bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of DNA Sequences from the β-Amylase Gene to Determine the Genetic Relationship among Sweetpotato, I. batatas and Other Ipomoea Species in Series Batatas (Convolvulaceae)
Authors: Rajapakse Sriyani , Ryan-Bohac Janice , Nilmalgoda Sasanda , Ballard Robert , Austin Daniel F.
Published: February 2019

The sweet potato Ipomoea batatas (L.) Lam. is classified in series Batatas (Choisy) in Convolvulaceae, with 12 other species and an interspecific true hybrid. The phylogenetic relationships of a sweetpotato cultivar and 13 accessions of Ipomoeas in the series Batatas were investigated using the nucleotide sequence variation of the nuclear-encoded β-amylase gene. First, flowers were examined to identify the species, and DNA flow cytometry used to determine their ploidy. The sweetpotato accession was confirmed as a hexaploid, I. tabascana a tetraploid, and all other species were diploids. A 1.1–1.3 kb fragment of the β-amylase gene spanning two exons separated by a long intron was PCR-amplified, cloned, and sequenced. Exon sequences were highly conserved, while the intron yielded large sequence differences. Intron analysis grouped species currently recognized as A and B genome types into separate clades. This grouping supported the prior classification of all the species, with one exception. The species I. tiliacea was previously classified as a B genome species, but this DNA study classifies it as an A genome species. From the intron alignment, sequences specific to both A and B genome species were identified. Exon sequences indicated that I. ramosissima and I. umbraticola were quite different from other A genome species. Placement of I. littoralis was questionable: its introns were similar to other B genome species, but exons were quite different. Exon evolution indicated the B genome species evolved faster than A genome species. Both intron and exon results indicated the B genome species most closely related to sweetpotato (I. batatas) were I. trifida and I. tabascana.
Screening Pecan Cultivars for Drought Tolerance Using Physiological Parameters
Authors: Sagaram Madhulika , Lombardini Leonardo
Published: February 2019

Pecan is a riparian species distributed over an area of geographic and climatic variation; such a wide distribution produces exposure to varied environmental conditions, providing a potential for genetic adaptation within the cultivars. Genotypes can be screened in order to obtain more drought tolerant cultivars using indirect screening parameters (chlorophyll fluorescence, osmotic adjustment, and abscisic acid assay) based on physiological responses of plants to abiotic stress conditions. A study was established at Texas A&M University, College Station, using a mixture of fritted clay (Quick dry) and pure sand in 1:1 (by weight) ratio to study the effects of drought on pecan rootstocks. The experiment was set up with the three water potential levels as treatments (–0.033 MPa, –0.1 MPa, –0.3 MPa) in a randomized complete-block design with three blocks. Measurements will include leaf water relations (relative water content, leaf water potential, osmotic adjustments, etc.), gas exchange parameters [net carbon dioxide assimilation rate (A), transpiration rate (E), stomatal conductance (gs)], chlorophyll fluorescence measurements [minimum (Fo), maximum (Fm), and variable fluorescence (Fv), quantum efficiency], water use efficiency, and abscisic acid assay on roots. Statistical analysis systems (SAS) package will be used for analysis. PROC GLM of the SAS will be used for statistical analysis of study involving plant response to water potential levels.
Use of the Horticultural Trade Show as a Guided Learning Experience in Undergraduate Horticulture Courses
Authors: Fitzpatrick George E. , Vendrame Wagner A.
Published: February 2019

One of the largest horticultural trade shows in the United States, the Tropical Plant Industry Exhibition, takes place each January in Fort Lauderdale, Fla. The timing of this show coincides with the offering, during the spring semester, of an undergraduate horticulture course, Palm Production and Culture (ORH 4321C, 3 credits). We have developed a guided activity in which we assign the students to visit several preselected exhibits in this show, so that each exhibit in the show is visited by at least one student. The students complete a questionnaire for each exhibit in which they note the identity of the palm species present, the number of species present, the number of individuals of each species, and the total number of palms in each exhibit. Data in the questionnaires are compiled and used to augment and reinforce class discussions on morphology, cultural requirements, interiorscape management, species richness, species diversity, and field laboratory work in morphology and taxonomy. Procedures used have the potential for adaptation to other types of horticultural trade shows and other types of horticultural crops, as well as for other courses in horticulture.
Project Management in a Regional USDA-funded Food Safety Program
Authors: Osborne Dennis J. , Sanders Douglas C. , Ward Donn R. , Rushing James W.
Published: February 2019

This paper summarizes the management framework of a multi-state, multi-institutional partnership delivering a targeted “train-the-trainer” program. Procedures associated with assuring on-schedule deliverables and budget compliance will be reviewed. The program provided Good Agricultural Practices (GAPs) and Good Manufacturing Practices (GMPs)-based training to southeastern U.S. fresh fruit and vegetable (produce) growers and packers. Twelve southern U.S. states cooperated in this project: Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia. The 2000–04 work was funded by U.S. Department of Agriculture–Cooperative State Research, Education, and Extension Service (USDA–CSREES) National Food Safety Initiative grants. This project developed materials, pilot-tested them, refined them for use by a regional group of specialized agents, assisted the agents in delivering the new programming, and evaluated the results.
Assessing Consumer Acceptance of Edamame-based Patties
Authors: Montri Dru N. , Kelley Kathleen M. , Sánchez Elsa S.
Published: February 2019

A sensory evaluation was conducted on 9–10 Feb. 2005 at The Pennsylvania State University, University Park campus, to determine consumer acceptance of two edamame [Glycinemax (L.) Merrill] -based patties. This value-added product was chosen because of the increasing popularity of vegetable-based burgers. Patties were mainly composed of edamame, mushrooms, and onion; however, they differed, based on the type of mushroom and seasonings used and the addition of walnuts to one of the recipes. One type of patty was evaluated each day with participants rating it on overall appeal, flavor, appearance, and texture. A total of 209 consumers participated in the 2-day sensory evaluation, 106 on the first day and 103 on the second; and 23.6% and 25.2%, respectively, were familiar with or had heard of edamame before. Overall mean liking for the patties was 6.38 and 6.58 (1 being dislike extremely and 9 being like extremely) and mean liking for flavor was 6.44 and 6.83, respectively. Based on the sample, 43.4% and 35.9% of participants each day indicated that they “probably would buy” or “definitely would buy” this item from a supermarket. Consumers also ranked select product characteristics that influence their decision to purchase new food items in terms of importance. Results were similar for both days with flavor, nutritional value, and price ranked as the three most important factors that influence their purchasing deci-sions. Verbal comments from participants indicated a strong interest in purchasing this product. Results suggested that consumers found the two edamame-based patties acceptable. Small-acreage growers could consider marketing edamame for use in value-added products such as these.
Patterns of Root Growth in Grape and Apple in Relation to Shoot Phenology
Authors: Eissenstat David M. , Neilsen Denise , Lakso Alan N. , Smart David R. , Bauerle Taryn L. , Comas Louise H. , Neilsen Gerry H.
Published: February 2019

Growers plan most of their horticultural activities around certain shoot phenological stages, such as bloom, veraison, and harvest. Timing of root growth in relation to these stages of the shoot is of interest in fertilization scheduling and in understanding carbon allocation demands of the root system. With the recent use of minirhizotron root observation tubes, a much greater understanding of patterns of root growth has been made possible. In Fredonia, N.Y., 5 years of root investigation in `Concord' grape indicate considerable variability in timing of root flushes. Root flushes could occur any time between bloom and veraison, but were generally not observed after harvest. Wine grapes in the Napa Valley exhibited similar patterns. In apple, root flushes may occur at bloom, but often not after harvest. Consequently, we rarely observed the bimodal distribution of root flushes commonly depicted in textbooks for apple and grape. Our data suggest that general perceptions of the timing of root growth may be in error.
New Genomics Resources for Strawberry
Authors: Davis Thomas M. , Folta Kevin M. , Shields M. M. , Brese Robin L. , DiMeglio Laura M. R. , Zhang Qian
Published: February 2019

The past year has brought substantial progress in the development of functional and structural genomic tools for strawberry. Sequencing of cDNA library clones from the cultivated strawberry Fragaria × ananassa and the diploid model species Fragaria vesca has provided more than 3000 new EST sequences. We have also constructed a large (∼40 kb) insert genomic (fosmid) library from F. vesca. About 33,000 fosmid clones have been picked and spotted onto hybridization filters. Filters have been successfully probed with three single copy gene probes, one gene family probe, and chloroplast DNA (cpDNA) and mitochondrial DNA (mtDNA) probe sets. The combined cpDNA and mtDNA clone content of the library is about 11%. After correction for organelle insert content, the nuclear genome coverage of the library is about 6×. Complete sequencing of two fosmid clones identified 12 putative protein-encoding genes, four of which were organized in colinearity with the corresponding chromosomal region of Arabidopsis thaliana. We will sequence an additional 50 fosmid clones, and use the resulting sequence data as the basis for developing a novel marker technology, to be described. These genomic tools will provide a basis for connecting specific genes to specific traits in the octoploid, cultivated strawberry, paving the way for implementation of gene-based, marker assisted selection as a tool for strawberry breeders. Opportunity for cross-species comparisons of gene sequence and composition, as well as genome organization and linkage group structure, between Fragaria and other members of the economically important Rosaceae family has been significantly enhanced, thus expanding the relevance of the project results to peach, cherry, apple, rose, brambles, and many other Rosaceous species.
(55) Root Pruning Techniques Do Not Help Pot-bound Plants
Authors: Gillman Jeffrey H. , Giblin Chad P. , Johnson Gary R.
Published: February 2019

Plants that have been grown in containers for a long period of time frequently develop roots that grow in circles, following the contour of the container in which they have been planted. This condition is commonly referred to as “pot-bound.” It is considered common knowledge that if a pot-bound plant is transplanted without any treatment, its roots will continue to follow the contour of the now-removed container. There are, however, a number of transplanting techniques that are intended to reorient the roots in a direction that will be conducive to helping roots to grow out of this potentially harmful situation. These techniques include: butterflying, or slicing the rootball into two halves before planting; scoring, or making inch-deep slices around the rootball at 90° increments and an X-shaped slice across the bottom; or teasing, where roots are manually pulled out of the shape of the container in a direction perpendicular to the stem. Severely pot bound Salixalba and Tiliacordata were treated with one of the three treatments previously listed or as a control and were transplanted into an experimental field and grown for two full seasons. After two seasons, the trees were harvested and the number and size of roots escaping from the pot-bound region were recorded. None of the treatments allowed roots of any size to escape the pot-bound mass more effectively than the control.
(3) Seed Regeneration of Short-day Onion Accessions in the U.S. Collection
Authors: Cramer Christopher S. , Robertson Larry D.
Published: February 2019

Numerous short-day onion accessions maintained at the Plant Genetic Resources Unit (PGRU) of Geneva, N.Y., were in danger of being lost from the U.S. germplasm collection due to sub-standard viability and low seed supply of those accessions. Seed regeneration of short-day onions at Geneva, N.Y., has been difficult because of improper daylengths and environmental conditions. A project was initiated in Sept. 2001 between PGRU and the onion breeding program at New Mexico State University to regenerate 75 accessions that were in the most danger of being lost from the collection. Even though germination rates were low for most accessions, plants were recovered from 72 accessions. Two accessions did not produce bulbs as it was likely they were long-day accessions. Of the remaining accessions, two accessions produced bulbs but did not produce seed. Several accessions bolted during bulb production and plants were covered with crossing cages, crosses were made, and seed was collected. Seed of 54 accessions were sent to PGRU to be incorporated back into the collection and to become available for distribution. Seventeen accessions produced less than 35 g of seed and were retained in order to produce additional seed in a second regeneration step. Some of the short-day accessions that have become available include `Amarela Globular Rio Grande', `Babosa', `Baia Performe Sintese No. 22', `Beth Alpha', `Burgundy', `California Early Red', `Dehydrator No. 5', `Early Crystal', `Eclipse L303', `Imperial 48', `New Mexico Yellow Grano', `Pusa Red', `Red Bermuda', `Red Creole', `Red Grano', `Red Patna', and `Rio Grande'.
Mitigation of Ethylene-promoted Leaf Senescence by a Natural Lipid, Lysophosphatidylethanolamine
Authors: Özgen Mustafa , Park Sookhee , Palta Jiwan P.
Published: February 2019

Mitigation of ethylene promoted leaf senescence by lysophosphatidylethanolamine (LPE) was studied. Micropropagated `Russet Burbank' potato (Solanum tuberosum L.,) plantlets were grown on MS media in sterile culture tubes. After 2 weeks of growth, tubes were sealed and ethylene gas was applied to obtain 5 nL·L–1 final concentration in the culture tubes. Observations and measurements were taken two weeks after ethylene injection. Potato plantlets treated with ethylene showed severe leaf senescence symptoms such as epinasty, lack of growth, yellowing and axillary shoot formation. These observations indicate that apical dominance has been lost with ethylene treatment. The same experiment was repeated with different concentrations of LPE in the MS medium. Inclusion of 50 or 100 mg·L–1 of LPE in the medium mitigated the damage normally caused by applied ethylene. Leaves of plantlets exposed simultaneously to LPE and ethylene had significantly higher chlorophyll content and more healthy leaves compared to plantlets grown on medium lacking LPE. Results of this study suggest that LPE may have the potential to retard ethylene-promoted leaf senescence and may mitigate ethylene induced loss in apical dominance of micropropagated potato plantlets.
Physical and Chemical Characteristics of Pomegranates
Authors: Drogoudi Pavlina D. , Tsipouridis Constantinos , Michailidis Zisis
Published: February 2019

Twenty pomegranate (Punica granatum L.) accessions were collected from different regions in northern Greece and evaluated under uniform conditions for leaf dimensions, frost resistance, and fruit physical and chemical characteristics, such as the juice antioxidant activity [ascorbate equivalent antioxidant activity (AEAC)], using the radical DPPH, ascorbic acid, total phenolic and total anthocyanin contents. Considerable variation in the characteristics studied was found and valuable pomological traits were exhibited. Cluster analysis produced cases of homonymy between some accessions. Principal component analyses showed that the component explaining the greatest variability positively correlated with percent juice, fruit chroma, AEAC, total anthocyanins, and soluble solids content (SSC), but negatively correlated with fruit fresh weight (FW), fruit and seed hue angle (less red color), total acidity, and leaf dimensions. Fruit size was positively correlated with acidity, while acidity was negatively correlated with SSC. Skin thickness and FW were correlated with fruit hue angle and chroma, suggesting that red color may better develop in thick-skinned and/or small-sized pomegranates. Total anthocyanin content was negatively correlated with FW and fruit hue angle. AEAC was positively correlated with total anthocyanin and ascorbic acid contents, the latter one constituted a 15% contribution to AEAC. The associations found among physical and chemical traits suggest that consumers interested in a healthier produce should be directed to small and red pomegranates.
Comparison of Antiproliferative and Antioxidant Properties among Nineteen Apple Cultivars
Authors: Yoshizawa Yuko , Sakurai Kenji , Kawaii Satoru , Asari Masayoshi , Soejima Junichi , Murofushi Noboru
Published: February 2019

Aqueous ethanol extracts prepared from 19 apple (Malus ×domestica Borkh.) cultivars were studied to explore their antiproliferative activity. Half of them showed strong inhibition on proliferation of human leukemic HL-60 cells, while the others were weak. Total polyphenols, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and total anthocyanins were measured and the results indicated that the antiproliferative activity was more strongly correlated to the polyphenols and radical scavenging activity than to the anthocyanin content. Several polyphenols in `Jonathan' were identified and quantified by high-performance liquid chromatography (HPLC) analysis. Among those compounds found during HPLC, catechin and epicatechin seemed partially responsible for HL-60 antiproliferation. A careful examination on parentage of the apple cultivars tested revealed that `Jonathan' and its progeny showed high antiproliferation toward HL-60. This is the first observation about the relationship between antiproliferative activity and parentage of apples, and the information would be useful to create new apple cultivars that posses more anticancer potential.
Plant and Fruit Characteristics of a Novel White Nectarine Type
Authors: Seker Murat , Kaynas Kenan , Yilmaz Ahmet , Us Uygar
Published: February 2019

In this study, we described some tree and fruit characteristics of a novel white nectarine type. The genetic diversity within this white nectarine population was investigated using six enzyme systems and its isozyme variation was also compared with common peach and nectarine cultivars. The results demonstrated that there was a significant variation within the white nectarine population in terms of plant and fruit characteristics probably due to the repropagation of the white nectarines using seedlings by growers. This variation was also verified by isozyme polymorphisms. Plants characteristics of white nectarines were similar to the trees of common peach or nectarine cultivars. However, the white nectarines produce less yield than the common peach or nectarine cultivars and they have small fruit with white-cream color and small flesh ratio making their fruit less attractive. We believe that the white nectarines have high market value and consumer acceptance because of its unique flavor which was confused with taste of either plums or apricots. So far, no standard white nectarine cultivar has been reported. This is the first report characterizing some plant and fruit characteristics of white nectarines which could be used for breeding of standard white nectarine cultivars with high yield and fruit characteristics while keeping its unique flavor. In addition, the white nectarines represent a novel source of germplasm for improvement of peaches and nectarines.
Identifying Superior Snow Pea Breeding Lines
Authors: De Ron Antonio M. , Magallanes Jorge J. , Martínez Óscar , Rodiño Paula , Santalla Marta
Published: February 2019

We evaluated 33 edible-pod pea (Pisum sativum L.) lines selected from single plants within 11 snow pea landraces and three elite cultivars for their horticultural value in three field trials at Pontevedra and Lugo (northwestern Spain). Field performance was estimated according to six traits related to earliness and duration, while horticultural value was determined by five pod traits. The global pod quality was estimated by a taste panel. Lines showed significant differences in nine quantitative traits. Significant differences were found among means of five landraces and the lines selected within them for pod length, width and weight. Cluster and principal component analysis identified a main group of 16 lines derived mainly from landraces PSM-0112 and PSM-0227 that had desirable earliness and pod quality. Some of the lines, such as MB-0298, MB-0324, MB-0325, MB-0326, MB-0332, and MB-0334 are appropriate for vegetable production as edible pod snow pea varieties and for use in breeding programs. Moreover, the lines MB-0298, MB-0321, MB-0322, and MB-0324 showed stable earliness and MB-0330 and MB-0332 stable pod quality across the three environments evaluated.
Plant Spacing Effects on Microclimate and Rhizoctonia Web Blight Development in Container-grown Azalea
Authors: Copes Warren E. , Scherm H.
Published: February 2019

Rhizoctonia web blight, caused by Rhizoctonia solani and binucleate Rhizoctonia spp., is an annual problem in compact cultivars of container-grown azalea (Rhododendron spp.) in the Gulf Coast states. Increasing the space between plants is commonly recommended for suppression of the disease, but experimental evidence for the effectiveness of this cultural practice in container-grown azalea is lacking. During the summers of 2002 and 2003, disease severity was measured weekly in the inoculated center plant of plots consisting of 49 potted `Gumpo White' azalea plants growing in 3.8-L containers and having a canopy diameter of about 30 cm. Plant spacing within plots was 0, 6, 12, 18, or 24 cm, and plots were arranged in three randomized complete blocks. Evaporation, leaf wetness (LW), relative humidity (RH), and temperature were monitored in each plot. Disease severity increased steadily from mid-July to late August or early September, after which it leveled off or declined. Evaporation increased and the number of hours within the temperature range favorable for disease development (25 to 30 °C) decreased significantly with plant spacing (P < 0.05), but LW and RH were not significantly different among treatments. Plant spacing also had no significant effect on disease severity. Daily overhead irrigation and compact plant form likely contributed to the lack of effect of spacing on disease development.
Chipped Pine Logs: A Potential Substrate for Greenhouse and Nursery Crops
Authors: Wright Robert D. , Browder Jake F.
Published: February 2019

Due to uncertainties of future supplies of pine bark (PB) and peatmoss, ground Pinus taeda logs [pine chips (PC)] were compared to ground PB as a potential container substrate for japanese holly (Ilex crenata Thunb. `Chesapeake'), azalea (Rhododendron obtusum Planch. `Karen'), and marigold (Tagetes erecta Big. `Inca Gold'). Plants were potted in 2.8-L plastic containers 8 Apr. 2004 with either 100% PC, 100% PB, or 75% PC:25%PB (v/v), and glasshouse grown 8 weeks for marigold and 13 weeks for holly and azalea. Plant dry weights were higher for marigold grown in 100% PB compared to 100% PC but not different from plants grown in 75% PC:25% PB. Plant dry weights of azalea were higher in 100% pine bark than both substrates containing chips. There was no difference in shoot dry weight for japanese holly between the three substrates. Root dry weight was higher for 75% PC:25% PB than for 100% PB, but root weight of 100% PB and 100% PC was the same. The percent air space for the PC was higher than the PB substrate but container capacity and available water was not different for the three substrates. Substrate solution electrical conductivity (EC) for PC, was lower than that of PB, possibly due to greater leaching with the more porous PC and nutrient retention by the PC. These factors could account for the cases where larger plants developed with the PB substrate. Nutrient analysis of the substrate solution indicated that there are no toxic nutrient levels associated with PC. The pH of PC is also acceptable for plant culture. As well, there was no apparent shrinkage due to decomposition during the course of this short-term experiment. Pine chips, therefore, offer potential as a container substrate for greenhouse and nursery crops.
Potential Sources of Resistance to Fusarium Wilt and Powdery Mildew in Melons
Authors: Alvarez José María , González-Torres Rafael , Mallor Cristina , Gómez-Guillamón María Luisa
Published: February 2019

In total, 139 Cucumis melo accessions were evaluated for resistance to races 0, 1, and 2 of Fusarium oxysporum fsp. melonis and 127 accessions were evaluated for resistance to races 1 and 2 of Sphaerotheca fuliginea. In addition, seven C. melo wild relatives were also tested. Artificial inoculations were performed and plants were scored for presence or absence of symptoms. The screening revealed that sources of natural resistance to these fungi are limited. However, several sources of resistance were found in C. melo accessions. Thus, the accession `CUM-334' from Tajikistan has shown resistance to the three races of F. oxysporum fsp. melonis, behaving similarly to the melon inbred line `MR1'. Two accessions of C. melo var. conomon, `CUM-190' and `Shiroubi Okayama', from Japan, were resistant to races 0 and 1 and twelve accessions were resistant to races 0 and 2. Intra-specific variability for resistance to powdery mildew in C. melo was found to be poor. Nevertheless, six Spanish cultivars and the accessions `TGR-1551', `CUM-313', and `CUM-129' were resistant to races 1 and 2 of S. fuliginea.
Accelerated Screening of Hazelnut Seedlings for Resistance to Eastern Filbert Blight
Authors: Molnar Thomas J. , Baxer Sara N. , Goffreda Joseph C.
Published: February 2019

An eastern filbert blight resistance screening technique was developed that reduces the time required to identify susceptible Corylus avellana L. seedlings from the previously reported 14 to 16 months after inoculation to 6 to 7 months. To accomplish this, hazelnuts were harvested at maturity, treated with GA3, germinated, and grown for about 8 weeks at 24 °C day/18 °C night with 16-hour daylengths. Seedlings were then moved to a humidity chamber and inoculated with ascospores of Anisogramma anomala (Peck) E. Müller 3 times over 2 weeks by misting until run off with a solution of 1 × 106 ascospores/mL in sterile distilled water. Following inoculation, seedlings were returned to the original greenhouse for 8 weeks and then were moved to a 10 to 15 °C day/5 to 10 °C night greenhouse with natural daylengths for 4 weeks. They were then moved to a 4 °C cold room for 8 weeks to receive chilling. Afterwards, seedlings were returned to a greenhouse at 24 °C day/18 °C night where stromata development was visible in 4 to 6 weeks.
Provide a Means to Develop Collard Cultivars
Authors: Farnham Mark W. , Ruttencutter Glen , Smith J. Powell , Keinath Anthony P.
Published: February 2019

Collard (Brassica oleracea L. Acephala Group) is a leafy green vegetable adapted to the southeastern United States. The number of commercially available collard cultivars is limited, and the most popular cultivars are susceptible to fusarium yellows, a disease that most cabbage (B. oleracea Capitata group) cultivars are resistant to. We hypothesized that hybrids of cabbage and collard would look more like collard, because heading of cabbage is at least partially recessive to the nonheading growth habit of collard. We also postulated that cabbage–collard hybrids might be used directly as collard cultivars. To test these postulates, cytoplasmic male sterile cabbage inbreds were crossed to different male fertile collard inbreds and hybrid seed was produced. Resulting cabbage–collard hybrids were compared to conventional collard cultivars in three replicated field trials in South Carolina. In all trials, cabbage–collard hybrids exhibited size and weight more similar to conventional collard than cabbage, and throughout most of the growing season the collards remained nonheading. In addition, the cabbage–collard hybrids were much more uniform than open-pollinated collard cultivars. Among cabbage–collard hybrids there was significant variation with some hybrids appearing more collard-like than others. The collard inbreds designated A and B may have the greatest potential for making promising cabbage–collard hybrids. Particular hybrids (i.e., A3 or B2), derived from these inbreds and tested in this study, can perform better than certain conventional collards and may serve as possible new cultivars of this vegetable crop.
Genetic Characterization of an Unknown Chinese Bulbous Leek-like Accession and its Relationship to Similar Allium Species
Authors: Bohanec Borut , Jakše Marijana , Šesek Predrag , Havey Michael J.
Published: February 2019

Bulbous leek-like plants are a poorly defined group usually assigned to the Allium ampeloprasum complex. Studies were initiated to determine the origin of an unusual bulbous accession received in Shanxi province in China, where it was used in diet as garlic but propagated by seeds, and to genetically compare this accession with morphologically similar plants from Europe. Genetic analyses included karyotypes and genomic in situ hybridization, pollination to leek, genome size determination and nuclear rDNA and plastid DNA polymorphisms. Results revealed that this agriculturally interesting accession from China is a so far unknown variant within tetraploid A. ampeloprasum cultivated taxa. We also observed that great-headed garlic did not share derived states in the chloroplast with leek, revealing that this cultivated plant does not possess the cytoplasm of leek or garlic, while its 1C genome size was 17% bigger than those of studied leek and bulbous-leek accessions.
Oxygen Content and its Diurnal Variation in a New Recirculanting Water Soilless Culture for Horticultural Crops
Authors: Urrestarazu Miguel , Mazuela Pilar Carolina , Boukhalfa Abdelaziz , Arán Antonia , Salas María del Carmen
Published: February 2019

Based on a new structure for plastic culture channels, a new system for soilless culture called New Growing Systems (NGS) has been developed. It is similar to the nutrient film technique (NFT) but with several potential advantages. Each NGS growing channel has five plastic layers and a large number of holes, there is a dripper every 0.5 m above the first layer of plastic, and each dripper supplies the nutrient solution which flows from the second layer over the others to the end. Three separate greenhouse experiments with tomato, cucumber, and sweet pepper using NGS channels were conducted in Almería (southeastern Spain). The oxygen content in the circulating nutrient solutions was determined at different points and different times along the channels of all crops. Depletion of oxygen content in the nutrient solution was lower than NFT channels. Oxygen content in NGS showed some advantages compared to NFT.
Growth of Container-grown Cork Oak Seedlings as Affected by Foliar and Soil Application of Paclobutrazol
Authors: Pardos Marta , Calama Rafael , Montero Gregorio , Pardos José A.
Published: February 2019

Four concentrations of paclobutrazol (PBZ) and two application methods (foliar spray–soil drench) were tested on 3-month-old container-grown cork oak (Quercus suber L.) seedlings. Shoot height was affected by PBZ concentration and application technique. Time course of height was modelled by nonlinear mixed model analysis. Reduced shoot height was the result of shortened and fewer internodes. A 25 to 625 ppm soil drench or 625 to 15,000 ppm foliar spray controlled over vegetative growth, resulting in a reduction between 13% and 90% in plant size relative to untreated controls. Seedlings responded to soil drench at a lower PBZ concentration than for a foliar spray, but the danger of irreversible overdosing seems greater for a soil drench. Soil drench—and foliar spray to a lesser extent—also affected other shoot and root growth traits. PBZ dose decreased root volume and dry weights in a quadratic fashion with increasing dose, but decreased diameter and number of leaves linearly.
Eggplant Tolerance to Halosulfuron Applied through Drip Irrigation
Authors: Webster Theodore , Culpepper A.
Published: February 2019

Halosulfuron is an alternative to methyl bromide for managing nutsedges (Cyperus spp.) in several vegetable crops. Field studies were conducted to evaluate eggplant growth and yield when halosulfuron was applied through drip-irrigation before transplant at four rates (0, 26, 39, or 52 g·ha–1 a.i.) or following transplant (26 g·ha–1 applied 1, 2, or 3 weeks after transplant) in spring and fall crops in 2002 and 2003. Inverse linear relationships were observed between rate of halosulfuron and eggplant growth and rate of halosulfuron and eggplant yield. Halosulfuron at 52 g·ha–1 reduced eggplant growth (crop height and canopy width) 19% to 22%. Eggplant fruit biomass at the first harvest was reduced 37% to 63% by halosulfuron applied before transplant. Eggplant was capable of recovering from the initial injury and there was no effect of halosulfuron rate on fruit biomass at the final harvest. Total season fruit biomass was reduced ≤4% from halosulfuron at 39 g·ha–1, while halosulfuron at 52 g·ha–1 reduced fruit biomass 33%. Delay in application of halosulfuron to 3 weeks after transplant (WAT) resulted in ≤7% reduction in fruit biomass and number for the entire season. When halosulfuron was applied 1 WAT, fruit biomass at the first two harvests was reduced >33%, however total season harvest from this treatment was >99% of the yield from the nontreated control. This preliminary study indicates that halosulfuron injected through drip tape may have the potential to assist in the replacement of methyl bromide for nutsedge management in eggplant. However, there are many issues that must be addressed and studied before adopting this practice in eggplant.
Effects of Supplied Nitrogen Form and Quantity on Growth and Postharvest Quality of Ranunculus asiaticus Flowers
Authors: Bernstein Nirit , Ioffe Marina , Bruner Moshe , Nishri Yair , Luria Gideon , Dori Irit , Matan Eli , Philosoph-Hadas Sonia , Umiel Nakdimon , Hagiladi Amir
Published: February 2019

The form of N supplied to the plant (NH4+ or NO3–) affects growth, morphology and a range of physiological processes in the plant. Little information is available concerning the effects of N form on development, production or quality of cut-flowers. The present study investigated for the first time the effects of N form and quantity on growth, flower production and flower quality of Ranunculus asiaticus L. The plants were cultivated in an inert mineral soilless medium (perlite) and were exposed to two levels of nitrogen fertilization (50 or 100 ppm) and three levels of NH +4 (10%, 20%, or 30%, under 100 ppm nitrogen fertilization). Larger shoots and increased shoot/root ratios were obtained in the lowest (50 ppm) N treatment. This treatment also excelled in flower yield production, resulting in higher numbers of total flower produced as well as higher numbers of long flowers. The results demonstrate an effect of N ferlilization treatments on cut-flower quality. Flowers grown under 50 ppm N application characterized by almost double vase life duration compared to flowers grown under the various 100 ppm N treatments. However, flower quantity and quality were not affected by the level of NH4 applied. The R. asiaticus L. root was less sensitive to the N fertilization treatments than its shoot. Contents of organic N, NO –3, P, K, Ca, Mg, Na, Cl, Fe, Cu, Zn, B, and Mo in the leaves were not affected by the fertilization treatments. Taken together, our results suggest a low requirement of R. asiaticus L. for N fertilization, and insensitivity to ammonium concentrations in the range of 10 to 30 ppm, 10% to 30% of the total N supplied. Detrimental effects in terms of growth, production and cut flower quality were apparent already under 100 ppm N supply.
The 'Maffei 15' Lima Bean Compensates for Reduced Plant Stand
Authors: Pill Wallace G. , Evans Thomas A. , Olszewski Michael W. , Mulrooney Robert P. , Kee Walter E.
Published: February 2019

'Maffei 15' baby lima bean seeds were sown every 6 cm in rows 76 cm apart to yield a nominal stand of 215,000 plants/ha at two locations in Delaware over 2 years. Seedlings were thinned within 2 weeks of planting to provide 0%, 16.7%, 33.3%, and 50.0% stand reduction at two in-row spacing patterns to determine subsequent effects on vegetative and reproductive growth. Shoot fresh weight per square meter was decreased only in 2003 by 21% and bean fresh weight per square meter was decreased only in 2004 by 13.8% when plant stand decreased to 50%. This disproportional vegetative and reproductive growth response to stand reduction resulted from a compensatory linear increase in shoot fresh weight, usable pod number, and bean fresh weight of individual plants. Thus, 'Maffei 15' lima bean tolerates a considerable loss of plant stand with little or no effect on yield.
Air Temperature Affects Biomass and Carotenoid Pigment Accumulation in Kale and Spinach Grown in a Controlled Environment
Authors: Lefsrud Mark G. , Kopsell Dean A. , Kopsell David E. , Curran-Celentano Joanne
Published: February 2019

Crop plants are adversely affected by a variety of environmental factors, with air temperature being one of the most influential. Plants have developed a number of methods in the adaptation to air temperature variations. However, there is limited research to determine what impact air temperature has on the production of secondary plant compounds, such as carotenoid pigments. Kale (Brassica oleracea L.) and spinach (Spinacia oleracea L.) have high concentrations of lutein and β-carotene carotenoids. The objectives of this study were to determine the effects of different growing air temperatures on plant biomass production and the accumulation of elemental nutrients, lutein, β-carotene, and chlorophyll pigments in the leaves of kale and spinach. Plants were grown in nutrient solutions in growth chambers at air temperatures of 15, 20, 25, and 30 °C for `Winterbor' kale and 10, 15, 20, and 25 °C for `Melody' spinach. Maximum tissue lutein and β-carotene concentration occurred at 30 °C for kale and 10 °C for spinach. Highest carotenoid accumulations were 16.1 and 11.2 mg/100 g fresh mass for lutein and 13.0 and 10.9 mg/100 g fresh mass for β-carotene for the kale and spinach, respectively. Lutein and β-carotene concentration increased linearly with increasing air temperatures for kale, but the same pigments showed a linear decrease in concentration for increasing air temperatures for spinach. Quantifying the effects of air temperature on carotenoid accumulation in kale and spinach, expressed on a fresh mass basis, is important for growers producing these crops for fresh markets.
Formulation of Flowering Index, Morphological Relationships, and Yield Prediction System in True Garlic Aerial Seed Bulbil Production
Authors: Mathew Deepu , Ahmed Zakwan , Singh N.
Published: February 2019

The phenomenon of flowering and aerial bulbil production in Asiatic garlic was observed under long photoperiodic conditions of Ladakh, India. Flowers were sterile and the bulbils produced on the umbel were true to type. Observations on a large number of flowering and nonflowering plants have led to the formulation of a precise flowering index (FI) in garlic. Plants with a minimum leaf number of 7, height 25 cm, collar width 0.6 cm, bulb diameter 3.7 cm, bulb weight 22.5 g, and functional leaf area of 182.4 cm2 had only shown the flowering. The flowering index formulated was a product of leaf number, plant height, functional leaf area, and bulb weight. For flowering, FI should be more than 788, and availability of a minimum photoperiod of 4020 hours during a growth period of 11 months was another prerequisite. Nonfulfillment of any one of the factors of flowering, although FI and photoperiod were satisfactory, led to nonflowering. Garlic aerial bulbil yield was positively correlated with leaf number, plant height, bulb weight, bulb diameter, length of flower stalk, 100 seed weight, and head diameter. Following the multiple regression model y = –11.9 – (0.00031 × number of bulbils) + (0.147 × 100 bulbil weight) + (4.95 × head diameter) + (0.0460 × length of flower stalk), aerial bulbil yield prediction was possible at a mean accuracy of 87%.
In vitro Effects of Muscodor albus and Three Volatile Components on Growth of Selected Postharvest Microorganisms
Authors: Ramin Ali A. , Braun P. Gordon , Prange Robert K. , DeLong John M.
Published: February 2019

Biofumigation by volatiles of Muscodor albus Worapong, Strobel & W.M. Hess, an endophytic fungus, was investigated for the biological control of three postharvest fungi, Botrytis cinerea Pers., Penicillium expansum Link, and Sclerotinia sclerotiorum (Lib) de Bary, and three bacteria, Erwinia carotovora pv. carotovora (Jones) Bergey et al., Pseudomonas fluorescens Migula (isolate A7B), and Escherichia coli (strain K12). Bacteria and fungi on artificial media in petri dishes were exposed to volatiles produced by M. albus mycelium growing on rye seeds in sealed glass 4-L jars with or without air circulation for up to 48 hours. The amount of dry M. albus–rye seed culture varied from 0.25 to 1.25 g·L–1 of jar volume. Fan circulation of volatiles in jars increased efficacy and 0.25 g·L–1 with fan circulation was sufficient to kill or suppress all fungi and bacteria after 24 and 48 hours, respectively. Two major volatiles of M. albus, isobutyric acid (IBA) and 2-methyl-1-butanol (MB), and one minor one, ethyl butyrate (EB), varied in their control of the same postharvest fungi and bacteria. Among the three fungi, IBA killed or suppressed S. sclerotiorum, B. cinerea, and P. expansum at 40, 25, and 45 μL·L –1, respectively. MB killed or suppressed S. sclerotiorum, B. cinerea, and P. expansum at 75, 100, and 100 μL·L –1, respectively. EB was only able to kill S. sclerotiorum at 100 μL·L –1. Among the three bacteria, IBA killed or suppressed E. coli (K12), E. carotovora pv. carotovora, and P. fluorescens at 5, 12.5, and 12.5 μL·L–1, respectively. MB killed or suppressed E. coli (K12), E. carotovora pv. carotovora, and P. fluorescens at 100, 75, and 100 μL·L–1, respectively. EB did not control growth of the three bacteria. This study demonstrates the need for air circulation in M. albus, MB, and IBA treatments to optimize the efficacy of these potential postharvest agents of disease control.
Greenhouse Pepper Growth and Yield Response to Copper Application
Authors: Zheng Youbin , Wang Linping , Dixon Mike
Published: February 2019

Copper (electrolytically generated or from cupric sulfate) is increasingly used to control diseases and algae in the greenhouse industry. However, there is a shortage of information regarding appropriate management strategies for Cu2+ (Cu) in greenhouse hydroponic production. Three greenhouse studies were conducted to examine the growth and yield responses of sweet pepper (Capsicum annuum L., Triple 4, red) to the application of Cu in hydroponic production systems. In the first two experiments, plants were grown on rockwool and irrigated with nutrient solutions containing Cu at concentrations of 0.05, 0.55, 1.05, 1.55, and 2.05 mg·L–1. Copper treatments were started either when plants were 32 days old and continued for 4 weeks, or when plants were 11 weeks old and continued for 18 weeks, respectively. In the third experiment, roots of solution cultured pepper seedlings were exposed to Cu (1.0, 1.5, and 2.0 mg·L–1) containing nutrient solutions for 2 hours per day for 3 weeks. Higher Cu treatment initialized when plants were 32 days old significantly reduced plant leaf number, leaf area, leaf biomass, specific leaf area, stem length and shoot biomass. The calculated Cu toxicity threshold was 0.19 mg·L–1. However, when treatment initialized at plants were 11 weeks old, Cu did not have significant effects on leaf chlorophyll content, leaf area or specific leaf area. Copper started to show significant negative effects on leaf biomass and shoot biomass at 1.05 mg·L–1 or higher levels. Copper treatments did not have any significant effect on fruit number, fresh weight or dry weight. Under all the Cu levels, fresh fruit copper contents were lower than 0.95 mg·kg–1 which is below the drinking water standard of 1.3 mg·kg–1. Seedling growth was significantly reduced by exposing roots to Cu (≥1.0 mg·L–1) containing solutions even for only 2 h·d–1.
Composted Yard Waste Affects Soil Displacement and Roadside Vegetation
Authors: Harrell Michael S. , Miller Grady L.
Published: February 2019

The benefits of composted yard waste applied as a mulch were demonstrated in a field study at two locations and supporting greenhouse research. Compost was applied to eroded roadside slopes of about 12° and 27° to determine the influence on soil displacement and establishment and/or enhancement of permanent roadside vegetation. Treatments consisted of compost rates of 5 cm and planted with asiastic jasmine (Trachelopermum asiaticum), 5 and 10 cm, seeded with 110 or 220 kg·ha–1 80:20 bahiagrass (Paspalum notatum Flugge): bermudagrass (Cynodon dactylon L.) seed mix by weight, straw erosion control mats, and bahiagrass sod. Compost treatments effectively controlled soil displacement regardless of compost rate or seeding with turfgrass at both locations. Effects on roadside vegetation and visual quality varied with location. Asiatic jasmine did not establish at either site. Compost mulch applications increased total vegetation, turfgrass density, and quality at the site with 27° slope and 4% initial soil organic matter content, but resulted in a decline in cover at the site with a 12° slope and <1% organic matter content. Compost mulch can effectively prevent soil displacement from roadside slopes, but may not promote establishment or enhancement of permanent vegetative cover.
'Aguedilla' Strawberry
Authors: López-Aranda José M. , Soria Carmen , Miranda Luis , Sánchez-Sevilla José F. , Gálvez Josefa , Villalba Rosalía , Romero Fernando , Santos Berta De Los , Medina Juan J. , Palacios Javier , Bardón Emilio , Arjona Antonio , Refoyo Antonio , Martínez-Treceño Anselmo , De Cal Antoñeta , Melgarejo Paloma , Bartual Rafael
Published: February 2019

Aguedilla is a short-day strawberry (Fragaria ×ananassa Duch.) cultivar obtained by the Spanish public breeding program (Agreement CC01-0008-F1). 'Aguedilla' produces excellent extra-early, early, mid-season, and late-season large-sized, wedge-shaped fruit, and a low percentage of second quality fruit. An agronomic and sensorial characterization of this new cultivar, in comparison with the well-adapted cultivars 'Camarosa', 'Medina', and 'Ventana', was undertaken during the 2002–03 and 2003–04 crop seasons.