bluuebunny/crossref_metadata_2025 huggingface dataset:
Wind Loads on Single-span Plastic Greenhouses and Solar Greenhouses
Authors: Yang Zai Q. , Li Yong X. , Xue Xiao P. , Huang Chuan R. , Zhang Bo
Published: December 2018

Wind tunnel tests were conducted in an NH-2-type wind tunnel to investigate the wind pressure coefficients and their distribution on the surfaces of a single-span plastic greenhouse and a solar greenhouse. Wind pressures at numerous points on the surfaces of the greenhouse models were simultaneously measured for various wind directions. The critical wind speeds, at which damage occurred on the surfaces of single-span plastic greenhouses and solar greenhouses, were derived. To clearly describe the wind pressure distribution on various surface zones of the greenhouses, the end surface and top surface of the plastic greenhouse and the transparent surface of the solar greenhouse were divided into nine zones, which were denoted as Zone I to Zone IX. The results were as follows: 1) At wind direction angles of 0° and 45°, the end surface of the single-span plastic greenhouse was on the windward side, and the maximum positive wind pressure coefficient was near 1. At wind direction angles of 90° and 180°, the entire end surface of the single-span plastic greenhouse was on the leeward side, and the maximum negative wind pressure coefficient was near −1. The maximum positive wind pressure on the end surface of the single-span plastic greenhouse appeared in Zone IV at a wind direction angle of 15°, whereas the maximum negative pressure appeared in Zone VIII at a wind direction angle of 105°. 2) Most of the wind pressure coefficients on the top surface of the plastic greenhouse were negative. The maximum positive and negative wind pressure coefficient on the top surface of the plastic greenhouse occurred in Zones I and II, respectively, at a wind direction angle of 60°. 3) At a wind direction angle of 0°, the distribution of wind pressure coefficient contours was steady in the middle and lower zones of the transparent surface of the solar greenhouse, and the wind pressure coefficients were positive. At a wind direction angle of 90°, the wind pressure coefficients were negative on the transparent surface of the solar greenhouse. A maximum positive wind pressure coefficient was attained at a wind direction angle of 30° in Zone IX, whereas the maximum suction force occurred in Zone VII at a wind direction angle of 135°. 4) The minimum critical wind speeds required to impair the single-span plastic greenhouse and solar greenhouse were 14.5 and 18.9 m·s−1, respectively.
Effects of Mulching and Preemergence Herbicide Placement on Yellow Nutsedge Control and Ornamental Plant Quality in Landscape Beds
Authors: Chen Yan , Strahan Ronald E. , Bracy Regina P.
Published: December 2018

Yellow nutsedge (Cyperus esculentus) is one of the most troublesome and widespread perennial weeds infesting landscape plantings in the United States. Few selective herbicides are available for managing this weed. A combination of organic mulch with preemergence herbicide may improve control efficacy at tuber emergence and reduce the need for subsequent postemergence applications. However, limited information is available on potential interactions between herbicide placement and mulching and their effect on yellow nutsedge control and landscape plant growth and quality. In this study, control efficacy of preemergence herbicide s-ethyl dipropylthiocarbamate (EPTC) applied at 0, 4, or 6 lb/acre above or under pine straw, pine nuggets, or shredded cypress mulches were evaluated in landscape beds infested with yellow nutsedge and planted with ‘Mystery’ gardenia (Gardenia jasminoides), ‘Stella de Oro’ daylily (Hemerocallis), and ‘Big Blue’ liriope (Liriope muscari). Pine nuggets provided greater yellow nutsedge control compared with shredded cypress during the first 6 weeks after treatment (WAT) in mulch-alone plots. All mulch-alone plots had similar yellow nutsedge shoot densities and were 40% to 60% less than untreated bare soil plots from 6 to 12 WAT. Control efficacy was greater when EPTC was applied under mulch compared with above-mulch applications regardless of mulch products. In addition, EPTC at low rate resulted in similar control as high rate when applied under mulch. No injury was observed on any ornamental plants treated with EPTC. Mulching improved growth, flowering, and overall visual quality of gardenia, but reduced number of flowers in daylily and aboveground biomass in liriope at some sample dates though their visual qualities were unaffected. Based on these preliminary data, EPTC applied preemergence before mulching a new landscape bed or replenishing an existing bed can improve yellow nutsedge control without injuring selected ornamental plants.
Asynchronous Continuing Education for Iowa’s Green Industry Professionals
Authors: VanDerZanden Ann Marie
Published: December 2018

A collaborative two-part project between Iowa State University Horticulture Extension and the Iowa Nursery and Landscape Association (INLA) resulted in an online, asynchronous training program to prepare green industry professionals for the Iowa Certified Nursery Professional (ICNP) exam, and to provide advanced training through webinars. Since 2008, members have accessed a set of 20 training modules that cover plant identification and content on the written portion of the certification exam. In the 6 years since the modules have been used, the pass rate for the written portion of the exam has increased from 57% (2005–07, 18 participants) to 85% (2008–13, 49 participants). A survey administered to participants between 2008 and 2013 gathered information on participant demographics, interest in learning in an online format, usefulness and applicability of information in preparing for the exam, module usability, and how the modules impacted their learning. Participants felt that the modules were an effective way to deliver content (4.45 out of 5) and reported they were comfortable using a web-based format to learn (4.89 out of 5). Advanced training was delivered to members through three webinar series: five webinars in 2011 and four webinars each in 2012 and 2013. Although attendance to the live webinar sessions was limited, the archived versions have been accessed a number of times.
Marketing Genetically Modified Organism Carnations by Future Floral Designers: Student-designed Policy Formulation
Authors: Anderson Neil O. , Walker Natalie J.
Published: December 2018

Genetically modified organism (GMO) crops provide new trait(s) that may benefit floral designers and consumers. A limited array of GMO cut flower cultivars exist in the floral markets worldwide: nine carnations (Dianthus caryophyllus) and one rose (Rosa ×hybrida). Labeling GMO flowers in the United States is not required. Thus, most distributors, flower auctions, brokers, wholesalers, floral designers and consumers are not aware that they exist. To test the acceptance of GMO cut flowers with potential future floral designers, n = 121 students enrolled in Floral Design (HORT 1013) at the University of Minnesota during 2005–07, 2009, and 2011, designed with standard and miniature GMO Moon™ series carnations. Each student created a Hogarth design with both types of carnations and assembled a price sheet. Students examined the differences between GMO lavender/purple carnations and those created with classic methods of spraying, dipping, or infusion. In 2009 only, students were also assigned to write a marketing paragraph about their GMO floral design. Each year, students were given an identical question on a subsequent midterm examination to determine their position on GMO cut flowers, including development of a floral shop policy to inform customers. Student examination responses ranged from not carrying GMO products [1/121 (0.8% response)], offering GMO/non-GMO carnation options to the consumer [81/121 (66.9% response)], or only selling only GMOs [33/121 (27.3% response)] that differed significantly from a 1:1:1 chi-square (χ2). A significant majority of students would inform their customers of the GMO crops [89/121 (73.6% response)]. In several instances, consumers were not to be informed of the GMO nature unless they queried about the higher price point. Similarly, marketing paragraphs did not uniformly highlight the GMO nature of the flowers. Implications for the next generation of floral designers demonstrate that, with the exception of students in 2005–06, most would sell both GMO and non-GMO flowers with a majority of shops clearly identifying GMOs.
Evaluation of Round and Roma-type Tomato Varieties and Advanced Breeding Lines Resistant to Tomato Yellow Leaf Curl Virus in Florida
Authors: Ozores-Hampton Monica , Stansly Philip A. , McAvoy Eugene
Published: December 2018

Tomato yellow leaf curl virus (TYLCV) is considered to be the most damaging tomato (Solanum lycopersicum) virus worldwide. Management of TYLCV has relied primarily on insecticidal control targeting the vector sweetpotato whitefly [SPW (Bemisia tabaci)]. However, resistance of the SPW to insecticides; increased length of the growing season, due in part to increased plantings of grape tomato; and asymptomatic hosts of TYLCV such as pepper (Capsicum annuum) have increased the need for wider use of TYLCV-resistant (TYLCV-R) varieties. The objective of this study was to evaluate horticultural characteristics of commercially available TYLCV-R varieties/advanced breeding lines of round and Roma-type tomato varieties in Florida. Sweetpotato whitefly populations and incidence of TYLCV were greater in 2007 than 2008. Under high TYLCV pressure, most of the TYLCV-R varieties/advanced breeding lines produced higher yield than susceptible varieties. In contrast, no clear advantage was found by using TYLCV-R varieties under low TYLCV pressure. Additionally, TYLCV-R varieties produced a high percentage of unmarketable fruit due to rough blossom end scars (BES), zippering, catfacing, sunscald, yellow shoulders, off shapes, and radial or concentric cracking compared with susceptible varieties in both years. Visual assessment of TYLCV-R varieties/advanced breeding lines for horticultural traits showed that ‘Security 28’, Sak 5443, and ‘Shanty’ were the best overall varieties/advanced breeding lines based on participants combined score rating, although ‘Tygress’ and Sak 5808 performed best based on empirical evaluation (numerical data) of total marketable yields and low unmarketable yield.
Wine Grape Cultivar Performance in the Four Corners Region of New Mexico in 2010–12
Authors: Lombard Kevin , Maier Bernd , Thomas Franklin J. , O’Neill Mick , Allen Samuel , Heyduck Rob
Published: December 2018

Commercial wine grape (Vitis sp.) production in northwestern New Mexico and the greater Four Corners region is now supported by four wineries. The challenges of growing grape vines in northwestern New Mexico include cold winter temperatures and killing spring frosts exacerbated by a semiarid climate and elevations exceeding 1700 m. Nineteen nongrafted European wine grape (Vitis vinifera) and interspecific hybrid wine grape cultivars were planted in 2007 and evaluated between 2010 and 2012. Among European wine grape cultivars, Agria, Malbec, Sangiovese, Viognier, Müller-Thurgau, and Sauvignon Blanc performed poorly or failed altogether. Interspecific hybrid cultivars Baco Noir, Kozma 55, Leon Millot, Chardonel, Seyval Blanc, Siegfried, Traminette, Valvin Muscat, and Vidal Blanc showed greater adaptability to a high-elevation intermountain western U.S. site, yielding on greater than 71% of their vines in each year (except Kozma 55 which only produced on 38% of its vines in 2012 due to severe spring frost damage). We speculate that fruit-bearing shoots on these vines arose from latent buds that survived when primary buds were killed from spring frost events. Once vines were established, grape berry sugar and pH appeared to be within acceptable ranges (3-year mean above 21% soluble solids and juice pH of 3.2), suggesting regional potential to produce favorable wines within acceptable commercial wine grape production ranges. Selection of sites without considerable frost risk and other mesoclimate variances is critical when considering vineyard establishment at high-elevation locations.
Advancing Wireless Sensor Networks for Irrigation Management of Ornamental Crops: An Overview
Authors: Lea-Cox John D. , Bauerle William L. , van Iersel Marc W. , Kantor George F. , Bauerle Taryn L. , Lichtenberg Erik , King Dennis M. , Crawford Lauren
Published: December 2018

Wireless sensor networks (WSNs) transmit sensor data and control signals over long distances without the need for expensive infrastructure, allowing WSNs to add value to existing irrigation systems since they provide the grower with direct feedback on the water needs of the crop. We implemented WSNs in nine commercial horticulture operations. We provide an overview of the integration of sensors with hardware and software to form WSNs that can monitor and control irrigation water applications based on one of two approaches: 1) “set-point control” based on substrate moisture measurements or 2) “model-based control” that applied species-specific irrigation in response to transpiration estimates. We summarize the economic benefits, current and future challenges, and support issues we currently face for scaling WSNs to entire production sites. The series of papers that follow either directly describe or refer the reader to descriptions of the findings we have made to date. Together, they illustrate that WSNs have been successfully implemented in horticultural operations to greatly reduce water use, with direct economic benefits to growers.
Wireless Sensor Network Design for Monitoring and Irrigation Control: User-centric Hardware and Software Development
Authors: Kohanbash David , Kantor George , Martin Todd , Crawford Lauren
Published: December 2018

Wireless sensor networks (WSNs) are increasingly becoming a critical tool for growers and researchers. We describe how the technology has advanced, starting with a commercially available WSN node and pushing the technology to make the data more meaningful, actionable and to add advanced irrigation control functionality. User features such as spatial views, custom charts, real-time data access, remote access, irrigation control, alerts, and plant models help create an advanced WSN system that is user centric. Growers and researchers were involved in the design process by directly communicating with the design engineers, and continuously using and testing new features, resulting in a user-centric design and experience. The results of this research are being rolled into a new line of commercial products and is continuously evolving based on user feedback and interaction.
Root System Distribution Influences Substrate Moisture Measurements in Containerized Ornamental Tree Species
Authors: Bauerle Taryn L. , Bauerle William L. , Goebel Marc , Barnard David M.
Published: December 2018

Substrate moisture sensors offer an affordable monitoring system for containerized tree production. However, root system distribution can vary greatly among species within ornamental container production systems, resulting in variation within substrate readings among sensors within a container. The aim of this study was to examine the relationship of substrate moisture sensor readings in six ornamental trees to their root distribution patterns within a container. Following root anatomical analysis, tree root systems were dissected by root order as a means to separate fine (uptake) roots and coarse (transport) roots. Substrate moisture variability was measured through the deployment of 12 substrate moisture sensors per container. Of the tree species studied, we found the following two patterns of root distribution: a shallow, “conical-shaped,” root system, with the broadest portion of the root system in the shallow soil layer, and a more evenly distributed “cylindrical-shaped” root system. Root system distribution type influenced substrate moisture reading variability. Conical root systems had lower substrate moisture variability and high fine root variability, whereas the opposite was true for cylindrical root systems—most likely due to the larger, coarse woody mass of roots. We were unable to find any correlations between fine root morphological features including root diameter, length, or surface area and substrate moisture variability. However, higher specific root length was associated with higher substrate moisture variability. Classifying a tree’s root system by its growth and distribution within a container can account for variation in substrate moisture readings and help inform future decisions on sensor placement within containerized systems.
Profitability of Sensor-based Irrigation in Greenhouse and Nursery Crops
Authors: Lichtenberg Erik , Majsztrik John , Saavoss Monica
Published: December 2018

Improvements in sensor technology coupled with advances in knowledge about plant physiology have made it feasible to use real-time substrate volumetric water content sensors to accurately determine irrigation timing and application rates in soilless substrates in greenhouse and container production environments. Sensor-based irrigation uses up-front investments in equipment and system calibration in return for subsequent reductions in irrigation water use and associated costs of energy and labor, spending on fertilizer, and disease losses. It can also accelerate production time. We present formulas for assessing profitability when benefits and costs are separated in time and apply those formulas using data from an experiment on production of gardenia [Gardenia augusta ‘MADGA 1’ (Heaven Scent™)]. Sensor-controlled irrigation cuts production time and crop losses by more than half. Annualized profit under the wireless sensor system was over 1.5 more than under the nursery’s standard practice, with the bulk of the increase in profit due to the reduction in production time. These results indicate that controlling irrigation using wireless sensor systems is likely to increase profitability substantially, even if efficiency gains are not as high as those achieved under experimental conditions.
Environmental Benefits of Wireless Sensor-based Irrigation Networks: Case-study Projections and Potential Adoption Rates
Authors: Majsztrik John C. , Price Elizabeth W. , King Dennis M.
Published: December 2018

We describe and estimate the potential environmental benefits associated with the adoption of wireless sensor irrigation networks (WSIN) in United States ornamental crop production. Benefit estimates are based on results from on-farm research conducted during the previous three years, using both conservative and optimistic assumptions about the levels of WSIN technology adoption. We project reductions in water use and air and water emissions for six U.S. agricultural regions, the U.S. overall, and the six states that make up the Chesapeake Bay watershed. Based on these analyses, an average nationwide WSIN adoption rate of 50% in ornamental operations would result in annual water use savings of ≈223 billion liters (enough for 400,000 U.S. households annually) or a 25% reduction in total water use for all ornamental production. Reductions in annual carbon dioxide emissions, assuming only the reduced energy use from pumping less water was 36,232 Mg (equivalent to removing 7500 cars annually). Reduced fertilizer applications and more efficient irrigation resulted in reductions of 282,000 kg nitrogen and 182,000 kg phosphorous. These efficiency gains and nutrient discharge reductions have been shown to generate significant profits for growers, but would cost hundreds of thousands of dollars to achieve using conventional urban or agricultural best management practices (BMPs). If WSIN technologies are adopted in other areas of specialty horticulture (e.g., fruit, vegetable, and nut production) or in agronomic crops [e.g., corn (Zea mays) and wheat (Triticum sp.)], the indirect and induced private and environmental benefits will likely be much higher. Since the environmental benefits of WSIN technologies depend critically on adoption rates, we also briefly describe potential pathways to increase WSIN adoption such as providing technical assistance or offering financing or loan guarantees.
The Challenges of Growing Strawberries in the Greenhouse
Authors: Paparozzi Ellen T.
Published: December 2018

As a floriculturist, when I first decided to grow strawberries (Fragaria ×ananassa) in the greenhouse, I thought it would be a snap. After all, I could practice what I preach to my classes in that I would use all the sustainable growing tricks from floriculture, create a production time line and it would be ready, set grow. However, moving a field-grown summer crop into a greenhouse as a winter crop was not the same as moving a winter greenhouse-grown crop outside for the summer. Not only were the plants typically grown in lush field soil, but also the fertilizer recommendations were not directly translatable (i.e., parts per million nitrogen). The pesticides used were not licensed for greenhouses and of course, there were no clues as to schedules of what to do when. Finally, there were the mystery problems that occurred. With high gas prices and the interest in local food production, it seems probable that over the next 5 to 10 years, more and more fruit, vegetables and even nut plants will be moved into greenhouse and high tunnel production. The purpose of this article is to identify the kinds of information needed to make a “smooth” transition from field to greenhouse for alternative crops, like strawberries, grown during nontraditional seasons.
Commercial Amendments for Sand-based Root Zones: Review and Interpretation
Authors: McCoy Edward L.
Published: December 2018

Amendments used in sand-based root zones are typically native peats, composts, or inorganic materials of diverse mineralogy. Literature-based guidelines for amendment inclusion include root zone capillary porosity (CP) values exceeding 0.2 m3·m−3 or soil surface water contents exceeding 0.1 m3·m−3. It is also suggested that the cation exchange capacity (CEC) need not exceed 4 cmolc·kg−1. Summarizing published data, native peat added to a U.S. Golf Association (USGA) guideline sand yielding organic matter (OM) content values of ≈15 g·kg−1 would typically yield benchmark values of CP = 0.2 m3·m−3, surface water content = 0.1 m3·m−3, and CEC values between 3 and 4 cmolc·kg−1. This OM content is roughly equivalent to 15% by volume of a fibric sphagnum or 7.5% by volume of a hemic reed-sedge. By comparison 15% by volume of an inorganic amendment would likely result in CP and surface water content values less than the benchmark values, and CEC values between 1.5 and 4 cmolc·kg−1. However, the CP benchmark measured at 30 cm of soil water suction should be re-evaluated because it may bias against the use of biosolids compost and inorganic amendments that reduce the thickness of the capillary fringe and create a broader pore size distribution. Also a weak relationship has been observed between longer-term turfgrass quality and 30-cm CP values. Measurement of CP at 40-cm suction would be a better indication of water retention in sand-based root zones for all amendment types. Lastly, inorganic amendments produce a drier root zone that may be preferred for both playability and long-term agronomic concerns.
Greenhouse and Landscape Growth of Tiger Lily Cultivars Following Flurprimidol Preplant Bulb Soaks
Authors: Barnes Jared , Whipker Brian , Buhler Wayne , McCall Ingram
Published: December 2018

Experiments were conducted to evaluate the appropriate concentration of flurprimidol for ‘Orange Tiger’ tiger lily (Lilium lancifolium), the persistence of residual effects the following year with ‘Orange Tiger’, and differences in flurprimidol’s effect between tiger lily cultivars. In Expt. 1 flurprimidol was applied as a preplant bulb soak to determine its efficacy on height control of ‘Orange Tiger’ tiger lily. Bulbs were hydrated in 17 °C water for 1 h, allowed to drain 1 h, given 10 min soaks of 0, 5, 10, 20, 40, 80, and 160 mg·L−1 flurprimidol, and then allowed to drain for 1 h before potting. In Expt. 2 ‘Orange Tiger’ tiger lilies from Expt. 1 were then planted into outdoor beds to evaluate residual carryover effects of flurprimidol. Expt. 3 involved comparison trials of ‘Pink Tiger’, ‘White Tiger’, and ‘Yellow Tiger’ tiger lilies to determine if cultivars responded differently to flurprimidol drenches. Flurprimidol at 10 to 20 mg·L−1 effectively controlled stem elongation of ‘Orange Tiger’. No residual effect of flurprimidol on ‘Orange Tiger’ plant growth was observed a year after application. Optimal concentrations of flurprimidol for ‘Pink Tiger’ and ‘White Tiger’ were 2 to 5 mg·L−1 and for ‘Yellow Tiger’ 20 to 30 mg·L−1. Results showed that preplant bulb soaks prevented excessive height and provided plants that were more suitable in height for retail sales. Differential responses of ‘Pink Tiger’, ‘White Tiger’, and ‘Yellow Tiger’ tiger lilies to flurprimidol indicate that trials are required to customize optimal concentrations for other cultivars.
Thinning Tall Spindle Apple Based on Estimations Made With a Hand-thinning Gauge
Authors: Kon Thomas M. , Schupp James R.
Published: December 2018

Trials were conducted in 2009 and 2010 to evaluate the use of a hand-thinning gauge [Equilifruit; Institut National de la Recherche Agronomique (INRA), Montpelier, France] on three cultivars of apple (Malus ×domestica) trees trained to tall spindle. Hand-thinning treatments were applied after June drop to trees with supra-optimal crop loads. Three hand-thinning treatments were applied using the hand-thinning gauge: 1) thinning to ≈6 fruit/cm2 branch cross-sectional area (BCSA) (F value), 2) subtracting the delta value [Δ (an adjustment factor to increase or decrease the number of fruit per BCSA] from the F value (F − Δ), and 3) F − 2Δ. These treatments were compared with a control and a traditional hand-thinning heuristic of spacing a solitary fruit every 7 to 8 inches of branch length. Use of the hand-thinning gauge generally improved fruit weight and maintained whole tree yields when compared with the control. Hand-thinning based upon traditional fruit-spacing heuristics reduced crop density and increased final fruit weight of apple, but significant reductions in yield were observed in two of four studies when compared with the control. We find the hand-thinning gauge a useful tool in adjusting final crop load of apple.
Eating Habits and Knowledge of Nutrition in Older Adults: A Comparison of Gardeners and Nongardeners
Authors: McFarland Amy , Waliczek Tina M. , Zajicek Jayne M. , Lineberger R. Dan
Published: December 2018

A survey was used to investigate gardeners’ and nongardeners’ nutritional attitudes, fruit and vegetable consumption, and nutritional knowledge. The survey was posted for 4 months on one of the largest online resources for Master Gardeners. During the 4 months, 402 responses were gathered. Additionally, identical “paper/pencil” format surveys were distributed to garden, church, and social and community groups with ≈400 responses received. In each group of participants, respondents differentiated themselves as gardeners or nongardeners by responding positively or negatively to the survey question, “do you garden?” No statistically significant relationships were found relating fruit and vegetable consumption to either income level or educational attainment status in the overall sample. Results indicated statistically significant differences in comparisons between gardeners and nongardeners with regards to nutritional attitudes and their consumption of fruit and vegetables where gardeners had more positive nutritional attitude scores and increased consumption of fruit and vegetables. However, no statistically significant differences were found between gardeners’ and nongardeners’ nutritional knowledge.
Deterioration of Three Potentially Biodegradable Plastic Mulches Before and After Soil Incorporation in a Broccoli Field Production System in Northwestern Washington
Authors: Cowan Jeremy S. , Inglis Debra A. , Miles Carol A.
Published: December 2018

Three potentially biodegradable plastic mulch products, Mater-bi®-based black film (BioAgri), experimental polyhydroxyalkanoate film (Crown 1), and experimental spunbonded polylactic acid fabric (SB-PLA-11), were evaluated over two broccoli (Brassica oleracea var. italica) growing seasons to determine deterioration before and after soil incorporation. Pretillage mulch deterioration was evaluated in both growing seasons by rating the percent visual deterioration (PVD). Crown 1 had the greatest PVD throughout the study (P ≤ 0.05) and BioAgri also had significant pretillage deterioration. SB-PLA-11 showed no appreciable deterioration based on PVD (<1.3%) in either growing season. Postincorporation mulch deterioration was measured for 13 months after rototilling at the end of the first growing season. The average fragment area of all mulch products decreased over time after soil incorporation. The number of postincorporation mulch fragments initially increased for all mulch products, with Crown 1 and BioAgri reaching maximum fragment counts 132 and 299 days after incorporation, respectively. As the number of fragments declined, the average area of fragments did not change, suggesting that a threshold fragment size may exist at which biodegradation accelerates. At the end of the study period, 397 days after soil incorporation, Crown 1 and BioAgri had deteriorated 100% and 65%, respectively; whereas SB-PLA-11 showed very little deterioration.
Spicy Pepper Consumption and Preferences in the United States
Authors: Lillywhite Jay M. , Simonsen Jennifer E. , Uchanski Mark E.
Published: December 2018

Little data are publicly available about U.S. spicy pepper (Capsicum sp.) consumers and their type-specific preferences. This research adds to the body of knowledge surrounding the demand side of the U.S. spicy pepper market by providing exploratory data to examine U.S. consumer preferences as they relate to seven common spicy pepper types: cayenne (Capsicum annuum), habañero (Capsicum chinense), jalapeño (C. annuum), New Mexico-type long green and red (C. annuum), paprika (C. annuum), poblano/ancho (C. annuum), and serrano (C. annuum) peppers. Data were collected using an online panel survey of 1104 consumers. Results suggest that jalapeño peppers were the most popular fresh spicy pepper purchased by participating food consumers. Paprika powder, a relatively mild spicy pepper product, was the most widely-consumed dried or ground pepper of the seven studied. Women appear more likely to be non-likers of spicy foods than men (P ≤ 0.05). Responses of this survey group suggest that many consumers enjoy spicy peppers and that consumption varies by pepper type. Finally, the most popular pepper types do not necessarily appear to be the “hottest” or “mildest” of those available in the market.
Specialty Melon Cultivar Evaluation under Organic and Conventional Production in Florida
Authors: Guan Wenjing , Zhao Xin , Treadwell Danielle D. , Alligood Michael R. , Huber Donald J. , Dufault Nicholas S.
Published: December 2018

Interest in producing specialty melons (Cucumis melo) is increasing in Florida, but information on yield performance, fruit quality, and disease resistance of specialty melon cultivars grown in Florida conditions is limited. In this study conducted at Citra, FL, during the 2011 Spring season, 10 specialty melon cultivars were evaluated, in both certified organic and conventionally managed fields, including: Creme de la Creme and San Juan ananas melon (C. melo var. reticulatus), Brilliant and Camposol canary melon (C. melo var. inodorus), Ginkaku and Sun Jewel asian melon (C. melo var. makuwa), Arava and Diplomat galia melon (C. melo var. reticulatus), and Honey Pearl and Honey Yellow honeydew melon (C. melo var. inodorus). ‘Athena’ cantaloupe (C. melo var. reticulatus) was included as a control. ‘Sun Jewel’, ‘Diplomat’, ‘Honey Yellow’, and ‘Honey Pearl’ were early maturing cultivars that were harvested 10 days earlier than ‘Athena’. ‘Athena’ had the highest marketable yield in the conventional field (10.7 kg/plant), but the yield of ‘Camposol’, ‘Ginkaku’, ‘Honey Yellow’, and ‘Honey Pearl’ did not differ significantly from ‘Athena’. Under organic production, ‘Camposol’ showed a significantly higher marketable yield (8.3 kg/plant) than ‘Athena’ (6.8 kg/plant). ‘Ginkaku’ produced the largest fruit number per plant in both organic (10 fruit/plant) and conventional fields (12 fruit/plant) with smaller fruit size compared with other melon cultivars. Overall, the specialty melon cultivars, except for asian melon, did not differ significantly from ‘Athena’ in terms of marketable fruit number per plant. ‘Sun Jewel’, ‘Diplomat’, and ‘San Juan’ showed relatively high percentages of cull fruit. ‘Honey Yellow’, ‘Honey Pearl’, and ‘Sun Jewel’ exhibited higher soluble solids concentration (SSC) than ‘Athena’ in both organic and conventional fields, while ‘Brilliant’, ‘San Juan’, and ‘Ginkaku’ also had higher SSC than ‘Athena’ under organic production. ‘Honey Yellow’, ‘Sun Jewel’, ‘Brilliant’, and ‘Camposol’ were less affected by powdery mildew (caused by Podosphaera xanthii) and downy mildew (caused by Pseudoperonospora cubensis) in the conventional field. ‘Honey Yellow’ and ‘Camposol’ also had significantly lower aboveground disease severity ratings in the organic field compared with ‘Athena’, although the root-knot nematode (RKN) (Meloidogyne sp.) gall rating was higher in ‘Honey Yellow’ than ‘Athena’.
Introducing Tree Structural Defect Recognition to Youth: An Exploration of Feasibility Through a Comparison of Two Teaching Methods
Authors: Sanagorski Laura A. , Fitzpatrick George E.
Published: December 2018

Trees in urban settings require more care because they are more likely to develop structural defects that can be costly, dangerous, or more maintenance-intensive than those in natural settings. People need to understand how trees grow in the urban environment and how to recognize potentially hazardous structural defects, yet this is not a topic regularly presented in school curriculum. The objectives of this study were to determine if structural defect recognition in trees is an appropriate topic for sixth grade curriculum, and to explore the efficacy of two methods of teaching this topic. We introduced structural defects in trees to sixth grade students, as part of the normal science instruction at three public middle schools located in Broward County, FL. We found sixth grade students to be capable of recognizing and comprehending the implications of structural defects in trees following a short period of instruction. We compared hands-on, experiential instruction with a passive, illustrated lecture style instruction for teaching students to recognize structural defects in trees and determined that students exposed to both methods of instruction increased their ability to recognize defects overall. Moreover, we observed that students exposed to defects in trees via illustrated lecture style classroom instruction received significantly higher scores in the post-test than students exposed to the same material via a hands-on approach.
Climate Change Literacy in Postsecondary Horticultural Education in the United States
Authors: Lohr Virginia I.
Published: December 2018

Horticultural crops are being affected by weather extremes consistent with predictions from climate change models. Impacts include crop losses and extended growing seasons. Negative effects on crop productivity are predicted to vastly overwhelm any positive effects. Students who graduate from our programs will need additional knowledge to succeed compared with those trained in previous decades. To determine the extent to which higher educational institutions across the United States are educating students about these issues, a survey was conducted to gather information on the incorporation of climate change literacy in horticultural curricula. Most programs do not currently offer classes with “climate change” or “global warming” in the formal title or description, but many instructors are including at least some information related to climate change in specific courses they teach. Instructors of courses in fruits, vegetables, or turf, and instructors who do not teach at 1862 land-grant universities, are more likely than other instructors to include content related to climate change in their courses. Instructors who do not have tenure and instructors who teach plant identification courses are more likely than other instructors to have increased the content on climate change in their classes over time.
Performance of Alternative European Wine Grape Cultivars in Southwestern Idaho: Cold Hardiness, Berry Maturity, and Yield
Authors: Shellie Krista , Cragin Jacob , Serpe Marcelo
Published: December 2018

The cold tolerance, phenology, yield, and fruit maturity of alternative red- and white-skinned wine grape cultivars (Vitis vinifera) of European origin were compared with those of ‘Merlot’ and ‘Cabernet Sauvignon’ over two growing seasons in southwestern Idaho. Variability among alternative cultivars was detected for cold hardiness, onset of phenological events, yield, and fruit composition. The red-skinned cultivars Montepulciano and Tinto Cão were the least cold hardy of the alternative cultivars. The red-skinned cultivars Aleatico, Aglianico, and Graciano had similar yield but matured later than the leading cultivars Merlot and Cabernet Sauvignon and were among the more cold-sensitive alternative cultivars. ‘Grüner Veltliner’, ‘Sauvignon Gris’, and ‘Trousseau’ cold acclimated early, had high midwinter bud cold hardiness, and had similar or higher yield and fruit maturity as the leading cultivars. The white-skinned cultivars Verdelho, Fernão Pires, Sauvignon Blanc Musqué, and Sauvignon Gris had similar or less vine injury, similar or earlier phenology, and similar yield and fruit maturity as the leading cultivars. The large berry size of the red-skinned cultivars Trousseau and Touriga Brasiliera warrants evaluation for wine quality. The cultivar variability identified in this study for cold hardiness, phenology, cluster architecture, and yield provides a useful guide for cultivar site selection.
Stem Cutting Propagation in Whole Pine Tree Substrates
Authors: Witcher Anthony L. , Blythe Eugene K. , Fain Glenn B. , Curry Kenneth J.
Published: December 2018

Wood-based substrates have been extensively evaluated for greenhouse and nursery crop production, yet these substrates have not been evaluated for propagation. The objective of this study was to evaluate processed whole loblolly pine trees (WPT) (Pinus taeda) as a rooting substrate for stem cutting propagation of a range of ornamental crops. Substrates included processed WPT, pine (Pinus sp.) bark (PB), and each mixed with equal parts (by volume) peatmoss (PM) (WPT:PM and PB:PM, respectively). Substrate physical (air space, container capacity, total porosity, bulk density, and particle size distribution) and chemical [pH and electrical conductivity (EC)] properties were determined for all substrates. Rooting percentage, total root length, total root volume, and total shoot length were evaluated for four species in 2008 and five species in 2009. Substrate air space was similar between PB and WPT in the 2008 experiment, and likewise between PB:PM and WPT:PM. In the 2009 experiment, PB and WPT had similar substrate air space. The addition of PM to PB and WPT resulted in reduced air space and increased container capacity in both experiments. The proportion of fine particles doubled for PB:PM and WPT:PM compared with PB and WPT, respectively. Substrate pH for all substrates ranged from 6.0 to 6.9 at 7 days after sticking (DAS) cuttings and 6.9 to 7.1 at 79 DAS. Substrate EC was below the acceptable range for all substrates except at 7 DAS. Rooting percentage was similar among substrates within each species in both experiments. The addition of PM resulted in significantly greater total root length for PB:PM and WPT:PM compared with PB and WPT, respectively, for five of the eight species. Shoot growth was most vigorous for PB:PM compared with the other substrates for all species. The study demonstrated a range of plant species can be propagated from stem cuttings in whole pine tree substrates alone or combined with PM.
Ornamental Willow Growth Response Across Five Concentrations of Controlled-Release Fertilizer
Authors: Saska Margaret M. , Kuzovkina Yulia A.
Published: December 2018

Growth response of five ornamental willows (Salix), with sales potential for the cut-stem industry, was assessed in a 1-year container trial studying various concentrations of fertilizer. Plants were grown in 3-gal nursery containers fertilized with five concentrations of 18N–2.6P–6.6K controlled-release fertilizer (100-day release period) with micronutrients, applied as top dressings at 0, 10, 20, 40, and 60 g/container. Yield data were collected on the commercially important parameters including total stem length, stem quantity, and fresh weight of stems. Additional effects of fertilization on the timing of tip abscission and floral bud burst were also evaluated. Total stem length and fresh weight increased for all willows in the fertilized treatments compared with control; however, treatments above 40 g/container did not result in an increase of these parameters. Kori-yanagi willow (S. koriyanagi) had the highest yields across all treatments of fertilization. Fertilizer applications extended the period of stem elongation by delaying tip abscission for all willows, and for ‘The Hague’ willow (S. gracilistyla × S. caprea) tip abscission was delayed by 44.0 days at 40 g/container treatment compared with control. Floral bud burst dates, which differed greatly among willows, were unaffected by applications of controlled-release fertilizer.
Gardening Tasks Performed by Adults are Moderate- to High-Intensity Physical Activities
Authors: Park Sin-Ae , Lee A-Young , Lee Kwan-Suk , Son Ki-Cheol
Published: December 2018

The objective of this study was to determine the exercise intensities of 10 gardening tasks for men and women in their 20s. Fifteen university students [(mean ± SD) age 24.7 ± 1.4 years and body mass index 23.5 ± 4.1 kg·m−2] participated in this study. On two occasions, the subjects completed 10 gardening tasks in a high tunnel and a grassy area with weeds located near the high tunnel in Cheongju, Chungbuk, South Korea. They performed five gardening tasks randomly ordered on each occasion. Subjects did each gardening task for 5 minutes and then sat and rested in a chair for 5 minutes before the next task. Each subject wore a portable telemetric calorimeter and respired into the facemask during the gardening tasks and resting periods to measure their oxygen uptake. The subjects also wore a heart rate monitor under their breast to record heart rate data during the gardening tasks and resting periods via radiotelemetry. The 10 gardening tasks performed by the subjects were determined to be moderate- to high-intensity physical activities [3.5 ± 0.5 to 6.3 ± 1.2 metabolic equivalents (MET)]. In conclusion, the exercise intensity of gardening tasks should be useful information for developing garden exercise programs that meet the recommended physical activity for health benefits in adults.
Increasing the Sugar Concentration in Tomato Fruit Juice by Coiling Wire Around Plant Stems
Authors: Takahata Ken , Miura Hiroyuki
Published: December 2018

Sugar concentration is an important aspect of fruit quality in tomato (Solanum lycopersicum) production. Salt and water stresses have been reported to increase the sugar concentration of fruit. Coiling wire around the lower part of the stems to reduce the capacity of xylem to transport water to shoot would result in low shoot moisture condition and increase the sugar concentration of fruit like salt and water stresses. The objective of this study was to determine whether a prototypic method of wire coiling increases the sugar concentration of fruit. Bonsai wire was coiled around the stems of seedlings in February in a greenhouse between the cotyledon node and the first leaf node. Eleven days after treatment (DAT), the stem diameters immediately above the wire coils were markedly greater in treated plants compared with the corresponding stem regions of control plants. The stems of treated plants were less elongated and developed fewer nodes at 39 and 51 DAT than the control plants. Marketable fruit harvested from the first to third trusses of the treated plants in April to May had average weights that were 49% to 89% of the weights of fruit from control plants. The juice of fruit from the first to third trusses in the treated plants had soluble solids concentrations of 116% to 120%, sucrose concentrations of 263% to 483%, and fructose and glucose concentrations of 135% to 155%, compared with juice from corresponding control fruit. At 112 DAT, the shoots and roots of treated plants had weights that were 58% and 32% of those of control plants, respectively. The basal wire coiling treatment increased the sugar and soluble solids concentrations of tomato fruit juice; however, further investigation will be necessary before the technique can be adopted for practical use.
Weed Control in Dune Sedge Transplants
Authors: Ingels Chuck , Roncoroni John
Published: December 2018

Dune sedge (Carex pansa) can be used as either a groundcover or mowed turf. It is planted as plugs or small pots, but at 9-inch spacing, it may take over 1 year to completely fill in as turf, allowing weeds to grow between plants. This research was conducted to evaluate control of annual weeds and crop phytotoxicity with several conventional and reduced-risk herbicides in newly transplanted dune sedge. Three experiments were conducted on the same planting over a 5-month period, with dune sedge plants and weeds recovering well to permit subsequent evaluations. In Expt. 1, four preemergent and four reduced-risk postemergent herbicides and shredded fir bark mulch were compared shortly after planting. The use of oryzalin, dithiopyr, an experimental fatty acid herbicide (experimental FA), and mulch led to good control of the young weeds; all others resulted in less than 50% control. The experimental FA and ammoniated soap of fatty acids caused phytotoxicity to the dune sedge. In Expt. 2, four postemergent conventional herbicides, the same four reduced-risk postemergent herbicides (including two at increased rates) and the continued mulch treatment were tested. Most reduced-risk herbicides severely burned back the weeds initially, but regrowth ensued. In Expt. 3, a grass herbicide, a broadleaf herbicide combination, and a mix of the two were compared on the remaining plots with healthy dune sedge and actively growing weeds. Fluazifop provided good control of wild oat, carfentrazone + 2,4-D + mecoprop + dicamba largely controlled broadleaf weeds, and the combination controlled most weeds; no phytotoxicity occurred to the dune sedge. The results of the three experiments suggest that an application of dithiopyr, oryzalin, or a 2-inch layer of mulch shortly after planting, followed if necessary by hand weeding or treating weeds with carfentrazone + 2,4-D + mecoprop + dicamba tank-mixed with fluazifop would be an ideal strategy for management of annual weeds during the establishment of dune sedge. For organic or reduced-risk management, bark or wood chip mulch followed by hand weeding would be the best approach.