bluuebunny/crossref_metadata_2025 huggingface dataset:
(39) Chlorine Dioxide Treatment Extends Longevity of Cut Gerbera Flowers
Authors: Macnish Andrew J. , Leonard Ria T. , Nell Terril A.
Published: February 2019

The vase life of many cut flowers is often limited by bacterial occlusion of stem bases. In this study, we tested the efficacy of a novel antimicrobial agent, aqueous chlorine dioxide (ClO2), to extend the longevity of cut Gerbera flowers by reducing the number of bacteria in vase water. Commercially mature and freshly cut Gerbera jamesonii `Monarck' flowers were placed into clean vases containing deionized water and 0, 2, 5, 10, 20, and 50 μL·L-1 ClO2. Stems were then maintained in solutions at 21 ± 0.5 °C and 42 ± 11% relative humidity until the end of vase life. Inclusion of 2, 5, and 10 μL·L-1 ClO2 in vase water had beneficial effects on flower longevity. For instance, treatment with 5 and 10 μL·L-1 ClO2 extended flower longevity by 1.4-fold or 3.7 days, as compared to control flowers (0 μL·L-1 ClO2). In contrast, exposure to the higher concentrations of 20 and 50 μL·L-1 ClO2 did not extend flower vase life. Relative to control flowers, treatment with 10 μL·L-1 ClO2 delayed the onset of detectable bacterial colonization of vase solutions from day 3 to day 6 of vase life. However, this ClO2 treatment did not reduce the number of bacteria that subsequently accumulated in vase water as compared to control flowers. Treatment with 10 μL·L-1 ClO2 also increased rates of solution uptake by stems and reduced the loss of flower fresh weight over time. These results highlight the potential use of ClO2 treatments to extend the postharvest longevity of Gerbera flowers.
(393) Diversifying Into a New Market—Medicinal Herbs
Authors: Davis Jeanine M. , Greenfield Jacqulyn T.
Published: February 2019

Seventeen North Carolina farmers received $5000 grants to grow medicinal herbs as part of a research study to determine the economic feasibility of producing herbs in different regions of the state, including producing the quality and quantity of medicinal herbs required by the industry at a price that is competitive in a global market. With the help of five buyers in the natural products industry, four medicinal herbs were selected to be grown: California poppy, dandelion, Echinacea purpurea, and valerian. The growers experimented with new crops, learned new production methods, and adapted existing methods and equipment to these crops. These growers were also introduced to new markets and made connections with buyers, statewide and nationally, in an industry that can be difficult to enter. Growers were responsible for keeping detailed records of production, harvest, and postharvest handling. To produce a marketable crop in 1 year, some of the growers started seedlings in their greenhouses, while others direct seeded into the field. With the natural products industry moving toward a nonchemically grown product, growers in this project had to produce their crop without pesticides. Weed pressures were the biggest challenge to most of the growers. Prior to harvest, bioactive constituents were tested on the dried raw material to see if levels met buyers' requirements. Other testing methods determined percentage of ash, moisture content, microbial limits, and heavy metal accumulation. For postharvest handling, tobacco farmers who had drying facilities experimented with different temperature regimes to produce a uniformed dried material. Buyers and growers were then introduced to each other to complete the sale of goods.
(395) Greater Inoculation Rate Enhances Biological Efficiency and Returns of Shiitake Mushrooms
Authors: Sabota Cathy M. , Beyl Caula A.
Published: February 2019

To determine if biological efficiency of shiitake mushrooms was affected by the density of spawn inoculation, white oak logs about 31 inches (0.79 m) long were cut from trees harvested 14 Apr. and inoculated 6 May 2003 with strain WR46 of Lentinula edodes using four rates of inoculation. The number of holes drilled and inoculated with spawn was determined by multiplying the weight of each log by 0.5, 1, 2, or 3. A 15-pound log (6.8 kg) inoculated at “3” times the weight would have 45 holes drilled and inoculated. Each rate of inoculation treatment was replicated three times with three subsamples per replication. After six harvests over a 21-month period, the biological efficiency (BE) of the logs increased by 1.94% per additional hole per pound (0.45 kg). This increase in BE would result in $1.15 in additional returns per log with a cost of only $0.15 more per log due to increased spawn use, resulting in a net profit, excluding increased labor and wax costs, of $1.00 per log.
(445) Responses of Several Herbaceous Perennials and Groundcovers to Salinity
Authors: Niu Genhua , Rodriguez Denise S.
Published: February 2019

In order to use reclaimed water to irrigate landscape plants and minimize damage and loss, salinity tolerance of commonly used landscape plants needs to be identified and characterized. Eight herbaceous perennials and groundcovers were obtained from a nursery, transplanted to 2.6-L plastic containers, and grown in the greenhouse for 2 weeks before salinity treatments (1.0, 3.2, 6.4, and 12 dS·m-1) were initiated. Plants were irrigated with measured amounts of saline solutions to obtain a 30% leaching when ≈50% water was depleted. After 12 weeks, half of the plants in each treatment were destructively harvested and dry weights of shoots and roots were taken. Three Penstemon species (pseudospectabilis, eatoni, and strictus) and Lavandula angustifoliaat 6.4 and 12 dS·m-1 and most of them at 3.2 dS/m did not survive. Shoot dry weight of Delosperma cooperidecreased by 25% at 12 dS·m–1, but there were no significant differences among the rest of the treatments. All plants of Teucrium chamaedryssurvived, but growth was reduced significantly with lower visual scores as salinity of irrigation water increased. Although growth was reduced in Gazaniarigensas salinity increased, no other signs of stress were observed. Ceratostigma plumbaginoides had less growth at 3.2 dS·m–1, and older leaves showed reddish pigmentation at 6.4 dS·m-1, whereas those at 12 dS·m-1 did not survive. Among the tested species, D.cooperiand G.rigensindicated a high tolerance to salinity; T. chamaedrysand C. plumbaginoides were moderately tolerant; and the rest were salt sensitive.
(450) Drought Responses of Ornamental Herbaceous Perennials
Authors: Z Nickolee , Kjelgren Roger , Cerny-Koenig Teresa , Koenig Rich , Kopp Kelly
Published: February 2019

We investigated drought responses of Echinacea purpurea, Gaillardia aristata, Lavandula angustifolia, Leucanthemum ×uperbum `Alaska', Penstemonbarbatus`Rondo', and Penstemo×mexicali `Red Rocks' established in a 10-gal pot-in-pot system in northern Utah. Plants were irrigated at frequencies of 1, 2, or 4 weeks between June and Sept. 2004. Osmotic potential, gas exchange, visual quality, leaf area, and dry biomass were assessed. In a confined root zone, P. barbatusshowed the greatest tolerance to drought, avoiding desiccation by increasing root: shoot ratio and decreasing transpiration as water became more limiting. Plants maintained high visual quality throughout the study and experienced little wilt, burn, or dieback. However, P. barbatus above-ground biomass was reduced by 15% for the 2-week treatment and by 40% for the 4-week treatment. Alternatively, G. aristata and L. superbum displayed drought avoidance mechanisms, dying back when water was limiting and resprouting after they were watered. Above-ground biomass declined by 50% and 84% for G. aristata and 47% and 99% for L. superbum, respectively, for the 2- and 4-week treatments. Root mass was affected similarly for both species. However, transpiration remained high for all treatment levels. Leaf burn and reduction in above- and below-ground biomass were also evident for E. purpurea at the 2- and 4-week treatments, but results were not as pronounced as for G. aristata and L. superbum. Overall, P. barbatusexhibited the greatest drought tolerance while maintaining an acceptable appearance. G. aristata, contrary to expectations, did not exhibit drought tolerance with a confined rooting volume, suggesting that it avoids drought in landscapes by means of deep rooting.
(451) Acclimation to Long-term Water Deficit Stress in Four Birch Taxa (Betula L.): Water Relations and Gas Exchange
Authors: Gu Mengmeng , Rom Curt R. , Robbins James A.
Published: February 2019

Four birch taxa, Betulaalleghaniensis, B. davurica, B. nigra `Heritage', and B. papyrifera, were grown in a greenhouse and exposed to water deficit stress for 35 days. Daily water was withheld from the plants until the combined weight of each container and the plant was reduced to 40% of the control. Supplemental water was supplied to each container to maintain 40% of the initial combined weight. Predawn water potential, gas exchange, and abscised leaf area were measured daily during the first week and at 3-day intervals after the first week. Predawn water potential dropped to lowest value before the containers were rehydrated and remained low throughout the treatment period. Net CO2 assimilation (A), stomatal conductance (gs) and evapotranspiration (Et) of all taxa decreased significantly during the first week of water deficits. Changes in A and Et varied among taxa after the first week of water deficits. Water use efficiency (WUE = A/Et) of four birch taxa decreased to significant lower values than control in the first week that water was withheld, and then increased to significantly higher values than control. Gas exchange data were fit into 2- or 3-segmented linear model. The type and shape of the models, and the joint of each segment gave an indication of how the gas exchange responded to the long-term water deficit stress. At the end of the water deficit treatment, B. papyrifera had abscised most of its leaves and maintained a high A, while B. alleghaniensis maintained more leaves on the tree, but had a relatively low A.
(323) Alternate Approaches for Evaluating Horticultural Efficiency
Authors: Righetti Timothy L. , Vasconcelos Carmo , Sandrock David R. , Ortega Samuel , Moreno Yerko
Published: February 2019

Four ratio-based efficiency expressions (yield/trunk cross-sectional area, yield/canopy area, yield/pruning weight, CO2 assimilation/leaf area) were evaluated. These expressions depend on the size of the denominator if the function describing the relationship between the denominator and the numerator has a non-zero intercept. When this occurs, it is difficult to determine if statistically different efficiency expressions reflect physiological differences or are caused by comparing expressions with different sized denominators. When denominators and numerators of efficiency expressions are plotted, the edge of the data cloud can often be statistically identified. The function describing the edge of the data cloud defines the maximum possible value (MPV) obtainable for a given value of the denominator. The percentage of MPV (%MPV) is an alternate efficiency expression that is not influenced by differing trunk cross-sectional area, canopy area, pruning weight, or leaf area. The difference between MPV and observed performance can be used to define improvement potential (IP). These alternate assessments can supplement traditional efficiency expressions. It is also possible to determine if statistical differences in traditional efficiency expressions are caused by differences in potential, differences in a plant or leaf's ability to achieve its potential, or differences in the size of the efficiency expression denominators.
(12) Detection of QTL for Three Individual Sugar Compositions in Muskmelon
Authors: Park S. , Sinclair J. , Crosby K. , Yoo K. , Pike L.
Published: February 2019

The ratio of individual sugar compositions is an important fruit quality trait in muskmelon. Our objective was to identify RAPD markers associated with QTL for percentage of each individual sugar (sucrose, glucose, and fructose) using bulked segregant analysis in an F2 population derived from the melon cross of `TAM Dulce' (high sucrose percentage of total sugars) x TGR1551 (low sucrose percentage of total sugars). Continuous distributions for sucrose, glucose, and fructose percentages of total sugars were observed in the genetic population indicating quantitative inheritance for the traits. A significant positive correlation was observed between sucrose percentage and sucrose (r= 0.89) or soluble solids (r= 0.33), whereas a significant negative correlation was noted between sucrose percentage and glucose percentage (r = –0.85) or fructose percentage (r = –0.58). A total of 500 primers was used to screen between low and high DNA bulks for three individual sugar percentages. Ten RAPD markers, four amplified from `TAM Dulce' and six amplified from TGR1551, were significantly associated with QTL for at least one individual sugar percentage. Of the 10 markers identified, six were consistently associated with two to three traits. The OAU13.1350 obtained from `TAM Dulce' accounted for 13% and 19% of the phenotypic variation for sucrose and glucose percentages, while OAW06.600 obtained from TGR1551 explained 17% and 18% of the variation for the two traits. The OAA09.350 and OAU05.600 markers accounted for 4% to 13% of the variation for three sugar percentages. These markers associated with QTL for three individual sugar compositions could be useful in melon breeding for improving the mature fruit quality.
(80) Calculating Base Temperature and Leaf Appearance Rate for Sweet Viburnum
Authors: Schoene Gisele , Yeager Thomas , Ritchie Joe
Published: February 2019

In crop models, it is important to determine the leaf area, because the amount of light interception by leaves influences two very important processes in the plant: photosynthesis and evaporation. Leaf area is dependent on leaf appearance and expansion rates. Leaf appearance rate is driven mainly by temperature. Although the influence of temperature on leaf area development is well known for several agronomic crops, there is no information for woody ornamentals. An experiment was conducted to study the relationship between temperature and leaf appearance of container-grown sweet viburnum. Plants were grown in field conditions in Gainesville, Fla., during two growing periods (Apr. to Aug. 2004 and Aug. 2004 to Jan. 2005). Daily maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and base temperature was assumed to be 8 °C. Thermal time (°C d) was calculated as daily average maximum and minimum air temperature minus the base temperature and was regressed against leaf number. The sum of accumulated thermal time was found to be linearly correlated with leaf number. Phyllochron, which is the thermal time between the appearances of successive leaves, was estimated 51 °C per day. The information presented in this study will be useful in modeling water use of sweet viburnum in response to environmental conditions.
(83) New Weed Problems in Midwest Turfgrass and Horticultural Crops
Authors: Trewatha Pamela B.
Published: February 2019

Through contacts, observations, and travel throughout the midwestern United States during Spring and Summer 2004, a number of weed species were noted to be relatively new problems, or growing problems in turfgrass and/or horticultural cropping situations. These include hophornbeam copperleaf (Acalyphaostryifolia), garlic mustard (Alliaria petiolata), blackgrass (Alopecurus myosuroides), Palmer amaranth (Amaranthuspalmeri), waterhemp species (Amaranthus spp.), biennial wormwood (Artemisiabiennis), lambsquarters complex species (Chenopodium spp.), windmillgrass (Chlorisverticillata), showy chloris (Chlorisvirgata), Asiatic dayflower (Commelinacommunis), horseweed (Conyzacanadensis), redstem filaree (Erodiumcicutarium), toothed spurge (Euphorbia dentata), dovefoot geranium (Geranium molle), pitted morningglory (Ipomoealacunosa), purple deadnettle (Lamium purpureum), birdsfoot trefoil (Lotuscorniculatus), roundleaf mallow (Malvarotundifolia), star-of-bethlehem (Ornithogalumumbellatum), cressleaf groundsel (Packeraglabella), striate knotweed (Polygonum erecta), creeping yellow fieldcress (Rorippa sylvestris), lanceleaf sage (Salviareflexa), sibara (Sibaravirginica), white campion (Silene latifolia ssp. alba), hairy nightshade (Solanumphysalifoium), spiny sowthistle (Sonchusasper), and others. Possibilities for this increase or spread include natural invasiveness of the weeds, control of previous weed competitors, resistance to widely used herbicides, changes in cropping practices, and other weed adaptations to current weed management methods.
(90) Coleus: Landscape Performance Results from 2003 and 2004
Authors: Owings Allen , Witcher Anthony , Broyles Allen
Published: February 2019

Coleus were trialed for landscape performance during 2003 and 2004 at Burden Center in Baton Rouge, La. This included a mid-spring through fall evaluation in 2003 and a spring through summer and summer through fall evaluation in 2004. Over 45 cultivars, including the Solar, Hurricane, Stained Glassworks, and Aurora series, were evaluated. Visual quality ratings were taken twice monthly and included compactness, foliage color, uniformity, and overall aesthetics. Flower observations were noted. Beds were located in full sun and consisted of a raised row of an Olivier silt loam soil. Plants were drip irrigated as needed to prevent stress. A separate study compared sun and shade (60%) performance of Kong coleus cultivars in the late summer through fall 2004. The Solar series performed well in 2003 and 2004, and generally had visual quality ratings signifi cantly greater than cultivars in the Hurricane, Stained Glassworks and Aurora series. Height was also greater in the Solar series. The Hurricane series had signifi cant flowering early in the evaluation periods, although `Louise' was slower to fl ower than `Benji' or `Jenni'. Kong coleus cultivars in 60% shade were about 50% shorter than those in full sun. `Aurora Black Cherry' was superior to the other cultivars in the series in terms of visual quality and slowness to fl ower. `Mississippi Summer Sun' (a/k/a Razzle Dazzle) and `Red Ruffle' were top performers among the nonseries cultivars evaluated.
(144) ePortfolios: A Philosophy for Improving Education in Horticulture
Authors: Reinert Michael E. , Stearns Dan T.
Published: February 2019

ePortfolios are gaining popularity in academic communities worldwide. Purposes of ePortfolios include: converting student work from paper to digital format, thereby allowing it to be centrally organized, searchable, and transportable throughout their academic lives and careers; promoting student centered learning and reflection; improving advising; and career planning and resume building. Pennsylvania State University is investing in the use of ePortfolios in course work throughout the university system. To facilitate these efforts, the university provides all students and faculty with 500 MB of hosted web space to create and share their portfolios. One of the courses using ePortfolios is Horticulture 120, Computer Applications for Landscape Contracting, in the Landscape Contracting program. Outcomes of implementing ePortfolios include increased availability of student work to potential employers, enhanced recruiting through displays of student work, and enabled reflection on completed work. Students showed improved quality in project work because their projects would be publicly available through the Internet to potential employers, faculty, family, and other students.
(99) Development of an Ohio Tree Liner Production System in Retractable Roof Houses; Field Comparisons with West Coast-grown Liners
Authors: Mathers Hannah M. , Grosskurth Elizabeth , Bigger Michele , Case Luke , Pope Jenny
Published: February 2019

Currently, the majority of tree liners used in the Ohio nursery industry are imported, mainly from the West Coast. The Ohio growing season is 156 days, whereas the Oregon season is 225 days. We are developing an Ohio liner production system, utilizing a retractable roof greenhouse (RRG) that extends the growing season. Liners grown in a RRG have shown greater caliper, height, and root and shoot dry weight than those grown outside of a RRG (Stoven, 2004). The objective of this research was to compare the growth of RRG-grown liners, outdoor-grown liners, and West Coast-grown liners when planted in the field. Four tree species [Quercus rubra, Malus `Prairifire', Acer ×freemannii `Jeffersred' (Autumn Blaze®), and Cercis canadensis] were started from either seed or rooted cuttings in early 2003. They were grown in a glass greenhouse and then moved to their respective environments in March (RRG) and May (outside). In Oct. 2003, the Ohio-grown liners were planted in the field at the Waterman Farm of The Ohio State University, Columbus. In Spring 2004, liners from the West Coast were purchased and planted in the same field setting. Caliper and height were measured in June and Sept. 2004. After one season in the field, trees grown from the RRG and outdoor environments resulted in greater height and caliper than the West Coast liners in Malus, Acer, and Cercis. Acer liners from Oregon had a greater increase in height from June to September than those grown outdoors or in the RRG. Quercus liners from the RRG and outdoor environments displayed greater caliper growth and growth in height than those from the West Coast. Across all species, liners grown from the RRG had the greatest increase in caliper growth.
(102) Monitoring Nutrient Mitigation at a Container Nursery Wetland: A 3-Year Study
Authors: Taylor Milton D. , White Sarah A. , Klaine Stephen J. , Whitwell Ted
Published: February 2019

Container-grown plants require large amounts of water and nutrients during their production cycle. This results in substantial runoff that is contaminated with nitrogen and phosphorus. At our study site, nutrients were delivered through incorporation in the potting media as timed-release prills and through liquid feeding by injection into irrigation water. Mitigation of nutrients in runoff water was dealt with proactively by the container nursery with construction of 3.77 ha of planted wetlands to receive runoff from a 48.6-ha drainage basin and excess water diverted from adjacent watersheds. Water flowed though drains between wetland cells and eventually into stilling ponds before it was allowed to exit the property. Water flow through the wetlands ranged from 1.1 to 3.1 million liters per day over the period. Three years of monitoring data indicate some seasonal differences in nitrogen removal efficiencies. Nitrogen removal between March and November averaged ≥95% while removal during winter (December through February) averaged ≥72%. Nitrogen (as nitrate) varied from 4.28 ppm to ≤0.01 ppm in wetland discharge, well below drinking water quality standards, but occasionally above levels that may cause downstream eutrophication. Orthophosphate phosphorus removal was highly variable with greatest removal occurring during late spring, late fall, and winter. There was a significant net export of phosphorus during some summer months for years 2 and 3. Phosphorus levels in wetland discharge ranged between 0.84 and 2.75 ppm. While there is currently no legal water quality standard for phosphorus, these levels were above the generally accepted level for preventing downstream eutrophication.
(173) Monolithic Slag as a Substrate for Rooting and Production of Bare-root Cuttings
Authors: Blythe Eugene K. , Sibley Jeff L. , Tilt Ken M.
Published: February 2019

Stem cuttings of Hydrangea paniculata Sieb., Rosa L. `Red Cascade', Salvia leucantha Cav., and Solenostemon scutellarioides (L.) Codd `Roseo' were inserted into six rooting substrates: monolithic slag [(MgFe)2Al4Si5O18], sand, perlite, vermiculite, Fafard 3B, or fine pine bark. Rooting, initial shoot growth, and ease of dislodging substrate particles from root systems upon bare-rooting by shaking and washing cuttings rooted in monolithic slag were compared to cuttings rooted in the five other substrates. Rooting percentage, number of primary roots per rooted cutting, and total root length per rooted cutting for cuttings rooted in monolithic slag were generally similar to the five other substrates. Particles of monolithic slag were dislodged more readily from root systems by shaking than were the other substrates. Gentle washing removed almost all particles of monolithic slag and sand from the root systems of all taxa and removed almost all particles of pine bark from all taxa except S. scutellarioides `Roseo'. Monolithic slag had a bulk density similar to sand, retained less water than the other substrates, and was similar to perlite, vermiculite, and pine bark in particle size distribution. Our studies indicate that monolithic slag, where regionally available, could provide a viable material for producing bare-root cuttings.
(178) Layering Propagation of Big tooth Maple, Acer grandidentatum
Authors: Rupp Larry A. , Varga William A. , Kjelgren Roger
Published: February 2019

Bigtoothmaple(Acer grandidentatum Nutt.) is of interest for its fall color and potential use in water-conserving landscapes. Clonal propagation of desirable selections would be beneficial. Since bigtooth maple commonly self-propagates by layering, we explored mound layering as a means of vegetative propagation. A stool bed was established in 1999 with seedlings grown from northern Utah seed. Beginning in 2001, seedlings were dormant pruned to their base and shoots allowed to grow until early July, when treatments were applied. At the time of treatment application for the reported experiments, shoot bases were girdled with 24-gauge copper wire, covered with conifer wood shavings, and kept moist during the growing season. The effects of rooting hormones and enclosure of the rooting environment on rooting were examined. On 7 July 2002, 32 trees were randomly selected and the four tallest shoots within each tree were treated with either 0, 1:5, 1:10, or 1:20 (v/v) solutions of Dip-N-Gro© rooting hormone (1% IBA, 0.5% NAA, boron). There was no significant difference in rooted shoots between treatments and 81% of the trees had at least one rooted shoot. On 9 July 2004, 39 trees were selected and two shoots per tree were girdled. One-half of the stool bed area was treated by underlaying the shavings with BioBarrier© (17.5% trifluralin a.i.). Measurements on 12 Nov. 2004 showed no apparent treatment effect on rooting and 90% of the trees had at least one rooted shoot. This research demonstrates that mound layering is an effective means of rooting shoots of juvenile bigtooth maples. Further research will examine the effectiveness of the technique in propagating mature clones.
(208) Production of Double-stemmed Grafted Tomato Plug Seedlings
Authors: Jung Ki-yun , Park Yu-Jin , Lee Jung-Myung
Published: February 2019

Cultivation of grafted tomatoes has been sharply increased in recent years. Millions of grafted seedlings were grown in California as well as other parts of the world, and the need for high quality grafted tomato seedlings is also rapidly growing. Since the price of grafted plug seedlings are 3–4 times higher than the nongrafted ones, production and commercial distribution of double-stemmed plugs, even though slightly more expensive than the single-stemmed plugs, will greatly cut down the expenses needed to purchase grafted seedlings. Several methods of producing double-stemmed grafted plug seedlings are presented and the advantages as well as the disadvantages of these methods will be fully discussed. Brushing or painting lanolin paste containing thidiazuron at 100–500 ppm to the lower node of the decapitated scion is effective in fast-growing cherry, whereas inducing double stems from the cotyledonary node of grafted scions appeared to be more practical for ordinary tomatoes for table use. Methods of grafting, especially in relation with machine grafting, will be discussed.
(211) Effect of Supplementary Light on Growth and Physiological Characteristics of Cucumber (Cucumis Sativus L.) Seedlings in the Greenhouse
Authors: Li Yuhe , Luan Feishi , Ma Hongyan
Published: February 2019

This experiment researched the effects of supplementary light on cucumber [Cucumissativus(L.)] seedling growth and some physiological characteristics under the same temperature. The purpose was to afford basic light condition control of cucumber cultivation in a greenhouse during winter to spring. Two cucumber cultivars, No. 3 `Jinchun' (greenhouse cultivar) and No. 7 `Longzahuang' (open field cultivar), were transplanted with supplementary light at different intensities. The experimental results indicate that plant height, leaf area, and stem diameter of cucumber seedlings were significantly increased with increasing intensity of supplementary light. Supplementary light at the cucumber seedling stage led to the increase of chlorophyll content, soluble sugar content, protein content, and CAT activity. At the same time, reduction in POD activity and MDA content with increasing levels of supplementary light was found. In addition, cells of supplementary light treatments have more chloroplasts, grana, and starch grains. Chloroplast growth of supplementary light treatments was better than CK. The grana lamella was arranged in order and its structure was clear. These results show that supplementary light could improve the growth of seedling plants, alleviate the damage of membrane lipid peroxidation, and facilitate chloroplast growth. The effects of supplementary light on the two cultivars were the same, but their extent was different. Effects on No. 7 Longzahuang were more significant than those on No. 3 Jinchun.
(371) Hydroponic Inoculation of Cranberry with Ericoid Mycorrhizal Fungus
Authors: Spada Piero A. , Workmaster Beth Ann A. , Kosola Kevin R.
Published: February 2019

Cranberry (Vaccinium macrocarpon) plants colonized with ericoid mycorrhizal fungi are capable of utilizing organic nitrogen sources that are unavailable to non-mycorrhizal plants. Despite the importance of mycorrhizal colonization in the nitrogen nutrition of wild cranberry, almost all measurements of cranberry nitrogen uptake and assimilation have been carried out with non-mycorrhizal plants. We have found that cranberry can be inoculated directly in solution culture. We cultured the ericoid mycorrhizal fungus Hymenoscyphusericaein liquid culture, harvested and rinsed hyphae, and added ≈200 mg fresh weight hyphae per rooted cranberry cutting (cv. Stevens) growing in a modified Johnson's solution. After 6 weeks, newly developed roots were most heavily colonized. We examined the effects of NH4+ concentration (5, 10, 20, 50, 100, and 500 μm NH4+) in solution on colonization rates. Colonization (% root length) increased with increasing ammonium concentration in solution, with maximum colonization at 50 and 100 μm NH4+; colonization was much lower at 500 μm NH4+. Cranberry inoculated with H. ericaein solution culture will be used for analysis of the effects of mycorrhizal colonization on uptake kinetics of NH4+, NO3-, and amino acids.
(350) A Water-wise Plant Recognition Program for Utah
Authors: Heflebower Rick , Cerny-Koenig Teresa , Waters Molly , Ward Ruby
Published: February 2019

A cooperative program to recognize water-wise plants for Utah landscapes was developed by 10 horticulture and water organizations throughout the state. Representatives from each of the organizations met to develop a plant list containing woody and ornamental species that were attractive in the landscape, water conserving, adapted to the climate, and available in the industry. A yellow tag with the words “water-wise plant” outlined by the state of Utah was designed by the committee and used to identify the plants. Tags were provided at no cost to garden centers due to the funding of the organizations. A survey conducted at the end of the first season gave very favorable results. Sixty-seven percent of the participating nurseries indicated they would “definitely” participate in the program again, and 27% indicated they “probably” would participate. The Water-Wise Plant Tagging Program serves as a model of how universities, governmental agencies, and private businesses can work together to accomplish a common goal.
(404) Effect of Seed Source, Light during Germination, and Cold-moist Stratification on Seed Germination in Three Species of Echinacea
Authors: Romero Fredy R. , Delate Kathleen , Hannapel David J.
Published: February 2019

With the increase in popularity of echinacea as a botanical supplement, organic production of this herb continues to grow. Echinacea seeds typically show a high percentage of dormancy that can be broken by ethephon or gibberellic acid, but these methods are not accepted in organic production. We examined in three experiments the effects of varying seed source and germination conditions on echinacea growth. To determine the efficacy of nonchemical treatments, we evaluated the effect of light with and without cold-moist stratification on seed germination of the three most important medicinal species of echinacea, E. angustifolia, E. purpurea, and E. pallida. We used cold-moist stratification under 24 h light, 24 h dark, and 16/8 h (light/dark) to break seed dormancy. We found that germination was enhanced in seeds from a commercial organic seed source, compared to a public germoplasm source. When seeds were not cold-moist stratified, light increased germination in E. angustifolia only, suggesting differential dormancy among the three species. We found that when seeds were cold-moist stratified under 16–24 h of light for 4 weeks, the percentage and rate of germination increased 10% over the control, suggesting this method as an alternative to chemical seed treatments.
(406) A Comprehensive Echinacea Germplasm Collection Located at the North Central Regional Plant Introduction Station, Ames, Iowa
Authors: McCoy Joe-Ann , Widrlechner Mark , Carstens Jeff
Published: February 2019

Echinacea is becoming a well-established, high-value crop, both as an ornamental and a dietary supplement. A comprehensive collection of Echinacea germplasm is conserved by the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa, and is available via seed distribution for research and educational purposes (ars-grin.gov/npgs). Representing all nine species collected throughout their respective North American geographic ranges, the Echinacea collection includes 179 accessions. Extensive morphological characterization data associated with this collection have been compiled and are available to researchers on the Germplasm Resources Information Network (GRIN) database to aid in selection criteria. The collection has been used extensively for various research projects, ranging from ornamental breeding studies to HPLC analyses of metabolites of interest to the phytopharmaceutical industry. This poster will summarize the Echinacea collection conserved at the NCRPIS, including a list of available accessions by species, illustrations of seed, and control-pollinated cage propagation methods; and facilities utilized for seed cleaning, testing, and storage. In addition, instructions on how to use the GRIN database to view evaluation data and acquire germplasm will be provided.
(408) Effects of Essential Oils on CO2 Assimilation, Stomatal Conductance, and Evapotranspiration of Apple
Authors: McAfee Jason , Rom Curt
Published: February 2019

Pesticides and alternative fruit thinners are needed for certified organic fruit growers. Transient reductions in photosynthesis (Pn) have proven an effective technique for fruit thinning. Pesticides can be detrimental to plant growth by Pn reduction. This study was developed to measure plant response to foliar applications of essential oils at 2% concentrations. Treatments were applied to vegetative apple trees grown under controlled environment conditions to study photosynthetic effects. There was no significant effect on Pn for treatments; however, clove oil was very phytotoxic and defoliated all trees in this study. Cinnamon oil and cedarwood oil significantly decreased evapotranspiration and stomotal conductance 1 day after treatment. Differences in plant growth were not significantly different for all treatments excluding clove oil. Studies on concentration effects may determine horticultural usefulness of these compounds.
(412) Tomato Diseases
Authors: Krizek Donald , Millner Patricia , Camp Mary , Clark David , Davis Mark , Butler Bryan , Teasdale John , Fravel Deborah , Reynolds Sara , Mangum Ruth , Currier Ted
Published: February 2019

Afield study of organic production of tomato (Lycopersiconesculentum Mill.) in high-tunnels was conducted in 2004. `Mountain Fresh' was transplanted 31 Mar.; `Ultra Sweet' and `Sun Leaper' were transplanted on 21 July. The primary objective was to determine the feasibility of obtaining two crops of fresh-market tomatoes by starting plants 4–8 weeks earlier than the average last spring-killing frost, and extending the growing season 4–6 weeks past the average first fall-killing frost. Plants were started at weekly intervals for 4 weeks in both seasons. Data and observations were recorded on the yield of marketable fruits, plant growth and development, and plant health. Other objectives were to evaluate: 1) the benefits of using a selective UV-blocking film on plant growth and development, disease events; and 2) compost amendments on soil improvement and disease control. Major cultural challenges included water management, soil texture/drainage, prevention of chilling injury, plant support, and adequate ventilation. Major disease/pest challenges involved stalk rot caused by Sclerotinia sclerotiorum in the spring, powdery mildew in spring and late summer, Alternaria and Septoria leaf blight in late summer, and aphids, tomato hornworm, corn earworm, and beet army worm also in late summer. In addition, macrofaunal intrusions by fox, mice, and birds occurred sporadically. Poor drainage and stalk rot in the spring necessitated relocating the tunnels to an uninfested site with better drainage. The fall crop yielded high numbers of marketable quality fruits, well beyond the 15 Oct. average killing frost date. The results suggest that with improved management, there is a considerable potential for profitable extended-season production of organic tomatoes in this region.
(419) The Relation of Cooperative Extension Programs, Materials, and Publications for Organic Farming Systems as Relates to Production
Authors: Harper Kristen , Rom Curt R.
Published: February 2019

Since the passage of the Organic Foods Production Act in 1990, certified organic produce has begun to make a large impact on national markets. However, USDA statistics indicate that many states in the southern region have considerably reduced certified organic acreage when compared to other regions in the United States. The absence of organic acreage may perhaps originate with a lack of training and educational materials provided to producers due to unanticipated growth of organic markets. A thorough review of all Arkansas Cooperative Extension Service (ACES) materials, such as bulletins, publications, and workshops over the past 10 years, would reveal what information has been provided to producers on certified organic production. This review of ACES materials defines the existing groundwork on which ACES could construct future organic publications and outreach programs in order to sustain and stimulate organic farming within the state.
(220) Determination of Water and Nitrogen Requirements of Cabbage using Fertigation
Authors: McKeown Alan , Bakker Cathy
Published: February 2019

Fertigation is a promising strategy to improve nitrogen use efficiency, yield, and quality of cabbage (Brassica oleracea var. capitata), but there is a lack of data relevant to growers in Ontario. Field trials were conducted in 2003 and 2004 to determine the optimum rate of water and nitrogen application in terms of yield and quality of `Huron' cabbage. Treatments consisted of combinations of target soil moisture levels (25% to 100% field capacity) and nitrogen fertilizer (0–400 kg·ha-1 N) as dictated by a central rotatable composite design. Nitrogen applications were split with 50% broadcast and incorporated before planting and the remaining split into weekly applications via a trickle irrigation system. Water was applied two to three times per week to bring soil moisture up to the target levels. Maximum marketable yield was reached at a combination of 400 kg·ha-1 N and a soil moisture target of 100% field capacity. Many heads were undersized or undeveloped at low rates of nitrogen. Applications of nitrogen required for high yield and quality can pose a risk of leaching; however, use of fertigation minimizes potential in-season leaching. Estimated total residual nitrogen at harvest ranged from 83–211 kg·ha-1 N, which could have a negative impact on the environment. Thus, there is a considerable challenge to reduce environmental impact without economic losses. Improved knowledge of in-season nitrogen requirements might further reduce the levels of nitrogen applied without reducing yield and quality.
(436) Comparative Cold Hardiness and Freezing Behavior of Leaves, Buds, and Flowers in Selected Woody Plants in Northern Latitudes
Authors: Shirazi A.M. , Thierry M.V.
Published: February 2019

It is not well known how cold-hardy new buds and emerging leaves or flowers are during spring. Extreme temperature fluctuations that sometimes bring early frost in spring (April–May) are very common in northern latitudes and cause severe damage to emerging leaves and flowers. Even though most woody plants can tolerate frost in spring, others show early tissue damage and can fully recover. There are some trees, e.g., Japanese maples (Acer palmatum) that when leaves are damaged due to spring frost, the results include severe dieback and eventual death. We tested new flowers and leaves of four crabapples: Malus ×micromalus, M. sargentii, `Mary Potter', and M. hupehensis, after budbreak for 3 years using electrical conductivity (EC) and differential thermal analysis (DTA) in spring: May 1997, Apr. 1998, and Apr. 2000, at The Morton Arboretum. Both flowers and leaves can tolerate from –6 to –12 °C and we observed higher ion leakage in leaves than flowers. The high temperature exotherm (HTE) of flowers were –8 to –10 °C in April. In a companion study, testing other species that had premature budbreak due to “near lethal” (sublethal) freezing stress in Jan. 2001, the following HTE were observed: Cornelian cherry (Cornus mas) flower (about –7.5 °C), Spindle trees leaves (about –6 °C), Judd's viburnum (Viburnum ×juddii) (about –8 °C), Brevipetala witch-hazel (Hamamelis mollis`Brevipetala') flower (about –5 °C), redbud (Cercis candensis) flower (about –9 °C), flowering quince (Chaenomeles ×superba) flower (–8 °C). Multiple LTE at –13, –18, –22, and –27 °C were observed for Judd's viburnum. This information could be useful for selection and breeding of woody plants.
(113) Quantifying Landscape Microclimates and Related Cold Injury
Authors: Taylor Shadd , Harp Derald A. , McDowell Kristen , Lemus Roque
Published: February 2019

It is generally accepted that plants closer to structures benefit from the warmth emitted via imperfect insulation and solar energy reemitted as long-wave, thermal radiation. However, while claims of protection are given, little quantifiable information exists on the extent or pattern of this protection. We studied existing plantings of Trachelospermum asiaticum, an evergreen groundcover that is frequently damaged in northeast Texas. The plantings studied were part of a landscape with at least five different identifiable microclimates: 1) near building (NB); 2) mid-bed (MB); 3) bed edge (BE); 4) beneath Quercus virginiana (LO); and 5) beneath Pyrus calleryana`Bradford' (BP). We placed HOBO temperature data loggers recording one temperature per minute in each location. Following our first damaging freeze, we waited 7 days before collecting leaf samples. Leaf samples were collected by using a 25-cm square, 2 cm deep on two sides. The square was placed on the groundcover so that the top of the groundcover was level with the top of the square. All leaves and stems that extruded through the top 2 cm of the square were excised. Four samples were taken from each location, and the number of damaged and nondamaged leaves were counted for each sample. Leaves that were at least 50% discolored were considered damaged. Leaf damage data were analyzed using SAS Proc ANOVA. Leaves in the BE and BP locations showed significantly fewer live leaves than any other locations. NB leaves were virtually undamaged. Average temperatures in the BE and BP locations were 4.5 to 5 °F colder than the “near building” locations, comparable to an a or b zone in the current USDA Plant Hardiness Zone map.
(287) Chloroplast Small Subunit Rubisco Protein Is Ingested by Migratory Endoparasitic Nematodes
Authors: Khaithong Tridate , Sipes Brent S. , Kuehnle Adelheid R.
Published: February 2019

Lack of a conclusive evidence of ingestion of plastid components by plant-parasitic nematodes cautions the use of plastid transformation technology for nematode resistance. Nematode-resistant effector proteins generally require ingestion by the nematode to be effective. Transgene-encoded proteins produced in plastids are not known to be exported into the cytoplasm. Disintegration of plant cell organelles after nematode feeding suggests that nematodes possibly ingest plastid components. Proof of ingestion will validate the development of plastid transformation for nematode resistance. Small subunit ribulose-1,5-bisphosphate carboxylase/oxygenase (SSRubisco) protein is prevalent in chloroplasts and thus chosen as a study molecule. The migratory endoparasitic nematodes Pratylenchus penetrans and Radopholus similis were cultured on green carrot callus containing chloroplasts. Total nematode proteins were extracted and subjected to western blot analysis using cross-reactive polyclonal antibody raised against spinach SSRubisco. Positive detection of SSRubisco occurred in protein extracts from nematodes fed on green carrot callus, but not in extracts from nematodes cultured on non-green alfalfa root callus as negative control. These results confirm the ingestion of plastid components of MW 14 kDA by migratory endoparasitic nematodes.
(293) Single Nucleotide Polymorphism in matK and Ribosomal ITS of Astilbe
Authors: Trader Brian W. , Veilleux Richard E. , Scoggins Holly L.
Published: February 2019

The genus Astilbe (Saxifragaceae) comprises about 13 species and is ranked consistently among the top 10 landscape perennials. Through extensive hybridization, selection and marketing, the lineage of many Astilbehas been lost. Subdioecious Astilbebiternatais the only species in the genus native to North America while other members of the genus are endemic to Asia and monoecious. Due to the unusual geographic distribution of the species and the variation in floral development among them, development of genetic markers using single nucleotide polymorphisms (SNPs) would confirm phylogenetic relationships and establish lineage within the genus. Astilbespecies, hybrids, and cultivars were obtained from plant nurseries and botanical gardens across the country. To elucidate relationships among the genus, we conducted phylogenetic analysis of DNA sequences of the chloroplast gene matKand the internal transcriber spacer (ITS) of ribosomal rDNA genes. DNA was extracted, and gene primers trnK3914 and trnK2R were used to amplify matK, and primers 1406F and ITS2 were used to amplify the ITS1 region between 18S and 5.8S ribosomal DNA units. Both matKand ITS were sequenced for each plant specimen and sequences were aligned to identify nucleotide diversity and detect SNPs. Variation in nucleotide sequence for either gene yielded similar dendrograms. Nucleotide variation among the Astilbeutilized in this study has allowed the development of SNP markers that may be useful for fingerprinting unknown hybrids or cultivars in the industry, and may be used for species alignment within the genus.