bluuebunny/crossref_metadata_2025 huggingface dataset:
(97) Performance of `Ginger Gold' and `Gala' on Malling 9 and Budagovsky 9 over Ten Years
Authors: Crassweller Robert M. , Smith Donald E.
Published: February 2019

An apple planting was established in 1996 comprised of two cultivars: `Ginger Gold' (GG) and `Crimson Gala' (CG) on Malling 9 NAKB T337 and Budagovsky 9 at the Horticulture Research Farm at Rock Springs, Pa. The trees were planted at a spacing of 1.5 × 3.7 m in a randomized complete-block design with 10 replications. The trees were trained to a vertical axe system with a single wire set at 2.8 m, to which the conduit was attached. Data collected included trunk cross-sectional area (TCA), tree yield, number of fruit, and number of rootsuckers. Calculated data included annual tree growth, tree efficiency, average fruit weight, and crop load. In most years, there were significant cultivar × rootstock interactions for some variables. At planting and for the first two growing seasons, GG/B.9 were significantly larger than GG/M.9 as measured by TCA. At planting, there were no differences in TCA for CG, but, by the end of 1996, M.9 trees were significantly larger and stayed this way for the rest of the study. The GG/M.9 trees did not have significantly larger TCA than those on B.9 until 2005. Trees on B.9 were 23% and 31% smaller in 2005 for GG and CG, respectively, for B.9 than on M.9. Flowering occurred first and in greater abundance for GG/B.9. At the end of the 10th growing season, there was no difference in number of fruit or total yield per tree within cultivars by rootstock. However, for both cultivars, efficiency was highest for trees on B.9. Rootsuckers were greatest for trees on B.9. Fruit weight, when adjusted with number of fruit/tree as a covariate, was different for GG in some years.
(98) Molecular Analysis of Abscission Layer Activation in Apple Fruit Pedicels
Authors: Sun Lingxia , Park Sunchung , Bukovac Martin , van Nocker Steven
Published: February 2019

Abscission of leaves, floral organs, and fruit is a developmentally and environmentally regulated process initiated in specialized thin layers of cells within abscission zones (AZs). Very little is known about early molecular events that drive abscission, especially of fruit. Commercial apple production relies on the use of flower and fruit abscission-promoting and -inhibiting compounds to enhance fruit quality, control preharvest fruit drop, and maintain consistent annual bearing. The success of chemical treatments is strongly influenced by numerous factors, including environment, genotype, developmental stage of the fruit, and physiological state of the tree. Toward developing improved strategies for regulating fruit abscission, we carried out transcriptional profiling of competent-quiescent and activated abscission layers. We found that a decisive event in the sequential process of abscission layer development is the transcriptional activation of the MdPEL1 gene, encoding a plant pectate lyase protein and potentially involved in the degradation of the middle lamella of adjacent abscission layer cells. Additionally, regulatory elements of at least 12 homologous pectate lyase genes in Arabidopsis thaliana were found to direct expression in floral AZs and in dehiscence zones along valve margins, suggesting that these genes have evolutionary conserved function. This work identifies a novel role for pectate lyases in plants. Furthermore, many abscission-related genes identified in this study are being used to track biochemical and regulatory pathways that participate in abscission in response to chemical treatments or environmental effects.
(99) Using Naphthalene Acetic Acid, Prohexadione-Ca, Ethephon, and Scoring to Reduce Vegetative Growth in Upper Canopy of Apple Trees
Authors: Autio Wesley R. , Krupa James , Clements Jon M. , Greene Duane W.
Published: February 2019

In 2004, at full bloom, 3-year-old `Cameo'/G.16, `Gala'/M.9 NA-KBT337, `Gala'/G.16, and `Redmax'/B.9 apple trees were treated with naphthalene acetic acid (NAA, 1.5% in latex paint) in a 7.5-cm band completely around the central leader at the base of 2-year-old wood. NAA treatment reduced 2004 extension growth of the central leader by 14% and total shoot growth above the treatment area by 32%. `Cameo'/G.16 trees also were sprayed with prohexadione-Ca (250 ppm with surfactant and water conditioner) at full bloom, and additional trees were sprayed with ethephon (500 ppm with surfactant) 1 week after full bloom. These spray treatments were made only to the stems and foliage from the base of the central leader's 2-year-old wood to the top of the canopy. Ethephon reduced total shoot growth in 2004 by 26%, and prohexadione-Ca reduced it by 63%. Prohexadione-Ca also reduced fruit set of `Cameo' in 2004. Scoring (single knife cut completely around the circumference of the trunk) at the base of the 2-year-old wood in the `Cameo' trees resulted in a 23% reduction in leader growth and a 22% in totals shoot growth in the upper canopy in 2004. In 2005 at full bloom, 4-year-old `Golden Delicous'/B.9 trees were treated with NAA similarly to trees in 2004, except treatment at the base of 2-year-old wood was compared to treatment at the base of 1-year-old wood. Treating the base of 1-year-old wood reduced growth to a greater degree than comparable treatment at the base of 2-year-old wood. For the 1- and 2-year-old-wood treatments, the number of laterals produced from the 1-year-old wood was reduced 42% and 17%, and total shoot growth from 1-year-old wood was reduced by 49% and 31%, respectively.
(157) Weed Control in Organic Edamame Soybean Production
Authors: Silvernail Anthony , Bomford Michael K.
Published: February 2019

Weed control is a major challenge confronting growers transitioning to organic vegetable production. Organic standards require that growers manage weeds without synthetic herbicides while maintaining or enhancing soil quality. In 2005, we evaluated the effects of two seedbed preparation methods and six weed management tactics, compatible with organic standards, on soil quality indicators, weed pressure, and yield of edamame soybean [Glycine max (L.) Merrill]. Seedbed preparation was conducted with either a moldboard plow and roto-tiller or a spading machine. Weeds were managed by a) regular hand weeding, b) pre-emergent flaming, c) post-emergent incorporation of 100 g of corn gluten meal/m2, or weekly passes from crop emergence until row closure with d) a spring-tine weeder, e) a rolling cultivator, or f) a between-row flame weeder. Dominant weeds were smooth pigweed [Amaranthus hybridus (L.)], goosegrass [Eleusine indica (L.) Gaertn.], and giant crabgrass [Digitaria sanguinalis (L.) Scop.]. Smooth pigweed dominated in the corn gluten meal and spring-tine weeder treatments; goosegrass and giant crabgrass dominated in the two flamed treatments. Weed pressure was lowest, and crop yield highest, in the hand-weeded control and rolling cultivator treatments. Relative to these, crop yield was severely depressed by weed pressure in other treatments. The labile carbon concentration and enzymatic activity of soils was tested midseason, and at harvest, showed no significant treatment effects. Results suggest that the rolling cultivator offered the best weed control among the tactics tested, without adversely affecting soil quality.
(159) Effects of Sulfur Compounds on CO2 Assimilation, Evapotranspiration, and Stomatal Conductance of Apple
Authors: McAfee Jason D. , Rom Curt R.
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. A two-part study was developed to measure plant response to foliar applications of sulfur compounds. In study 1, 2% concentrations of various sulfur compounds were observed for potential physiological or pesticidal effects. Foliar treatments were applied to vegetative apple trees grown under controlled environment conditions to study photosynthetic effects. No treatments significantly reduced CO2 assimilation (A) and stomatal conductance (gs). Copper sulfate, ammonium sulfate, and potassium sulfate significantly reduced evapotranspiration (Et) 7 days after treatment. No significance was observed for plant growth. In study 2, a 2% potassium sulfate concentration significantly reduced A 22 days after treatment; however, no differences were observed for Et and gs. Differences in plant growth were not significantly different among treatments.
(161) Nitrogen and Carbon Cycling and Partitioning in Managed Understories of Organic Apples
Authors: Hoagland Lori , Carpenter-Boggs Lynne , Granatstein David , Peryea Frank , Smith Jeff , Reganold John
Published: February 2019

Organic orchards represent a significant and growing component of Washington state agriculture. Comparison studies have shown that organic apple systems can be equally profitable yet more environmentally sustainable than their conventional counterparts. Despite this success, sustainable methods of weed control, fertility, and soil quality stabilization and improvement have remained a challenge. Intensive cultivation is commonly used to control weeds in organic orchards. This can lead to reduced or degraded soil organic matter, structure, water infiltration, aerated pore space, and other soil productivity parameters. In addition, tillage accelerates nutrient cycling and can result in the loss of valuable nutrients from the system. To address the need for sustainable organic methods of weed management, an integrated study of alternative understory management options was established in a newly planted orchard in 2005. Weed control measures included efficient tillage using a Wonder weeder, organically approved herbicide, wood chip mulch, and living cover mulches. Three rates of nitrogen (low, medium, and high) were applied across the Wonder weeder, wood chip, and living cover mulch plots in order to determine ideal N fertility rate. Analyses of total C and N and N-15 in organic fertilizers, soil pools, living cover biomass, and tree leaves are being used to track N and C cycling and partitioning, N-use efficiency, soil quality, and to determine optimal fertility guidelines. Preliminary results indicate intense competition between living mulch understory and orchard trees, and a trade-off may exist between maximizing soil quality and orchard productivity.
(221) Phenotypic Plasticity as an Indicator for Exotic Noxious Plants
Authors: Luo Jing , Tay David , Cardina John
Published: February 2019

Exotic noxious plants, including invasive plants and exotic weeds, have caused huge economic loss and ecological damage around the world. To prevent further introductions of such species as crops or ornamental plants, biological and ecological traits associated with invasiveness and weediness need to be identified so that prediction can be made on the potential of being noxious for proposed species. It was suggested that weeds were usually generalists that can survive and reproduce in a wide range of environments; i.e., they were quite “plastic” in response to different environments. In accordance to this idea, phenotypic plasticity has been recently proposed as an indicator and predictor for weeds and invasive plants. This hypothesis is tested using two exotic dandelion species: Taraxacum officinale (common dandelion), widespread weed, and T. laevigatum (red-seeded dandelion), which occurs in a much lower frequency in Ohio. A greenhouse experiment was conducted in which the two species were grown in two soil moisture levels (dry vs. wet) combined with two light exposure levels (full sun vs. shade). Various traits were measured to see whether T. officinale is more plastic than T. laevigatum in these four environments. The results show that, when using coefficient of variance (CV) as a measurement of plasticity, T. officinale has significantly larger CV than T. laevigatum in plant diameter (P = 0.02), shoot: root ratio (P = 0.04) and soil pH (P = 0.02). This indicates that T. officinale is more plastic in some of the resource-capture-related traits such as leaf morphology and biomass allocation, and presumably also in root exudates, which alter the soil pH.
(223) Profiling of Physical and Molecular Characteristics in Neotyphodium Isolates
Authors: Geary Brad , Benson Jared , Wood Steven , Logan James , Brulotte Ben , Chambers Alan , Maughan Jeff , Stevens Mikel
Published: February 2019

Endophytic fungi that are classified into the genus Neotyphodium have developed into a very unique niche. Their specific host plants are the fescues and ryegrasses. Through fungal biosynthesis of secondary metabolites, the host plant receives several benefits. These benefits include resistance to insects such as aphids, chinch bug, and argentine stem weevil, increased drought tolerance, and increased competiveness. These secondary metabolites comprise four groups of alkaloids. The alkaloids are loline, peramine, Lolitrem B, and ergovaline. The quantitative alkaloid profile is unique for each isolate. The characterization of these endophytes is necessary for identification of specific isolates. We report the characterization of ten endophytic strains Lp1, Lp2, Lp3, Lm4, Lm5, Fp6, Fp7 Fp8, Fp9, Fp10. The characterization of each isolate includes: morphology, sporulation, growth rates, microsatellite fingerprint, and alkaloid profile. The isolated colonies bear resemblance to raised brain-like structures and are yellow to tan in color. Growth rates range between 0.1 and 0.25 mm/day. No colonies produced any form of sporulation. Fp6 was found to have the highest loline concentration of any isolate. AFLP analysis was performed on the isolates to test for relatedness. Distinct clades were formed and grouped by host. The main groups were those isolated from Lolium or Festuca varieties. Isolates Fp8 and Fp9 were most related to each other, and have also been found to be doubly infected. The double infection is described to be Phialophora-like, due to the presence of thin highly branched hyphae when observed under light microscopy with aniline blue staining.
(277) Morphological and Molecular Diversity in Coreopsis leavenworthii Populations
Authors: Czarnecki David M. , Deng Zhanao , Rao Madguhuri N. , Gmitter Frederick G. , Choi Young A. , Norcini Jeffrey G. , Clark David G.
Published: February 2019

As one of the Florida's state wildflowers, Coreopsis leavenworthii is highly desirable for roadside plantings in all parts of the state. Seeds of this species are being produced by growers. Where should seed be produced for different ecotypes? Where can the seed be used? These are among questions that have arisen in commercial seed production and distribution. To address these questions, it was necessary to assess the levels of genetic diversity. Eleven populations (242 total individuals) were collected from different parts of Florida, grown at one location in central Florida, and observed for morphological variations. North Florida natural populations had more complex leaves, while south Florida natural populations had smaller flowers. Principal component analyses revealed that two of the seven characteristics studied accounted for as much as 88% of the morphological variations observed. Molecular diversity was analyzed by using the fluorescent amplified fragment length polymorphism (AFLP) technique and the capillary sequencing system. Four primer combinations detected 320 AFLP fragments, of which 90.6% were polymorphic. The overall genetic diversity in the species was 0.2206 (estimated using AMOVA), of which 77.9% was within populations and 22.1% was among populations. The genetic distance among populations seemed to be loosely correlated with geographical distances. A high level of gene flow was found in several populations. Based on the results, a model has been developed to describe the genetic relationship of Coreopsis leavenworthii populations.
(278) Genetic Variability and Relationship of Caladium Cultivars As Revealed with Molecular Markers
Authors: Deng Zhanao , Hu Jinguo , Goktepe Fahrettin , Vick Brady A. , Harbaugh Brent K.
Published: February 2019

Cultivated caladiums are valued for their bright colorful leaves and are widely used in containers and landscapes. More than 1500 named cultivars have been introduced during the past 150 years, yet currently only about 100 cultivars are in commercial propagation in Florida. Caladium tubers produced in Florida account for 95% of the world supplies. Loss of caladium germplasm or genetic diversity has been a concern to future improvement of this plant. In addition, the relationship among the available cultivars, particularly those of close resemblance, has been lacking. This study was conducted to assess the genetic variability and relationship in commercial cultivars and species accessions. Fifty-seven major cultivars and 15 caladium species accessions were analyzed using the target region amplification polymorphism marker technique. This marker system does not involve DNA restriction or adaptor linking, but shares the same high throughput and reliability with the amplified fragment length polymorphism system (AFLP). Eight primer combinations amplified 379 scorable DNA fragments among the caladium samples. A high level of polymorphism was detected among the species accessions as well as among cultivars. These markers allowed differentiation of all the cultivars tested, including those hardly distinguishable morphologically. Clustering analysis based on these DNA fingerprints separated the cultivars into five clusters and Caladium lindenii far from other caladium species. The availability of this information will be very valuable for identifying and maintaining the core germplasm resources and will aid in selecting breeding parents for further improvement.
(106) Delay of Flower Bud Phenology of Rabbiteye and Southern Highbush Blueberries With Soybean Oil and Abscisic Acid
Authors: Deyton Dennis E. , Sams Carl E. , Ballington Jim R. , Cummins John C.
Published: February 2019

`Legacy' southern highbush blueberry plants at the Middle Tennessee Research and Education Center were sprayed on 22 Feb. 2005 with 0%, 6%, 9%, or 12% soybean oil. The treatments were arranged in a randomized complete-block design with five replications. Flower bud abortion was evaluated by sampling 25 flower buds/plant on 21 Mar., dissecting, and visually examining buds for browning of ovaries. Flower bud phonology was rated periodically until first bloom and then percentage of open bloom was rated every 2 to 3 days. Fruit were harvested for yield and 50-berry samples taken weekly for the first 4 weeks to determine berry size. Sprays of 6%, 9%, and 12% soybean oil delayed the 50% open bloom date of `Legacy' by 2, 4, and 9 days, respectively, but also caused 9%, 35% and 87% mortality of flower buds. `Legacy' bushes sprayed with 0%, 6%, 9% and 12% soybean yielded 11.6, 13.7, and 10.3, and 4.5 lb/bush, respectively. Berry size was increased by 14% to 23% by oil sprays. In a second experiment, `Climax' blueberries in a commercial planting in Spring City, Tenn., were sprayed on 4 Mar. with water, 5% TNsoy14 (96% soybean oil, a.i.), 500 ppm abscisic acid (ABA) (Valent BioSciences Corp., Long Grove, Ill.), or the combination of oil and ABA (seven replications). Flower bud development and bloom were rated as previously described. Spraying 5% TNsoy14 or 500 ppm ABA delayed the 50% open bloom date by 1 day and the combination of the two delayed bloom by an additional day. On 5 Apr., `Climax' bushes sprayed with 5% TNsoy14, 500 ppm ABA, and 5% TNsoy14 plus 500 ppm ABA had 49%, 41%, and 20% open bloom compared to 70% open bloom on control plants. The 5% oil, 500 ppm ABA, and the oil plus ABA treatments did not significantly affect crop load or berry size.
(242) Callus Induction and Regeneration in Hydrangea macrophylla (Thunb.) Ser.
Authors: Fargo Erik C. , Adkins Jeffrey A.
Published: February 2019

Development of a reliable method for Hydrangea macrophylla (Thunb.) Ser. organogenesis is critical for developing an in-vitro mutagenesis protocol. Container-grown (11.8 L) H. macrophylla `Nikko Blue' plants were maintained in a controlled environment greenhouse, with supplemental lighting (1600 hr to 2400 hr mercury vapor lamp), fertilized with 65 g Nutricote total (18N–2.6P–6.6K, Agrivert, Inc., New York, N.Y.) and hand-watered. To reduce fungal contamination, stock plants were sprayed to run-off biweekly with Alliette WDG (375 mg·L-1, aluminum tris), Bayleton (250 mg·L-1, triadimefon), and Heritage (25 mg·L-1, azoxystrobin). Leaf explants were sterilized with 0%, 10%, 15%, or 20% bleach (5.25% sodium hypochlorite) (by volume) for 10 or 15 min, and stem explants were sterilized with 0%, 10%, 25%, or 50% bleach (5.25% sodium hypochlorite) for 10 or 15 min. About 97% of fungal contaminates were eliminated from leaf and stem explants when treated with 10% bleach for either 10 or 15 min. Leaves were plated on Gamborg B5 media at pH 5.7 containing 0, 2.5, 5, or 10 μM 2,4-D and 0, 0.25, 0.5, or 1.0 μM BAP and placed in a controlled environment growth room under a 14-h photoperiod or in a dark growth chamber. Callogenesis followed by root organogenesis was observed on explants treated with a variety of concentrations and combinations of 2,4-D and BAP. Strongest callogenesis was observed on media supplemented with 10 μM 2,4-D. A greater callus concentration was observed along the edges of dark cultured leaf discs. Indirect root induction was greatest on 10 μM 2,4-D.
(59) Encore Azalea Selections for the Mid South
Authors: Windham Mark , Trigiano Robert , Fare Donna , Pounders Cecil , Vito Lisa , Mynes James
Published: February 2019

Encore Azaleas® have become very popular in the Deep South due to multiple bloom cycles. All cultivars are rated for plant hardiness zone 7 and have also performed well in zone 8. The ability of Encore Azalea® cultivars to perform well in the Mid South (zones 6a and 6b) is unknown. A 3-year study was undertaken to determine the performance of 21 cultivars of Encore Azaleas® in multiple locations in zones 6a and 6b. After one winter, several cultivars have had multiple bloom cycles in zone 6a and 6b and suffered little or no freeze damage. These cultivars were Autumn Amethyst™, Autumn Bravo™, Autumn Carnival™, Autumn Chiffon™, Autumn Coral™, Autumn Monarch™, Autumn Rouge™, and Autumn Ruby™. Autumn Amethyst™ had the most consistent bloom cycles in both spring and fall cycles of all cultivars tested. Superior winter hardiness of Autumn Amethyst™ may be due to known winter hardiness of its female parent – `Karen's' (Hindodegiri × Rhododendron yeodensis var. poukhanese).
(189) Cultivar and Maturity Effects on Fruit Quality and Antioxidant Properties in Blackberry
Authors: Woods Floyd M. , Dozier William A. , Ebel Robert C. , Thomas Raymond , Nesbitt Monte , Wilkins Bryan S. , Himelrick David G.
Published: February 2019

Changes in fruit quality attributes and antioxidative properties from six cultivars of thornless blackberries (Rubus sp.) (`Apache', `Arapaho', `Chester', `Loch Ness', `Navaho', and `Triple Crown') during four different ripening stages (red, mottled, shiny-black, and dull-black) were determined under Alabama growing conditions. Berry fruit samples were evaluated for pH, titratable acidity, total soluble solids, TSS/TA ratio, soluble sugars, vitamin C (reduced, oxidized and total), and antioxidant capacity (measured as trolox equivalent antioxidant capacity, TEAC). Significant variation among cultivars were noted in fruit quality attributes and antioxidative properties, which were influenced by maturity at harvest. An increase in fruit pH concomitant with a decline in titratable acidity (TA) was observed during ripening for all cultivars. Total soluble solids (TSS) values increased from 5.7% to 11.6%, with associated TSS/TA ratio values ranging from 11.92 to 63.56 in ripening fruit. Highest reducing and total sugar content were contained in dull-black fruit. Vitamin C content either declined or remained unchanged with ripening, and the pattern was dependent on cultivar, maturity at harvest and form determined. In general, antioxidant activity declined between red and dull-black ripening stages. The results suggest that the TSS/TA ratio may provide the best maturity index in determining optimal eating quality and antioxidant capacity in terms of TEAC value the best indicator of optimal nutritional quality as influenced by maturity at harvest.
(191) UVC Light Treatment Reduces Decay of Blueberries
Authors: Perkins-Veazie Penelope , Collins Julie
Published: February 2019

Ultraviolet light treatment has been used successfully to reduce postharvest fungal decay in tomatoes, strawberries, peaches, and citrus, presumably through elevated spore death and/or increased phytoalexins. The purpose of this experiment was to determine the effectiveness of UVC light as a postharvest treatment for blueberries. `Blue Crop' and `Collins' fruit were harvested from a local grower in 2003 and 2004 and exposed to 0, 1000, 2000, and 4000 Joules of light (354 nm) supplied from 30-W germicidal bulbs. Fruit were held at 5 °C for 14 days. Application of 1000 to 2000 J UVC light reduced decay incidence by 10% compared to controls. The major decay organism was ripe rot (Collectotrichum gloeosporioides). Total phenolics, total anthocyanin, and ferric reducing absorbance power differed with variety, increased with storage, and were similar among light treatments. Firmness of non-decayed fruit was not affected by storage or treatment. Application of UVC light offers a means for reducing fungal decay in blueberries if applied at rates between 1000 and 4000 J.
(193) Effect of Pectin Oligomers on Strawberry Fruit Decay and Ethylene Production
Authors: Baldwin Elizabeth , Narciso Jan , Cameron Randy , Plotto Anne
Published: February 2019

Strawberry fruit were harvested on three different dates from the Strawberry Association plot (cv. Festival), a commercial farm (cv. Camino Real), and at the University of Florida Gulf Coast Research and Education Center (cv. Sweet Charlie), in central Florida in 2005 and 2006. Fruit were transported to the USCSPL in Winter Haven, Fla., sorted, dipped for 10 s in treatment solutions, drained and stored in commercial clam-shells at 15 to 19 °C. Percentage of decay (number of fruit with lesions) was monitored during storage. There were 10 fruit per replicate clamshell, and three to four replicates per treatment for each harvest. Treatments included three size classes of galacturonic acid (GA) oligomers with a degree of polymerization (DP) ranging from 1–13, 8–24, and 22–46 and undigested polygalacturonic acid at 0.2% in 50 mmol LiOAC, LiOAC/NaOAC, with 22% ETOH, or KOAC buffer (all buffers at pH ≈4.4), prepared by enzymatic digestion followed by differential pH and alcohol precipitation. The main pathogens found on these fruit were Rhizopus stolonifer and Botrytis cinera at 1×105 cfu/g fruit in 2005 and 5×107 in 2006. The medium range oligomers (DP 8-24) reduced decay significantly compared to buffer alone or to the lower or higher DP GA oligomers, and elicited ethylene production. Oligomers in this pectin size class have previously been reported to elicit ethylene and plant defense responses in plant tissues.
(320) Photographic and Post-processing Techniques for Horticultural Images
Authors: McConnell James
Published: February 2019

Numerous shooting and post-production techniques can be used to improve the quality of images used in horticultural publications. Certain lenses, lens attachments, and camera accessories are useful for enabling greater success in photographing plants. Small diffusers and reflectors allow the shooting of close-ups in the field, even when the sun is directly overhead. Shift lenses can be used to photograph trees at a closer distance without the extreme distortion of wide focal length lenses. Stitching of multiple images to produce panoramic shots can produce images with increased resolution, less distortion, and without the need for a wide-angle lens. Experiences with digital asset management management and post-production workflows are also presented.
(112) Bird Control in Production Strawberries with Falconry
Authors: Daugovish Oleg , Yamomoto Michi
Published: February 2019

California leads national strawberry fruit production with annual value in Ventura County alone near $300 million. Bird damage to fruit routinely accounts for 3–5% losses and may exceed 50% in some fields. Conventional bird control tools have limited or no effect on fruit damage and may contribute to noise pollution. A four-site study at Oxnard, Calif., from Jan. to Apr. 2005 (highest value fresh market season) showed that release of Peregrine, Saker, or Barbary falcons in combination with helium balloon launching (site 4) in response to fruit damage reduced fruit damage from 80–90% to 15–20% after 1 week. When fruit damage increased again (>20%) a repeated 1-week daily program completely reduced fruit damage during the rest of the season. Falconry alone at site 2 (near man-made structures) for two consecutive days reduced fruit damage from 70–80% to 10–20%, however, at site 3, near giant reed, three weeks of daily releases did not eliminate the damage, but confined it to the strawberry beds adjacent to reed shelter (reducing overall damage from 100% to 25–50%). High frequency of release is likely unfeasible and destruction of shelter habitat may be justified. Falconry alone before damage occurrence (site 1) seemed to prevent fruit damage; however, lack of birds and fruit damage before, during, and after releases made it difficult to draw conclusions about the success of the preventive program. In April, no fruit damage occurred even during bird presence suggesting the change in their diet. The study showed that seed-eating birds were the main pests at Oxnard, Calif., and that trained falcons can disperse them, thus, reducing fruit damage. The success of falconry was site-specific and depended on proximity of suitable habitat and availability of food sources for pest birds.
(115) Competition Between Vegetative and Reproductive Growth in Cranberry
Authors: Heuvel Justine E. Vanden , DeMoranville Carolyn J.
Published: February 2019

Competition between fruit and upright growth in cranberry has not been previously studied, but negative correlations reported between upright length/dry weight and yield indicate that sink demand from vegetative tissues may reduce fruit production. `Stevens', `Howes', and `Early Black' uprights and fruit were collected on either a weekly or bi-weekly basis through the growing seasons of 2002–04. The data indicated a shifting of resource allocation from leaf area and dry weight accumulation to fruit growth when about 1500 growing degree days (GDD, base 4.5 °C) had accumulated. Following the initial surge in fruit growth, leaf area and dry weight accumulation resumed at roughly 2300 GDD, resulting in a competition for resources with the developing fruit until after 3000 GDD. A lag phase in fruit diameter and dry weight accumulation was noted in some cultivars in some years, and may be partially due to the resumption of leaf growth. Roots, uprights, and fruit may all compete for resources during the hottest portion of the growing season.
(263) Rodent Preference for Pear Germplasm
Authors: Hunter David M. , Collucci Cheryl A.
Published: February 2019

Fall-dug nursery trees stored in a jacketed cold storage were damaged by rodent feeding over Winter 2004–05. Damage was primarily confined to the lower trunk region of the scion cultivar, with very little feeding damage to the Bartlett seedling rootstocks. Damage ranged from slight nibbling of some buds to complete girdling and bark removal of considerable length of the trunk. Position of the tree bundle in the storage appeared to have no effect on severity of damage. An arbitrary 7-point scale was used to rate the incidence and severity of damage on 22 cultivars. The least damaged cultivars were Moonglow, Giffard, and Butirra Precoce Morettini, while Thornless Seckel, Conference, and AC Harrow Gold showed the most severe damage. In late Spring 2005, all trees were replanted back into a nursery row to allow trees to recovery rates. However, only trees with damage ratings in the slight to moderate range showed signs of recovery during the 2005 growing season.
(266) Identifying Molecular Markers Correlating with High Beta-carotene Content in Muskmelon
Authors: Napier Alexandra B. , Crosby Kevin M. , Park Soon O.
Published: February 2019

Muskmelons (Cucumis melo L.) play an important role in the American diet. Ranked as one of the top 10 most-consumed fruits by the USDA, cantaloupe melons have the highest amount of beta-carotene of all the ranked fruits. Beta-carotene, also called pro-Vitamin A, is an essential nutrient required for eye health, and may have the potential, as an antioxidant to reduce the risks associated with cancer, heart disease, and other illnesses. Breeding melons with increased levels of beta-carotene will benefit consumer health. Research has found phytonutrients are most bioavailable when consumed in their fresh form, rather than as vitamin supplements. The high level of beta-carotene found in some melons has a genotypic component, which may be exploited to breed melons high in beta-carotene. Molecular markers and marker-assisted selection (MAS) can be used to increase the efficacy of the breeding process, while lowering breeding costs. An F2 population was created using `Sunrise', the female parent, containing no beta-carotene crossed with `TAM Uvalde', a high beta-carotene variety. A field population consisting of 115 F2 individuals and a greenhouse population containing 90 F2 individuals were grown. The resulting fruit were screened phenotypically and ranked according to beta-carotene content. Chisquare values fit the previously reported model of a single dominant gene for presence of beta-carotene (orange-flesh) vs. absence (green or white flesh). A continuous distribution of beta-carotene concentrations from high to low suggested quantitative inheritance for this trait. Two eight-plant DNA bulks composed of either high or low beta-carotene F2 individuals were screened for polymorphic molecular markers using the amplified fragment-length polymorphism technique.
(195) Optimizing Storage Conditions for Fresh Cranberries
Authors: Forney Charles F. , Bishop Stephanie , Elliot Michele , Agar Vivian
Published: February 2019

Extending the storage life of fresh cranberries (Vaccinium macrocarpon Ait.) requires an optimum storage environment to minimize decay and physiological breakdown (PB). To assess the effects of relative humidity (RH) and temperature on storage life, cranberry fruit from four bogs were stored over calcium nitrate, sodium chloride, or potassium nitrate salts, which maintained RH at 75%, 88%, and 98%, respectively. Containers at each RH were held at 0, 3, 5, 7, or 10 °C and fruit quality was evaluated monthly for 6 months. Both decay and PB increased with increasing RH in storage. After 6 months, 32%, 38%, and 54% of fruit were decayed and 28%, 31%, and 36% developed PB when stored in 75%, 88%, and 98% RH, respectively. The effects of RH continued to be apparent after fruit were removed from storage, graded, and held for 7 days at 20 °C. The decay of graded fruit after 4 months of storage in 75%, 88%, or 98% RH was 10%, 13%, and 31%, respectively, while PB was 12%, 12%, and 17%, respectively. Fresh weight loss decreased as RH increased averaging 1.9%, 1.4%, and 0.7% per month for storage in 75%, 88%, and 98% RH, respectively. Fruit firmness was not affected by RH. Storage temperature had little effect on decay. However, PB was greatest in fruit stored at 10 °C, encompassing 55% of fruit after 5 months of storage. When graded fruit were held an additional 7 days at 20 °C, decay and PB were greater in fruit previously stored at 0 or 3 °C than at 5, 7, or 10 °C. Fresh weight loss increased as storage temperature increased, averaging 0.8%, 1.0%, 1.3%, 1.7%, and 1.9% per month at 0, 3, 5, 7, and 10 °C, respectively. Fruit firmness decreased during storage, but was not affected by storage temperature. To maximize storage and shelf life, cranberry fruit should be stored in a RH of about 75% at 5 °C.
(198) Common Strategies to Manipulate Pre- and Postharvest Ripening of Fruit Fail with Pawpaw
Authors: Galli Federica , Koslanund Rumphan , Archbold Douglas D. , Pomper Kirk W.
Published: February 2019

Ripening pawpaw [Asimina triloba (L.) Dunal] fruit exhibit climacteric peaks of ethylene and CO2 production 48 to 72 hours after harvest, and thus may be considered climacteric. The development of desirable quality traits and the loss of fruit firmness during ripening is extremely rapid, and a variety of strategies to slow these processes via manipulation of ethylene production and/or response and by more direct techniques like postharvest heat treatment have been attempted. Fruit, branches with fruit, and/or whole trees have been sprayed with ethephon or aminoethoxyvinylglycine to hasten or delay ripening, respectively. After harvest, fruit have been treated with commercial and higher rates of 1-methylcyclopropene for various durations at ambient and cold storage temperatures. Fruit have also been heat-treated at various temperatures, using both brief “shock” treatments above 40 °C and longer periods at 35 °C to 40 °C. In addition, in an attempt to alleviate the loss of ripening capacity as well as the development of injury symptoms from cold storage for longer than 4 weeks, cold-stored fruit were warmed to ambient temperature intermittently and then returned to cold storage. While some effects of the treatments were noted, the responses to all of these treatment strategies have failed to appreciably alter fruit ripening, the rapid loss of firmness, or otherwise maintain fruit quality beyond that without treatment.
(281) Micropropagation of Trifoliate Orange Rootstock (Poncirus trifoliate Raf.)
Authors: Al-Wasel Abdelrahman
Published: February 2019

In vitro propagation of trifoliate orange rootstock (Poncirus trifoliate Raf.) was achieved using axillary buds taken from new flushes of mature trees and then cultured on Murashige and Skoog medium (MS). The addition of growth regulators [0.5 mg·L-1 gibberellic acid (GA3) or 0.1 mg·L-1 6-benzyladenine (BA) and 0.1 mg·L-1 indol-3-butyric acid (IBA)] were necessary to promote bud breakage and shoot elongation. Shoot proliferation was induced on MS medium supplemented with various levels of BA (0.0, 0.5, 1.0, 1.5, and 2.0 mg·L-1) and α-naphthalene acetic acid (NAA) (0.0, 0.1, and 0.5 mg·L-1). Maximal shoot multiplication (9.3 shoots/explant) and elongation (2.3 cm) occurred on media containing either 1.0 mg·L-1 BA alone or with 0.1 mg·L-1 NAA. Shoots rooted better and gave high root number (7.6 roots/shoot) and long roots (5.4 cm) when cultured on a liquid MS medium provided by 0.1 mg·L-1 NAA. Rooted shoots were successfully established in soil (≥90%).
(283) Biolistic Genetic Transformation of Carica papaya L. using the Helios™ Gene Gun
Authors: Guzmán-González Salvador , Valadez-Ramírez Pedro , Robles-Berber Rosa-Edith , Silva-Rosales Laura , Cabrera-Ponce José-Luis
Published: February 2019

Biolistic genetic transformation of plants with viral genes is a method for controlling plant virus diseases; however, optimization of the particle bombardment parameters according to the transformation system is a key factor for an appropiate transgene expression and, therefore, a stronger resistance mechanism in transgenic plants. In order to optimize biolistic parameters, somatic papaya (Carica papaya L.) cv. Maradol embryo masses were bombarded with the CAMBIA 1301 plasmid construction that contains the coat protein gene (CP) of the papaya ringspot virus isolate of Colima, Mexico, driven by the double constitutively CaMV 35S promoter and flanked for the GUS and hygromycin (hpt) resistance genes. Particle bombardment protocol was carried out using the Helios™ Gene Gun device (BioRad) and the manufacturer's instruction manual. Helium pressure (50, 100, and 150 psi) and gold particle size (0.6, 1.0, and 1.6 μm) were evaluated. Five days after bombardment, somatic embryo clusters were used for GUS transient expression and, during 2 months, were selected into 50, 75, and 150 mg·L-1 hygromycin-containing media to its later CP-PCR detection. Results showed that 50 psi and 1.0 μm were the two optimal values for the assayed analyses. This is the first report of genetic transformation of papaya using the Helios™ Gene Gun device as a new tool compared to conventional PDS-1000/He.
(45) Root Growth of Three Horticultural Crops Grown in Pine Bark-amended Cotton Gin Compost
Authors: Jackson Brian E. , Wright Amy N. , Sibley Jeff L.
Published: February 2019

In the southeastern United States, inconsistent pine bark (PB) supplies and overabundance of cotton gin by-products warrant investigation about the feasibility of replacing PB with cotton gin compost (CGC) for container horticultural plant production. Most research on the use of composted organic substrates for horticultural plant production has focused on shoot growth responses, so there is a need to document the effect of these substrates on root growth. In 2004, `Blitz' tomato (Lycopersicon esculentum), `Hot Country' lantana (Lantana camara `Hot Country'), and weeping fig (Ficus benjamina) were placed in Horhizotrons to evaluate root growth in 100% PB and three PB:CGC substrates containing, by volume, 60:40 PB:CGC, 40:60 PB:CGC, and 0:100 PB:CGC. Horhizotrons were placed in a greenhouse, and root growth in all substrates was measured for each cultivar. Physical properties (total porosity, water holding capacity, air space, and bulk density) and chemical properties (electrical conductivity and pH) were determined for all substrates. Physical properties of 100% PB were within recommended guidelines and were either within or above recommended ranges for all PB:CGC substrate blends. Chemical properties of all substrates were within or above recommended guidelines. Root growth of all species in substrates containing CGC was similar to or more enhanced than root growth in 100% PB.
(313) Utilizing Distance Education to Teach Emerging Topics in Horticulture Science: A Report on Four Years of Teaching Introduction to Agricultural Biotechnology
Authors: Orvis Kathryn
Published: February 2019

Advances in biotechnology are rapidly changing the way we work and live, but are often met with controversy or raise ethical questions. Approaches that enhance learning and awareness of biotechnology are essential to increasing citizen understanding of these topics. Educators, both formal and informal, need skills to understand the science associated with these technologies, as they may not have been previously exposed to the topics in their training, especially with the rapidly changing science. To address the need for unbiased agricultural biotechnology information, a graduate level internet-based course was developed entitled: “Introduction to Agricultural Biotechnology”. This course focuses on agricultural biotechnologies related to horticulture and plant science. Online courses are especially useful for students not able to travel due to various constraints, such as working full-time or being physically distant from campus. The goal is a population better able to understand the science behind rapidly advancing biotechnologies and that is better equipped to make informed decisions regarding those technologies. Course assignments are designed to help students as they teach others about topics associated with biotechnology in both formal and informal settings, such as a high school class or an Extension seminar. In the past 5 years, 54 students (teachers, college instructors, or Extension staff) from across the United States have taken the course. Course ratings have been consistently very good (avg. 4.45) on a 1–5 scale (1 = very poor, 5 = excellent). Former students have indicated that they have a better understanding of biotechnology and would be better able to relate it to others. Students also gained an improved awareness of the resources that are available for teaching agricultural biotechnology.
(142) Hydraulic Resistance: A Determinant of Short-term Stomatal Conductance Signaling in Disparate Xylem Anatomy of Red Maple (Acer rubrum L.) and Shumard Oak (Quercus shumardii Buckl.)
Authors: Inman William W. , Bauerle William L.
Published: February 2019

Recent work has shown that stomatal conductance (gs) and net photosynthesis (Anet) are responsive to the hydraulic conductance of the soil to leaf pathway (Xp). Two tree species with differing xylem structures were used to study the effect of systematic manipulations in Xp that elevated xylem hydraulic resistance. Simultaneous measures of gs, Anet, bulk leaf abscisic acid concentration (ABAL), leaf water potential (L), and whole plant transpiration (Ew) were taken under controlled environment conditions. Quercus shumardii Buckl. (shumard oak), a ring porous species and Acer rubrum L. `Summer Red' (red maple), a diffuse porous species, were studied to investigate the short-term hydraulic and chemical messenger response to drought. Both species decreased Anet, gs, L, and Ew in response to an immediate substrate moisture alteration. Relative to initial well-watered values, red maple Anet, gs, and Ew declined more than shumard oak. However, gs and Anet vs. whole-plant leaf specific hydraulic resistance was greater in shumard oak. In addition, the larger hydraulic resistance in shumard oak was attributed to higher shoot, as opposed to root, system resistance. The results indicate hydraulic resistance differences that may be attributed to the disparate xylem anatomy between the two species. This study also provides evidence to support the short-term hydraulic signal negative feedback link hypothesis between gs and the cavitation threshold, as opposed to chemical signaling via rapid accumulation from root-synthesized ABA.
(144) Landscape Growth and Aesthetic Quality of Coleus Managed with Irrigation Deficits
Authors: Scheiber Sloane M. , Beeson Richard C.
Published: February 2019

Previous research indicated that bedding plants can be maintained in landscape soils allowed to dry to substantially less than field capacity before irrigation; however, canopy size and aesthetic quality were compromised. Continuing this research, Solenostemon scutellarioides (coleus) were grown in drainage lysimeters in an open-sided clear polyethylene-covered shelter to assess growth characteristics and landscape quality when irrigated at various managed allowable deficits. Using tensiometers, plants were irrigated back to field capacity when 30%, 40%, or 50% of plant available water within a soil was depleted. Deficits were evaluated against a control treatment of 1.25 cm daily irrigation. Additional plants were grown in a companion open field plot. Growth indices, biomass, irrigation volumes, and landscape quality ratings were recorded. No differences in final height, growth index, shoot or root dry weights, total biomass, or shoot-to-root ratios were found among treatments for either lysimeter or companion field plots. Landscape quality was comparable among treatments. However, total irrigation volume applied was significantly greater for the control treatments than deficit irrigation treatments. On average, irrigation volumes were 4.75-fold greater for daily irrigation in comparison to other treatments.