bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Drill and Broadcast Methods for Establishing Cover Crops on Beds
Authors: Brennan Eric B. , Leap Jim E.
Published: February 2019

Cover crop stands that are sufficiently dense soon after planting are more likely to suppress weeds, scavenge nutrients, and reduce erosion. Small-scale organic vegetable farmers often broadcast cover crop seed to establish cover crops but lack information on the most effective implements to incorporate the seed into the soil. Experiments were conducted with winter- and spring-sown cover crops to compare drilling vs. broadcasting methods for establishing rye (Secale cereale L.) mixed with either purple (Vicia benghalensis L., winter) or common vetch (V. sativa L., spring) on bed tops at a seeding rate of 140 kg·ha−1 in Salinas, CA. Broadcast seed was incorporated with a rototiller, cultivator, or tandem disc. Cover crop stand uniformity was assessed visually, and cover crop emergence over time and seeding depth were measured. Stands were more uniform after drilling or broadcast + rototiller incorporation compared with the other methods. Cover crops emerged sooner and in higher densities after drilling compared with broadcasting. The delayed emergence of broadcast seed was most apparent during the cooler winter experiment, particularly with purple vetch. Most drilled seed emerged from 2-cm depth compared with the broadcast seed that emerged from up to 11-cm depth with the greatest variability after disc or rototiller incorporation. The data indicate that the cultivator and rototiller are preferable implements to incorporate broadcast seed on beds, but that 50% to 100% higher seeding rates for broadcasting than drilling are needed. The practical implications for weed and soil management, and planting costs are discussed.
Growth Reductions by Exogenous Abscisic Acid Limit the Benefit of Height Control in Diploid and Triploid Watermelon Transplants
Authors: Agehara Shinsuke , Leskovar Daniel I.
Published: February 2019

Height control is important to produce compact vegetable transplants that are suitable for shipping and transplanting. Although abscisic acid (ABA) inhibits stem elongation, it can also induce other growth modifications. To optimize its application timing for effective height control, we examined age-dependent sensitivity of various growth variables to ABA in diploid ‘Summer Flavor 800’ and triploid ‘Summer Sweet 5244’ watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai]. Seedlings were sprayed once with 1.9 mm ABA at 25, 18, or 11 days before transplanting (DBT) or twice with 0.95 mm ABA at 25 and 18 DBT. The application rate was 0.55 mg ABA per plant with a spray volume of 0.61 L·m−2 (1.1 mL/plant). Only the single-spray treatment at 25 DBT (cotyledon stage) suppressed plant height by inhibiting petiole elongation. This effect was similar in both cultivars with 13% to 14% reductions at the transplanting stage compared with the untreated control. Undesirable growth modifications were also induced by ABA. In both cultivars, all ABA treatments caused 16% to 23% shoot biomass reductions mainly by inhibiting leaf expansion. Additionally, ABA treatments reduced stem diameter and root biomass in ‘Summer Flavor 800’. The double-spray treatment had similar growth-modulating effects as the single-spray treatments, except that it induced cotyledon abscission in ‘Summer Flavor 800’. These results suggest that although ABA applied at the cotyledon stage can reduce watermelon transplant height, the benefit is limited because of overall growth reductions, which can occur regardless of application timing. On the other hand, in triploid ‘Summer Sweet 5244’, moderate shoot growth delay by ABA may be of value as a growth-holding strategy when transplanting is delayed because of inclement weather at the time of field establishment. Importantly, field evaluations demonstrated that the growth modulation by ABA is only transient with no negative impact on marketable yield and fruit quality.
Evaluation of Direct Application of Enzymes to Remediate Soil Water Repellency
Authors: Zeng Lusheng , Liu Jiayang , Carrow Robert N. , Raymer Paul L. , Huang Qingguo
Published: February 2019

Organic coatings on sand particles can cause soil water repellency (SWR) where a soil does not spontaneously wet; this leads to challenges in water management and crop production. In laboratory studies, we evaluated a novel approach using direct application of 10 enzymes at three (low, medium, high) dosages to remediate SWR on two sand turfgrass soils in a 3-day incubation study and a second study at high dosage with 1-day incubation. A soil:solution ratio of 1:1 (10 g soil and 10 mL solution) was used and a deionized water control included. For Soil 7, a very strongly hydrophobic soil from a localized dry spot turfgrass area with a water drop penetration time (WDPT) of 7440 seconds (untreated) and 332 to 338 seconds (water-treated), the high dosage rates of laccase, chitinase, and protease at 1 and 3 days incubation resulted in WDPT of less than 60 seconds (i.e., hydrophilic soil). Pectinase exhibited similar results only in the 3-day incubation study. On the strongly hydrophobic Soil 21 (WDPT of 655 seconds untreated; 94 to 133 water-treated) from the dry area of a fairy ring-affected area on a turfgrass site, high dosages of chitinase, laccase, pectinase, and protease reduced WDPT to less than 60 seconds in both studies; and medium dosage rates were also effective for all but protease in the 3-day incubation study. Each of the four most effective enzymes for reducing WDPT, noted previously, demonstrated a significant exponential or logarithmic relationship between decreasing WDPT and increasing enzyme dosage. Further studies in field situations will be required to determine enzyme effectiveness on SWR and water management.
Exploration of Three Solanum Species for Improvement of Antioxidant Traits in Tomato
Authors: Top Oğuz , Bar Cantuğ , Ökmen Bilal , Özer Duygu Yüce , Rusçuklu Dane , Tamer Nilüfer , Frary Anne , Doğanlar Sami
Published: February 2019

Wild tomato species have been widely used for improvement of tomato disease resistance but have not been extensively explored for health-related traits. In this work, three interspecific populations derived from backcrosses between cultivated tomato and Solanum pimpinellifolium (LA1589), S. habrochaites (LA1223), and S. peruvianum (LA2172) were analyzed for water-soluble antioxidant activity, phenolic content, vitamin C content, and basic agronomic traits including fruit weight, shape, and color. The wild species accessions significantly exceeded S. lycopersicum for all three antioxidant traits with only one exception: vitamin C content in S. habrochaites LA1223. Several populations and traits showed transgressive segregation indicating that the backcross populations contained individuals with allele combinations that allowed antioxidant activity/content to exceed that of both parents. The S. habrochaites LA1223 population provided the best starting material for improvement of water-soluble antioxidant activity and phenolics content with 20% and 15% of the population, respectively, significantly exceeding the parental values for these traits. Moreover, the S. habrochaites population contained individuals that had nearly 2-fold more water-soluble antioxidant activity and phenolic content than cultivated tomato. The S. peruvianum LA2172 population was best for improvement of vitamin C content with 3-fold variation for the trait and individuals, which had twice as much vitamin C as cultivated tomato.
Artificial Hybridization between U.S. Native Ruellia caroliniensis and Invasive Ruellia simplex: Crossability, Morphological Diagnosis, and Molecular Characterization
Authors: Freyre Rosanna , Tripp Erin
Published: February 2019

The potential for natural hybridization to occur between non-native, invasive species and closely related native species is of interest to biologists, conservationists, and land managers, particularly in regions such as the southeastern United States where numerous non-native species have become serious environmental pests. To explore this potential between the invasive plant species Ruellia simplex and the closely related, sympatric Ruellia caroliniensis, we conducted a study of reproductive crossability and hybrid viability. Results indicate that the production of interspecific hybrids is possible, but only in one direction (i.e., with R. caroliniensis as the maternal parent). Artificial hybrids were weak, slow-growing, and sterile. These data suggest that it is unlikely that R. caroliniensis × R. simplex hybrids could invade the gene pool of native R. caroliniensis. We also characterized hybrids at the molecular level by sequencing parents plus F1 progeny for the nuclear ribosomal internal transcribed spacer (ITS) + 5.8S region. All hybrid genotypes formed a strongly supported clade with the maternal parent, Ruellia caroliniensis. Within this clade, hybrid individuals were not differentiable from maternal genotypes. We then examined general plant morphology of hybrid individuals and the two parents. Unlike results from the molecular characterization, there was a strong signal of hybrid intermediacy from this morphological work. We conclude that morphology but not molecular sequence data (from nrITS) can be used to distinguish the two parents and their F1 hybrids.
Phenotype and Fertility of Intersectional Hybrids between Tetraploid Highbush Blueberry and Colchicine-treated Vaccinium stamineum
Authors: Lyrene Paul M.
Published: February 2019

Several hundred hybrid seedlings were produced by pollinating flowers of tetraploid highbush blueberry cultivars with pollen from 13 plants of Vaccinium stamineum that were selected as tetraploids following colchicine treatment. The hybrids were intermediate between the parents in many characteristics. They were less vigorous than the parents, but 46 plants flowered when 1.3 years old from seed. The F1 hybrids produced pollen abundantly, but only 30% of the microspores appeared potentially viable when viewed at 250X. F1 flowers that were pollinated with pollen from either parent taxon or with pollen from a different F1 hybrid produced thousands of well-developed seeds. The F1 hybrids were less successful when used as male parents in backcrosses to highbush, but 4790 well-developed seeds were obtained by pollinating 3250 highbush flowers. Flowers on F1 plants had long peduncles and pedicels, giving an open raceme. The flowers were open in the bud and had anther awns, two characteristics from V. stamineum. Berries on the F1 plants had black skins, and the ripe berries of 11 F1 plants had red to purple pulp like their V. stamineum parent. Berries on the hybrids were juicy. They had little or no bitterness typical of V. stamineum, and most had a pleasing balance of sugar and acid.
Development of Highly Polymorphic Expressed Sequence Tags-Simple Sequence Repeat Markers and Their Application in Analysis of Genetic Diversity of Chinese Bayberry (Morella rubra)
Authors: Wang Wenting , Feng Chao , Zhang Zehuang , Yan Liju , Ding Maomao , Xu Changjie , Chen Kunsong
Published: February 2019

Chinese bayberry (Morella rubra) is an economically important subtropical evergreen fruit crop native to China and other Asian countries. For facilitating cultivar discrimination and genetic diversity analysis, a total of 38 high-quality and highly polymorphic expressed sequence tags-simple sequence repeat (EST-SSR) markers, with little or no polymerase chain reaction (PCR) stutter bands, including 21 screened from those obtained previously and 17 newly developed markers, were developed. The average number of alleles (Na) per locus was 5.6, and polymorphism information content varied from 0.34 to 0.86, with a mean value of 0.57. With these markers, all 42 Chinese bayberry accessions analyzed were successfully discriminated and the phylogenetic relationship between accessions was revealed. The accessions can be separated into two groups with six subgroups. The grouping of four main cultivars in three subgroups and 12 white-fruited accessions, each with little or no anthocyanin accumulation in ripe fruit, into five subgroups suggested the preservation of broad diversity among cultivated populations. These EST-SSR markers and the findings obtained in this study can assist the discrimination of cultivars and lines and contribute to genetic and breeding studies in Chinese bayberry.
Visual Assessments of Biodegradable Mulch Deterioration Are Not Indicative of Changes in Mechanical Properties
Authors: Cowan Jeremy S. , Saxton Arnold M. , Liu Hang , Leonas Karen K. , Inglis Debra , Miles Carol A.
Published: February 2019

The functionality of biodegradable mulch can be evaluated in agricultural field settings by visually assessing mulch intactness over time (a measure of deterioration), but it is unclear if mulch deterioration is indicative of mulch degradation as measured by mechanical properties (like breaking force and elongation). This 3-year study (2010–12) examined mulch percent visual deterioration (PVD) during the summer growing season in open-field and high tunnel production systems, and compared these to mulch mechanical properties at mulch installation (12–30 May), midseason (22 July–9 Aug.), and season end (6–25 Oct.), to determine if the field-based measures reliably predict degradation as revealed by changes in mulch mechanical properties. Four different types of biodegradable mulches [two plastic film mulches marketed as biodegradable (BioAgri and BioTelo); one fully biodegradable paper mulch (WeedGuardPlus); and, one experimental spunbonded plastic mulch designed to biodegrade (SBPLA)] were evaluated against a standard nonbiodegradable polyethylene (PE) mulch where tomato (Solanum lycopersicum L. cv. Celebrity) was planted as the model crop. Each year for the 3 years, PVD increased earlier for WeedGuardPlus than the other mulches in both the high tunnel and open field, and WeedGuardPlus had the greatest PVD in both high tunnels and the open field (6% and 48%, respectively). Mechanical strength of WeedGuardPlus also declined by the end of the season both in the high tunnel (up to 46% reduction) and in the open field (up to 81% reduction). PVD of BioAgri and BioTelo reached a maximum of 3% in the high tunnel and 28% in the open field by the end of the season. Mechanical strength of BioAgri and BioTelo did not change over the course of the season in either the open field or high tunnel, even though the ability of these mulches to elongate or stretch declined 89% in the open field and 82% in the high tunnel. SBPLA and PE mulches did not show a change in PVD or mechanical properties in either the high tunnel or the open field. Overall, PVD was three to six times greater by midseason in the open field than in the high tunnels. Although there were significant relationships between visual assessments and various mechanical properties for each mulch except SBPLA, the relationships differed for each mulch when evaluated separately and had coefficients of determination (R2) below 30%. Furthermore, PVD overestimated mechanical deterioration of BioAgri and BioTelo. Results of this study indicate that mulch visual assessments may reflect general trends in changes in certain mechanical properties of the mulch; however, visual assessment and mechanical properties provide different information on deterioration. Each should be used as needed, but not as a substitute for each other.
In Vitro Regeneration from Longitudinal Sections of Seedlings of Beaucarnea purpusii Rose, an Endemic and Endangered Species
Authors: Vadillo-Pro María del Carmen , Hernández-Sandoval Luis , Malda-Barrera Guadalupe , Osorio-Rosales María Luisa , Mata-Rosas Martín
Published: February 2019

The present study establishes an efficient protocol for in vitro propagation from longitudinal sections of seedlings of Beaucarnea purpusii, a threatened and highly appreciated ornamental species. The effect of three cytokinins: N6-benzyladenine (BA), kinetin (Kin), and thidiazuron, 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (TDZ), in semisolid media and three different concentrations, as well as the effect of BA and TDZ pulses at higher concentrations in liquid culture medium, were investigated. Adventitious shoot formation by direct organogenesis was observed from all treatments. Additionally, adventitious shoot formation was recorded from the leaves of the new shoots; this particular response was exclusive to treatments supplemented with TDZ. In the experiment using semisolid culture media, the highest means of shoots per explant were obtained from treatments containing TDZ, particularly at a concentration of 0.45 μm (25.8 shoots per explant). For the pulses experiment, the liquid culture media supplemented with TDZ at 22.35 µm for 24 hours and 136.21 µm for 96 hours, induced a mean of 3.9 and 3.3 shoots per explant, respectively. Subculturing individual shoots on MS and half-strength MS (1/2MS) media, both supplemented with activated charcoal at 1 g·L−1, induced rooting in 85% to 95% of shoots. A survival rate of 100% under greenhouse conditions was achieved. The results of this study provide an efficient alternative for mass propagation of B. purpusii and may also contribute to the conservation and sustainable use of this valuable natural resource.
Writing Scientific Journal Manuscripts in English
Authors: Shock Clinton C. , Shock Myrtle P. , Shock Candace B. , Reitz Stuart R.
Published: February 2019

With the intensification of horticultural research around the world, increasing numbers of scientific manuscripts are being written in English by authors whose primary language is not English. English has become the standard language of science, and English language manuscripts are readily accessible to the global scientific community. Therefore, non-native English speakers are encouraged to publish appropriate studies in English. Reviewers of manuscripts written in English by non-native speakers are encouraged to focus on scientific content and to provide constructive criticisms to facilitate the international exchange of information. Problems associated with writing scientific manuscripts in English can impede the publication of good science in international journals. This article describes problems in horticultural manuscripts that are often encountered by authors who are non-native English speakers and provides suggestions and resources to overcome these problems. References have been selected that provide clear help for authors in horticulture and other plant sciences.
Diversity of Iron and Zinc Content in Bananas from East and Central Africa
Authors: Pillay Michael , Fungo Robert
Published: February 2019

Bananas and plantains (Musa sp.) are major staple foods in many developing countries of the world. Although bananas are rich in carbohydrate, fiber, protein, fat, and vitamins A, C, and B6 they are largely deficient of iron (Fe), iodine, and zinc (Zn). A small increase in the micronutrient content of bananas could play a major role in combating disorders that are due to deficiency of mineral micronutrients such as Fe and Zn. The objective of this study was to determine the Fe and Zn content of 47 banana genotypes from a germplasm collection in Uganda using atomic absorption spectrophotometry. The Fe and Zn content showed wide variability and highly significant differences (P < 0.001) within and among the different banana categories selected for this study. The highest average Fe content (1.42 mg/100 g) was found in ‘Saba’ (ABB) while the least Fe content (0.06 mg/100 g) was found in ‘Kikundi’ (AAA). The highest average Zn content (1.21 mg/100 g) among the analyzed accessions was found in ‘Kivuvu’ (ABB) while Zn was not detectable in both ‘Kabucuragye’ (AAA) and ‘Grand Naine’ (AAA). Considering these figures, there is a greater than 20-fold variation in the Fe and Zn levels of the banana genotypes used this study suggesting that genetic improvement of genotypes for enhanced micronutrient levels may be achieved by breeding.
Diversity of Papaya ringspot virus Isolates in Puerto Rico
Authors: Zambrana-Echevarría Cristina , De Jesús-Kim Lorriane , Márquez-Karry Rocio , Siritunga Dimuth , Jenkins David
Published: February 2019

Papaya ringspot virus (PRSV) devastates papaya production worldwide. In Puerto Rico, papaya fields can be completely infected with PRSV within a year of planting. Information about the diversity of the Puerto Rican PRSV (PR-PRSV) population is relevant to establish a control strategy in the island. The coat protein gene (cp) of PRSV was sequenced from 62 isolates from different regions in Puerto Rico. The viral population of PRSV in Puerto Rico has 4% nucleotide and 5% amino acid diversity. Analysis of the coat protein (CP) amino acid sequence showed a variable amino terminal (N-terminal) region with a conserved aphid transmission motif and a variable EK repeat region. The core and carboxyl terminal (C-terminal) region were conserved. In the phylogenetic analysis, Puerto Rican isolates grouped independently of their geographical origin, with the exception of southern isolates that formed two separate subgroups and were the most divergent. Sequences of the cp from the Puerto Rican isolates, when compared with sequences from other countries, showed least genetic distance with isolates from the United States and Australia, followed by other American and Caribbean isolates. The U.S. and Australian isolates are sister taxa to the Puerto Rican isolates in the phylogenetic tree. This suggests that PRSV from Puerto Rico and the isolates from the United States and Australia have a common origin thought to be from a Mexican population.
Temperature Effect on Seed Germination in the Genus Leucocoryne (Amaryllidaceae)
Authors: De la Cuadra Carlos , Vidal Alexis K. , Lefimil Susana , Mansur Leví
Published: February 2019

Leucocoryne is a Chilean endemic genus from the Amaryllidaceae family. It is an emerging crop with some registered varieties, currently oriented to a niche ornamental market. In the present work, seed germination in Leucocoryne dimorphopetala, Leucocoryne coquimbensis, Leucocoryne purpurea, Leucocoryne aff. vittata, Leucocoryne aff. violacescens, and Leucocoryne ixioides for seeds stored for 4 months and in L. purpurea, Leucocoryne vittata, L. aff. vittata, and L. ixioides for seeds stored for up to 16 months was analyzed at 10, 15, 20, or 25 °C. Germination data were analyzed by the previously developed time-germination model p = A{1 − exp[−k(t − t0)]}. Each germination curve had a coefficient of determination (R2) higher than 0.89, except when there was lack of germination. Results show that higher germination was better achieved at lower (10 or 15 °C) rather than at the higher temperatures (20 or 25 °C). When comparing germination results at temperatures of 10 and 15 with results at 20 °C, germination decreased by at least 30% and became near zero at 25 °C in seed stored for 4 months. Similarly when seeds were stored for 16 months, germination decreased by ≈20% at 20 °C, and again was near zero for germination at 25 °C. These germination habits of Leucocoryne are interpreted as an adaptive strategy to its natural habitats. In addition, L. dimorphopetala presents a type of dormancy and other species (L. purpurea, L. ixioides, and L. aff. vittata) may be sensitive to after-ripening changes during storage.
Carotenoid Concentration and Composition in Winter Squash: Variability Associated with Different Cultigens, Harvest Maturities, and Storage Times
Authors: Bonina-Noseworthy Jennifer , Loy J. Brent , Curran-Celentano Joanne , Sideman Rebecca , Kopsell Dean A.
Published: February 2019

In the present study, carotenoid concentrations and profiles of carotenoids were determined at harvest and during storage in fruit of several cultigens of winter squash, including several New Hampshire (NH) breeding lines, the cultivars Waltham Butternut and Puritan Butternut in Cucurbita moschata (Duch.), and the hybrid cultivars Sunshine, Eclipse, Space Station, and Thunder in Cucurbita maxima (Duch.). Cultigens were grown at research farms in either Madbury or Durham, NH, in 2007, 2008, and 2009, and fruit were harvested at either 40 or 60 days after pollination (DAP), and stored for 0, 30, or 60 days at 14 °C before sampling. Total carotenoid concentrations were determined spectrophotometrically and carotenoid profiles were determined using high-performance liquid chromatography (HPLC). Carotenoid concentrations in fruit samples of C. maxima cultigens harvested at 60 DAP ranged from 146 to 320 μg·g−1 fresh weight (FW), compared with concentrations of 274 to 623 μg·g−1 FW after storage for 60 days. Carotenoid concentrations were lower among C. moschata cultigens, ranging from 42 to 145 μg·g−1 FW at 60 DAP, and from 84 to 239 μg·g−1 FW after 60-day storage. The nutritionally important carotenoids, lutein, zeaxanthin, and β-carotene, comprised 41% to 63% of the total carotenoid profile in the C. maxima kabocha hybrids; whereas, the carotenoids neoxanthin and flavoxanthin comprised 37% to 59%. β-Carotene and lutein were the major nutritionally beneficial carotenoids identified in ‘Waltham Butternut’ and three inbred lines of C. moschata, along with much smaller concentrations of α-carotene. Neoxanthin and violaxanthin comprised between 14% and 29% of the total carotenoid profiles among the four cultigens analyzed. In the popular cultivar Waltham Butternut, the β-carotene concentration was 17.3 μg·g−1 FW at 60 DAP, but increased to a maximum of 57.8 μg·g−1 FW after storage for 30 days; whereas, lutein concentrations increased from 27.3 μg·g−1 FW at 60 DAP to 44.6 μg·g−1 FW after 60-day storage. In Sunshine, a popular kabocha cultivar, β-carotene increased from 26.0 μg·g−1 FW at 60 DAP to 104 μg·g−1 FW after 60-day storage. Lutein + zeaxanthin concentrations in ‘Sunshine’ were 58.8 μg·g−1 FW at 60 DAP, but increased only to 71.8 μg·g−1 FW after 60-day storage. Total carotenoid concentrations and carotenoid profiles in ‘Sunshine’ over three growing seasons, and in ‘Waltham Butternut’, ‘NH.Mo421’, and ‘NH.Mo851’ over two growing seasons, were similar.
In Vitro Segregation of Tetraploid and Octoploid Plantlets from Colchicine-induced Ploidy Chimeras in Echinacea purpurea L.
Authors: Li Qingling , Yang Yuesheng , Wu Hong
Published: February 2019

Echinacea purpurea L. is one of the important ornamental and medicinal plant species. Ploidy manipulation is a valuable tool for improving plant quality or production in E. purpurea as well as in many other plants. To study the segregation of pure ploidy plantlets from colchicine-induced ploidy chimeras in E. purpurea, we used a chimera plantlet that consisted of 1.93% diploid, 35.04% tetraploid, and 63.03% octoploid cells as the source material for experiments. The results showed that three factors significantly influenced the segregation, i.e., the component ratios of different ploidy cells in the chimera, the number of sequential passages, and the methods of segregation culture of the chimera plantlets. Other factors, such as explant types (i.e., leaf, petiole, or root) and 6-benzyladenine (BA) concentrations (i.e., 0.2, 0.4, 0.8, and 1.2 mg·L−1) occasionally influenced the segregation. Pure chromosome-doubled polyploids are not easily obtained in various plant species, so segregation culture of ploidy chimeras may potentially be more effective. The morphological characteristic and content of cichoric acid were compared among diploid, tetraploid, and octoploid plants. Results indicated that tetraploid and octoploid plants had more stunted growth, larger stomata, lower stomata frequency, more chloroplast number in guard cells, and higher cichoric acid content than original diploid lines.
Spring Nitrogen Uptake, Use Efficiency, and Partitioning for Growth in Iris germanica ‘Immortality’
Authors: Zhao Xiaojie , Bi Guihong , Harkess Richard L. , Varco Jac J. , Blythe Eugene K.
Published: February 2019

This study investigated how spring nitrogen (N) application affects N uptake and growth performance in tall bearded (TB) iris ‘Immortality’ (Iris germanica L.). Container-grown iris plants were treated with 0, 5, 10, 15, or 20 mm N from 15NH415NO3 through fertigation using a modified Hoagland’s solution twice a week for 6 weeks in Spring 2013. Increasing N rate increased plant height, total plant dry weight (DW), and N content. Total N content was closely related to total plant DW. The allocation of N to different tissues followed a similar trend as the allocation of DW. In leaves, roots, and rhizomes, increasing N rate increased N uptake and decreased carbon (C) to N ratio (C/N ratio). Leaves were the major sink for N derived from fertilizer (NDFF). As N supply increased, DW accumulation in leaves increased, whereas DW accumulation in roots and rhizomes was unchanged. This indicates increasing N rate contributed more to leaf growth in spring. Nitrogen uptake efficiency (NupE) had a quadratic relationship with increasing N rate and was highest in the 10 mm N treatment, which indicates 10 mm was the optimal N rate for improving NupE in this study.
Effect of Irrigation Frequency and Shade Levels on Vegetative Growth, Yield, and Fruit Quality of Piquin Pepper (Capsicum annuum L. var. glabriusculum)
Authors: Valiente-Banuet Juan I. , Gutiérrez-Ochoa Alejandro
Published: February 2019

In Mexico, piquin peppers are highly valued horticultural products with limited cultivated production due to low seed germination, morphologic and genetic variability, disease susceptibility, and limited environmental physiology information. The objective of this study was to evaluate the effects of irrigation frequency and shade level treatments on vegetative growth, yield, and fruit quality of a commercial ecotype of piquin pepper. The study was conducted during two consecutive years using a hierarchical linear mixed-effects model design, with yearly data of irrigation frequency as main treatment blocks and shade levels as secondary blocks (nested within irrigation frequency treatments). Our results indicate that more frequent irrigation and increased shade levels favored vegetative growth. In addition, moderate shade levels (interception of 35% of full sunlight) and daily irrigation provided the best conditions for fruit production. This effect could be attributed to an increase in vegetative growth (thus higher photosynthetic and crop load capacity); more moderate conditions (temperatures and relative humidity) that favored flowering and fruit set, or a combination of these factors. Fruit size and pungency were not significantly affected by the treatments. Our results provide basic information for the development of guidelines for the cultivation of piquin pepper plants.
Environmental Variances of Fruit Traits in a Mandarin-related Population Used in Citrus Breeding in Japan
Authors: Hamada Hiroko , Nonaka Keisuke , Yoshioka Terutaka , Yamada Masahiko
Published: February 2019

We estimated environmental variance components for fruit weight (FW), ease of peeling (EP), firmness of segment membrane (FSM), soluble solids content (SSC), and acidity of 20 mandarin and related cultivars used as cross-parents in citrus breeding in Japan. The variance by year was largest for FW (38% of the total) and SSC (23%), but negligible for EP, FSM, and acidity. Variance among trees and tree × year interaction were negligibly small except for FW, whereas the genotype × year interaction variance ranged from 9% to 22% of the total. Variance among fruits from the same tree was the largest environmental component for EP and FSM. Broad-sense heritability (hB2) was 0.29 for FW, 0.52 for EP, 0.11 for FSM, 0.34 for SSC, and 0.65 for acidity in evaluations performed using single-year measurements of one tree with one fruit. Yearly repetition was more efficient than tree replication for increasing hB2 of all traits investigated. Increasing fruit number from one to five in combination with yearly repetition also increased hB2, especially for EP and FSM.
Assessment of Freeze Injury of Grapevine Green Tissues in Response to Cultivars and a Cryoprotectant Product
Authors: Centinari Michela , Smith Maria S. , Londo Jason P.
Published: February 2019

Spring frosts and subsequent crop losses threaten the economic sustainability of fruit crop producers all over the world. This study used a controlled-freezing technique to impose a post-budburst freezing stress to grapevine shoots forced from one-node cuttings [‘Albariño’, ‘Cabernet Franc’, ‘Cabernet Sauvignon’, and ‘Pinot Grigio’ (Vitis vinifera)] and whole plants [‘Noiret’ (Vitis hybrid)]. Our goal was to investigate the incidence of freeze injury among cultivars, stage of phenological development, and a potassium salt-based fertilizer (KDL) with potential cryoprotectant activity. Among the V. vinifera cultivars, the incidence of mortality of shoots exposed to −3.5 °C was highest for ‘Albariño’ (71%) and lowest for ‘Cabernet Sauvignon’ (51%). Cuttings sprayed with KDL 24 hours before cold temperature exposure exhibited 16% lower shoot mortality and lower osmotic potential (Ψs) (−0.92 MPa) than the unsprayed cuttings (−0.77 MPa). However, application of KDL did not impact shoot mortality for whole ‘Noiret’ vines. Mortality for ‘Noiret’ shoots greatly increased with the advancement of phenological development, ranging from 10% in wooly buds to 78% in shoots ≈10-cm long. The practical significance of KDL remains questionable; cultivar selection still appears to be a more reliable method for avoiding spring frost, by planting late bursting cultivars in more frost-prone areas.
Under-vine Management Impacts Soil Properties and Leachate Composition in a New York State Vineyard
Authors: Karl Adam D. , Merwin Ian A. , Brown Michael G. , Hervieux Rebecca A. , Vanden Heuvel Justine E.
Published: February 2019

Four under-vine management treatments were established in 2011 in a Vitis vinifera L. ‘Cabernet Franc’ vineyard in the Finger Lakes region of New York: cultivation (CULT), native vegetation (NV), white clover Trifolium repens L. (WC), and glyphosate herbicide (GLY) as the control. Previously installed drainage lysimeters were used to monitor nutrient and pesticide concentrations in leachate water samples. Differences in the physical structure of soils among treatments were only observed in the 4th year of the study when the top 6 cm of CULT soils had greater bulk density than the other treatments, and less porosity and available water capacity than WC soils. WC soils had 17% greater organic matter than CULT soils, and 46% greater aggregate stability than GLY soils. Soil microbial respiration was generally greater in NV and WC treatments than GLY and CULT. Dissolved organic carbon (DOC) leachate concentrations were greater in GLY and CULT compared with NV and WC, having annual mean DOC leachate concentrations as much as 36% greater than the cover crop samples. Mean annual total nitrogen (TN) leachate concentrations of CULT and NV were less than GLY and WC samples by as much as 86%. In 2012, GLY soils leached greater concentrations of imidacloprid insecticide and more imidacloprid metabolites than the other three treatments, with the proportion of samples testing positive for measurable concentrations of imidacloprid or imidacloprid metabolites at least five times greater in GLY than the other treatments. Cumulatively, these factors demonstrate the potential of under-vine cover crops to maintain soil quality and decrease the leaching of nutrients and agrochemicals in vineyards in comparison with conventional practices.
Vegetative and Reproductive Growth and Yield of Plukenetia volubilis Plants in Responses to Foliar Application of Plant Growth Regulators
Authors: Yang C. , Jiao D.Y. , Cai Z.Q. , Gong H.D. , Li G.Y.
Published: February 2019

Plukenetia volubilis Linneo, a tropical recurrent woody oilseed plant native to South America, was successfully introduced in China. A field experiment was conducted to determine the effect of the dry-season foliar sprays once every 2 weeks with 50 μm water or five different plant growth regulators (PGRs) viz., gibberellic acid (GA3), kinetin (KIN), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) on the growth and yield of P. volubilis plants in Xishuangbanna, southwest China. Results showed that PGRs affected the leaf stomatal conductance (gS) and water-use efficiency (WUEi), rather than the net photosynthetic rate (PN). The phenological development of P. volubilis plants, including the time of flowering and maturity, and the dynamic pattern of fruit ripening, was not altered by PGR treatments. ABA and SA resulted in highest fruit set, seed oil content, and total fruit or seed oil yield, whereas GA3, IAA, and KIN were effective in increasing seed size. The nonstructural carbohydrates (NSC) are related to subsequent abscission or retention of the developing fruit, which was indicated by the positive relationship between carbohydrate concentration and fruit set across PGR treatments. The positive influences of PGRs on the total fruit yield (increased 4.3% to 15.2%) and total seed oil yield (increased 4.9% to 24.9%) per unit area throughout a growing season were found when compared with the control, depending to a great extent on the balance between vegetative and reproductive growth during the reproductive stage. This study suggests that PGRs, especially for ABA and SA, can become a valuable tool for promoting the seed oil yield of P. volubilis plants while maintaining high seed quality in the field.
Statistics in a Horticultural Journal: Problems and Solutions
Authors: Kramer Matthew H. , Paparozzi Ellen T. , Stroup Walter W.
Published: February 2019

We examined all articles in volume 139 and the first issue of volume 140 of the Journal of the American Society for Horticultural Science (JASHS) for statistical problems. Slightly fewer than half appeared to have problems. This is consistent with what has been found for other biological journals. Problems ranged from inappropriate analyses and statistical procedures to insufficient (or complete lack of) information on how the analyses were performed. A common problem arose from taking many measurements from the same plant, which leads to correlated test results, ignored when declaring significance at P = 0.05 for each test. In this case, experiment-wise error control is lacking. We believe that many of these problems could and should have been caught in the writing or review process; i.e., identifying them did not require an extensive statistics background. This suggests that authors and reviewers have not absorbed nor kept current with many of the statistical basics needed for understanding their own data, for conducting proper statistical analyses, and for communicating their results. For a variety of reasons, graduate training in statistics for horticulture majors appears inadequate; we suggest that researchers in this field actively seek out opportunities to improve and update their statistical knowledge throughout their careers and engage a statistician as a collaborator early when unfamiliar methods are needed to design or analyze a research study. In addition, the ASHS, which publishes three journals, should assist authors, reviewers, and editors by recognizing and supporting the need for continuing education in quantitative literacy.
Repetition as the Performative Syndrome of Dying
Authors: Chukhrov Keti
Published: February 2019

In his Difference and Repetition Deleuze reveals an aporia: repetition is singular, solitary, it is torn away from any original or source; nevertheless it preserves a genetic tie with certain event to which it is a repetition. This solitariness of the repetition is not, however, confined to mere difference between the act of repetition and the repeated source that cancels the original just to differentiate two performative procedures. An act of repetition is solitary only when it evolves in specific time-regime, which even ontically diverges from the regular ontology of time. Deleuze calls such temporality “empty”, Nietzsche defines it as amor fati, Heidegger sees in it convergence of eternity and an instant. The stake in this case is a specific kind of repetitive regime which unfolds as the performative syndrome of ‘dying’ – a “repetition into death” (Deleuze) which paradoxically executes itself as performative plenitude. But who is the Subject undergoing such a syndrome and what should have happened to her/him so as to impose the regime of dying on any act of repetition?
Estimating the Effect of a Teacher Training Program on Advanced PlacementÂ® Outcomes
Authors: Brown Richard , Brown Emily Anne
Published: February 2019

This study employs a potential outcomes modeling approach to estimate the causal effect of Code.orgâ€™s Professional Learning Program on Advanced Placement (AP) Computer Science Principles test taking and qualifying score earned for a recent cohort of 167 schools compared to a matched group of comparison schools. Results indicate substantial and significant increases in both Computer Science AP test taking and qualifying score earning for all students. In addition, the significant effects were even greater for Computer Science AP test taking and qualifying score earned by female and minority students when impact ratios are analyzed separately. This study provides evidence of a teacher training program that is having a significant and important impact on preparing more students to succeed in computer science and improve the future of computer science education in this country.Keywords: computer science, professional development, teacher training
A stormwater user fee model for operations and maintenance in small cities
Authors: Tasca Fabiane Andressa , Finotti Alexandra Rodrigues , Goerl Roberto Fabris
Published: January 2019

In this paper, a stormwater fee specifically for small municipalities was developed through a simplification of the Equivalent Residential Unit (ERU) system, which is the main method applied in the United States. The Simplified ERU is based on the amount of impervious area and the fee considers the operations and maintenance costs, besides having a single class of billing. It was applied in Santo Amaro da Imperatriz city, located in the southern region of Brazil, which can be classified as a small city. The value of the Simplified ERU (294.32 m2) was similar to the average impervious area in the United States (269.42 m2) and it was equivalent to $0.28 per square meter (within the range of other countries' fees). The method proved to be a feasible and rapid technique for funding stormwater services, and its simplicity allows its application in different locations. This funding model can generate revenue to address current stormwater problems, such as the lack of funding for existing drainage infrastructure, and contribute to downstream flooding reduction. This paper also intends to encourage discussion about the methods for designing a stormwater fee in the academic community, which is still incipient.
Preparation of graphene oxide–montmorillonite nanocomposite and its application in multiple-pollutants removal from aqueous solutions
Authors: Zhang Chengyu , Luan Jingde , Chen Wei , Ke Xin , Zhang Haijun
Published: January 2019

It is of interest to develop a novel fabrication method of a mineral adsorbent for wastewater treatment to remove the combination of heavy metal ions and refractory organic contaminants. The crosslinking agent stearyl trimethyl ammonium chloride was added into a suspension of montmorillonite and graphene oxide to implement their recombination to fabricated graphene oxide–montmorillonite nanocomposite (GMN). The fabricated nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis and zeta potential. Results indicated that GMN exhibited a honeycomb texture, providing the chemical reaction site for the simultaneous adsorption of Pb2+ and p-nitrophenol (PNP). Factors including pH value, contact time, contact temperature and GMN dosage in the adsorption process were crucial for both Pb2+ adsorption and PNP adsorption. The optimum adsorption capacities of Pb2+ and PNP onto GMN were 19.39 mg·g−1 and 14.90 mg·g−1 under the condition of pH = 6, contact temperature 55 °C, contact time 60 min and GMN dosage 0.10 g, respectively. Data from experimental studies on simultaneous adsorption was well described by the pseudo-second-order model. The implementation of this work shows that GMN is a promising material for application in the simultaneous removal of heavy metal ions and refractory organic contaminants.
Sobrecarga del cuidado y morbilidad sentida en cuidadores de niños con discapacidad
Authors: Gómez-Ramírez Esperanza , Calvo-Soto Andrea Patricia , Dosman Belling Tatiana , Ángulo María De los ángeles
Published: January 2019

Estudio realizado para analizar la carga de cuidado y su asociación con la morbilidad sentida de cuidadores de niños con discapacidad. Estudio cuantitativo, descriptivo, correlacional y de corte transversal. Participaron 56 cuidadores de niños escolarizados en una asociación de Cali, Colombia. La morbilidad sentida se midió con el cuestionario Nórdico y la carga al cuidado con la entrevista de Zarit. Los resultados se presentaron mediante estadística descriptiva y coeficiente de relación de Pearson. Los participantes son en su mayoría mujeres, edad media de 48 años, más de diez años desempeñando dicho oficio y 21 horas promedio de cuidado al día. Prevaleció el dolor dorso-lumbar (50%), seguido de dolor en el hombro (37,5%). La sobrecarga subjetiva se ubicó entre los de mayor edad y con desempeño en otras actividades adicionales; esta asociación resultó estadísticamente significativa (p=0,04). Los cuidadores que dedican más tiempo, asociado a la realización de otras tareas, presentaron mayor sobrecarga subjetiva y morbilidad sentida osteomuscular en la región dorso-lumbar y hombros. Algunos manifiestan sentimientos de carga, dolor y frustración. La falta de ingresos económicos fue relacionada por ellos con el desmejoramiento de la actividad que ejercen.
Comprometimento acadêmico
Authors: Zarpelon Edinéia , Martins de Resende Luis Mauricio
Published: February 2019

Este artigo apresenta resultados parciais de uma pesquisa de mestrado, cujo objetivo foi analisar quais variáveis são significativas para a reprovação de alunos ingressantes em Engenharia, na disciplina de Cálculo I. Uma das hipóteses investigadas foi que o comprometimento acadêmico é um fator relevante, interferindo diretamente no desempenho estudantil. Trata-se de uma pesquisa aplicada, de cunho explicativo com abordagem qualitativa, cuja amostra era composta por 17 alunos de Engenharia que cursaram a disciplina de Cálculo I. Os dados foram coletados por meio de entrevistas semiestruturadas e examinados sob a perspectiva da análise de conteúdo proposta por Bardin (2011). Os relatos estudantis indicam que as posturas adotadas na época foram determinantes para o desempenho obtido em Cálculo I, sugerindo que o comprometimento acadêmico é uma variável significativa no contexto de aprovações ou reprovações na disciplina. Ademais, as narrativas sinalizam outras variáveis, evidenciando a natureza multifatorial implícita no fenômeno das reprovações em Cálculo I.
Prolegômenos à antropologia filosófica: histórico de um programa de pesquisa
Authors: De Almeida Cleber Ranieri Ribas
Published: February 2019

Este artigo pretende reconstituir a história da Antropologia Filosófica como disciplina acadêmica e como programa de pesquisa. Tal reconstituição será feita a partir da tese de Odo Marquard, segundo a qual há uma contraposição indissolúvel entre Antropologia Filosófica e Filosofia da História. O propósito é distinguir entre “humanismo” e Antropologia Filosófica. Ambos têm história conceitual, trajetória etimológica e programas disciplinares absolutamente dissociados. O “humanismo” e as filosofias do homem estão ancorados numa Filosofia da História. Em contraposição, a Antropologia Filosófica está ancorada numa Filosofia da Natureza. Portanto, contrariamente ao que afirma parte significativa da bibliografia especializada, “humanismo” e Antropologia Filosófica constituem programas de pesquisa absolutamente antitéticos. Por fim, para provar esta antítese, serão enumerados e caracterizados os princípios antropológicos e os imperativos metodológicos de investigação que definem o programa de pesquisa da Antropologia Filosófica.