bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Interactive Television in Expanding the Teaching Mission of the Land-grant University
Authors: Storey J. Benton
Published: February 2019

The Trans Texas Video Conference Network (TTVN) has been linked to all Texas A&M Univ. campuses and most of the Regional Research and Extension Centers. The College of Agriculture and Life Sciences has funded an aggressive project of establishing TTVN class rooms in many departments across the College Station campus, including The Horticultural Science Dept. in 1997. The first two Hort courses taught were HORT 422 Citrus and Subtropical Fruits in Fall 1996 and HORT 418 Nut Culture in Spring 1997. This extended the class room 400 miles south to Weslaco, 300 miles north to Texarkana and Dallas, and 700 miles west to El Paso. Students at each site had video and audio interaction with the professor and with each other. Advantages included the availability of college credit courses to areas where this subject matter did not previously exist, which helps fulfill the Land-grant University Mission. Quality was maintained through lecture and lab outlines on Aggie Horticulture, the department's Web home page, term papers written to ASHS serial publicationspecifications, and rigorous examinations monitored by site facilitators. Lecture presentations were presented via Power Point, which took about twice as long to prepare than traditional overhead transparencies. Administrative problems remain, but will be solved when the requested Distance Education Registration Category is initiated so that subvention credit can be shared. The lecture portion of the graduate course, HORT 601 Nutrition of Horticultural Plants, will be taught in the fall semester 1997 at eight sites throughout the state.
Horticultural Teaching Resources on the Internet
Authors: Rhodus Tim
Published: February 2019

Horticulture Teaching Resources is a web site at The Ohio State Univ. designed to provide high school and higher education horticulture educators free-access to curriculum resource materials. The information has been structured to facilitate the instruction of basic concepts in plant biology, propagation, nutrition, and plant materials. A searchable database interface is used to access color photos, lab exercises, and test questions. Users of the system can also provide URL addresses to their own resources for inclusion in the database. (http://hortwww-2.ag.ohio-state.edu/hvp/htr/htr.html)
Amelioration of Blossom-end Rot of Bell Pepper by Rowcovers and Supplemental Calcium
Authors: Clough George H. , Alexander Shara E.
Published: February 2019

A 2-year study was conducted in eastern Oregon to evaluate the effects of hooped spunbonded polypropylene rowcovers and calcium fertilization on yield and quality of drip-irrigated bell pepper grown on black plastic mulch. The experiment was a complete factorial with four replications of two varieties, covered and uncovered plots, and three levels of supplemental calcium fertilization at 0, 34 and 68 kg·ha–1 applied through the drip irrigation system as Ca(NO3)2. Marketable yields increased with rowcover, both at the first harvest and over the season. Blossom-end rot and sunscald were reduced substantially by rowcovers; the effect was greatest during the earlier harvests. First harvest and season total yield of fancy grade peppers increased linearly as rate of supplemental calcium increased, as did total marketable yield at the first harvest. There was a trend to decreasing yield of fruit with blossom-end rot as calcium rate increased, and the percent fruit with blossom-end rot at the first harvest decreased linearly with increasing rate of calcium fertilization. Yield of fruit affected by sunscald decreased linearly as supplemental calcium rate increased at the first harvest; overall, yield of sunscald fruit was reduced by application of calcium at either rate.
Inheritance of High Levels of Resistance to Microtubule-disrupting Herbicides in a Weedy Grass, and Molecular-tagging of the Genetic Locus
Authors: Zeng Linghe , Baird Wm. Vance
Published: February 2019

Dinitroaniline herbicides exert their phytotoxic effect by interfering with tubulin dimer polymerization; thus, these and other anti-mitotic drugs destabilize cytoplasmic and spindle microtubules. The dinitroanilines are particularly effective on monocotyledonous species. A naturally occurring mutant of goosegrass [Eleusine indica (L.) Gaertn.], resistant (R) to the DNHs, and the widely distributed susceptible, wild-type (S) have been collected from a number of agricultural sites throughout the southeastern U.S. Pairs of these accessions were cross-pollinated to create F1 individuals, from which F2 and F3 generations were developed through natural self-pollination. Analysis of the dinitroaniline herbicide response phenotype (DRP) has shown the F1s to be susceptible, and the F2 and F3 to be segregating 3:1 for susceptibility and resistance, respectively (i.e., 3S:1R). This genetic data is consistent with the DRP being encoded by a single, nuclear locus. Random amplified polymorphic DNA (RAPD) analysis of a segregating F2 population (N = 60), which identified 32 linked and 33 unlinked molecular markers, supports this hypothesis of simple Mendelian inheritance. Furthermore, this RAPD analysis coupled with restriction fragment length polymorphism (RFLP) analysis, localized the DRP locus to a single chromosomal region and identified two RAPD-markers, and at least one RFLP-marker, flanking the DRP locus. This information provides a starting point for map-based (i.e., positional) cloning of the resistance (DRPr) and susceptibility (DRPs) alleles.
Lowbush Blueberry Response to Phosphorus-containing Fertilizers: Assessment by Leaf Phosphorus Concentration and Content
Authors: Smagula J.M. , Dunham S.
Published: February 2019

Lowbush blueberries (Vaccinium angustifolium Ait.) in three commercial fields were treated with 67.2 kg P/ha from triple super phosphate(TSP), monoammonium phosphate (MAP), or diammonium phosphate (DAP), and compared to a control in a randomized complete block design with 12 blocks. Correction of P deficiency by fertilizers with different ratios of P to N was assessed by leaf and stem nutrient concentrations and contents (concentration × weight). Samples of stems collected in July from three 0.03 m2 quadrates per treatment plot indicated MAP and DAP had no effect on dry weight of stem tissue, but increased average dry weight of leaf tissue. Leaf nutrient concentrations and contents showed similar results; P and N were raised to higher levels by MAP and DAP than by TSP. TSP had no effect on leaf N concentration or content but raised leaf P concentration but not content, compared to controls.
Characterization of Ice Nucleation and Propagation in Bean (Phaseolus vulgaris cv. Bush Blue Lake) using Infrared Video Thermography
Authors: Wisniewski Michael
Published: February 2019

Frost-sensitive plant species have a limited ability to tolerate ice formation in their tissues. Most plants can supercool below 0°C and avoid ice formation. Discrepancies exist about the role of intrinsic and extrinsic ice-nucleating agents in initiating ice formation in plants. Previous research has demonstrated the ability of infrared video thermography to directly observe and record the freezing process in plants (Wisniewski et al., 1997. Plant Physiol. 113:4378–4397). In the present study, the ability of droplets of a suspension of the ice-nucleating-active (Ice+) bacterium, Pseudomonas syringae, and droplets of deionized water, to induce ice formation in bean plants was compared. The activity of these agents were also compared to intrinsic ice formation in dry plants. Results indicated that the presence of the Ice+ bacteria in droplets ranging from 0.5–4.0 μL always induced freezing at a warmer temperature than droplets of deionized water alone (no bacteria) or intrinsic nucleators in dry plants. When droplets of Ice+ bacteria were allowed to dry, they were no longer effective but were active again upon rewetting. Droplets of water would often supercool below temperatures at which ice formation was initiated by intrinsic agents. When a silicon grease barrier was placed between the droplets of Ice+ bacteria and the leaf surface, the bacteria were no longer capable of inducing ice formation in the plant, despite the droplets being frozen on the plant surface. This indicates that ice crystals must penetrate the cuticle in order to induce freezing of the plant.
Effects of Chilling and Ethanol Treatments on the Antioxidant Systems of Cucumber Seedling Roots
Authors: Boyd Windy A. , Jennings Paul H.
Published: February 2019

Previous experiments have shown that soaking 24-hr-old cucumber seedlings in ethanol leads to an increase in chilling tolerance. Seedlings were immersed in a 500-mM ethanol solution for 2 hr prior to chilling, rinsed, and placed in chilling immediately after treatment. All seedlings (except the control group) were treated for 2 hr after a 24-hr germination period at 25°C and a second group was held for 3 hr to allow the ethanol-induced chilling tolerance to dissipate. At this time, the seedlings were retreated with a second ethanol treatment identical to the first. The induction of chilling tolerance seen in both treatment groups was measured as an increase in root growth and decreases in lipid peroxidation and electrolyte leakage after exposure to chilling temperatures (2°C). Although ethanol treatment does clearly enhance chilling tolerance, the mechanisms by which it does so are unclear. Some hypotheses have suggested that ethanol acts as an anaesthetic, preventing a membrane phase change from a liquid to a gel-like state. Other evidence indicates that ethanol is a scavenger of the hydroxyl radical, working in concert with enzymatic-reducing systems and antioxidants to directly prevent damage caused by active oxygen species. Because enzymatic reducing systems and antioxidants have been shown to combat stress, the activities of three H2O2-scavenging enzymes (catalase, glutathione reductase, and ascorbate-specific peroxidase), along with the relative concentrations of reduced and oxidized forms of glutathione and ascorbate as affected by both chilling and ethanol treatments will be discussed in relation to chilling susceptibility.
Electronic Support of California Cooperative Extension for Fruit and Nut Crops
Authors: Hirsch Naomi , Ferguson Louise
Published: February 2019

For California pomology, it is ideal to communicate and disseminate information electronically because of its large size and diversity of fruit and nut crops. In support of statewide extension, the Fruit & Nut Research and Information Center's World Wide Web site 9 http://pom44.ucdavis.edu) focuses on providing information and links for temperate, subtropical and tropical fruits and nuts and keeping all interested persons well informed about University of California research and outreach activities. The Internet has been proven ideal for its user friendliness and rapid dissemination of current information. The Center supports this electronic change for growers and industry by collaborative projects with industry and involving Internet education and demonstrations at short courses, symposia, and educational days throughout the state. By this outreach to fruit and nut crop industries, the needs of the growers can be addressed. Also, it is important to address interdisciplinary cooperation and efficiency in the Agricultural Experiment Station and Cooperative Extension programs, especially in view of the recent reduction in staff and resources. By creating electronic listserv groups for each crop through the Center, extension specialists and farm advisors have the ability for increased communication. A more visible and active focal point —both within and outside the University—for research and outreach activities related to fruit and nut production, handling, processing, marketing and consumption has been created since the Center was established in Dec. 1995.
Optimization of Intracanopy Lighting for Hydroponically Grown Cowpea in Controlled Environments
Authors: Frantz Jonathan M. , Mitchell Cary A.
Published: February 2019

A major source of power consumption in controlled-environment crop production is plant-growth lighting. Methods developed to minimize this source of power consumption will reduce the negative environmental impact of crop production through more-efficient management of non-renewable resources. One such method uses “intracanopy lighting,” in which the plants are allowed to grow through multiple levels of low-intensity lamps to irradiate the understory that normally is shaded when traditional overhead lighting is used. Early results with cowpea (Vigna unguiculata L. Walp `IT87D-941-1') indicate a significant reduction in net power consumption within a given growth area or volume while enhancing the harvest index (HI = percent edible biomass). Incorporation of mylar reflectors and manipulation of lamp geometries for more-efficient use of available photosynthetically active radiation, while maintaining low power consumption are the focus of present experiments. Photosynthetic rates by leaves of different ages and positions within the canopy are measured as a way of determining lighting efficiency. The productivity parameters HI, edible yield rate (EYR = gDW × m–2 × day–1), yield efficiency rate (YER = gDW edible × m–2 × day–1 [gDW non-edible]-1), energy conversion efficiency (ECE = EYR × [kW·h]–1), and energy partition efficiency (EPE = YER × [kW·h]–1) express the costs of edible biomass production in terms of the spatial, temporal, energetic, and non-edible biomass penalties. [Research supported in part by NASA grant NAGW-2329.]
Sodium Recycling through Plants for Bioregenerative Life Support
Authors: Mackowiak C.L. , Garland J.L. , Wheeler R.M.
Published: February 2019

As humans explore the solar system, life support will need to be increasingly self-sufficient. Growing higher plants and using recycling technologies can improve self-sufficiency. Sodium is an essential mineral for humans, but not typically for plants. Recycling sodium back to humans through food crops may reduce the need for sodium supplements in the human diet. However, if sodium from waste streams is added to the plant system in greater quantities than it is removed, then plant toxic levels may result. The recommended daily sodium requirement is 3000 mg per person. Based on a 20-m2 growing area per person, 150 mg·m–2 sodium would need to be removed each day. Most crops will not remove enough salt when grown at very low sodium levels; however, when grown in 20 mM sodium, plant uptake may meet the 3000 mg/d human sodium requirement without affecting yields. We grew four different salad crops (lettuce, radish, spinach, and table beet) hydroponically and calculated plant uptake rates and partitioning with 0, 20, 40, or 80 mM sodium supplemented nutrient solutions (corresponding to ≈1.4, 4.0, 8.0, and 13.0 dS·m–1 electrical conductivity). Sodium at 40 and 80 mM reduced edible yields. Sodium replaced tissue potassium in most cases, whereas calcium and magnesium concentrations were much less affected, particularly at 20 mM sodium. This data will be used to model sodium flows within a bioregenerative life support system and determine the feasibility of sodium recycling using food crops.
Environmental Effects and Postharvest Flux of Antiplatelet Activity, Pungency, and Solids in Onion (Allium cepa)
Authors: Debaene Jan E.P. , Goldman I.L.
Published: February 2019

Onion is a species within the Allium genus with great culinary importance. Onion extract contains organosulfur compounds that influence pungency and inhibit blood platelet aggregation. Antiplatelet activity has the potential of reducing cardiovascular disease. Onions are typically held in postharvest storage for up to 160 days, during which time volatile organosulfur compounds may be affected. A study was conducted to evaluate antiplatelet activity, pungency, and percent solids during cold storage of onions grown in replicated plots in Wisconsin and Oregon in 1994 and 1995. Organosulfur compound concentration and antiplatelet activity were also measured in progeny derived from crosses of inbred lines contrasting for pungency grown during 1995 and 1996 in Wisconsin. For the first study, bulbs were evaluated for antiplatelet activity, percent solids and pungency at 40day intervals after harvest. Significant differences were detected for these traits among years, states, dates of sampling, and lines. During the 120-day postharvest period in 1994, antiplatelet activity increased by 25% and 80% for Oregon and Wisconsin, respectively, averaged over all lines. During the same period in 1995, antiplatelet activity decreased by 35% and 4% in the two locations. For three out of four lines, antiplatelet activity was 4.6% higher for Wisconsin than Oregon. Averaged over states, antiplatelet activity was 9.7% higher in 1994 compared to 1995. Pungency was positively correlated with antiplatelet activity in Wisconsin. Broad-sense heritabilities were calculated for antiplatelet activity and organosulfur compound concentration. These data demonstrate that environmental factors influence postharvest flux of antiplatelet activity and pungency in onion.
Comparison of Genetic Diversity between Nuña and and Other Andean bean (Phaseolus vulgaris) Populations
Authors: Nienhuis James , Skroch Paul , Beebe Steve
Published: February 2019

Nuñas are a type of common bean (Phaseolus vulgaris) that possess the unusual characteristic of popping or expanding their cotyledonary tissue when heated. Numerous landraces of nuña beans were domesticated in the Andean region of South America (Peru, Bolivia, and Ecuador) and have been grown and consumed in this region since antiquity. The practical consideration in the domestication of nuñas in the high Andes was likely due to the greater energy efficiency in cooking toasted vs. boiled seeds.The Phaseolus germplasm bank at CIAT (Centro Internacional de Agricultura Tropical) has developed a core collection of Andean beans that includes numerous nuña landraces. Based on the wide range of phaseolin types observed among nuña landraces, it has been hypothesized that nuñas may represent a greater source of genetic diversity compared to other landraces and cultivars of common bean. Eighty nuña accessions and 120 nonpopping common bean accessions were randomly sampled from the CIAT Andean germplasm core collection. The 200 accessions were characterized for 140 mapped RAPD markers. The objectives of our research were to 1) understand the genetic structure of nuña bean accessions relative to other Andean common beans, and 2) to measure the genetic distance and genetic diversity between nuña and other Andean bean populations.
RAPD Marker Facilitated Analysis of Genetic Diversity among Capsicum Genetic Resources from the Asian Vegetable Research and Development Center
Authors: Villand Julie , Berke Terry , Engle Liwayway , Nienhuis James
Published: February 2019

Significant effort has been made in the collection of Capsicum germplasm throughout the world for maintenance by genebanks. The largest Capsicum germplasm collection is held by the Asian Vegetable Research and Development Center (AVRDC), consisting of 6844 accessions and eight species. The paradox of any germplasm collection is that, as the number of accessions and the probability of preserving genetic variability increases, the ability of users to efficiently utilize this resource decreases. Genetic variation can be quantified using RAPD molecular marker allele frequency and allelic variation to understand the genetic structure and variation within and among populations. The comprehensive Capsicum collection held at the AVRDC provides an opportunity to sample a range of germplasm representative of the variability that exists in available Capsicum germplasm. Accessions were sampled from the AVRDC collection to represent the range of genetic variation available in Capsicum 1) based on cluster analysis using morphological traits among 1500 accessions and 2) based on pedigree information from the Capsicum breeding program. Our objectives include understanding the structure and magnitude of genetic diversity among these AVRDC accessions and comparing the genetic diversity within sub-populations of these accessions. RAPD fingerprints of these accessions were collected using markers dispersed over numerous linkage groups based on a genetic map we have constructed. RAPD band frequencies and RAPD band diversity were used to test differences among and within sub-populations. The understanding of the distribution of genetic variation among and within these sub-populations will be useful for prioritizing collection, conservation, and sampling of these genetic resources.
Long-term Effects of Nitrogen and Drip Irrigation Water Levels on Almond Yields
Authors: Meyer R.D. , Edstrom J.P. , Schulbach H. , Deng J.
Published: February 2019

Five rates of urea-N each at two water levels (0.6 & 1.0 ETc) were applied to three varieties (Butte, Carmel, and NonPareil) of almonds [Prunus dulcis (Mil) D. A. Webb] planted in 1981 on a 3.65 × 5.47-m spacing (550 trees/ha) on Arbuckle gravelly loam (Fine-loamy, mixed, thermic Typic Haploxeralf). Trees were drip-irrigated to basins (three per tree) ≈7 cm deep and 30 cm in diameter, located 76 and 183 cm on either side of the trees in the tree row. N rates ranged from 0–57, 0–198, 0–454, 113–907, 170–1361, 227–1814, 227–1814, 170–1361, 113–907, 113–907, 113–907, 0–907, 0–907 and 0–907 g per tree, respectively, during 1982–1995 and were applied on a monthly basis in four to six increments beginning in April. Almond meat yields were >1500 kg·ha–1 in 1984 and as high as 3800 kg·ha–1 during the 12-year period for the 1.0 ETc water treatment and optimum N rate. Nitrogen response was generally in the 600–1000 kg·ha–1 range, with water treatment response in the 200–500 kg·ha–1 range. The three varieties generally responded to higher N and water rates in the order Butte > Carmel > NonPareil. Leaf analyses (three to six each year) were used to monitor treatment effects and evaluate need for other nutrients.
Implications of Genotypic Selection and Production Practices on Root Regeneration Potential and Field Establishment of Container-grown Trees
Authors: Arnold Michael A. , Shoemake Larry J. , Goyne Mitchell W.
Published: February 2019

Transplant studies were conducted on Taxodium distichum L., Platanus occidentalis L., Quercus shumardii Buckl., Fraxinus velutina Torr., and Chilopsis linearis (Cav.) Sweet seedlings grown in 2.2- to 9.1-L black plastic containers. Effects of half-sib family selection on post-transplant root regeneration potential (RRP) and field establishment were investigated with P. occidentalis. Taxodium distichum, Q. shumardii, and P. occidentalis were used to determine seasonal variation in relationships among RRP characteristics and measures of successful transplant establishment. Post-transplant effects of avoidance of circling root development vs. remediation practices were investigated with Q. shumardii. Effects of container media composition on field establishment and RRP of container-grown plants were studied using F. velutina and C. linearis. Impacts of rotation time on RRP and field establishment were investigated with T. distichum. Rates of RRP were the measure most consistently linked to improved post-transplant shoot growth of P. occidentalis. Utilization of locally adapted genotypes and avoidance of summer transplant were important in establishment of P. occidentalis and T. distichum. Increased small diameter root regeneration was linked to reduced water stress during transplanting of Q. shumardii. Physical characteristics of the container media impacted initial post-transplant growth of F. velutina and C. linearis.
Micropropagation, Decontamination, Transcontinental Shipping and Hydroponic Growth of Cattleya while Sealed in Semipermeable Membrane Vessels
Authors: Adelberg Jeffrey , Pollock Robert , Rajapakse Nihal , Young Roy
Published: February 2019

Two varieties of Cattleya orchids (C. Loddigessi `Elen' × C. Loddigessi Alba `Extra' and Brassolaeliocattleya. Mem. `Helen Brown' Sweet Afton) were micropropagated in sealed, three-dimensional polypropylene vessels with microporous, semi-permeable membrane films to allow diffusion of water, dissolved nutrients, and gas to plant material inside the vessels. During tissue culture on sugar-containing media, chance contaminants were eliminated on the vessels outer surface using 5% bleach solution. Proper decontamination treatment did not effect carbohydrate content or subsequent growth of tissues contained within the vessels. Plantlets remaining in membrane vessels were shipped (7 days at 14–30°C) from Japan to the United States in the dark in a plastic tray and arrived without changes in fresh or dry weight of whole plantlets. However, shoot dry weight did increase significantly. Sucrose, glucose, and fructose reserves established on sugar-containing media were greater in root than shoot tissue and were largely expended during shipping concurrent with increased shoot dry weight. It is likely carbohydrate catabolism provided energy for these CAM plantlets to continue carbon fixation, resulting in positive net carbon assimilation in the dark shipping environment. Changes in starch concentrations during shipping were not significant. Plantlets grew photoautotrophically in hydroponic culture in the greenhouse, following transport in the same sealed membrane vessels. Carbohydrate concentration of plantlets following hydroponic culture was not significantly different than after the shipping process. Sealed-membrane vessels for micropropagation, decontamination, shipping and greenhouse growth were useful for culture of Cattleya to facilitate scale-up of materials handling and international commerce of tissue-cultured plants.
Flowering Patterns of Reverse Pinwheel Chimeras Produced during in Vitro Culture of Saintpaulia ionantha `Silver Summit'
Authors: Sandall Sharon K. , Lineberger R. Daniel
Published: February 2019

The pinwheel flowering African violet `Silver Summit', a periclinal chimera, has bicolor flowers with violet-blue 93B corolla segment margins and white 155B central stripes. Several off-types were produced during in vitro culture of `Silver Summit', the two of greatest potential value having reversed color patterns with violet-blue stripes and white margins. The off-types varied in color, one with deep violet-blue stripes (DR, dark reverse) and the other with lighter stripes of the same color (LR, light reverse). Unexpanded inflorescences of both off types were cultured on Murashige and Skoog medium containing 0.1 mg/L benzyladenine and 0.1 mg/L naphthaleneacetic acid. Plantlets resulting from expansion and multiplication of the dormant buds in the inflorescences were removed, acclimated, and grown on to flowering. Thirteen LR inflorescences produced 55 plants; 51 were true to type and four had solid violet-blue flowers (non-chimeral). Thirteen DR inflorescences produced 64 plants; only eight were true to type, 17 produced solid violet-blue flowers, 38 produced flowers with mixtures of the DR chimeral pattern and solid violet-blue flowers, and one was solid white flowering. To visualize the chimeral arrangement of the meristems of the off-types, flower patterns of all plants were recorded and “fl oral maps” were constructed. Floral maps of LR were constant from plant to plant and varied little as the plants aged, indicating LR to be a stable periclinal chimera. Floral maps of DR were highly variable from plant to plant, and changed considerably over time indicating that the DR meristems were less stable.
Seasonal Effects on ex Vitro Growth and Corm Formation in Micropropagated Sagittaria latifolia Ecotypes
Authors: Philman Nancy , Gillis Murdock Ray , Kane Michael E.
Published: February 2019

Commercial micropropagation of wetland plants used for habitat restoration provides an alternative to field collection and facilitates production of difficult-to-propagate species and possibly selection of ecotypes that are physiologically adapted to specific habitat conditions. Knowledge of the degree of ecotypic variation within and between wetland populations is very limited. The feasibility of screening ecotypic differences in growth of micropropagated wetland plants, following acclimatization, was examined using Sagittaria latifolia Willd. (Duck-potato), a highly variable rhizomatous herbaceous wetland species that is widely distributed in southeastern Canada and the eastern United States. Plants were obtained from populations in Rhode Island, North Carolina, South Carolina, and Florida. Stage I cultures of each Sagittaria latifolia ecotype were established from surface-sterilized rhizome shoot-tips cultured in a liquid basal medium (BM) consisting of half-strength Murashige and Skoog mineral salts, 0.56 mM myo-inositol and 1.2 μM thiamine supplemented with 87.6 mM sucrose. Stage I cultures were indexed for cultivable bacteria prior to clonal multiplication of each ecotype by rhizome production on agar-solidified BM supplemented with 1.1 μM benzyladenine (BA). At 4-week intervals for 24 months, Stage II microcuttings of each ecotype were acclimatized and rooted in soilless growing medium under intermittent mist for 10 days. Plantlets were transferred to a shadehouse (50% sunlight reduction) and maintained under prevailing environmental conditions. Plant height, leaf length and number, rhizome number, corm number and weight, and flowering were determined 6 weeks post-transplant. Significant seasonal differences in leaf growth, rhizome production, corm formation and flowering were observed between ecotypes. During the growing season, induction of corm formation occurred progressively earlier in the more northern ecotypes.
Nursery Selection for High Early Fruit Yield in Subtropical Strawberries
Authors: Lopez P.J.S. , Chandler C.K.
Published: February 2019

Development of new strawberry cultivars for winter fruit production in Florida entails growing of hybrid seedlings in a nursery in the summer of the first year for runner plant production. Two runner plants are taken from each seedling and planted in the fruiting field in the fall. An experiment was conducted to see if it is possible to predict which genotypes in the nursery will have the highest early season fruit yield. Seedlings from 24 families from a 6 × 4 factorial mating design were grown in a nursery. From each family, daughter plants of 20 seedlings with the highest vigor and 20 randomly picked seedlings were then evaluated in the fruiting field. Plants from selected (high-vigor) seedlings were more vigorous, but had fewer crowns and runners, than unselected plants. More inflorescences were counted in selected plants than in unselected plants during the second week of January. This could account for higher early yield (yield at the end of January) and total yield (yield at the end of March) in selected than in unselected plants.
Effects of Atmospheric CO2 Enrichment and Root Restriction on Photosynthesis and Dry Matter Partitioning in Tropical Fruit Crops
Authors: Schaffer B. , Whiley A.W. , Searle C.
Published: February 2019

Banana (Musa sp.), mango (Mangifera indica), and avocado (Persea americana) plants were grown in controlled-environment glasshouses in ambient (350 μmol CO2/mol) and enriched (700–1000 (mol CO2/mol) atmospheric CO2 concentrations. At each CO2 concentration, plants were either exposed to sink-limiting (root restriction) or non-sink-limiting conditions (no root restriction). Total carbon assimilation and dry matter accumulation were generally greater for plants in the enriched CO2 environment than for plants grown in ambient CO2. However, plants grown in the enriched CO2 environment were less efficient at assimilating carbon than plants grown in ambient CO2. There was a downward regulation of net CO2 assimilation due to root restriction that resulted in less dry matter accumulation than in non-root-restricted plants. This may explain the lower net CO2 assimilation rates often observed for tropical fruit trees grown in containers compared to those of field-grown trees. Atmospheric CO2 enrichment generally did not compensate for reductions in net CO2 assimilation and dry matter accumulation that resulted from root restriction.
Measurement and Modeling of Carbon Balance of Apple Trees
Authors: Lakso Alan N.
Published: February 2019

Apples have very high record yields (about 140 tons/ha sustained) that demand large amounts of carbon to be produced and partitioned into both fruit and vegetative structures. Even though large quantities of dry matter can be produced, profitability depends on the management of the carbon production and partitioning to produce the optimal balance of yield and fruit quality. The productivity is mostly related to moderate photosynthesis rates per leaf area, long leaf area duration, high seasonal radiation interception, relatively low respiration, and very high harvest index. Due to the perennial nature and large size, few good estimates of seasonal carbon balance are available. Models have been developed, but are not wellvalidated yet, but general seasonal trends are apparent. Daily net CO2 exchange begins negative with early spring growth, reaches zero near bloom, peaks about 6 to 10 weeks after bloom, then gradually declines until leaf fall. The demand of the fruit appears to increase exponentially during cell division, then levels off to a relatively constant demand until harvest. Experiments and modeling suggests that if fruit development is limited by carbon availability, the probability increases in heavily cropping trees, and will occur at about 2 to 4 weeks after bloom and before harvest. Best carbon balance appears to occur in relatively cool temperatures and in very long seasons.
Modification of Carbohydrate Content in Developing Tomato Fruit
Authors: Schaffer Arthur A. , Petreikov Marina , Miron Daphne , Fogelman Miriam , Spiegelman Moshe , Bnei-Moshe Zecharia , Shen Shmuel , Granot David , Hadas Rivka , Dai Nir , Bar Moshe , Friedman Michael , Pilowsky Meir , Gilboa Nehama , Chen Leah
Published: February 2019

The carbohydrate economy of developing tomato fruit is determined by wholeplant source–sink relationships. However, the fate of the imported photoassimilate partitioned to the fruit sink is controlled by the carbohydrate metabolism of the fruit tissue. Within the Lycopersicon spp. there exists a broad range of genetic variability for fruit carbohydrate metabolism, such as sucrose accumulation and modified ratios of fructose to glucose in the mature fruit and increased starch synthesis in the immature fruit. Metabolic pathways of carbohydrate metabolism in tomatoes, as well as natural genetic variation in the metabolic pathways, will be described. The impact of sink carbohydrate metabolism on fruit non-structural carbohydrate economy will be discussed.
Developing, Converting, and Maintaining Information-rich Resources on the Web
Authors: Peet Mary M.
Published: February 2019

“Sustainable Practices for Vegetable Production in the South,” 174 pages long, including 250 references, was written as a traditional college textbook. I will be discussing my experiences converting it to a web document and simultaneously releasing web and print versions. I will also discuss some of the issues we will confront if we depend on the web for delivering and receiving information. These issues are: 1)There are no conventions for websites comparable to those that have evolved for print documents. At the same time, users expect sites to function certain ways. 2) Consistency between parts of the website is more difficult to maintain than in a print document, but is critical in order to correctly orient the user. 3) The optimal size and structure of the information “chunk” or subdivision is unclear—Should it be a whole chapter or article, a single paragraph, or a functional unit of facts that does not have a name or correspond to anything in print media? 4) How do you let a person accessing any one part of your website know about all the other parts and how they fit together—You can flip through a book to view it, but a person following a link to a page on your site is like the blind person touching the elephant's trunk—they can not visualize the whole. 5) There is no one intuitively obvious or logical place to put references and footnotes because of the subdivision of information into “chunks” or functional facts. 7) There is no obvious starting or stopping point in making revisions. 8) People accessing the site will send messages and ask questions. 9) Meaningful evaluation of usage and usefulness is difficult.
The Composition of Strawberry Aroma as Influenced by Cultivar, Maturity, and Storage
Authors: Forney Charles F. , Kalt Willy
Published: February 2019

The aroma of fresh strawberries is composed of a mixture of volatile compounds with no single compound responsible for the characteristic strawberry aroma. Volatiles produced in strawberries are predominately esters, although alcohols, ketones, and aldehydes are also present in smaller quantities. The major volatiles contributing to aroma include ethyl butanoate, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, ethyl hexanoate, methyl butanoate, linalool, and methyl hexanoate. There are qualitative and quantitative differences in volatile composition between cultivars. Headspace concentration of volatiles from 5 cultivars were 0.4, 1.7, 5.6, 5.8, and 14.3 mol·m–3 for `Honeoye', `Cavendish', `Micmac', `Kent', and `Annapolis', respectively. During fruit maturation on the plant, aroma volatile synthesis coincides with color formation, and continues to increase until the fruit is over-ripe. Volatile concentration increases about 4-fold in the 24-hr period required for fruit to ripen from 50% red to fully red on the plant. Volatile composition continues to change after harvest and is affected by storage temperature, atmosphere composition, and light. The concentration of ethyl esters increases while methyl esters remain constant in fruit held at 0°C, but, when fruit are warmed to 15°C, the reverse is true. Holding strawberries in 10 to 20 kPa of CO2 may increase concentrations of ethyl esters in the fruit. Light increases the production of volatiles in stored strawberries. Methods to control strawberry aroma will be discussed.
Using HortBase
Authors: Green Jim
Published: February 2019

How can HortBase and other electronic information systems benefit horticulturists in developing countries? If Nation-wide distribution of the workload and costs of creation, review, revision, and distribution of individual information files to produce an electronic information system for decision support can be achieved in the U.S., can this collaboration occur world-wide? The European Agricultural Multimedia Network (http://www.stoas.nl/mmnet/), established in 1995, is an international network of more than 37 European institutes and organizations that are active in agricultural education. Its goals are to exchange knowledge and ideas and foster cooperation in development and exchange of agricultural education and extension multimedia products. EUROPEA, created in 1993, is a network of about 500 agricultural colleges and institutes in Europe to optimize transnational cooperation in development of distance education and lifelong learning and to provide an international dimension to students. The international membership of ASHS coupled with global communication technology facilitates global collaboration on information development and access.
A New Look at the Bioactive Properties of Anthocyanin-rich Horticultural Crops
Authors: Smith M.A.L.
Published: February 2019

The bright red pigmentation in edible, anthocyanin-rich fruits and vegetables is a definite bonus in terms of market appeal. As a result, breeders have worked consistently to intensify anthocyanin levels or alter composition in crops. The positive links between consumption of crops and food products containing natural anthocyanin pigments, and reduced incidence of cardiovascular and other chronic diseases, have been established anecdotally and more recently validated in research trials including those from our laboratory group. The protective events, most attributed to the potent antioxidant properties of anthocyanin pigments and associated phytochemicals, place anthocyanin-rich crops in the category of “Functional Foods,” yielding health protection unrelated to nutritional value. In vitro bioactivity assays have identified components from these crops capable of blocking the initiation stages of carcinogenesis, while a completely separate class of phytochemicals and sets of assays establish efficacy against the promotion stages of tumorigenesis. Animal models for carcinogen-induced damage to mammary gland and skin DNA subsequently demonstrate the in vivo potency of the same target compounds. Similarly, to establish cardioprotective properties, demonstrations of ability to inhibit platelet aggregation, relax vascular muscle tissue, and reduce total serum cholesterol are demonstrated in a series of in vitro assays, and via animal models and human studies. While activity-directed fractionations seek to identify specific responsible compounds, it is increasingly evident that bioactivity is drastically attenuated once specific compounds are isolated, and the synergistic interaction of associated phytochemicals in horticultural crops is prerequisite to realizing health benefits. These complications have slowed the establishment of effective minimum “dosages,” but all the more strongly promote consumption of the crops.
Nutrient Demand-driven Macronutrient Uptake in Fruit Crop
Authors: Weinbaum Steven A.
Published: February 2019

Our understanding of the quantities and seasonal patterns of nutrient uptake by mature fruit trees has been limited by the difficulties in working with the large woody biomass of these organisms, tree-to-tree variability, and the resolution to distinguish between recently acquired nutrient from the nutrient background of the tree. We have coupled the use of stable isotopes of nitrogen (N) with periodic whole-tree excavations and nutrient analyses during the year. Vegetative growth, reproductive growth, and nutrient storage in perennial tree parts during tree quiescence represent nutrient sinks. Data obtained using mature pistachio, prune, and walnut trees indicate that macronutrient accumulation in metabolic sinks is associated with increases in tree macronutrient uptake. These data are consistent with the concept that sink removal of phloem-mobile nutrients from vascular circulation may provide the stimulus to further uptake of the nutrient(s) sequestered. We propose that the recognition of those patterns can be used to increase the efficiency of tree nutrient recovery and utilization.
The Wiley-Boone Aviary: A Bird Garden
Authors: Travis Amanda R. , Haque Mary T.
Published: February 2019

The Wiley-Boone Aviary is a collection of domestic/exotic birds established at the Morgan Poultry Center at Clemson University in the mid-1970s. The area receives 3000 visitors per year, mostly school children. To make the site more aesthetically pleasing and conducive to educational programs, a new design was necessary. The Aviary was selected for redesign as an independent project in Fall 1995. Objectives of the design were: 1) creating an area conducive to housing, attracting, and viewing birds; 2) educating visitors through interactive display areas; 3) creating a bird garden that will attract and educate the public while providing natural food sources, cover, and nesting sites. Plants such as Pyracantha coccinea, Amelanchier arborea, and Juniperus virginiana provide winter berries production and protection from predators. Final plans feature: 1) individual aviary structures for exotic, game, and domestic birds; 2) open habitats for mallards and song birds; and 3) an amphitheater for educational purposes. Project steps include research, site analysis, preliminary design, and final master plan. As part of fund-raising activities, the master plan was displayed at the spring festival of the South Carolina Botanical Garden. This, combined with publications, will stimulate community awareness and participation as we approach the implementation phase of the project in Spring 1997.
Visits to Public Gardens: Its Meaning for Avid Gardeners
Authors: Hamilton Susan Wilson
Published: February 2019

This study examined how avid gardeners experience a public garden. Phenomenological interviewing was the qualitative research method used to collect data from six avid gardeners who frequently visited a public garden. Data about the gardener's beliefs and actions regarding their gardening history, gardening practices, and involvement with public gardens were gathered. From an inductive analysis, a conceptual model of a gardener's world was delineated. This study found that a gardener's world is composed of four dimensions that include: 1) personal history, 2) social connections, 3) human well-being, and 4) learning experiences. The dimensions of a gardener's world are the personal learning constructs through which gardeners experience their plant world. It is through these dimensions that the avid gardeners in this study experienced a public garden. Each of the four dimensions of an avid gardener's composition influenced how participants experienced a public garden. Participants used a public garden to socially interact with others, enhance their human well-being, strengthen their gardening background, and extend their gardening knowledge and skill. Several categories of activities and events emerged within the four dimensions of an avid gardener's world to inform us how gardening plays an integral role in gardeners' lives.
Extracurricular Activities Enhance Landscape Horticulture Programs
Authors: Williams J. David , Eakes D. Joseph , Ponder Harry G.
Published: February 2019

Strong academic abilities and practical work experience are important to employers of horticulture graduates. In greatest demand are students with competent personal and leadership abilities and technical skills. Increased class size and increased university core curriculum requirements hinder our capacity to develop these added skills within our curriculum. However, through extracurricular offerings we can offer students ways to develop skills that are not fully expressed in the academic arena. Student interaction in the traditional horticulture club requires practicing interpersonal relation and often conflict resolution skills. Students learn to work as a team to accomplish goals that they have set for themselves as a group. The Associate¥ Landscape Contractors of America (ALCA) Student Career Days experience offers a highly effective means for reinforcing cognitive skills gained in the classroom and laboratory, as well as supplementing academic learning opportunities with technical activities beyond those offered in the curriculum.
Cooperative Education and Internships at the Birmingham Botanical Gardens
Authors: Gerlach Gary G.
Published: February 2019

The BBG is a facility of the City of Birmingham Park and Recreation Board and operates as a coalition of the City's professional staff and resources as well as those of the Botanical Society (Friends), Alabama Cooperative Extension System (both groups maintaining offices at the BBG), 2 local community colleges, 12 specialized plant societies (that aid in the maintenance of collections), 100+ garden clubs, numerous related groups, and a strong community support. Current discussions with the University of Alabama in Birmingham will lead to certified programs at the Gardens. There are no formal contracts but informal agreements that are formed for each project. The Society sponsored the 1980 Master Plan and updates it every 10 years, employs a professional educator, and sponsors numerous special activities and programs, many in conjunction with the previously mentioned groups. Internships are hired and paid through the City. Students are rotated weekly through the various operations of the Gardens, including administration, education, taxonomy, and the Library. A special project is done in the area of interest to the student.