The advent of horticulture, backed by research, teaching, and extension in the State of Minnesota during the 1800s, had long-term ramifications for initiating opportunities for the newly formed University of Minnesota, the Minnesota Agricultural Experiment Station, and the Minnesota State Horticultural Society—all of which worked closely together. The founding of the horticulture department in 1888, then known as the Division of Horticulture and Forestry, provided long-term commitment to address the needs of the horticulture field. The integration of female students in 1897 provided inclusivity of gender perspectives in horticulture and enabled essential services during World War I (WWI), when male students, faculty, and administrators were drafted into military service. After the sudden death of Dr. Samuel Green, the first Department Head, in 1910, Dr. LeRoy Cady (who served as an Acting Department Head) instituted a novel idea at the time of having weekly departmental seminars. These formally commenced on 13 Jan. 1913, with the first seminar entitled “Organization of the Seminar.” A survey across the country of horticulture or plant science-based departments revealed its uniqueness as being the oldest seminar series in the country and, undoubtedly, the world. An early seminar tradition included taste-testing of fruit. Early seminars were conducted in the department office of the newly built Horticulture Building (opened in 1899). This idea of the seminar format—as a valuable mechanism of exchanging ideas and increasing department associations—was spread by faculty and Dr. Cady at national and regional meetings of the American Society for Horticultural Science. The seminar concept stretched across the country to other universities and colleges with horticulture programs to make such a forum commonplace to convey research, teaching, and outreach findings in academic settings. Knowledge of the history of the seminar series remained obscure until the record book was discovered in 2010, which provided documentation of its founding and the early years of knowledge-sharing in seminar format. To mark this unique event in horticultural science, a centennial celebration of the seminar series occurred on 13 Jan. 2013. An estimated total of 1899 seminars have been presented during this century-long period. However, a gap in the seminars during 1916 to 1925 was unexplained in the record book. Examination of the departmental, college, and university archives during this time period revealed two primary reasons for this: WWI and the 1918 influenza epidemic. The War Department’s takeover of all college and university campuses in 1918 resulted in the decimation of the faculty and student body by mandatory service (all males age 18–45 years), the institution of a wartime curriculum (which limited the number and types of horticulture classes), the takeover of essential departmental functions by nondrafted men and all female students/faculty, the building of barracks (many of which were on horticultural research plots), and the cessation of all activities, including the seminar. Concurrently, the 1918 influenza outbreak prohibited social gatherings, thus limiting interactions such as seminars. Only a few photographs exist of students wearing masks in 1918, but the impact of the flu seriously affected the ability of students to return to the University of Minnesota after WWI. One subtle benefit in 1918 was the first-ever admission of disabled students (veterans) to horticulture classes. The deaths of students, faculty, and administrators on WWI battlefields, in training camps, or by influenza, as well as post-traumatic stress disorder, devastated the department for years. Lessons learned from these tragedies resonate with the modern-day continuation of the seminar series in the context of the current Covid-19 pandemic.
Sarah Cato, Amanda McWhirt, and Lizzy Herrera
Misinformation relating to horticulture can spread quickly among laypersons. Although some misinformation may be harmless, such as the myth that bell pepper (Capsicum annuum) fruit can be either male or female, other misinformation is generated to sway consumer decisions. The demand from Cooperative Extension Service (CES) agents for support to combat the spread of horticultural misinformation, horticulture specialists at the University of Arkansas System Division of Agriculture Cooperative Extension Service (UACES) created a “Horticulture Fact or Fiction” series of blog posts that targeted common horticulture myths with science-based explanations and used graphics interchange format (GIFs) to promote the blog posts on social media. The integrated social media campaign was shared on the authors’ UACES Horticulture social media accounts and by eight UACES agents during 2021. The effort reached 13,397 social media users, and the blog posts had a total of 45,544 pageviews. Although social media was not the major driver of traffic to the blog post series, GIF-based outreach on social media did direct more than 1000 additional users to the blog posts. Through this integrated approach of using social media and GIFs shared by both specialists and CES agents, we were able to connect a large number of stakeholders to research-based content, resulting in higher average traffic to our webpage-based blogs than the average UACES webpage. This type of integrated approach using multiple online means of communication including GIFs, blogs, and social media to create a toolkit of resources for CES agents may be useful for extension professionals targeting stakeholders online.
Catherine G. Campbell, Jorge Ruiz-Menjivar, and Alia DeLong
Florida, like much of the southeastern United States, is rapidly urbanizing. With this urbanization, there is an increasing interest in commercial urban agriculture (CUA) as an important sector for agriculture in the state. The U.S. Department of Agriculture Census of Agriculture does not report data about CUA operations, thus limiting the knowledge about the status of CUA operations regarding basic features such as farm size, operator demographics, production systems, sources of revenue, barriers to business operations and profitability, and future opportunities for development. Because previous research has found differences in urban farmers’ demographics and their perceptions of barriers and opportunities, the purpose of this research was to characterize CUA operations in Florida and to understand the urban farmers’ perceptions of the primary needs, barriers, and opportunities for developing CUA, as well as CUA operators’ informational needs and preferred informational formats. We performed a cluster analysis to identify salient groups of urban growers in Florida to identify subgroups based on shared characteristics that revealed three distinct groups of urban farmers with differing perceptions of barriers, opportunities, informational needs, and preferred informational formats.
Sandhya Neupane and Fulya Baysal-Gurel
Phytophthora root rot, caused by Phytophthora nicotianae Breda de Haan, is one of the destructive diseases of boxwood (Buxus sempervirens L.) and can affect all growth stages of field- and container-grown boxwood plants. Management is a problem and is only possible through an integrated approach. In this study, the efficacy of fungicides, biofungicides, host-plant defense inducers, and fertilizer were evaluated to manage Phytophthora root rot of boxwood. The objective of this experiment was to develop fungicide and biofungicide recommendations for Phytophthora root rot management in boxwood production. Field and greenhouse experiments were conducted in 2019 (Trial 1) and 2020 (Trial 2). The field experiment was arranged in a completely randomized design with four plots per treatment with five single ‘Green Velvet’ boxwood plants per plot. The greenhouse experiment was arranged in a completely randomized design with five single ‘Green Velvet’ container-grown boxwood plants per treatment. Plots/containers were inoculated with P. nicotianae grown on rice grains. Plant growth data such as height and average width were recorded at the beginning and end of the experiments. Total plant fresh weight and root fresh weight were recorded at the end of the experiments. Roots were assessed for root rot disease severity using a scale of 0% to 100% roots affected. Treatments used in both experiments were fungicides—ametoctradin + dimethomorph, fluzapyroxad, mefenoxam, oxathiapiprolin, pyraclostrobin, pyraclostrobin + boscalid; host-plant defense inducers—aluminum tris-drench, aluminum tris-foliar, potassium salts of phosphoric acid; biofungicides—Trichoderma harzianum Rifai strain T-22 + Trichoderma virens strain G-41, Bacillus amyloliquefaciens Priest; fertilizer—water-soluble nitrogen (nitrogen 5%) and soluble potash; and combination of water-soluble nitrogen, soluble potash, and T. harzianum Rifai strain T-22 + T. virens strain G-41. All treatments were drench applied except one of the aluminum tris, which was applied as foliar. The controls were nontreated, inoculated and nontreated, and noninoculated boxwood plants. In the greenhouse experiments, treatments that effectively reduced disease severity were pyraclostrobin, ametoctradin + dimethomorph, and oxathiapiprolin. In the field experiments, treatments such as pyraclostrobin, oxathiapiprolin, mefenoxam, fluzapyroxad, and combination of water-soluble nitrogen (nitrogen 5%), soluble potash, and T. harzianum Rifai strain T-22 + T. virens strain G-41 effectively reduced Phytophthora root rot severity. Oxathiapiprolin and pyraclostrobin are the chemical fungicides that were effective in both field and greenhouse experiments.
Eric T. Stafne
Passiflora incarnata L., commonly known as maypop, is a wild passion fruit native to many areas of the eastern and southern United States where the climate ranges from subtropical to temperate. Although P. incarnata has had little attention paid to it for breeding purposes, it could be used in breeding for fruit production and possibly contribute cold hardiness genes in combination with other Passiflora species. The study was performed in 2018, 2019, and 2021 at the Mississippi State University South Mississippi Branch Experiment Station in Poplarville, MS, United States. Passiflora propagules were collected from various locations: Florida (FL), Illinois (IL), Mississippi (MS), Missouri (MO), and Oklahoma (OK). Of the 122 flowers across the five P. incarnata genotypes from differing locations, none of them produced a fruit or had any indication of successful or partially successful fertilization when selfed, indicating strong self- incompatibility. If self-compatibility does exist in nature, it is likely to be rare. However, certain combinations of P. incarnata from different locations produced successful fruiting, including IL × MO (52% success), FL × MO (85%), FL × OK (80%), MS × OK (40%), MO × IL (50%), MO × OK (40%), and OK × MO (80%). The differences across provenances show that incompatibility exists within P. incarnata but can depend on location. Overall, fruit weight, fruit size, and soluble solids content measured in this study were similar to and, in some cases, greater than those previously reported. These differences help to illustrate the diversity within P. incarnata and the still-untapped potential for breeding improvements. The problem of self-incompatibility is complex and there is much to learn about how Passiflora species, especially P. incarnata, function. Much of the U.S. domestic market is not familiar with passion fruit, especially as a table fresh product. This could be a barrier to adoption, but it could also prove to be an opportunity to create a niche within the present market and expand it. Although maypop fruit quality is not equal to that of Passiflora edulis Sims, selecting superior wild genotypes with desirable attributes to be used in future intra- and interspecific breeding is possible based on the results of this study.
Barbara J. Smith, Amir Rezazadeh, Eric T. Stafne, and Hamidou F. Sakhanokho
Supplemental lighting is frequently used to extend daylength for strawberries (Fragaria ×ananassa) grown in greenhouses and high tunnels; however, information is limited on the effect of these lights on disease development. We evaluated the effect of ambient light and six supplemental light treatments [red, blue, and white light-emitting diodes (LEDs), separately; a combination of red, blue, and white LEDs; wide-spectrum fluorescent (WSF); and WFS + ultraviolet B (UV-B)] on plant growth and disease response of strawberries grown in a greenhouse. Plants were exposed to supplemental light treatments for 17 h each day. In the WSF+UV-B treatment, plants were exposed to WSF light during the day and to UV-B light for 3 hours during the night. Two trials were conducted; each trial contained five or six cultivars and was replicated three times. Twice during each trial, detached leaves from each cultivar in each light treatment were inoculated with a conidial suspension of the anthracnose crown rot pathogen, Colletotrichum gloeosporioides and rated for disease severity 10 days later. There was a significant difference due to light treatment and to cultivar in relative chlorophyll content and plant growth parameters. Plant injury ratings were lowest in the white LED, WSF, and WSF+UV-B treatments. Plants in the combination LED and red LED light treatments received higher injury, lower vigor scores, and lower relative chlorophyll content values than plants in all other light treatments. After inoculation of detached strawberry leaves with C. gloeosporioides in Trial 1, there was a significant effect due to light treatments on disease severity ratings (DSRs) after 18 weeks’ exposure to light treatments with the DSRs in the WSF+UV-B treatment being lower than those in all other treatments except those in the red LED treatment. There was not a significant effect in DSRs due to light treatments after 24 weeks in Trial 1 or after 4 or 22 weeks in Trial 2. There were significant effects due to cultivar on DSRs in both trials: ‘Strawberry Festival’, ‘Pelican’, and ‘Seascape’ received the lowest DSRs. This study showed an effect of supplemental light on several strawberry plant growth parameters, including a harmful effect of high-intensity red LED irradiation.
Teal Hendrickson, Bruce L. Dunn, Carla Goad, Bizhen Hu, and Hardeep Singh
Hydroponic systems have become increasingly popular for growers in recent years for year-round local production. Whereas optimal air temperature for plant growth has been considered, optimal root zone temperatures have not been examined as thoroughly. The objective of this research was to determine the optimal water temperature for growing different types of basil hydroponically. Research was conducted at the greenhouses in Stillwater, OK. Seventeen cultivars were selected from six main types of basil and transplanted into Nutrient Film Technique hydroponic systems, and three water temperature treatments were applied: 23, 27.5, and 31 °C. Height, width, average leaf area, leaf number, chlorophyll concentration (chlorophyll readings obtained with the Minolta-502 SPAD meter), shoot fresh weight, shoot dry weight, and root dry weight were evaluated. In general, the 27.5 and 31 °C treatments were not greater than each other in terms of leaf number and root dry weight but were greater than the 23 °C treatment. The 31 °C treatment had the greatest height, whereas width, average leaf area, shoot fresh weight, and shoot dry weight were not different from the 27.5 °C treatment. The 23 °C treatment had the greatest chlorophyll concentration (SPAD) value. Cultivar differences were significant in average leaf area and SPAD, with ‘Spicy Bush’ having the smallest leaf area and purple basil having the greatest SPAD value. For all cultivars except purple basil and ‘Large Leaf Italian’, a 27.5 °C water temperature would be recommended for greater plant growth.
Biwek Gairhe, Peter Dittmar, Davie Kadyampakeni, Ozgur Batuman, Fernando Alferez, and Ramdas Kanissery
The use of glyphosate as a post-emergent weed management tool is crucial in Florida citrus production. However, extensive and nonjudicious application of glyphosate has drawn increasing concerns about its inadvertent effects on citrus, mainly linked to its possible impacts on preharvest fruit drop. Our study investigated the effect of applying glyphosate in the tree rows near the fruit harvesting window on fruit drop and yield in ‘Valencia’ sweet orange. Field trials were conducted at Southwest Florida Research and Education Center, Immokalee, FL. The experiments had a randomized complete block design with four replications. Three different doses of glyphosate within the labeled range of rates in citrus (i.e., low, medium, and high at 0.84, 2.10, and 4.20 kg acid equivalents of glyphosate per hectare, respectively) along with a water control treatment were sprayed in ‘Valencia’ citrus tree rows close to the harvesting period and assessed for their effects on preharvest fruit drop and yield. Our findings show that glyphosate application near the harvesting window may influence the fruit detachment force (FDF) in Valencia citrus; however, no significant effect on increasing fruit drop or reducing yield was observed during this 2-year study.
Sofía Gómez and Celina Gómez
Biostimulant products have various reported benefits for plant production in the field or using hydroponic systems in protected structures. However, limited information is available describing their potential use for indoor farming applications. Considering that lettuce (Lactuca sativa) is one of the most popular crops produced in commercial indoor farms, the objective of this study was to compare growth and quality of lettuce grown indoors using nine biostimulant products derived from humic substances, amino acids, hydrolyzed proteins, or seaweed extracts. ‘Monte Carlo’, ‘Fairly’, and ‘Lalique’ lettuce were grown hydroponically for 30 to 33 days under a daily light integral, day/night temperature, relative humidity, and carbon dioxide concentration of ≈13 mol·m‒2·day‒1, 22/21 °C, 70%, and 800 µmol·mol‒1, respectively. There were no positive effects from using any of the biostimulant products evaluated in our study as growth (leaf area, leaf number, shoot diameter, and shoot and root dry weight), yield (shoot fresh weight), and quality (bolting, tipburn index, leaf color, and SPAD index) of treated plants were generally similar to those from the untreated control. Applications from one seaweed extract caused slight negative growth effects, possibly due to phytotoxicity. Cultivar differences showed that Fairly plants had the highest susceptibility to tipburn and bolting, and none of the biostimulant products countered these symptoms. Overall, the products evaluated provided marginal advantages for indoor hydroponic lettuce production.
Svoboda V. Pennisi, Mussie Habteselassie, Genti Kostandini, and Freddie C. Waltz Jr.
Golf course superintendents are often under pressure to maintain high-quality turf. Such demand entails use of inputs, which can include biostimulants that are often marketed as a way of combating plant stress and improving turf quality. However, the extent of their use by superintendents and their level of efficacy are not well understood. This survey study was designed to better describe biostimulant use by the golf industry and to gain insights on the research needs of superintendents to address them effectively. A survey instrument was developed using online software and included a total of 13 questions relating to general familiarity with biostimulants and specific familiarity with five biological products. The instrument was disseminated electronically via the online survey tool to attendees (N = 80) during the annual conference of the Georgia Golf Environmental Summit in 2022. The respondents were from 62 golf courses, geographically representing the entire state of Georgia. The response rate was 62.5%. The majority of the respondents (86%) were familiar with biostimulants. The main reason for using biostimulants was predominantly agronomic, indicating a focus on turf performance and aesthetics. Of the respondents who used biostimulants, the overwhelming majority (93%) use humic acids and plant growth hormone-containing biostimulants. Respondents also indicated that research in microbial products would be the most relevant to the industry. This may be explained by the challenges in using such products (shelf life and microbial survival in soil). In conclusion, the survey indicated that Georgia golf course superintendents have high a level of familiarity with biostimulants. The survey yielded useful results to help formulate future research objectives to better serve the Georgia golf course industry.