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Open access

Chengyan Yue, Jingjing Wang, Eric Watkins, Yiqun Xie, Shashi Shekhar, Stacy A. Bonos, Aaron Patton, Kevin Morris and Kristine Moncada

Identifying sources of turfgrass cultivar performance data can be difficult for many consumers. Currently, the best source for data of this type is the National Turfgrass Evaluation Program (NTEP). Unfortunately, these data are made public in a format that is not readily usable for most consumers. Ideally, turfgrass cultivar data would be available in an easily accessible database. We conducted an online survey to investigate user preferences for accessing publically available turfgrass performance data in the United States. We found users desire a turfgrass cultivar performance database that allows for the identification of cultivars best adapted and tolerant to environmental stresses. The information on turfgrass mixtures and blends is also important to most users. Users’ sociodemographic backgrounds, such as gender, education, occupation, and experience in the turf industry, affected their attitudes toward information provided in the turfgrass database. Turfgrass consumers need the new database to provide information on identifying turfgrass options that are resource efficient and endophyte resistant. Turfgrass breeders, researchers, and extension specialists use the turfgrass database to compare different turfgrasses cultivars to do further analysis. The results of this study provide important implications on how an updated turfgrass cultivar performance database and platform can fulfill the different needs of turfgrass researchers, extension personnel, breeders, and stakeholders.

Open access

Andrzej K. Noyszewski, Neil O. Anderson, Alan G. Smith, Andrzej Kilian, Diana Dalbotten, Emi Ito, Anne Timm and Holly Pellerin

In cases where invasive species are presumed to be strictly exotic, the discovery that the species is also native can be disconcerting for researchers and land managers responsible for eradicating an exotic invasive. Such is the case with reed canarygrass (Phalaris arundinacea), for which decades of misinformation led to the call for nationwide control of this species in the United States. However, native populations were first reported by LaVoie and then later confirmed by Casler with molecular analyses. This, coupled with the discovery by Anderson that this species has been used in weavings by Native Americans for centuries, also made the native forms of interest for protection. Identifying the native status of historic, herbarium specimens via molecular analyses is of great interest to determine localities of native populations for confirmation with extant specimens. Genetic-based methods describing DNA polymorphism of reed canary grass are not well developed. The goal of the presented research is to assess the utility of genomic DNA obtained from historic (herbaria) and extant (fresh) tissue of reed canarygrass and the application of using Diversity Arrays Technology sequencing low density for genetic population studies.

Open access

Kenneth W. Leonhardt

Most invasive species are prolific seed-producing landscape ornamental plants that have been introduced to non-native habitats with limited or no natural controls on their reproduction and spread. Techniques for converting prolific seed-producing landscape ornamentals into sterile or nearly sterile forms are available. Oryzalin and colchicine have been used to double chromosomes, resulting in autotetraploids with reduced fertility and potential parent plants of sterile triploids. Guard cell measurements and flow cytometry have been used to determine ploidy conversion and identify polyploids. Complete sterility has been achieved in three species of shower trees (Cassia sp.), and up to a 95% reduction in seed production has been achieved in royal poinciana (Delonix regia) and african tulip tree (Spathodea campanulata). Monkey pod (Albizia saman) crosses have produced triploid progeny to evaluate for sterility.

Open access

Lyn A. Gettys

Conventional wisdom suggests that native aquatic plants have evolved to fill a specific ecological niche, and that their growth is regulated by environmental conditions or the presence of natural enemies that limit the distribution or abundance of the species. However, it is becoming obvious that native species are not always well-behaved and can develop populations that quickly reach nuisance levels that require management to avoid negative ecological impacts. This work summarizes information presented at the American Society for Horticultural Science Invasive Plants Research Professional Interest Group Workshops in 2017 and 2018, and it highlights the phenomenon of species that are considered both native and invasive in the aquatic ecosystems of Florida. These “natives gone rogue” are compared with the introduced species they mimic, and the consequences of excessive aquatic plant growth, regardless of the origin of the species, are described.

Open access

Ji Jhong Chen, Yuxiang Wang, Asmita Paudel and Youping Sun

Screening salinity-tolerant plants is usually time intensive and only applicable to a limited number of salinity levels. A near-continuous gradient dosing (NCGD) system allows researchers to evaluate a large number of plants for salinity tolerance with multiple treatments, more flexibility, and reduced efforts of irrigation. Rose of sharon (Hibiscus syriacus), ninebark (Physocarpus opulifolius), and japanese spirea (Spiraea japonica) were irrigated using an NCGD system with eight electrical conductivity (EC) levels ranging from 0.9 to 6.5 dS·m–1. At 11 weeks after irrigation was initiated, there were no significant differences among EC levels in terms of visual score, growth index [(Height + Width 1 + Width 2)/3], stem diameter, number of inflorescences, and shoot dry weight (DW) of rose of sharon. However, the root DW, relative chlorophyll content (SPAD), and net photosynthesis rate (Pn) of rose of sharon decreased linearly as EC levels increased. Ninebark and japanese spirea had increased foliar salt damage with increasing EC levels. The growth index, stem diameter, number of inflorescences, shoot and root DW, SPAD, and Pn of ninebark decreased linearly as EC levels increased. The growth index and SPAD of japanese spirea decreased quadratically with increasing EC levels, but its stem diameter, number of inflorescences, shoot and root DW, and Pn decreased linearly with increasing EC levels. The salinity threshold (50% loss of shoot DW) was 5.4 and 4.6 dS·m–1, respectively, for ninebark and japanese spirea. We were not able to define the salinity threshold for rose of sharon in this study. However, rose of sharon was the most salinity-tolerant species among the three landscape plants.

Open access

Laura Irish, Cynthia Haynes and Denny Schrock

Participation in field days increases adoption of new techniques and fosters learning. Since 1977, the Iowa State University (ISU) Department of Horticulture has hosted several Home Demonstration Garden (HDG) field days at ISU research farms each year to educate consumers on best practices and cultivars for growing annual flowers and vegetables. Gardens are planted at the farms and feature a specific topic or theme. In 2016 and 2017, 12 HDG field days were hosted in July or August. The objective of these field days was to showcase cultivars of vegetables that are in demand at food pantries and that home gardeners could grow easily for donation to these pantries. In addition to showcasing crops, presentations were delivered that focused on food insecurity implications in Iowa and how community members could impact food security locally. Of more than 400 field-day attendees in 2016, 151 (38%) participated in an optional survey at the end of the day. Similarly, in 2017, 140 of 350 (40%) attendees participated in the survey. Participants reflected on their food security knowledge and intentions to donate fresh produce before and after participation in the field day. Slightly more than a third (39.53% and 37.12%, respectively) of attendees reported some increase in food-security knowledge after participation. In addition, 85% and 72.5% of respondents reported that they will or would consider donating fresh produce to a local pantry after participation in this field day in 2016 and 2017, respectively. This was a change of more than 40% from previous donation patterns in both years. Results from this study are being used to focus future programming of the HDG field days and content of the field day surveys.

Open access

Jessica R. Goldberger, Lisa W. DeVetter and Katherine E. Dentzman

Although agricultural plastic mulches can have significant horticultural benefits for specialty crops such as strawberry (Fragaria ×ananassa), there can also be significant economic and environmental costs. In particular, polyethylene (PE) plastic mulch requires labor and financial investments for removal and disposal. Micro- or nanoparticles may persist in soil and negatively affect microbial activity, physical soil properties, and nutrient availability. A possible alternative to PE mulch is biodegradable plastic mulch, which has similar horticultural benefits but does not need to be removed from the field at the end of the growing season. Biodegradable plastic mulch can be tilled into the soil, where it is converted by soil microorganisms into water, carbon dioxide, and microbial biomass. Although horticultural and environmental research into the impacts of PE and biodegradable plastic mulch is ongoing, it is also important to understand farmers’ practices and perceptions related to these mulches. We conducted a survey of strawberry growers in three growing regions of the United States: California, the Pacific Northwest, and the Mid-Atlantic. Our results indicate several regional differences, with California farmers being more likely to have used biodegradable plastic mulch, and growers from California and the Pacific Northwest being more likely to perceive negative impacts of PE mulch compared with growers in the Mid-Atlantic. Regardless of region, a majority of growers were interested in learning more about biodegradable plastic mulch. We conclude with several suggestions for biodegradable plastic mulch development and outreach that may promote strawberry growers’ adoption of this technology.

Open access

J. Harrison Ferebee IV, Charles W. Cahoon, Michael L. Flessner, David B. Langston, Ramon Arancibia, Thomas E. Hines, Hunter B. Blake and M. Carter Askew

Chemical desiccants are commonly used to regulate tuber size, strengthen skin, and facilitate harvest for potato (Solanum tuberosum) production. Glufosinate is labeled for potato vine desiccation; however, limited data are available. Saflufenacil, a protoporphyrinogen oxidase–inhibiting herbicide, is an effective desiccant in other crops. Field research was conducted to evaluate glufosinate and saflufenacil as desiccants applied to ‘Dark Red Norland’ potato. Desiccants consisted of diquat, glufosinate, saflufenacil, glufosinate plus carfentrazone, and glufosinate plus saflufenacil applied at three timings, DESIC-1, DESIC-2, and DESIC-3, when size B potatoes averaged 43%, 31%, and 17% of total potato weight. Potato vine desiccation was more difficult at DESIC-1 and DESIC-2 because of immature vines. Diquat was the most effective desiccant 7 days after treatment (DAT), desiccating potato vines 88% at DESIC-1 7 DAT. Glufosinate alone desiccated potato vines 65% at the same timing; however, carfentrazone and saflufenacil added to glufosinate increased vine desiccation 8% and 16% compared with glufosinate alone, respectively. Vine desiccation by all treatments ranged 99% to 100% at 14 DAT. Desiccant and timing effects on skin set were determined using a torque meter before harvest. Skin set resulting from all desiccants and timings ranged between 1.88 and 2 lb-inch, and no significant differences were observed. No significant differences in yield were noted among desiccants. This research indicates that glufosinate and saflufenacil are suitable alternatives to diquat for potato vine desiccation; however, safety of saflufenacil applied to potatoes before harvest has not been determined.

Open access

Heidi C. Anderson, Mary A. Rogers and Emily E. Hoover

Consumer demand for local and organic strawberries (Fragaria ×ananassa) is increasing. Growers who can meet this demand have a competitive edge in the direct-to-consumer market. Innovations in strawberry production for northern climates offer new opportunities for growers to meet the demand for local organic strawberries. Typically adopted for season extension, the use of poly-covered tunnels for crop protection provides other benefits including protection from adverse weather. Low tunnels are easy to install, low cost, temporary protective structures that are well-adapted for annual day-neutral strawberry production, and they are more space efficient than high tunnels for these low-stature crops. A range of specialty tunnel plastics that modify and diffuse light are available, but there is little information on how these influence strawberry plant growth and performance in the field. Our objectives were to determine the effects of experimental ultraviolet blocking and transmitting plastics on light and microclimate in low tunnel environments and assess differences in fruit yield and quality in the day-neutral strawberry cultivar Albion in an organic production system. This research was conducted on U.S. Department of Agriculture-certified organic land over 2 years, in 2016 and 2017. We found that ultraviolet intensity and daily light integral (DLI) were lower in covered plots than in the open field. Maximum daily temperatures were slightly higher in covered plots. Both ultraviolet-blocking and ultraviolet-transmitting plastics improved marketable fruit yield compared with the open-field control. Strawberries grown in the open-field treatment were lower in chroma than covered plots in 2017, and there was no difference in total soluble solids between treatments in either year. Low tunnel systems allow for increased environmental control and improved fruit quality and are well-adapted for day-neutral organic strawberry production systems.