Biobased sprayable mulch (BSM) films are a potential alternative to herbicides, polyethylene plastic mulch film, and hand weeding for specialty crops. We developed a series of BSM films using locally available biomaterials [including corn (Zea mays) starch, glycerol, keratin hydrolysate, corn gluten meal, corn zein, eggshells, and isolated soy (Glycine max) protein] and tested their effects on weeds and crop yield during a total of seven greenhouse or field trials between 2017 and 2019 in Nebraska, USA. Application rates of BSM films applied in pots (greenhouse), planting holes in plastic film (field), or bed tops (field) ranged from 0.9 to 18.2 L⋅m−2; they were applied before and after the emergence of weeds. Weed control efficacy was variable, and results of greenhouse pots were rarely replicated under field conditions. Increasing the viscosity of the final suspension tested [BSM7; a mix of corn starch (72.8 g⋅L−1), glycerol (184.7 mL⋅L−1), keratin hydrolysate (733.3 mL⋅L−1), corn zein (19.8 g⋅L−1), and isolated soy protein (19.8 g⋅L−1)] reduced weed biomass by more than 96% in field-grown kale (Brassica oleracea var. sabellica) when applied to bare soil bed tops before or after weed emergence, but kale yield in treated plots was not different from the weedy control. The results demonstrated the potential for postemergence applications of BSM films, which increase application timing flexibility for growers. Further research is needed to explore the effects of BSM films on soil properties and crop physiology and yield.
Eliott Gloeb, Sibel Irmak, Loren Isom, John L. Lindquist, and Sam E. Wortman
Matthew D. Clark, James J. Luby, and Amaya Atucha
Chad T. Miller
Students enrolled in a landscape plant identification course were assigned a plant project at the beginning of the semester that comprised a written portion and a presentation portion. During the Spring 2014 semester, an electronic slide presentation portion was replaced by a “trade show” display presentation format. The modification was implemented to provide a more meaningful and applicable learning experience because trade shows are important events in the horticulture industry. Using this format, students were required to present or sell their plant genus by constructing an informative display, similar to that used for a tradeshow. Groups of students presented on different days. Students who were not presenting or selling were the “customers,” and they perused the trade show to learn about the various genera. A postactivity assessment survey was administered to gain insight into the student learning experience. The activity was evaluated during five spring semesters. Students responded that they were more comfortable with the trade show style of presentation than with a traditional presentation style, with a Likert scale rating of 1.5 (1–5). When asked to rate their ability to be creative with this activity, students agreed (Likert scale rating of 4.2) that the trade show activity allowed them to be creative. Eighty-nine percent of the students liked the activity. When asked to rate the activity compared with a more traditional speech in front of the class, students gave it a rating of 1.4, which is between excellent and above average. During the five semesters, nearly all students (97%) recommended that the trade show activity should be implemented again in future classes. The trade show format was well-received by students and can assist with the professional skills development of students.
Mariam P. Berdeja, Qiuhong Ye, Taryn L. Bauerle, and Justine E. Vanden Heuvel
Agricultural bioinoculants containing arbuscular mycorrhizal fungi represent a potential opportunity to reduce the dependence of grapevines (Vitis) on agrochemicals. This field study assessed the ability of four commercial bioinoculants to colonize grapevine roots and their effects on petiole nutrient concentration, berry composition, and root morphology of ‘Pinot noir’ (Vitis vinifera) grafted onto rootstock ‘Couderc 3309’ (Vitis riparia × Vitis rupestris) and ‘Riesling’ (V. vinifera) grafted onto ‘Couderc 3309’ and Selection Oppenheim four (Vitis berlandieri × V. riparia). Three bioinoculants increased root mycorrhizal colonization; however, regardless of the treatment, mycorrhizal fungal structures were enhanced. Grapevine petiole nutrient concentration was improved by bioinoculants. Root diameter, root length density, and specific root length increased with greater mycorrhizal root colonization. Using bioinoculants to reduce chemical fertilizers may be a good strategy to improve grapevine productivity and health in cool climates; however, the impact of mycorrhizal bioinoculants in the vineyard may differ among scion–rootstocks, edaphoclimatic conditions, and vineyard soil microbiomes.
Hayley M. Nelson, José F. González-Acuña, Ajay Nair, Nieyan Cheng, Kephas Mphande, Sharon Badilla-Arias, Wendong Zhang, and Mark L. Gleason
Organic growers of cucurbit (Cucurbitaceae) crops in the midwestern United States have difficulty managing bacterial wilt—a fatal disease with a pathogen (Erwinia tracheiphila) that is transmitted by striped and spotted cucumber beetles (Acalymma vittatum and Diabrotica undecimpunctata howardi, respectively). Registered organic insecticides lack effectiveness, and host plant resistance is rare in commercial cultivars of many cucurbit crops. Row covers are widely used as barriers to minimize pest access, but the spunbonded polypropylene fabric covering traditional low tunnels must be removed at bloom to prevent overheating and facilitate pollination, thereby exposing the crop for the rest of the season. “Mesotunnels”—nylon mesh fabric covering 3.5-ft-high hoops—provide more space than low tunnels and mitigate overheating. In field experiments at Iowa State University (Ames, IA, USA) during 2016–18, two variations of mesotunnels—full-season tunnels [with purchased bumble bees (Bombus impatiens) added for pollination] and part-season tunnels (with covers removed for 2 weeks during bloom to provide pollinator access)—were compared with low tunnels and a noncovered treatment for organic ‘Athena’ muskmelon (Cucumis melo) production. Based on scouting results, full-season mesotunnels required no insecticides and part-season mesotunnels averaged 0.6 spray per season compared with 1.0 and 5.0 sprays per season for the low-tunnel and noncovered treatments, respectively. Incidence of pest and disease damage was zero for the full-season mesotunnels, 5% to 22% for the part-season mesotunnels, and 37% to 70% for both of the other treatments. Marketable yield for the full-season mesotunnel treatment exceeded the noncovered treatment significantly each year, and mean marketable yields were greater numerically than for the other treatments. Both mesotunnel treatments had a marketable yield that averaged more than twice that of the noncovered treatment in each year. Economic analysis (partial budget and cost-efficiency ratio) indicated that mesotunnels were likely to be more profitable in Iowa, USA, than either the low-tunnel or noncovered systems, but also that the year-to-year differential among treatments in profitability could be substantial. Additional experiments are needed to evaluate the efficacy of these integrated pest management practices and their profitability at spatial scales representative of commercial farms.
Claire H. Luby, Sarah Doane, Ted Mackey, and Wei Q. Yang
Firmness is an important fruit quality trait in northern highbush blueberry (Vaccinium corymbosum). Many researchers, growers, and packers rely on machines for measuring firmness right after harvest and during postharvest cold storage of fresh fruit. In this study, we compared two machines that use compression firmness measurements to determine a force-deformation value. The first firmness-testing machine has been in use for the past 30 years by blueberry (Vaccinium) researchers and packers worldwide. The second has been on the market for the past 5 years. We compared fruit firmness and size measurements for several commercial cultivars and breeding accessions of northern highbush blueberry by both machines at harvest and 2 weeks postharvest. In general, we found there were slight differences in fruit firmness and size measurements between the two machines, but these measurements were generally consistent across the machines. Our study suggests that, in general, one machine can predict the measurements taken on the other machine.
Chad T. Miller, Richard L. Harkess, Cindy L. Haynes, Kimberly A. Williams, and Amy N. Wright
Preparing faculty to conduct quality teaching is critical to maximize student learning and the educational experience. As increased attention to faculty effectiveness and effect of their teaching program is observed, the more important it becomes for faculty to engage in the scholarship of teaching and learning (SoTL). The workshop “Developing a scholarship of teaching and learning portfolio in applied horticulture” was conducted at the 2022 American Society for Horticultural Science conference in Chicago, IL, USA, and featured a panel of teaching scholars who provided insight and guidance for developing, enhancing, evaluating, and promoting SoTL for both traditional classroom teachers and extension educators.
Carlos E. Carpio, Luis A. Sandoval, and Mario Muñoz
In Honduras and El Salvador, coffee (Coffea arabica) is one of the leading agricultural exports, and the share of specialty coffee is growing each year. However, despite the importance of specialty coffee production and exports, there is a knowledge gap regarding its cost structure and profitability, particularly those associated with labor costs. The specific objectives of the study were to determine the cost structure of specialty coffee in Honduras and El Salvador and to estimate the costs and profitability of producing specialty coffee in these countries. A semi-structured survey instrument was administered to 14 farmers in Honduras and El Salvador selected as a convenience sample to represent different farm sizes, regions, and specialty-conventional and organic production systems. Specialty-conventional refers to high-quality coffee with or without certifications. Then,cost-profitability models were developed using an economic cost approach, which considered cash, noncash cost, and the opportunity costs of inputs. The results showed that although both countries are neighbors and economically and culturally similar, the cost structure of producing specialty coffee differed significantly. Costs were lower and profits were higher in Honduras than in El Salvador, and the specialty-conventional coffee production system was more profitable than the organic production system.
Govinda Sapkota, Efren Delgado, Dawn VanLeeuwen, F. Omar Holguin, Nancy Flores, Robert Heyduck, and Shengrui Yao
Jujube (Ziziphus jujuba Mill.) is also called Chinese date. There are ∼100 jujube cultivars with limited commercial availability, and the majority of them have scant details in the United States. In this study, nutrient dynamics during fruit maturation of different jujube cultivars grown at Las Cruces, Los Lunas, and Alcalde, NM, were examined in 2018 and 2019. Cultivars varied by location and year, and included ‘Li’, ‘Lang’, ‘Sugarcane’, ‘September Late’, and ‘Sherwood’. Parameters tested were total phenolic content (TPC), proanthocyanidins (PAs), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant capacity: 2,2-diphenylpicrylhydrazyl radical scavenging capacity and ferric reducing antioxidant potential (FRAP). Moisture, TPC, PAs, FRAP, and vitamin C content decreased with fruit maturity; however, the latter stage of fruit maturity showed an increase in cAMP. Compared with fruit at full-red maturity, creamy fruit had TPC, PA, FRAP, and vitamin C concentrations that were 1.0 to 1.8, 4.4 to 12.4, 1.9 to 2.6, and 0.1 to 1.3 times higher, respectively, depending on location (P < 0.05). From creamy to full-red maturity, cAMP increased by 0.9 to 4.5 times. At full-red maturity, estimated TPC in jujube fruit ranged from 10.6 to 16.8 mg gallic acid equivalent per gram dry weight (DW), whereas estimated PAs ranged from 1.8 to 5.3 mg PA B2/g DW. Jujube fruit at full-red maturity had a vitamin C content that ranged from 649.0 to 1153.3 mg/100 g DW. At full-red maturity, the concentration of cAMP ranged from 148.1 to 277.6 μg/g DW in Las Cruces samples.
Chad T. Miller, Merritt Drewery, Tina M. Waliczek, Ryan N. Contreras, and Chieri Kubota
A primary goal of undergraduate education is to provide a comprehensive and diverse educational experience to prepare and promote student success in their professional and personal pursuits. Increased academic success and program connectivity have been demonstrated when undergraduate students are engaged in research early in their degree programs. Despite the known benefits of undergraduates engaging in research, there are challenges associated with conducting undergraduate research programs. Reported barriers include the lack of student knowledge about research methods, lack of preparedness, and lack of student identification and understanding of their specific interests which may not facilitate research ideas and affinity to conduct research. Additional challenges are related to the lack of faculty resources (e.g., time, specific equipment, research space, etc.), the ability to train and supervise undergraduates who may have very limited or no research experience and those students who are true beginners lacking foundational skills. Moreover, involving, engaging, and supporting underrepresented students (e.g., first-generation college students, females, ethnic minorities) in undergraduate research experiences can require different approaches for mentors to be effective. The “Engaging Undergraduate Students in Research” workshop was organized by the Vice Presidents of the American Society for Horticultural Science (ASHS) Research and Education Divisions at the ASHS 2022 Annual Conference in Chicago, IL, USA. The workshop featured three speakers who described their experiences engaging undergraduate students in research. After each speaker provided comments for ≈5 minutes, the workshop attendees self-selected into three breakout groups with the speakers for roundtable discussions related to engaging students in research through coursework, engaging students via formal research projects, and engaging underrepresented students in research. After the breakout group discussions, a summary was given by each group, and whole group discussions and comments were facilitated. This is a summary of the information discussed and shared during the workshop, along with information that can assist faculty with developing and implementing undergraduate research experiences.