bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of the Importance of Plant Material Knowledge by Practicing Landscape Architects in the Southeastern United States
Authors: Brzuszek Robert F. , Harkess Richard L. , Stortz Eric
Published: December 2018

This study evaluates the attitudes and perceptions of practicing landscape architects in the southeastern United States with regards to the importance of horticultural knowledge for their profession. A 20-question survey instrument was mailed to 120 landscape architects who were listed as members of the American Society of Landscape Architects. The survey included various questions related to education and experience of the respondents and their peers with plants. The response rate was 52.5% (n = 63) and the majority of respondents were seasoned landscape architects in the states of Louisiana, Mississippi, Arkansas, Tennessee, Alabama, Georgia, and Florida that primarily served residential and commercial markets. The results from this study showed that the population of respondents strongly felt that plant knowledge is an important part of their professional skills, and recent graduates of landscape architecture and the profession as a whole appear more distanced from having strong plant expertise. Despite the increasing challenges for more formal plant education, there continues to be a need for both formal and informal extended education classes.
Early Flurprimidol Drench Applications Suppress Final Height of Four Poinsettia Cultivars
Authors: Currey Christopher J. , Lopez Roberto G.
Published: December 2018

Plant growth retardants (PGRs) are commonly applied to control poinsettia (Euphorbia pulcherrima) stem elongation to meet a target final height. Two weeks after pinching, 4-fl·oz substrate drenches containing 0.0, 0.05, 0.10, 0.15, 0.20, or 0.25 mg·L−1 flurprimidol were applied to high-vigor ‘Orion’ and low-vigor ‘Polly Pink’ poinsettia (Expt. I); while drenches containing 0.0, 0.05, 0.10, or 0.15 mg·L−1 flurprimidol or a foliar spray containing 1250 mg·L−1 daminozide and 750 mg·L−1 chlormequat chloride were applied to high-vigor ‘Classic Red’ and low-vigor ‘Freedom Salmon’ poinsettia (Expt. II). Final height of ‘Orion’ and ‘Polly's Pink’ poinsettia was suppressed by 12% to 25% and 13% to 30%, respectively, as flurprimidol concentration increased from 0.05 to 0.25 mg·L−1. Final height of ‘Classic Red’ and ‘Freedom Salmon’ was suppressed by 11% to 30% and 10% to 19%, respectively, as flurprimidol concentration increased from 0.05 to 0.15 mg·L−1. Although the daminozide and chlormequat chloride spray had no significant effect on bract area index compared with untreated plants, bract area index was smaller for all plants treated with flurprimidol. However, the bract area to height ratio of all cultivars was not impacted by any PGR application, indicating aesthetic appearance was not negatively affected with smaller bract area. Time to anthesis was delayed by up to 4 days when 0.10 mg·L−1 was applied to ‘Classic Red’, although no significant delays were observed for the remaining cultivars. Based on these results, flurprimidol may be applied as an early drench to suppress height of poinsettia without adversely impacting finished plant quality or crop timing.
Methyl Iodide plus Chloropicrin Rates and Formulations for Nutsedge Management in Tomato
Authors: Gilreath James P. , Santos Bielinski M.
Published: December 2018

Two independent field studies were conducted to determine the efficacy of methyl iodide (MI) formulations and rates on mixed nutsedge [purple nutsedge (Cyperus rotundus) and yellow nutsedge (Cyperus esculentus)] stands and their effects on tomato (Solanum lycopersicum) yields. In both studies, treatments were rates of two formulations of MI + chloropicrin (Pic) at the 98:2 (v/v) and 50:50 (v/v) proportions. In the MI + Pic 98:2 study, the fumigant rates were 0, 100, 125, 150, 175, and 200 lb/acre in Spring 2004 and 0, 125, 150, 175, and 200 lb/acre in Fall 2004. In the MI + Pic 50:50 study, the rates were 0, 200, 250, 300, 350, and 400 lb/acre during both seasons. Additionally, a grower standard was included in each study, which consisted of plots fumigated with methyl bromide (MBr) + Pic 67:33 (v/v) at a rate of 350 lb/acre. Higher rates of MI + Pic 98:2 and 50:50 significantly reduced mixed nutsedge densities and increased relative marketable fruit weight of tomato. Plots fumigated with MBr + Pic were weed-free at the sampling times during both studies. Data from both studies indicated that MI + Pic 98:2 and 50:50 rates of 125 and 200 lb/acre, respectively, consistently provided the highest marketable fruit weights and mixed nutsedge control, which were similar to those obtained in plots treated with MBr + Pic.
Nitrogen and Vine-harvest Method Affect Cranberry Vine Production and Yield
Authors: Sandler Hilary A.
Published: December 2018

Four nitrogen (N) rates (0, 50, 100, and 150 lb/acre) were applied annually, and two spring vine-harvest methods (heavy pruning and mowing) were applied biennially in all combinations at one commercial ‘Stevens’ cranberry (Vaccinium macrocarpon) farm in southeastern Massachusetts for six consecutive years. Vine weights generated from each treatment combination were collected in Years 1, 3, and 5 (vine-harvest years). Mean vine weight across N treatments from the biennial pruning and mowing events was 1.4 and 3.6 tons/acre, respectively. Vine-harvest method affected yield components (number and weight of reproductive uprights) since mowed plots had values near zero in the vine-harvest year, and pruned vines were always productive. Increasing N rate increased overall vine weight produced. Pruned vines produced more marketable fruit than mowed vines in Year 4 and Year 6. Net income declined with increasing N rate (except Year 1). Averaged over 6 years, increasing N rate decreased net income of and had no effect on pruned and mowed vines, respectively. Although an alternate-year mowing program provides minimal opportunity for sustained vine recovery and would not be recommended for use over an extended period, mowing provided similar net income as heavy pruning (assuming income and/or cost savings from both vines and fruit) when 50 lb/acre N was applied. The incorporation of mowing, in conjunction with other cultural practices that manage the cranberry canopy and generate fruit, can be a viable economic option.
Increasing Effectiveness of Cooperative Extension's Master Gardener Volunteers
Authors: Bauske Ellen M. , Kelly Lelia , Smith Kerry , Bradley Lucy , Davis Timothy , Bennett Pam
Published: December 2018

Extension Master Gardener (EMG) volunteers are key to effective dissemination of horticultural information to the public. The goal of this workshop was to identify techniques to increase the capacity and effectiveness of EMG volunteers. The workshop focused on projects and tools that reduce the administrative burden of managing volunteers, increase the scope of issues that volunteers are prepared to address, and pool volunteer efforts and resources across county lines. Two online systems for managing and reporting EMG volunteer activities were described. Both systems are intuitive, user-friendly, and updated without the assistance of web managers. Regional web-based, advanced training on specific topics was used to expand educational messages of EMG volunteers and eliminate the costs associated with face-to-face training. Presentations were made using distance learning technologies and resources were shared online. Hosting agents tailored hands-on supporting activities to meet local needs. Volunteers expanded extension outreach by answering noncommercial landscape and garden telephone questions. Many of the administrative, logistical, and resource burdens associated with the EMG helpline phone service were overcome by working across county lines, standardizing training, centralizing supporting resources, and clustering volunteers into regional telephone helpline offices. Other projects and tools presented in the workshop focused on the need to affirm and/or foster the volunteers' connection with the university and the outreach mission of Cooperative Extension.
Impact of Fertigation versus Controlled-release Fertilizer Formulations on Nitrate Concentrations in Nursery Drainage Water
Authors: Wilson P. Chris , Albano Joseph P.
Published: December 2018

Nitrate-nitrogen (N) losses in surface drainage and runoff water from ornamental plant production areas can be considerable. In N-limited watersheds, discharge of N from production areas can have negative impacts on nontarget aquatic systems. This study monitored nitrate-N concentrations in production area drainage water originating from a foliage plant production area. Concentrations in drainage water were monitored during the transition from 100% reliance on fertigation using urea and nitrate-based soluble formulations (SF) to a nitrate-based controlled-release formulation (CRF). During the SF use period, nitrate-N concentrations ranged from 0.5 to 322.0 mg·L−1 with a median concentration of 31.2 mg·L−1. Conversely, nitrate-N concentrations during the controlled-release fertilization program ranged from 0 to 147.9 mg·L−1 with a median concentration of 0.9 mg·L−1. This project demonstrates that nitrate-N concentrations in drainage water during the CRF program were reduced by 94% to 97% at the 10th through 95th percentiles relative to the SF fertilization program. Nitrate-N concentrations in drainage water from foliage plant production areas can be reduced by using CRF fertilizer formulations relative to SF formulations/fertigation. Similar results should be expected for other similar containerized crops. Managers located within N-limited watersheds facing N water quality regulations should consider the use of CRF fertilizer formulations as a potential tool (in addition to appropriate application rates and irrigation management) for reducing production impacts on water quality.
Greenhouse Production of Jatropha, a Potential Biofuel Crop
Authors: Moore Kimberly , Greenhut Scott , Vendrame Wagner
Published: December 2018

The objective of this study was to evaluate greenhouse techniques for the production of jatropha (Jatropha curcas). Jatropha seedlings were transplanted into 1-gal containers filled with bark mix, coir, or peat-based substrate and fertilized with 0, 4.1, 5.9, or 8.3 oz/ft3 of a 15N–4.05P–9.96K controlled-release fertilizer (CRF). Plants were watered every 2, 3, or 4 days for 80 days in the greenhouse. Jatropha plants grown in peat-based substrate had greater stem diameter and shoot dry weight (SDW) than plants grown in bark mix. For each growing substrate, plants fertilized with 8.3 and 5.9 oz/ft3 of CRF had greater SDW than plants fertilized with 4.1 and 0 oz/ft3 of CRF. Similarly, for all three substrates, plants irrigated every 2 or 3 days had greater SDW than plants irrigated every 4 days. Although jatropha has been classified as a low–nutrient and water requiring plant, the results of this study suggest that increased inputs of fertilizer and water produce larger plants. Further research needs to be conducted on the benefit of larger plants from the greenhouse on subsequent oil production in the field.
Temporal and Spatial Distribution of Tomato Bacterial Wilt on Virginia's Eastern Shore
Authors: Wimer Adam F. , Rideout Steven L. , Freeman Joshua H.
Published: December 2018

Bacterial wilt of tomato caused by Ralstonia solanacearum is one of the most devastating diseases of tomato (Solanum lycopersicum) on the Eastern Shore of Virginia (ESV). Four research trials were conducted on the ESV over three growing seasons to determine the temporal and spatial distribution of bacterial wilt throughout commercial tomato fields. Individual plants were assessed at ≈1-week intervals throughout the growing seasons with the incidence of bacterial wilt for each individual plant being recorded. Bacterial wilt increased gradually during each growing season. An increase in the clustered distribution of symptomatic plants was determined to exist within rows but not across rows. There were positive correlations between disease incidence and the percentage of rows exhibiting a significantly clustered distribution in every trial. These findings suggest that as bacterial wilt incidence increases in tomato fields by either the intimate contact between roots of adjacent tomato plants or the movement of the pathogen in surface irrigation water, symptomatic plants become more clustered within rows.
Growing Minds: The Relationship Between Parental Attitudes Toward Their Child's Outdoor Recreation and Their Child's Health
Authors: Hammond Danielle E. , McFarland Amy L. , Zajicek Jayne M. , Waliczek Tina M.
Published: December 2018

The objective of this study was to investigate the relationship between parental attitudes toward nature and their child's outdoor recreation and how these attitudes related to their reports of their child's health problems. The sample for this study consisted of parents of 6- to 13-year-old children from the United States, who accessed the survey from an informational website for gardeners between Mar. and Aug. 2009. Surveys were collected until 142 completed questionnaires were received. The online survey included questions about parents' attitude toward nature, parents' attitudes toward their child's outdoor recreation, an inventory of potential children's health problems, the time children spent in various indoor and outdoor activities, and demographic questions. Descriptive statistics were used to tabulate mean scores on the parental attitude toward nature (PAN) scale and parental attitude toward their child's outdoor recreation (PACOR) scale, both of which indicated overall positive views. Pearson's product–moment correlations indicated statistically significant relationships between the PAN scale, the PACOR scale, and time children spent outdoors. Relationships between time spent indoors on video games or watching television and health problems in children were identified. Time spent outdoors in free play was inversely related to reports of health problems in children.
Blackberry Propagation by Non-leafy Floricane Cuttings
Authors: Takeda Fumiomi , Tworkoski Thomas , Finn Chad E. , Boyd Charles C.
Published: December 2018

One- or two-node hardwood cuttings were taken from 9-year-old ‘Triple Crown’ and ‘Siskiyou’ blackberry (Rubus) plants on 5 Nov. 2009, 3 Dec. 2009, and 21 Jan. 2010. The response of cuttings with and without partially excised axillary buds to an application of cytokinin was compared with control cuttings with intact axillary buds and no cytokinin. Differences in root development were evident in the two cultivars tested. The cuttings of ‘Siskiyou’ and ‘Triple Crown’ callused on cut ends, but many of the adventitious roots developed from the base of the axillary buds. Shoots emerged from the bud in ≈90% of ‘Siskiyou’ cuttings stuck in November, December, and January. Rooting occurred in more than 90% of cuttings stuck in November and December but declined in cuttings stuck in January. In ‘Siskiyou’, bud excision had no effect on shoot and root emergence, but cytokinin treatment suppressed rooting in cuttings collected in November and January. Shoot emergence and rooting were poorer in ‘Triple Crown’ cuttings than in ‘Siskiyou’. In ‘Triple Crown’ cuttings, partial excision of buds reduced shoot emergence only in January but had no effect on rooting at three sticking dates. Cytokinin treatment improved shoot emergence in November and December but reduced rooting in January. The enclosed system is a viable method for propagating ‘Siskiyou’ blackberry by non-leafy floricane cuttings.
The Nitrogen Use Efficiency: Meaning and Sources of Variation—Case Studies on Three Vegetable Crops in Central Italy
Authors: Benincasa Paolo , Guiducci Marcello , Tei Francesco
Published: December 2018

Nitrogen (N) use efficiency (NUE) of crops is examined by taking into account both plant N uptake efficiency, focusing on the recovery of fertilizer-N, and the utilization efficiency of the absorbed N. The latter is further analyzed as the overall effect of the absorbed N on crop leaf area, light absorption, photosynthesis, crop growth, biomass partitioning, and yield. The main sources of variation for the NUE of crops are considered, and several of them are discussed based on results from field experiments carried out at the University of Perugia (central Italy) between 1991 and 2008 on sweet pepper (Capsicum annuum), lettuce (Lactuca sativa), and processing tomato (Solanum lycopersicum). More specifically, the effects of species, cultivar, fertilizer-N rate, form and application method (mineral and organic fertilization, green manuring, fertigation frequency), and sink limitation are reported. Implications for residual N in the soil and leaching risks are also discussed. The fertilizer-N rate is the main factor affecting crop NUE for a given irrigation management and rainfall regime. Indeed, avoiding over fertilization is the first and primary means to match a high use efficiency and economic return of fertilizer-N with limited environmental risks from nitrate leaching. The form and application method of fertilizer-N also may affect the NUE, especially in the case of limiting or overabundant N supply. Particularly, high fertigation frequency increased the recovery of fertilizer-N by the crop. It is suggested that species-specific curves for critical N concentration (i.e., the minimum N concentration that allows the maximum growth) can be the reference to calibrate the quick tests used to guide dynamic fertilization management, which is essential to achieve both the optimal crop N nutritional status and the maximum NUE.
Measuring Soil Water Content: A Review
Authors: Bittelli Marco
Published: December 2018

Soil water content (SWC) is a soil property that plays a crucial role in a large variety of biophysical processes, such as seed germination, plant growth, and plant nutrition. SWC affects water infiltration, redistribution, percolation, evaporation, and plant transpiration. Indeed, the quantification of SWC is necessary for a variety of important applications in horticultural systems, such as optimization of irrigation volumes, fertilization, and soil-water-budget computations. In recent decades, a substantial number of different experimental methods have been developed to determine the SWC, and a large body of knowledge is now available on theory and applications. In this review, the main techniques used to determine the SWC are discussed, first by describing the physical principles behind the most popular methods and then by addressing how the various spatial scales might affect the different methodologies when applied.
Traditional and New Approaches to Irrigation Scheduling in Vegetable Crops
Authors: Pardossi Alberto , Incrocci Luca
Published: December 2018

Intensive vegetable cropping systems use large amounts of water and nutrients. Excess application of water and nutrients results in economic losses (higher fertilizers and pumping costs) and contributes to nutrient leaching and environmental degradation. Increasing nutrient use efficiency (NUE) and water use efficiency (WUE) should be a priority for sustainable horticulture. This increased NUE, WUE, or both depend on the utilization of efficient irrigation technology, including appropriate methods for irrigation scheduling (IS).Various methods are available for IS based on determination of crop water balance (weather-based method), soil/substrate moisture level, or plant water relations. Rather than discussing the physical and biological basis of irrigation management, this article focuses on currently available irrigation control devices for open-field and greenhouse production systems, with particular emphasis on soil moisture sensors (SMSs). SMS regulates the frequency of irrigation and, possibly, the water dose by continuously monitoring volumetric water content (θ) or matrix potential (ψm) of the growing media. A new generation of dielectric SMS has been developed to measure both θ and the electrical conductivity (EC) of pore water in soil and artificial media. This provides the possibility of controlled fertigation based on measured EC. Despite the development in IS, in most regions worldwide, especially in less developed countries, many growers still rely on personal experience for determining crop water requirements and the timing of irrigation. Therefore, the main constraints to the improvement of irrigation efficiency are related to the overall cost of these technologies and to the policies adopted for their dissemination and transfer to professional growers.
Evaluation of Six Nitrogen Fertility Programs on Marketable Yield and Development of Skin Separation in Bell Pepper Fruit
Authors: Kline Wesley L. , Wyenandt Christian A. , Ward Daniel L. , Sudal June F. , Maxwell Nancy L.
Published: December 2018

In this study, the effects of six nitrogen fertility programs and two bell pepper (Capsicum annuum) cultivars were evaluated for marketable yield and incidence of skin separation in fruit. In 2006 and 2007, bell pepper cultivar Aristotle, which is tolerant to the crown rot phase of phytophthora blight (Phytophthora capsici), and a susceptible cultivar, Camelot, were established in a split-plot design with cultivar as the whole-plot factor and fertilizer regime as the subplot factor. Each year, fertility treatments included 1) 180 lb/acre of soluble nitrogen (N) plus phosphorus (P) and potassium (K) as 20N–8.7P–16.6K, 2) 300 lb/acre of soluble N (4N–0P–6.6K), 3) 180 lb/acre of soluble N (30N–0P–0K), 4) 135 lb/acre of soluble N (30N–0P–0K), 5) 180 lb/acre of granular N (43N–0P–0K), and 6) 135 lb/acre of granular N (43N–0P–0K). Soluble fertilizer treatments 1–4 were applied weekly through drip irrigation during the production season. Granular fertility treatments 5 and 6 were applied after bed making but before laying black plastic mulch each year. Additionally, all plots received 180 lb/acre each of P and K (0N–2.6P–4.9K) plus 2 lb/acre of boron distributed season-long in weekly fertilizer applications. In 2006 and 2007, cultivar had no effect on marketable yield or percent marketable fruit. In 2007, the percentage of harvested fruit with skin separation was significantly higher in fertility programs 1 and 2 compared with program 5. In 2006 and 2007, there were no significant interactions between cultivar and fertility program for marketable yield per plot, fruit with skin separation, percent marketable fruit, or marketable yield per acre. In both years, harvest date has a significant effect on marketable yield per plot, fruit with skin separation, percent marketable fruit, and marketable yield per acre. The percentage of harvested fruit with skin separation was higher in phytophthora-tolerant ‘Aristotle’ compared with phytophthora-susceptible ‘Camelot’ in 2006 and 2007. Results of this study suggest that the development of skin separation in bell pepper fruit is more influenced by genotype than N fertility program.
Pennsylvania Statewide Bell Pepper Cultivar Evaluation
Authors: Sánchez Elsa S. , Butzler Thomas M. , Bogash Steven M. , Elkner Timothy E. , Oesterling R. Eric , Orzolek Michael D. , Stivers Lee J.
Published: December 2018

Sixteen cultivars of green bell peppers (Capsicum annuum) were evaluated on the basis of yield in three locations across Pennsylvania during the growing seasons of 2008–09. Cultivars were evaluated in comparison with the cultivar Paladin. In central Pennsylvania, all the cultivars trialed had marketable yields (based on weight) not different than ‘Paladin’ except ‘Lynx’, ‘Socrates’, and ‘Escape’. In terms of fruit number, all cultivars were not different than ‘Paladin’ except ‘Socrates’. For large-sized fruit, all the cultivars trialed are recommended. In southeastern Pennsylvania, all the cultivars trialed except SP-05–47 had marketable yields not different than ‘Paladin’. For large-sized fruit, ‘Revolution’ outperformed all other cultivars, including ‘Paladin’. In southwestern Pennsylvania, all the cultivars trialed except Lynx and SP-05–47 produced comparable marketable yields to ‘Paladin’. None of the cultivars evaluated, including Paladin, consistently outperformed Revolution in terms of large fruit. Statewide, all the cultivars, except Lynx and SP-05–47, are recommended on the basis of marketable yields. For growers looking for large-sized fruit to meet market demand the cultivar Revolution is recommended over ‘Paladin’.
High Tunnel and Open Field Production of Floricane- and Primocane-fruiting Raspberry Cultivars
Authors: Hanson Eric , Von Weihe Mike , Schilder Annemiek C. , Chanon Ann M. , Scheerens Joseph C.
Published: December 2018

Identical trials were conducted in a multibay high tunnel and an adjacent open field in southwestern Michigan to compare primocane-fruiting cultivars (Autumn Britten, Caroline, Chinook, Heritage) and floricane-fruiting cultivars (Canby, Encore, Heritage, Nova) of red raspberry (Rubus idaeus). Floricane-fruiting plots of ‘Heritage’ were pruned to produce fruit on floricanes and primocanes (double cropping). The most productive cultivars in both environments were ‘Nova’ and ‘Canby’ (floricane) and ‘Caroline’ and ‘Heritage’ (primocane). These cultivars produced annual yields of 5.5 kg·m−1 row in the tunnel and 2.5 kg·m−1 row in the field. The order of primocane harvest (earliest to latest) was the same in the tunnel and field: ‘Autumn Britten’, ‘Caroline’, ‘Chinook’, and ‘Heritage’. Cultivars with the greatest average berry weight in the tunnel and field were Encore and Nova (floricane) and Autumn Britten and Caroline (primocane). ‘Chinook’ and ‘Autumn Britten’ tended to have the highest incidence of gray mold (Botrytis cinerea) of primocane-fruiting cultivars, but incidence was similar in floricane cultivars. Overall mold incidence was 1% in the tunnel and 13% in the field. Leaf spot (Sphaerulina rubi), cane anthracnose (Elsinoe veneta), spur blight (Didymella applanata), and botrytis cane blight (B. cinerea) were common in the field but absent in tunnel. Phytonutritional analyses of primocane fruit indicated that genotype differences were not consistent across the two environments. Relative cultivar characteristics (harvest season, yield, berry quality) were similar in the field and tunnels, but the tunnel environment tended to increase plant vigor, yield, and fruit quality and suppress several diseases.
Literature in the Garden Curriculum Effects on Life Skills of Children
Authors: Fleener A.W. , Robinson C.W. , Williams J.D. , Kraska M.
Published: December 2018

Children's gardens have recently been shown to increase life skills. The purpose of this study was to assess the effects that gardening/plant activities from the Junior Master Gardener curriculum, Literature in the Garden, have on children's life skills. The life skills examined were leadership, teamwork, self-understanding, decision-making skills, and communication skills. About 130 third-grade students from a Lee County, AL, school participated in the study. Students were equally divided into control and experimental groups, and each student was given the youth life skills inventory (YLSI) as a pre- and posttest. The experimental group participated in eight gardening/plant activities after the pretest, whereas the control group did not complete the activities. No significant differences were found between pretests and posttests for teamwork, self-understanding, decision making, communication, and overall life skills. Significant decreases from pretest to posttest were found on leadership skills for the experimental group. Several trends were observed with students who read more for fun, read more each week, and read more garden books generally increasing in life skills.
Primocane-fruiting Raspberry Production in High Tunnels in a Cold Region of the Upper Midwestern United States
Authors: Yao Shengrui , Rosen Carl J.
Published: December 2018

Five primocane raspberry (Rubus idaeus) cultivars were evaluated in a high tunnel and in the field at Grand Rapids, MN, which is located in U.S. Department of Agriculture (USDA) plant hardiness zone 3b. Bare root plants of five cultivars (Autumn Bliss, Autumn Britten, Caroline, Joan J, and Polana) were planted in the high tunnel and in the field, each with a randomized complete block design at 2 × 5.2-ft spacing on 8 May and 14 May 2008, respectively. A propane heater was used periodically for frost protection in the high tunnel. All five cultivars overwintered well and primocanes emerged with minor or no winter damage in the high tunnel in 2009. The high tunnel extended the growing season for ≈4 weeks in both years. Raspberry plants in the high tunnel produced higher yield than those in the field, total 154 lb (6655 lb/acre) from the high tunnel vs. 0.5 lb (43 lb/acre) from the field in 2008 and 379 lb (16,378 lb/acre) vs. 80 lb (3457 lb/acre) in 2009. ‘Caroline’ and ‘Polana’ had higher yields than ‘Autumn Bliss’; ‘Joan J’ and ‘Autumn Britten’ yields were intermediate and not different from ‘Caroline’, ‘Polana’, or ‘Autumn Bliss’ yields. In terms of harvest date, ‘Polana’ was the earliest among the five cultivars tested, followed by ‘Autumn Britten’, ‘Autumn Bliss’, and ‘Joan J’. ‘Caroline’ was the latest. Essential nutrients in leaves for all cultivars both in the field and in the high tunnel were within sufficient ranges. Spider mites (Tetranychidae) and raspberry sawflies (Monophanoides geniculatus) were the major insect problems. In conclusion, primocane-fruiting raspberries can be successfully grown in high tunnels and produce substantially higher yields than in field plantations in northern Minnesota or areas with similar climatic conditions.
Evaluation of Irrigation Threshold and Duration for Tomato Grown in a Silt Loam Soil
Authors: Coolong Timothy , Surendran Susmitha , Warner Richard
Published: December 2018

Soil moisture-based, high-frequency, low-volume (pulsed) irrigation management strategies have saved water while maintaining yields of vegetables grown in coarse textured soils. However, little is known regarding the efficacy of soil moisture-based pulsed irrigation on finer textured soils. Therefore, five tensiometer-based, automated irrigation treatments were tested for tomato (Solanum lycopersicum) grown in a Maury silt loam soil in 2009 and 2010 in Lexington, KY. Irrigation treatments consisted of paired-tensiometer systems with on/off setpoints of −30/−10, −30/−25, −45/−10, and −45/40 kPa in both 2009 and 2010 and a single-tensiometer system with setpoints of −35 kPa in 2009 and −40 kPa in 2010. In 2009, the pulsed systems (−30/−25, −45/−40, and −35 kPa) irrigated more frequently but for a shorter duration than non-pulsed systems (−30/−10 and −45/−10 kPa). Soil moisture measurements in 2009 suggested that probes set at a depth of 6 inches were more closely matched to irrigation setpoints than those at 12 inches. In both years, the −45/−40 kPa setpoint treatment used the least amount of water while maintaining total marketable yields that were not significantly different from other treatments. Yields were significantly higher in 2009 than 2010, though atypical air temperatures in 2010 may have been the cause. Leaf water potential and relative water content were measured predawn and midday throughout the growing season in 2009 and 2010. Leaf water potential was not significantly affected by the treatments in either year, though leaf relative water content was affected in 2010. In this trial, an automated, soil moisture-based irrigation system maintained yields and saved water when compared with a non-pulsed irrigation system using similar irrigation setpoints for tomato grown in a silt loam soil.
Palma Corcho: A Case Study in Botanic Garden Conservation Horticulture and Economics
Authors: Kay Judy , Strader Arantza A. , Murphy Vickie , Nghiem-Phu Lan , Calonje Michael , Griffith M. Patrick
Published: December 2018

Horticulture is an essential part of plant conservation programs, and botanic gardens are uniquely suited for conservation horticulture work. Here, we present a case study of a successful cycad (Cycadales) propagation program at Montgomery Botanical Center (MBC, Miami, FL), using palma corcho (Microcycas calocoma) as an example. This species is highly sought in the nursery trade, and overcollection of wild plants is one factor leading to imperilment of natural populations. Thus, propagation and distribution of palma corcho can make a strategic contribution to in situ conservation. Provenance history of the living collections is reviewed, and techniques for propagation and establishment are detailed. An innovative botanic garden/industry partnership to provide seed for cultivation is discussed. Finally, we present analysis of market forces with regard to rare plant availability and conservation, using palma corcho as an example. Average price per seed has fallen by over half since offered on public auction. This inversely correlates with seed supply, which has been steadily increasing during the last 15 years and helping meet the high market demand. We project the cost of palma corcho will fall further to a point where collection from the wild has no further economic incentive.
Development and Evaluation of a Training Program on Whole Farm Nutrient Planning for Organic Farms
Authors: Sánchez Elsa S. , Karsten Heather D.
Published: December 2018

Organic growers have indicated a need for help with the challenge of nutrient management. To address this challenge, an intensive training program for agricultural educators was convened to study this issue. Through the program, existing soil and compost analysis recommendations were modified to make them more relevant for organic growers; computer-based whole farm nutrient planning tools were evaluated using situations common to organic farms; and educational materials on using organic nutrient sources were developed for grower audiences. Educational workshops, presentations, and farm visits reached 714 growers and publications reached over 2575 people. Survey respondents of the intensive training program rated their ability to help organic growers with nutrient management as 3.50 before and 5.50 (7-point scale, with 7 = excellent) after the sessions. About 1 year later, all survey respondents rated their ability to help growers using organic nutrient sources as excellent or above average. Grower knowledge of using organic nutrient sources improved to 5.92 from 3.92 as a result of a workshop and to 5.62 from 3.89 (7-point scale, with 7 = excellent) after a 1-day class developed by intensive training participants. Methodology used allowed for expansion of individual and collective knowledge of a complicated topic and development of high impact, relevant, and effective educational programming for clientele.
Interactive Online Tools for Teaching Plant Identification
Authors: Campbell Kristin R. , Wilson Sandra B. , Wilson P. Christopher , He Zhenli
Published: December 2018

Interactive review exercises were developed as an online learning component of an existing native plant landscaping course. The instruments were designed with specific goals for students to 1) test their plant identification knowledge, 2) practice leaf terminology with specific plant examples, and 3) associate landscape performance with native ecosystem characteristics. The plant identification tool was developed within a spreadsheet application using formulas consisting of logic statements. This tool tests the students’ ability to identify plants and spell scientific and common names associated with high-resolution plant images. The leaf terminology tool was developed using a multimedia platform. It uses a drag-and-drop interface where students are asked to associate a specific leaf term (i.e., margin, apex, base, texture, arrangement) with a scanned image that best matches the taxonomic term. The ecosystem tool, also developed using a multimedia platform, uses digital images captured for each of Florida's major ecosystems in conjunction with sets of plant combinations and site characteristics. Students select the appropriate choices and submit their answers online, after which they receive immediate feedback. Students reported an improvement in plant recognition after they had access to these identification tools. These interactive learning tools not only benefit students enrolled in this specific course but can be adapted to a variety of online courses nationwide.
Influence of Pumice and Plant Roots on Substrate Physical Properties Over Time
Authors: Altland James E. , Owen James S. , Gabriel Magdalena Z.
Published: December 2018

An experiment was conducted to test the hypothesis that either pumice or plant roots maintain air space (AS) and porosity over time, or renders substrates more resistant to shrinkage. Treatment design was a 3 × 2 factorial with three substrate types and either presence or absence of a plant. The three substrates were composed of douglas fir (Pseudotsuga menziesii) bark alone or amended with 15% or 30% (by volume) pumice. Substrates were packed in aluminum cores to facilitate measurement of physical properties with porometers at the conclusion of the experiment. Half of the cores with each of the three substrate types were packed with a single plug of ‘Autumn Blush’ coreopsis (Coreopsis sp.) (Expt. 1) or ‘Blue Prince’ holly (Ilex ×meserveae) (Expt. 2). The remaining cores were maintained in the same production environment, but without a plant. Substrate physical properties were measured before the experiment and after 48 days for coreopsis plants and 382 days for holly. Both experiments had relatively similar responses despite using different crops and production times. Summarizing in general overall treatments, AS decreased, container capacity (CC) and total porosity (TP) increased, and bulk density remained constant over time. The presence of a plant in the core tended to exacerbate the decrease in AS and the increase in core capacity. Shrinkage was decreased by the presence of a plant, but only minimally.
Irrigation Lowers Substrate Temperature and Enhances Survival of Plants on Green Roofs in the Southeastern United States
Authors: Price Julie Guckenberger , Watts Stephen A. , Wright Amy N. , Peters Robert W. , Kirby Jason T.
Published: December 2018

Green roofs are becoming increasingly prevalent in the United States due to their economical and environmental benefits as compared with conventional roofs. Plant selection for green roofs in the variable climate of the southeastern United States has not been well evaluated. Shallow substrates on green roofs provide less moderation of temperature and soil moisture than deeper soils in traditional landscapes, necessitating empirical evaluation in green roof environments to make informed recommendations for green roof plant selection. Nineteen species and cultivars, including succulents, grasses, and forbs, were evaluated under seasonal irrigated and non-irrigated conditions in experimental green roofs. Plants were planted on 26 Oct. 2009 and each evaluated for survival and increase in two-dimensional coverage of the substrate during establishment, after overwintering, and after the first growing season. The winter 2009–10 was colder than normal, and some plants, such as ice plants (Delosperma spp.), considered to be cold-hardy in this climate did not survive through the winter. Irrigation influenced survival for the summer period and only succulent plants like stonecrops (Sedum spp.) survived without irrigation. Irrigated experimental green roofs had significantly lower summer substrate temperatures (up to 20 °F lower) and plants survived in irrigated conditions. Plants that survived both winter and summer under irrigated conditions include pussytoes (Antennaria plantaginifolia), mouse-ear tickseed (Coreopsis auriculata), eastern bottlebrush grass (Elymus hystrix), glade cleft phlox (Phlox bifida stellaria), and eggleston's violet (Viola egglestonii). Irrigation is recommended on extensive green roofs to increase the palette for plant selection by protecting against plant mortality due to drought and extreme soil temperatures.
Crop Load Adjustment in ‘Seyval Blanc’ Winegrape: Impacts on Yield Components, Fruit Composition, Consumer Wine Preferences, and Economics of Production
Authors: Berkey Tyler G. , Mansfield Anna Katharine , Lerch Steven D. , Meyers James M. , Vanden Heuvel Justine E.
Published: December 2018

Crop load management treatments were applied to ‘Seyval Blanc’ grapevines (Vitis hybrid) as a 2 × 2 factorial design: no shoot thinning (ST)/no cluster thinning (CL) (i.e., control), ST combined with CL (ST + CL), ST only, and CL only. All treatments reduced yield and crop load (yield/pruning weight) in 2009 and had a smaller impact in 2010 due to the carryover effect of previous year treatments on crop potential. Soluble solids were improved by up to 3.2% by the ST + CL treatment in 2009, but were not impacted by treatments in the second year when the range of yield was smaller and the ripening conditions more favorable. Rank sum analysis for the 2009 vintage indicated that wines produced from the CL treatment were preferred by the sensory panel compared with the control wine, but there were no differences in consumer preference for wines produced in the 2010 season. Grower preferred price in 2009 (required to compensate the grower for labor costs and lost yield) increased from $556/t in the control to $824/t in the CL treatment, an increase which could be justified by the demonstrated consumer preference for the CL wine. Grower preferred price was $1022/t in the ST + CL treatment in 2009, a price increase that was not justified by a demonstrated consumer preference for the wine. In 2010, grower preferred price ranged from $541/t for the control to $610/t for the ST + CL treatment, an unjustified increase based on the lack of demonstrated consumer preference for the wines.
An Economic Analysis of a University Educational Cafeteria Composting Program—Bobcat Blend
Authors: Sanders Jason , Waliczek Tina Marie , Gandonou Jean-Marc
Published: December 2018

At Texas State University, a cafeteria-composting pilot program was established in which students source-separated their organic waste at one of the food courts while the program educated students on the value of organic waste and compost. Waste sorting bins were set up in a dining hall to direct students to sort trash into recyclables, compostables, and trash. Waste audit results demonstrated the value of the operation to the university in terms of savings in waste hauling expenditures, as well as showed the percent contamination, and percent waste diverted to the university's recycling and composting program. There was a significant difference between pre and post-test waste audits. The pilot site composting program resulted in a net loss of $3741.35 to the university during the first year, but was expected to produce a positive net return of $2585.11 in subsequent years. The pilot test showed the program was most successful when ongoing education at the dining hall occurred. Additionally, the student-run composting program resulted in hands-on training for students in producing a valuable horticultural commodity in an emerging waste management field. Results also indicated opportunities for further diversion such as the incorporation of compostable cups and utensils, as well as through expanding the operation to include more collection locations. With more collection sites and, therefore, more efficiency, the expanded composting program has the potential to become a self-supporting operation.
Elevating Carbon Dioxide in a Commercial Greenhouse Reduced Overall Fuel Carbon Consumption and Production Cost When Used in Combination with Cool Temperatures for Lettuce Production
Authors: Frantz Jonathan M.
Published: December 2018

Greenhouses that are well sealed can result in carbon dioxide (CO2) drawdown and suppressed plant growth. While growers can add supplemental CO2, it is unknown how supplemental CO2 fits within the framework of sustainable crop production in greenhouses. In this study, supplemental CO2 was used in combination with reduced temperatures to evaluate the productivity of ‘Grand Rapids’ lettuce (Latuca sativa) compared with a traditionally maintained, warmer, and well-insulated greenhouse without supplemental CO2 at a commercial facility. Simulations using Virtual Grower software based on identical greenhouses compared fuel use and carbon (C) consumed because of heating and CO2 supplementation. Models were verified with measurements in a well-sealed commercial greenhouse; CO2 quickly decreased to below 300 ppm in a nonsupplemented greenhouse containing plants. Supplemental CO2 boosted total leaf number and mass of lettuce even though temperatures were maintained 3 °F lower in elevated CO2 than in the traditional management scenario. Maintaining a cooler greenhouse but adding CO2 decreased total carbon (C) consumed (by combined fuel use and CO2 supplementation) by 7% during the 3-month season that required a well-sealed greenhouse. Additionally, fuel savings because of lower temperature set points paid for the cost of adding CO2. The use of CO2 enrichment should be considered as a tool in sustainable systems when its use can counteract the plant growth and development reductions brought on by lowered temperatures.
Application of the “4R” Nutrient Stewardship Concept to Horticultural Crops: Getting Nutrients in the “Right” Place
Authors: Bryla David R.
Published: December 2018

Right fertilizer placement is one of the 4Rs of an effective nutrient stewardship system and should be combined with considerations for the right fertilizer source, rate, and timing. Fertilizer placement decisions depend on mobility of applied nutrients in the soil and the depth and distribution of the crop's root system. Various methods are used to apply fertilizers to horticultural crops, including broadcasting, banding, fertigation, foliar application, and microinjection. Generally, the most appropriate method for any crop increases productivity and profitability and improves fertilizer use efficiency but varies depending on the nutrient element, fertilizer source, soil characteristics, cultural practices, stage of crop development, weather conditions, and farming enterprise constraints. Comparisons among application methods are available for many crops and provide useful information for improving fertilizer placement practices, but many practical questions such as how fertilizer source and availability are affected by irrigation interactions or whether there are ways to manage crop roots for more effective nutrient uptake still remain.
Long-term Effects of Peach Production Systems for Standard and Pillar Growth Types on Yield and Economic Parameters
Authors: Glenn D.M. , Tworkoski T. , Scorza R. , Miller S.S.
Published: December 2018

The lack of dwarfing rootstocks for peach has led to cultural and genetic approaches that reduce tree size and vegetative growth to establish high-density plantings. The objectives of the study were to evaluate the interactions of pruning strategies, groundcover management, tree densities, and peach (Prunus persica) architecture combined in eight peach production systems on components of yield and economic value. The use of sod management reduced pruning time and costs, but the reduction of crop load reduced net return. High-density plantings in large vegetation-free areas (VFAs) had greater economic return than low-density plantings.