bluuebunny/crossref_metadata_2025 huggingface dataset:
Curiosity: The Story of a Mars Rover by M. Motum
Authors: Pasterfield Thomas
Published: June 2019

Motum, Markus. Curiosity: The Story of a Mars Rover. Candlewick Press, 2018.

Curiosity: The Story of a Mars Rover, written and illustrated by Markus Motum, would be a welcome addition to any classroom’s library. With exceptional pacing and flow, Motum takes us through the true story of one of science’s great achievements: successfully landing a rover on Mars.

Many young readers have an inherent interest in outer space and science fiction. In this book, Motum expounds the science of science fiction in detailing the story of how Curiosity ended up on Mars (where it still roves today) in a somewhat narrative form. It would be appropriate for all grade levels, though younger grade students would likely need experienced help in order to read it. The font size and colour vary making them readable to most audiences, and they serve the story well.

The story is told from the point of view of the rover itself, named Curiosity. It begins by introducing itself as if it were a sentient creature before it goes back to the beginning, in a very cosmic sense, to plant its story within the wider view of space exploration in general. Motum’s choice in this case allows the reader to gain greater perspective for Curiosity’s story. Curiosity itself is as developed as it needs to be for the purposes of the narrative; that is to say, Motum does not imbue the rover with emotion or opinions within the story. However, the emotions and opinions of the astronauts, scientists and engineers who are namelessly featured throughout the story are indeed explored, which gives a sense of urgency and peril as we travel alongside Curiosity on its adventure.

In addition to authoring this picture book, Motum also illustrates it in a mixed media style that is both alien and historic. The solid colours and painted portions evoke the artistic style of old postcards from days gone by, while simultaneously making the Martian landscape seem exotic and alien, as if Mars were a travel destination, welcoming travellers like Curiosity. Though beautiful, the illustrations do not add much information to the story of Curiosity; in some instances, they provide some spatial context like when Curiosity tries to land on Mars. The illustrations lend a hand to create atmosphere, both in the context of the story and for the reader. Some of the text is also placed in unconventional locations on the page, so the text and the illustrations work together to create meaning and story. One finds that the eye is drawn to specific parts of the image on each page, and it is masterfully done.

For these and many other reasons, Curiosity: The Story of a Mars Rover is a great example of modern children’s literature. It is suitable for a variety of ages, and it is worthwhile reading in many ways.

Highly Recommended: 4 out of 4 stars Reviewer: Thomas Pasterfield

Thomas Pasterfield is a fourth year undergraduate student in Elementary Education at the University of Alberta. His reading interests include fantasy novels, vegetable gardening manuals, and religious books.
Penguinaut by M. Colleen
Authors: Metcalfe Erika
Published: June 2019

Colleen, Marcie. Penguinaut. Scholastic, 2018.

In the book Penguinaut, Marcie Colleen uses the story of a hopeful penguin to convey a message about adversity to young children. It is a story about a small penguin named Orville who overcomes challenges in order to achieve his big dream of going to space.

Emma Yarlett’s illustrations are creative, entertaining, and fun. They help the reader understand just how small little Orville is in comparison to all of his other animal friends, reinforcing the idea that one should not be afraid of failure when achieving their dreams, despite any challenges they may face.

It is evident that Marcie Colleen decided to use the style of text, paired with the illustrations, to help add enthusiasm, detail, and voice. The words “big” and “bigger” are in large capital letters, and sound effects are bolded. Speech bubbles are used for dialogue instead of quotation marks. The sentence “He was all alone” is accompanied by an illustration of stars in the dark outer space. And a picture of a note given to Orville by his friends to show their support is written in handwriting, including a hand-drawn picture.

Penguinaut is a heart-warming book that offers lessons about adversity, resiliency, and friendship. Considering the length of the book, I believe there is room to explore these topics by including some additional detail to the story of Orville, the penguin. The messages this book conveys makes Penguinaut a good addition to an elementary school or public library.

Recommended: 3 out of 4 starsReviewer: Erika Metcalfe

Erika is a grade one/two teacher in Edmonton and is currently completing her Master of Education at the University of Alberta. When she is not teaching or studying, Erika is on the hunt for new books to read to her students!
The Study of Customer Experience Design and Optimization of Shopping Website: Case Analysis of Amazon in China
Authors: Yang Songming
Published: June 2019

Customer experience design plays an important role in the development and optimization of shopping websites (Menon and Kahn, 2002). To satisfy the increasing demands of customers and to attract additional loyal customers, customer experience design is increasingly valued by e-commerce enterprises (Ribbink et al., 2004). Since 1995, Amazon has become the leader in online shopping (Amblee and Bui, 2011). Therefore, the study of Amazon's customer experience design can provide successful experience and offer valuable information for other shopping sites.This project adopts textual analysis and case study methods. Firstly, it introduces the concept, importance, and influencing factors of customer experience and shopping website’s customer experience design. Furthermore, the project provides a detailed description of Amazon China's current development situation in the Chinese market. Secondly, comparing Amazon China with its major competitors highlights the differences in customer experience design in terms of product, design, service, and marketing, while listing the pros and cons of Amazon's customer experience. Finally, the project summarizes the importance of customer experience for shopping website development and proposes the optimization and improvement suggestions to Amazon China.
Data-Driven Bicycle Network Analysis Based on Traditional Counting Methods and GPS Traces from Smartphone
Authors: Rupi Federico , Poliziani Cristian , Schweizer Joerg
Published: June 2019

This research describes numerical methods to analyze the absolute transport demand of cyclists and then to quantify the road network weaknesses of a city with the aim to identify infrastructure improvements in favor of cyclists. The methods are based on a combination of bicycle counts and map-matched GPS traces and are demonstrated with the city of Bologna, Italy: the dataset is based on approximately 27,500 GPS traces from cyclists, recorded over a period of one month on a volunteer basis using a smartphone application. A first method estimates absolute, city-wide bicycle flows, by scaling map-matched bicycle flows of the entire network to manual and instrumental bicycle counts of the main bikeways of the city. As there is a good correlation between the two sources of flow data, the absolute bike-flows on the entire network have been correctly estimated. A second method describes a novel link-deviation index, which quantifies for each network edge the total deviation generated for cyclists in terms of extra distances traveled with respect to the shortest possible route. The deviations are accepted by cyclists either to avoid unpleasant road attributes along the shortest route or to experience more favorable road attributes along the chosen route. The link deviation index indicates the planner which road links are contributing most to the total deviation of all cyclists – in this way, repelling and attracting road attributes for cyclists can be identified. This is why the deviation index is of practical help to prioritize bike infrastructure construction on individual road network links.
Prevalence of Anemia and Its Associated Factors among Chronic Kidney Disease patients at University of Gondar Hospital, North West Ethiopia: a Hospital-based Cross Sectional Study
Authors: Adera Hailemariam , Hailu Workagegnehu , Adane Ayineshet , tadesse abilo
Published: June 2019

Background

chronic kidney disease (CKD) is a global public health problem associated with progressive decline in kidney function and adverse cardiovascular outcome. Anemia in CKD has substantial adverse outcomes in CKD patients. There is paucity of published data on prevalence of anemia and its associated factors among CKD patients in Northwest Ethiopia.

Objective

This study aimed to determine the prevalence of anemia and its associated factors among CKD patients at University of Gondar hospital, Northwest Ethiopia.

Methods

A hospital-based cross-sectional study was conducted from May1, to September 30, 2018. Consecutive sampling was used to recruit 251 study subjects. Data regarding patient’s socio-demographics, clinical characteristics and laboratory parameters were collected from patients’ interview and medical records. Data was analyzed using SPSS version 20. Bi-variate and multi-variate logistic regression analyses were used to identify predictors of anemia in CKD patients. P<0.05 was used to declare association.

Results

The prevalence of anemia was high (64.5%), and tended to increase as eGFR declined. Hypertension (45%), chronic glomerulonephritis (24%) and diabetes (20%) were common causes of CKD. Multivariate logistic regression analysis revealed rural residence (AOR= 2.75, 95% CI: 1.34-5.65, p=0.006), BMI<18.5 kg/m2 (AOR=6.78, 95% CI: 1.32-34.73, p=0.022) and BMI of 18.5-24.9 kg/m2 (AOR=5.04, 95% CI: 1.26-20.10, p=0.022), and having hemodialysis history (AOR=3.59, 95% CI: 1.24-10.38, p=0.018) were predictors of anemia in CKD patients.

Conclusion

Prevalence of anemia in CKD patients was high (64.5%). Rural residence, non-obese body habitus and having hemodialysis history were found to be predictors of anemia in CKD patients. Periodic screening and intervention for anemia in CKD patients should be practiced to prevent its sequelae.
Red Cell Distribution Width Before Intravenous Thrombolysis in Prediction of 1-year Outcome and Mortality in Patients with Acute Ischemic Stroke
Authors: Ye Weiyi , Li Jia , LI Xiang , Yang Xuezhi , Weng Yiyun , Xiang Weiwei , Zhang Xu
Published: June 2019

Background: It is well known that red blood cell distribution width(RDW)is a parameter reflecting the heterogeneity of red blood cell volume，which recently may be associated with the development of cardiovascular events or mortality in patients after myocardial infarction .However, little is known about the association between RDW and stroke, especially regarding indisputable endpoints such as death. The purpose of the study was to explore the prognostic value of RDW and its effect on mortality among patients with acute ischemic stroke (AIS) undergoing Intravenous thrombolysis (IVT).
Methods: We carried out retrospective analysis of acute anterior ischemic strokes cases treated with IVT between January 2016 and March 2018.The effect of RDW on poor outcome (modified Rankin score 3-6) and mortality in 1 year were assessed. Use multivariate logistic regression to explore the predictors. Receiver operating characteristic (ROC) curve was used to evaluate the predictive capability of variables, furthermore, we applied Cox proportional-hazards models to analyze the impact of factors on survival.
Results: RDW (Multivariate OR 1.179;95%CI 0.900-1.545,p=0.232) was not associated with clinical outcome. Surviving patients have lower baseline RDW compared with patients who later died. Adding RDW to NIHSS could improve the prediction of the mortality of stroke clinical outcomes.
Conclusions: The finding of our study implied that higher RDW was a potential predictive factor of mortality in 1 year in patients with AIS undergoing IVT，but RDW might not be associated with worse survival function among stroke survivors.
Acquiring Cherry Germplasm from Central and Eastern Europe
Authors: Iezzoni Amy F.
Published: June 2019

The sour cherry (Prunus cerasus L.) industry in the United States is a monoculture of a 400-year-old cultivar from France named `Montmorency'. To provide a solid germplasm base to breed alternatives to `Montmorency', cherry germplasm was systematically collected over a 15-year period from its ancestral home in Central and Eastern Europe and introduced to the U.S. The strategy of germplasm collection using pollen, seed and budwood importation of highly quarantined species is discussed. Germplasm resulting from this effort is highlighted as well as an example of commercial success. Finally, the “recycling” of this immense germplasm collection to search for dwarfing precocious rootstocks for sweet cherry is described.
Heritability of Terbacil Herbicide Tolerance in Strawberry
Authors: Weber C.A.
Published: June 2019

A partial diallel design was used to investigate the inheritance of tolerance to terbacil herbicide in cultivated strawberry, Fragaria ×ananassa Duch. Two tolerant cultivars, `Honeoye' and `Earliglow', two moderately tolerant cultivars, `Lester' and `Allstar', and two susceptible cultivars, `Red Chief' and `Guardian' were used as parents to create populations that segregated for tolerance to the herbicide. Tolerance rankings of the populations closely coincided with expected rankings based on the published tolerance levels of parental cultivars. `Honeoye' and `Earliglow' derived populations had the highest average tolerance ratings, while `Guardian' derived populations had the lowest tolerance ratings. Heritability was estimated at h2 = 0.50, indicating that significant progress in increasing the tolerance of new cultivars to terbacil can be achieved through traditional recurrent selection procedures. General and specific combining abilities suggest that the tolerant cultivars in this study may be fixed in their tolerance and that increased mean tolerance will be most apparent in progenies combining tolerant and susceptible cultivars. As such, a broader pool of germplasm may be needed to develop cultivars that are more tolerant than those in this study. Chemical names: terbacil (3-tert-butyl-5-chloro-6-methyluracil)
Cytological Analysis of a Clethra alnifolia `Hokie Pink' × C. pringlei Hybrid
Authors: Reed Sandra M.
Published: June 2019

Clethra alnifolia L., a native deciduous shrub cultivated as an ornamental, was recently hybridized with C. pringlei S. Wats. The purpose of this hybridization was to combine the cold hardiness and adaptability of C. alnifolia with the ornamental foliage of C. pringlei. While most of the C. alnifolia × C. pringlei hybrids more closely resembled C. alnifolia than the paternal species, a `Hokie Pink' × C. pringlei hybrid (NA71586) with foliage that flushes red like C. pringlei was recovered. The objectives of this study were to analyze cytologically the F1 and produce a F2 population from NA71586. Chromosome counts from root tips cells indicated that NA71586 has 32 chromosomes. Since the chromosome number of C. alnifolia is 2n = 32 and that of C. pringlei was found to be 2n = 16, NA71586 appears to have developed following fertilization of a C. alnifolia egg with an unreduced male gamete from C. pringlei. Both `Hokie Pink' and C. pringlei exhibited primarily bivalent pairing in pollen mother cells (PMCs). Over half of the PMCs from NA71586 contained 16 bivalents, indicating substantial homology within the C. alnifolia genome. It was theorized that C. alnifolia is either an autotetraploid that exhibits bivalent pairing or a segmental allotetraploid produced from hybridization of species with similar genomes. More than 700 F2 progeny were obtained from self-pollination of NA71586. Although many of the F2 progeny resembled NA71586, variation in foliage color, size and shape was apparent in the population.
Adaptation of Pachysandra terminalis Sieb. & Zucc. to Freezing Temperatures by the Accumulation of mRNA and Cold-induced Proteins
Authors: Zhou Suping , Sauvé Roger J. , Mmbaga Margaret T.
Published: June 2019

A cold acclimatization mechanism regulated by the accumulation of mRNAs and proteins has been tentatively identified in japanese spurge (Pachysandra terminalis Sieb. & Zucc.). Two polypeptides and several cDNA fragments were observed in leaf tissue after acclimation. When these proteins were probed with type III fish antifreeze antibodies, an immune-cross reaction occurred. Nonacclimatized young leaves and stems of japanese spurge survived 20-minute exposures at -5 °C. Although newly emerged leaves and stems were damaged, plants resumed growth at higher temperatures. After acclimation by gradual cold treatments (4 to -5 °C), new proteins began to accumulate in young leaves and plants were more tolerant to extended treatments at -5 °C. Changes in accumulation of proteins and mRNA in leaf tissue of japanese spurge appear to be an adaptation mechanism to subfreezing conditions. This is the first report of the immune-cross reaction between antibodies of type III fish antifreeze proteins and plant proteins
Pollination Study of Mandarins and the Effect on Seediness and Fruit Size: Implications for Seedless Mandarin Production
Authors: Chao Chih-Cheng T.
Published: June 2019

A pollination study was conducted using `Nules', `Fina Sodea', `Marisol', `Fina' Clementine, `Afourer', `Tahoe Gold', and `Gold Nugget' mandarin. The fruit sets from selfing of `Fina', `Marisol', `Fina Sodea', `Nules' Clementines and `Afourer' mandarin were very low or near 0. The open pollinated Clementines had very low fruit set and there were very few seeds per fruit. Fruit set was highest (20% to 40%) in cross-pollination between two Clementines, `Nules' and `Fina Sodea', and `Afourer' mandarin and their reciprocal crosses. There were averaged 23 to 32 seeds per fruit in Clementines × `Afourer' mandarin crosses and averaged 5 to 12 seeds per fruit in `Afourer' mandarin × Clementines crosses. Compatibility among Clementine mandarins and `Afourer' mandarin is very high and caution should be taken to properly isolate these two types of mandarins when planting to produce seedless fruit. The diploid `Nules' Clementine × triploid `Tahoe Gold' mandarin gave 14% and 17% fruit sets in 2002 and 2003, with an average 2 seeds and 9 seeds per fruit in 2002 and 2003, respectively. Caution should also be taken when planting triploid seedless `Tahoe Gold' mandarin near diploid `Nules' Clementine to avoid seeds. The compatibilities and seediness between diploid mandarin cultivars and new seedless triploid mandarin cultivars need to be tested to ensure the pollen of the new triploid cultivars will not cause seeds in the existing diploid cultivars.
Influence of Arbuscular Mycorrhizae Indigenous to Peru and a Flavonoid on Growth, Yield, and Leaf Elemental Concentration of `Yungay' Potatoes
Authors: Davies Fred T. , Calderón Constantino M. , Huaman Zosimo
Published: June 2019

The influence of arbuscular mycorrhizal fungi (AMF) [two Peruvian mixed isolates, a pure isolate of Glomus intraradices] and the flavonoid, formononetin, were tested on growth, yield, and leaf elemental concentration of the Peruvian potato (Solanum tuberosum L.) `Yungay'. Plants started from tissue culture-produced prenuclear minitubers of `Yungay' were subjected to seven treatments, which included noncolonized (non-AMF) plants fertilized with Long Ashton nutrient solution modified to supply P at 11 and 44 μg·mL-1. All AMF plants received low P (11 μg·mL-1) and were inoculated with either a sierra-maize mixed isolate, sierra-papa mixed isolate, pure isolate of G. intraradices, sierra-maize mixed isolate + formononetin, or a sierra-papa mixed isolate + formononetin. Plants were grown in 3-L containers under shade house conditions in Lima, Peru. Non-AMF plants at low P had the poorest growth, while high P plants had the greatest overall growth. All AMF plants had greater growth, including a higher root to shoot ratio, higher phosphorus use efficiency [(g tuber)/(g P/kg tissue)], and a lower leaf to tuber ratio (indicating greater leaf efficiency in producing tuber dry matter), compared to non-AMF plants at low P. The mycorrhizal inoculation effect (MIE) ranged from +44% to +57%, indicating that `Yungay' was moderately to highly mycorrhizal dependent. Plants colonized with the sierra-papa isolate + formononetin had the same tuber development and leaf to tuber ratio, compared to high P, non-AMF plants. Formononetin increased extraradical hyphae formation. Mycorrhizal enhancement was in part due to greater P, Fe, and Mg uptake, a higher phosphorus-use efficiency and greater extraradical hyphae formation.
Consumer Preferences for Tabletop Christmas Trees
Authors: Behe Bridget K. , Walden Rachel M. , Duck Marcus W. , Cregg Bert M. , Kelley Kathleen M. , Lineberger R.D.
Published: June 2019

An aging American population may be less willing than a younger population to install and remove a live, fresh-cut evergreen tree in their home for Christmas celebrations. An alternative to using traditional, large, fresh-cut or potted Christmas trees could be forcing these evergreen species in a small (≈1-L) container that could be displayed on a tabletop. We initiated this study to determine consumer preferences and marketability for six evergreen tree species produced for tabletop display and used three decoration themes and three price points. We constructed a web-based survey in which 331 participants were compensated with a $5 e-coupon for viewing 27 photographs of tabletop trees and providing preference and use information. The conjoint model accounted for 91.2% of the variance and showed that consumers valued tree species as the most important attribute (61% of the tree value), with decoration color/theme the second most important feature (27%) and, last, price (12%). Black Hills spruce (Picea glauca var. densata (Moench) Voss) was the most preferred species overall, and red was the most preferred decoration theme. Logically, the lowest price point was the most preferred. However, price was the most important attribute for participants younger than 25 years. The importance of price decreased as participant age increased until age 60, when price became a more important component. With a cost of production of $5.45 and decoration and shipping estimated at an additional $4.00, the product could be a profit generator priced at any of the tested price points ($14.95 and above).
Storage Quality and Composition of Sweetpotato Roots after Quarantine Treatment Using Low Doses of X-ray Irradiation
Authors: Wall Marisa M.
Published: June 2019

Sweetpotato [Ipomoea batatas (L.) Lam.] roots of three Hawaii-grown cultivars (`Mokuau', `Okinawan', and `Yoshida') were treated with 0, 200, or 400 Gy x-ray irradiation and stored for 12 weeks at 15 °C. The storage quality of nonirradiated and irradiated roots was compared for weight loss, sprouting, firmness, color, postharvest decay, and carbohydrate concentrations. Nonirradiated roots lost 3 to 4% weight during storage, whereas roots treated with 400 Gy lost 4.7% to 8.6% weight. Sprouting was negligible for all treatments. Storage tended to increase root firmness, while irradiation tended to decrease firmness. When all cultivars were averaged, sweetpotatoes treated with 400 Gy and stored for 12 weeks had the lowest starch concentrations and highest total sugar concentrations. Glucose and fructose concentrations were not affected by irradiation, but these sugars increased during storage. Sucrose concentrations of roots irradiated with 400 Gy were double those of nontreated roots after 12 weeks storage. The purple-fleshed cultivars, `Mokuau' and `Okinawan', retained good quality following irradiation and storage, but firmness decreased somewhat for roots treated with 400 Gy. The `Okinawan' sweetpotato is the primary export cultivar from Hawaii. For the white-fleshed cultivar, `Yoshida', postharvest decay adversely impacted the internal color, firmness, and overall quality of roots treated with 400 Gy and stored for 12 weeks.
Improved Cucumber Transformation by a Modified Explant Dissection and Selection Protocol
Authors: Rajagopalan Prem Anand , Perl-Treves Rafael
Published: June 2019

Agrobacterium-mediated transformation of Cucumis sativus L. cotyledons was investigated, to identify important factors that affect transformation efficiency. The factors evaluated were initial explant preparation, including preculture, pricking of the explant, inoculation time and co-cultivation regime. We also modified the selection regime, compared to previously published protocols. Our results show that dissecting the proximal half of the cotyledon by a V-shaped cut resulted in a higher transformation rate, compared to two other methods of dissection, as indicated by transient β-glucuronidase gene expression. Selection on 100 mg·L-1 kanamycin resulted in the early development of nontransformed shoots, whereas a gradual increase of kanamycin concentration up to 200 mg·L-1 resulted in the subsequent formation of transgenic shoots on the same medium. The overall transformation frequency in these experiments, expressed as the number of rooted, confirmed transgenic plants per initial number of explants, was 1.7%. The stable integration of T-DNA was confirmed in the primary transformants and their progeny. Abbreviations: ABA = abscisic acid; AdS = adenine sulfate; AS = acetosyringone; BA = 6-benzylaminopurine; GA3 = gibberellic acid; IBA = indolebutyric acid.
Effects of Red light on the Growth of Zantedeschia Plantlets in vitro and Tuber Formation Using Light-emitting Diodes
Authors: Jao Ruey-Chi , Lai Chien-Chou , Fang Wei , Chang Sen-Fuh
Published: June 2019

Effects of light generated by red and blue light-emitting diodes on the photomixotrophic growth of Zantedeschia jucunda `Black Magic' plantlets in vitro and tuber formation after transplant under the same PPF and photoperiod were investigated. All five treatments had the same photosynthetic photon flux (PPF, 80 ± 5 μmol·m-2·s-1) and photoperiod (16 hours daytime/8 hours nighttime), leading to the same daily light integral. Results showed that the tubular fluorescent lamp (TFL) treatment had the highest value on chlorophyll content and dry weight accumulation than other treatments using light-emitting diodes (LEDs). In LED treatments, there were no significant differences on dry weight and growth rate but with significant differences on chlorophyll content and plant height when blue light LEDs were added. It revealed that blue light was involved in plant height and chlorophyll development control mechanism. Results also showed that minor difference in 28 days of transplant production (in vitro) among treatments does not extends after 6 months of tuber formation stage grown in greenhouse. At present, blue LEDs cost much more than that of red LEDs, results of this study suggested that using red LEDs alone and powered with AC is feasible for the commercial production of Zantedeschia plantlets in vitro.
Development of In-ground Container Plants of Mexican Elders Exposed to Drought
Authors: Feser Cathleen , Hilaire Rolston St. , VanLeeuwen Dawn
Published: June 2019

Mexican elder (Sambucus mexicana Presl.) is used in arid landscapes of the Southwest, but the plant is known for its unpredictable performance in those landscapes. We studied drought responses of mexican elder plants grown in an arid environment using an in-ground nursery production system. Plants were maintained as well-irrigated controls or exposed to cyclic drought and irrigated based on evapotranspiration. Drought treatment lasted 165 days. Plants exposed to drought had more negative predawn and midday water potentials than well-watered plants. The ratio of variable to maximal fluorescence (Fv/Fm) for the drought group (0.76), was near the optimum value of 0.8, suggesting that chloroplasts of drought-stressed plants maintained high levels of activity. Drought cycle, but not drought treatment affected stomatal conductance. Drought-stressed plants had lower transpiration rates than controls except at drought cycle five when transpiration rates were similar between irrigation treatments. Relative water content was higher in controls (76%) than plants exposed to drought (66%). Leaf area of well-irrigated plants was over four times higher than that of plants exposed to drought. Leaf area to root dry weight ratio of drought-stressed plants was 79% lower than control plants. Severely reduced leaf area of drought-stressed plants might be one reason why landscape personnel conclude that mexican elder plants perform poorly in arid landscapes.
Fertilization of Two Container-grown Woody Ornamentals Based on Their Specific Nitrogen Accumulation Patterns
Authors: Sandrock David R. , Azarenko Anita N. , Righetti Timothy L.
Published: June 2019

Nitrogen accumulation patterns were established for Weigela florida (Bunge.) A. DC. `Red Prince' (fast growth rate) and Euonymus alatus (Thunb.) Sieb. `Compactus' (slow growth rate). From these, daily and biweekly N delivery schedules were designed to match N supply with N accumulation patterns of each taxon. Delivery schedules were sliding scales in that total N applied was controlled by independent increases (or decreases) of N concentration and solution volume. Daily and biweekly N delivery schedules were tested against a constant N rate (200 mg·L-1) and Osmocote 18N-2.6P-9.9K (The Scotts Co., Marysville, Ohio). Plants were grown in 3.8-L containers in 7 douglas fir bark: 2 sphagnum peatmoss: 1 silica sand (0.65 mm; by volume) outdoors in full sun on a gravel pad for 142 d. Within each taxon, Weigela and Euonymus grown with sliding-scale N fertilization schedules had similar total dry weights, leaf areas, and total plant N contents to plants grown with a constant N rate (200 mg·L-1) or Osmocote 18N-2.6P-9.9K. Sliding-scale liquid fertilization based on plant N requirements introduced less total N to the production cycle and resulted in higher N uptake efficiency than fertilization with a constant N rate of 200 mg·L-1. In general, liquid N fertilizer treatments resulted in plants with higher shoot to root ratios than plants treated with Osmocote 18N-2.6P-9.9K. Weigela and Euonymus treated with biweekly schedules were similar to plants treated with daily schedules (same total amount of N delivered with each treatment).
Mowing Operations Influence Creeping Bentgrass Putting Green Ball Roll following Plant Growth Regulator Applications
Authors: McCullough Patrick E. , Liu Haibo , McCarty Lambert B.
Published: June 2019

Plant growth regulators (PGRs) are commonly used to enhance putting green quality and ball roll distances but their effects with various mowing operations have not been reported. Three experiments were conducted and repeated at Clemson University, Clemson, SC, on an `L-93' creeping bentgrass putting green to evaluate the effects of mowing operations and PGRs on diurnal ball roll distances. The PGRs tested included ethephon at (a.i.) 3.8 kg·ha-1, flurprimidol at (a.i.) 0.28 kg·ha-1, paclobutrazol at (a.i.) 0.28 kg·ha-1, and trinexapac-ethyl at (a.i.) 0.05 kg·ha-1. Mowing operations tested included rolling vs. mowing, morning mowing vs. morning plus afternoon mowing, and single vs. double morning mowing, all with and without PGRs. PGR by mowing operation interactions did not occur in any experiments. Ball roll distances decreased from 12:00 hr to evening observations in all experiments. In Experiment 1, rolling the green without mowing reduced ball roll distance 4% (5 cm) compared to mowing. Turf rolled without mowing in the morning and treated with flurprimidol, paclobutrazol, and trinexapac-ethyl produced similar ball roll at 12:00, 15:00, and 18:00 hr to mowed untreated turf. In Experiment 2, all plots were mowed at 08:00 hr and half of each plot was remowed at 12:30 hr. The second mowing at 12:30 hr enhanced ball roll distances 6% (8 cm) over the day. Turf mowed only at 08:00 and treated with paclobutrazol and trinexapac-ethyl had greater or equal ball roll distances at 12:30, 15:30, and 18:30 hr to untreated turf that had a second mowing at 12:30 hr. Turf receiving ethephon and 08:00 hr mowing had 4% to 12% (4 to 17 cm) shorter ball roll distances throughout the day compared to untreated turf mowed at 8:00 and 08:00+12:30 hr, respectively. In the third experiment, mowing twice in the morning increased ball roll 3% (4 cm) compared to mowing once. Trinexapac-ethyl and paclobutrazol treated turf mowed once in the morning had greater or equal ball roll distances throughout the day to untreated turf mowed twice in the morning. Overall, PGR use may provide putting green ball roll distances similar to or greater than untreated turf despite additional mowing; however, ethephon reduced ball roll distances regardless of mowing operations. Chemical names used: [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester] (trinexapac-ethyl); {α-(1-methylethyl)-α-[4-(trifluoro-methoxy) phenyl] 5-pyrimidine-methanol} (flurprimidol); (+/-)-(R*,R*)-β-[(4-chlorophenyl) methyl]-α-(1, 1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol); [(2-chloroethyl)phosphonic acid] (ethephon).
`Medina' Strawberry
Authors: López-Aranda José M. , Soria Carmen , Sánchez-Sevilla José F. , Gálvez Josefa , Medina Juan J. , Arjona Antonio , Marsal José I. , Bartual Rafael
Published: June 2019

Public and private institutions in Spain are increasing strawberry (Fragaria ×ananassa Duch.) breeding efforts to obtain new strawberry cultivars well-adapted to growing conditions in Huelva and other Spanish areas, such as Valencia on the eastern Spanish coast. The new `Medina' is a short-day cultivar that is remarkable for its high production of first quality fruits, and large fruits. `Medina' has also an appropriate harvest calendar for the economic interest of the Huelva area.
`Hannah's Choice F1': A New Muskmelon Hybrid with Resistance to Powdery Mildew, Fusarium Race 2, and Potyviruses
Authors: Henning Mark J. , Munger Henry M. , Jahn Molly M.
Published: June 2019

`Hannah's Choice F1' is a new, high quality eastern type muskmelon (Cucumis melo L.) with multiple disease resistance. It was developed in the Department of Plant Breeding at the Cornell University Agricultural Experiment Station in Ithaca, N.Y. It is well adapted for northeastern U.S. conditions and shows potential for good adaptation in the northwest. With multiple disease resistance it is well suited for home gardeners, market gardeners, and commercial growers. `Hannah's Choice F1' has excellent resistance to powdery mildew races 1 and 2 (Podosphaera xanthi) and some tolerance to Fusarium root rot (Fusarium oxysporum f. sp. melonis) race 2. In addition, it has resistance to watermelon mosaic virus (WMV), papaya ringspot virus (PRSV), and zucchini yellow mosaic virus (ZYMV). This is the first commercial melon to have combined resistance to these three potyviruses. Also, it has shown some field tolerance to spider mites (Tetranychus urticae). Lastly, it has shown some field tolerance to downy mildew (Pseudoperonospora cubensis), angular leaf spot (Pseudomonas syringae pv. lachrymans), and gummy stem blight (Didymella bryoniae). In 2001, 2002, and 2003 it was grown in replicated trials in New York and in 2002 and 2003 in Oregon.
New Promising Citrus Triploid Hybrids Selected from Crosses between Monoembryonic Diploid Female and Tetraploid Male Parents
Authors: Recupero G. Reforgiato , Russo G. , Recupero S.
Published: June 2019

The breeding of citrus triploid hybrids started at Istituto Sperimentale per l'Agrumicoltura spell out in Acireale, Italy, in 1978 (Starrantino and Reforgiato, 1981). The strategy used has been to cross a monoembryonic 2x female parent with a 4x male parent. The imbalance between the embryo and endosperm ploidy (3:4) makes seeds from such crossings incapable of germinating in vivo. However, in vitro cultivation has been used to rescue the embryos. In this paper we report the main characteristics of triploid hybrids from 22 different parents, including sweet orange [Citrus sinensis (L.) Osbeck], mandarin (C. reticulata Blanco), clementine (C. reticulata Blanco), grapefruit (C. paradisi Macf.), pummelo [C.maxima], tangor (C. reticulata × C. sinensis), lemon [C. limon (L.) Burm. f.], citron (C. medica L.), and Fortunella hindsii (Champ.) Swing. Tetraploid parents are duplex because they originate from the doubling of chromosome number of the nucella or of other somatic tissues. The segregation and recombination process results in triploid hybrids with characteristics that are nearer to the 4x parent than the 2x one. This strategy is important in obtaining seedless hybrids similar to a parent after generations of backcrossing.
Development and Evaluation of St Jean-Morden Apple Rootstock Series
Authors: Khanizadeh Shahrokh , Groleau Yvon , Levasseur Audrey , Granger Raymond , Rousselle Gilles L. , Davidson Campbell
Published: June 2019

Two hundred and nine hybrid seedlings developed by crossing Nertchinsk × M.9, Osman × Heyer 12, and Nertchinsk × M.26 were evaluated since 1970 in Agriculture and Agri-Food Canada (AAFC), Horticultural Research and Development center (HRDC), Quebec. Canada. `McIntosh' was used as the scion. Seven of these rootstocks obtained from crossing `Nertchinsk' with M.9 and M.26 were found to be winter hardy, disease resistant, dwarfing, with good yield efficiency and easier to propagate than O.3 under North Eastern Central Canada climate. O3A, a mutation of O.3 (Ottawa 3) was also added to the advanced lines and evaluated along with seven rootstocks in replicated trials compared to M.26, M.9, M.111 and O.3 in four locations during 1995–2002. These seven rootstocks (SJM15, SJM44, SJM127, SJM150, SJM167, SJM188, SJM189, along with O3A are being released for commercial evaluation.
Frost Tolerance of Eight Olive Cultivars
Authors: Barranco Diego , Ruiz Natividad , Campo María Gómez-del
Published: June 2019

This study aims to determine the relationship between laboratory frost-resistance data for the leaves of eight olive cultivars and observed field resistance in the same genotypes undergoing natural frost damage. The lethal freezing temperature (LT50) for each cultivar was established by measuring the electrical conductivity (EC) of the medium into which solutes from damaged leaf tissue were leaked. The value obtained was then correlated with percentage frost shoot for the same eight cultivars damaged by natural frosts in a field test. A negative correlation was observed between the percentage frost shoot and leaf LT50 for all the cultivars under study. The most frost-hardy cultivars (`Cornicabra', `Arbequina', and `Picual') were those presenting the lowest percentage frost shoot and lowest LT50. Conversely, the most frost-susceptible cultivar (`Empeltre') displayed 100% frost shoot, together with one of the highest LT50 values (–9.5 °C). According to these results, lethal freezing temperature (LT50) calculated from leaf ion leakage at a range of freezing temperatures, seem to be a valid parameter for evaluating frost tolerance in olive cultivars.
Kaolin-based Foliar Reflectant Affects Physiology and Incidence of Beet Curly Top Virus but not Yield of Chile Pepper
Authors: Creamer Rebecca , Sanogo Soumaila , El-Sebai Osama A. , Carpenter Jared , Sanderson Robert
Published: June 2019

Kaolin reflectant treatments have been shown to reduce stress due to the environment, pests, and pathogens in many plants. We tested the effect of kaolin on yield, beet curly top virus (BCTV) incidence, and physiological parameters (measured as hyperspectral reflectance) of field-grown chile pepper (Capsicum annuum L.) in southern New Mexico. Curly top incidence was significantly lower in kaolin-treated chile blocks than untreated blocks. Peppers treated with the kaolin-reflectant showed significantly less water stress and higher photochemical reflectance than untreated plants during active growth periods. Treated plants had significantly higher levels of chlorophyll a and higher reflectance than untreated plants. Yield from treated plants was not significantly different from that from untreated plants. We did not detect any deleterious effects on peppers due to application of kaolin. Kaolin treatments suppressed beet curly top virus on chile and reduced water stress parameters during the hottest months of the growing season, suggesting that it would be useful in New Mexico chile production in years with moderate disease pressure.
Vertical Distribution of Crop Load and Fruit Quality within Vase- and Y-shaped Canopies of `Elegant Lady' Peach
Authors: Farina Vittorio , Bianco Riccardo Lo , Inglese Paolo
Published: June 2019

Canopy shape and depth may influence crop uniformity of peach trees at harvest. To test this hypothesis we examined yield distribution and fruit quality changes at different canopy levels of peach trees trained to delayed vase (DV) and perpendicular Y (Y). Trees of both training forms were divided vertically into six or seven 50-cm-deep layers and fruit was harvested at commercial ripening from each layer separately. Regardless of training form, number of fruit and yield per layer were highest in the central part of the canopy, but more evenly distributed among canopy layers in Y trees. In DV trees, fruit weight decreased linearly from top to bottom, whereas it remained constant along the top and middle portion of Y canopies to decrease rapidly at the bottom. In DV trees, 83% of the fruit fell into AAA, AA and A size categories, whereas fruit of Y trees was more evenly distributed among all size categories. Hue of fruit peel color increased linearly with distance from canopy top in both training forms, but more sharply in DV trees. Fruit soluble solid content decreased linearly from canopy top to bottom, regardless of training form. A more uniform crop load distribution within the canopy in combination with a light penetration gradient resulted in greater variability of quality parameters for Y than DV trees.
Cultural Conditions Contributing to Vine Decline Syndrome in Watermelon
Authors: Makam Srinivas N. , Peer Wendy Ann , Blakeslee Joshua J. , Murphy Angus S.
Published: June 2019

Since the mid-1980s, a syndrome known as mature watermelon vine decline (MWVD) has had a serious effect on watermelon (Citrullus lanatus Thunb.) crops in Southern Indiana. As efforts to identify a pathogen responsible for MWVD have been unsuccessful, we have examined cultural conditions that might contribute to the syndrome. Field conditions were simulated in greenhouse pot trials to assess the impact of one or more factors on watermelon growth. Alone, low organic matter, soil acidity, black plastic mulch, and liming did not significantly affect root fresh weight; however, when these conditions were combined, root fresh weight was significantly reduced. Alanap-treated watermelons in combination with simulated cultural conditions resulted in further reduction of root fresh weight and had symptoms similar to MWVD. Watermelon plants grown in Alanap-treated, aged soil (from the previous year's experiments) under combined deficient cultural conditions demonstrated increased symptoms of MWVD and susceptibility to the pathogens Rhizoctonia and Pythium spp. Alanap, N-1-naphthylphthalamic acid (NPA), is a preemergent herbicide that functions as an inhibitor of auxin efflux and is widely used by watermelon farmers to impede obnoxious weeds. Metabolism of Alanap in planta involves aryl amidases (aminopeptidases) that also function in defense responses. We hypothesize that negative cultural practices are likely to inhibit defense responses and watermelon resistance to residual Alanap, leading to MWVD. We suggest that MWVD incidence is increased by certain common cultural conditions and that the incidence of MWVD can be reduced by altering these cultural practices.
Alternative Management Strategies for Tomato Affect Cultural and Economic Sustainability
Authors: Sterrett S.B. , Hohlt H.E. , Savage C.P.
Published: June 2019

Off-site movement of sediment, nutrient and agricultural chemicals from plasticulture production of green-pack tomatoes on water quality is a serious environmental concern, particularly for the clam aquaculture industry of eastern Virginia. Thus, the development of ecologically sound, economically sustainable cultural management strategies for tomato (Lycopersicon esculentum Mill.) production is needed. Two plantings were made within each of the three tomato harvest seasons [summer, bridge (late summer) and fall] in 1998 and 1999 (one summer crop in 1999). Between-bed treatments included clean culture or pearl millet [Pennisetum glaucum(L.) R. Br.] sown at bed establishment. On-bed treatments included standard plasticulture with fumigation on a 76-cm-wide bed (std), plasticulture without fumigation on a 76-cm-wide bed (std-fum), plasticulture on a 61-cmbed with fumigation (narrow) and organic mulch [wheat straw (Triticum aestivum L.) in 1998; desiccated hairy vetch (Vicia villosa Roth.) in 1999]. Total and marketable yields for the three plasticulture on-bed treatments (std, std-fum and narrow) were similar in 1998 and 1999. Yield was suppressed for the organic mulch on-bed treatments in all but the bridge plantings in 1999. Improved yield with plasticulture treatments and high market price for the summer crop in 1998 resulted in elevated crop value and return to land and management (return) compared to that of organic mulch. The return for later plantings was low, but positive. Return was negative for both bridge and the first fall crops in organic mulch in 1998. Low yields in all treatments and low prices in 1999 resulted in negative to negligible return for on-bed treatments in all but the summer planting using plasticulture. Return was consistently lower with organic mulch compared to plasticulture for the high value summer crop in Virginia with between-bed millet in 1998 and with or without millet in 1999. The use of organic mulch on the beds in this study was not economically feasible for the high value summer crops. Adjustments (desiccation of cover, control of weeds) in cultural management of the between-bed management strategy are needed before large-scale commercial implementation will occur.
Propagule Type and Planting Time Affect Subsequent Mayapple Growth
Authors: Cushman Kent E. , Maqbool Muhammad
Published: June 2019

Leaves of american mayapple (Podophyllum peltatum L.) contain podophyllotoxin, a compound of interest to the pharmaceutical industry. Cultural practices for establishment of mayapple in field plantings for commercial harvest have not been investigated. A factorial arrangement of three planting dates (Fall 2000, Spring 2001, or Summer 2001) and three propagule types (Nt+N1, Nt, or Nx; as described by Maqbool et al., 2004) were used to investigate strategies for establishing mayapple plantings. Rhizome segments were harvested from the wild and transplanted into plant beds in full sun in northern Mississippi. Plant emergence was recorded during March and April of each year from 2001 to 2004. Leaves within each plot were harvested as soon as they began to yellow, from the third week of April to the first week of June each year. Propagule type and planting time interacted to affect subsequent plant growth when measured on an area basis (per square meter of growing area). In 2004, spring-planted Nt+N1 produced more shoots with greater total leaf area and dry mass than spring-planted Nx or Nt. In contrast, Nt+N1 transplanted during fall or summer was equal in performance to that of Nx or Nt. Performance of summer-planted Nt was poor, producing far less leaf area and dry mass than any of the other treatment combinations. On a per plant basis, fall-planted propagules produced greater leaf area and dry mass in 2004 than spring- or summer-planted propagules, and Nt+N1 produced greater leaf area than Nx or Nt. The effect of year was not analyzed in this study due to complications of the experimental design. In conclusion, overall plant growth and performance of spring-planted Nt+N1 can be recommended as excellent and that of fall-planted Nt as poor. All other treatment combinations can be recommended as good. These results will assist growers of specialty crops in establishing mayapple plantings under field conditions in full sun.