, and Nicholas R. Bloedow
Virtual plant walk maps were developed for an ornamental plant identification (ID) course, with the goal of providing an additional study resource to potentially enhance student learning. The maps provided students an opportunity to revisit plants covered in lecture and laboratory sections at their own convenience, using either a computer or mobile device. Each map plotted the locations of the plants from the corresponding list and provided photographs of specimens, plant family, common and scientific names, and plant type information. At the end of the course, a survey was given to collect information about student use and perceptions of the virtual plant walk maps for two fall semesters (n = 87). Survey results indicated 63% of the students used the virtual plant walk maps as a study resource. Students who used the maps reported accessing the maps an average of 3.2 times between receiving the maps and taking the plant ID quiz in laboratory. Students mainly used the maps to study the most current plant list and accessed previous plant list maps to a lesser extent. About 67% of students who used the virtual maps, used the maps to visually review the plants online only, although 31% of students used the maps for both visual review and to physically retrace the plant walk to view the live specimens. Of the students who did not use the maps, most found other study resources/methods more useful or they forgot about the maps as a resource. When asked to rate usefulness of the maps on a scale from slightly useful (1) to very useful (3), 43% of students indicated that the virtual maps study tool was very useful, 25% indicated the maps were useful, and 8% indicated that the maps were slightly useful. A significant dependence between student use frequency and student usefulness ratings of virtual plant walk maps was observed. As students’ use of the virtual maps increased, they perceived the maps to be more useful to their studies in preparing for ID quizzes. No differences between plant ID quiz scores were associated with virtual plant walk map use, learning style, or use by learning style. Our survey indicated that students used the virtual plant walk maps as a resource and perceived the maps as a useful tool in preparation for ID quizzes.
Kimberly A. Williams, Chad T. Miller, and Ward Upham
In recent years, many horticulture departments around the United States have been concerned with recruiting and retaining an adequate number of students. One potential recruitment opportunity is the horticulture Future Farmers of America (FFA) Career Development Events (CDEs). For the time period of 1999 to 2012 (14 years), 1462 students participated in the annual state-level horticulture contests, comprising floriculture and nursery/landscape CDEs, held at Kansas State University (KSU). Using the rosters from these two CDEs, we referenced the university’s student information database to determine whether the high school students who participated as FFA horticulture CDE contestants ultimately matriculated to KSU. Fifty-two percent of former FFA horticulture CDE participants were accepted to KSU and 32% matriculated. Of these, 58% enrolled in the College of Agriculture and 19% majored in horticulture. Therefore, 3.5% of total horticulture CDE participants majored in horticulture at KSU. Students who participated in more than one horticulture CDE over time were more likely to major in horticulture at KSU compared with students who competed only once. Thirty-nine percent of students who participated in both horticulture CDEs pursued a baccalaureate program in horticulture. These two student characteristics could be used as indicator data points to target recruitment of future horticulture students. Data about the high school programs that generated contest participants were also summarized. Exceling in the CDE contests was not an indicator CDE participants would pursue a baccalaureate degree in horticulture. These analyses suggest FFA CDEs have some potential to optimize student recruitment efforts.
Chad T. Miller, Krystal Snyder, and Mark P. Bridgen
The National Floriculture Forum (NFF) is an annual meeting that brings together floriculture focused industry members from greenhouse growers and industry leaders and experts, to university faculty and graduate students, along with government scientists from various institutions and agencies. Attendance varies from year to year, averaging 45–50 attendees. The forum was first convened in 1999, meeting annually, (with the exception of 2010 and 2012) at important industry-related locations around the United States. The NFF has even gone international with meetings in the Netherlands, Germany, and one in Canada (
Joshua K. Craver, Chad T. Miller, Kimberly A. Williams, and Daniel L. Boyle
Many plant species are prone to physiological disorders in which lesions develop on the leaf tissue. Nomenclature for such lesions has included intumescences, excrescences, neoplasms, galls, genetic tumors, enations, and oedemata. Interchangeably using these terms causes confusion as to whether these names refer to the same or different disorders. Two of the most commonly used names are oedema and intumescence. The objective of this research was to characterize the development of lesions on ornamental sweetpotato (Ipomoea batatas ‘Blackie’), tomato (Solanum lycopersicum ‘Maxifort’), interspecific hybrid geranium (Pelargonium × ‘Caliente Coral’), and bat-faced cuphea (Cuphea llavea ‘Tiny Mice’) to determine similarities and differences in morphology and nomenclature among these physiological disorders. Light microscopy was used to characterize differences in cross-sectional height, width, and area of lesions on each species. Additionally, leaf tissue samples were embedded in paraffin, and 10-μm cross-sections were stained with Toluidine blue O and observed using light microscopy to identify specific cell layers involved with lesion development. Field emission scanning electron microscopy (SEM) and digital photography were used to observe the microscopic and macroscopic stages of lesion development, respectively, on each species. The lesions observed on ornamental sweetpotato were significantly greater in height and area than on the other three species, whereas tomato lesions were significantly greater in width. Lesions on ornamental sweetpotato and bat-faced cuphea occurred predominantly on the adaxial surface of the leaf, whereas lesions on geranium and tomato occurred predominantly on the abaxial surface. With lesions on tomato, ornamental sweetpotato, and bat-faced cuphea, the epidermis was often subjected to the same hypertrophy apparent in the underlying parenchyma cells, ultimately allowing for greater cell expansion. However, in geranium, the epidermis resisted the expansion of the underlying cells, resulting in the eventual tearing of this tissue layer. Previous research indicates that lesion development on geranium is closely related to water status within the plant and may result in a wound response or provide a means of facilitated gas exchange. On the contrary, development of lesions on ornamental sweetpotato and tomato is believed to involve light quality. Based on these results and observations, two disorders occur across these species. The term “intumescence” should be used when referring to abnormal lesions on ornamental sweetpotato and tomato, and the term “oedema” should be used when referring to lesions on geranium. The term “intumescence” should also be used when referring to bat-faced cuphea lesions resulting from the morphological and anatomical aspects of these lesions closely resembling development on ornamental sweetpotato and tomato. Future research should investigate the role of light quality regarding development on this species.
Joshua K. Craver, Chad T. Miller, Kimberly A. Williams, and Nora M. Bello
Intumescences are a physiological disorder characterized by hypertrophy and possibly hyperplasia of plant tissue cells. Ultimately, this disorder results in the death of the affected cells. Previous observations and research suggest that the quality and quantity of light to which plants are exposed may be a factor in development of the disorder. The purpose of this study was to assess the preventive effect of ultraviolet-B (UVB) radiation on intumescence development in ornamental sweetpotato (Ipomoea batatas). Two sweetpotato cultivars, Sidekick Black and Ace of Spades, were grown under light treatments consisting of 1) normal greenhouse production conditions; 2) supplemental UVB lighting; 3) supplemental UVB lighting with Mylar® sleeves over the lamps to block UVB radiation; and 4) control lighting with full spectrum lamps. Treatments were administered for 2 weeks, and the experiment was repeated twice. ‘Ace of Spades’ was highly susceptible to intumescence development, whereas ‘Sidekick Black’ was much less susceptible to the disorder. For ‘Ace of Spades’, the addition of UVB radiation significantly reduced the number of leaves affected with intumescences when compared with plants grown under the other light treatments; this UVB effect was not apparent for ‘Sidekick Black’. Furthermore, there was no evidence for reduced plant growth under UVB light in either cultivar, but side effects from the radiation included leaf discoloration and deformities. This study indicates a cultivar-specific effect of UVB light in preventing intumescence development on ornamental sweetpotato, therefore suggesting a potential genetic component in intumescence susceptibility. These results provide further insight in better understanding intumescence development and how to prevent the disorder.
Karen K. Schneck, Cheryl R. Boyer, and Chad T. Miller
Dahlia (Dahlia ×hybrida) is an important floriculture crop that has gained popularity in recent years. Greenhouse growers have recently reported a phenomenon known as “dahlia decline,” that can affect potted dahlias in greenhouse production. The crop exhibits graying foliage, root decline, and plant death, and the phenomenon has reportedly caused partial or total crop loss and has no known initiating factor. We hypothesized that plant exposure to supraoptimal root-zone temperatures (RZTs) during production may decrease dahlia root quality, especially above 40 °C and could initiate dahlia decline. Because there is a lack of understanding on how supraoptimal RZT may impact dahlia growth and development, experiments were conducted to evaluate the effects of supraoptimal RZTs on seven dahlia cultivars in Spring 2019 and 2020. Dahlias were grown for 4 to 5 weeks in the greenhouse and then root zones were exposed to ≈22 (control), 35, 40, 45, or 50 °C using a water bath. Root quality was rated before treatment and rated weekly after the hot water bath treatment, along with vegetative growth parameters for 4 weeks. In both years, significant decline in root ratings were observed. ‘XXL Veracruz’ and ‘XXL Sunset’ average root ratings decreased after a 45 and 50 °C treatments in year 2 and both cultivars demonstrated increased root rating averages by 3 weeks after treatment. Cultivars exhibited a significant increase in root rating in the final observations when compared with root ratings taken 1 week posttreatment even if the initial decline after treatment was not significant. Overall plant height was significantly impacted, resulting in shorter heights in both years for all cultivars as treatment temperatures increased to 50 °C in comparison with the control and 35 °C, and a few cultivars exhibited significantly shorter height at 40 and 45 °C. Ultimately, our research did not show typical plant responses that were consistent with reported dahlia decline, but we were better able to characterize dahlia response to supraoptimal RZT.