bluuebunny/crossref_metadata_2025 huggingface dataset:
Rubus Pharmacology: Antiquity to the Present
Authors: Hummer Kim E.
Published: February 2019

The genus Rubus L., indigenous to six continents, includes blackberries, raspberries, and their hybrids and is commonly referred to as brambles or briers. Rubus species were a food and medicinal source for native peoples soon after the Ice Age. This short article presents only a sample of the wealth of historical reports of medicinal uses for Rubus. Brambles were documented in the writings of the ancient Greeks: Aeschylus, Hippocrates, Krataeus, Dioscorides, and Galen; Romans: Cato, Ovid, and Pliny the Elder; Asian medicinal traditions; traditional Chinese medicine; and the Ayurvedic tradition of India. Folk traditions of native peoples throughout the world have also applied Rubus for multiple medicinal uses. Although in modern times Rubus is grown for its delicious and vitamin-rich fruit for fresh and processed product consumption, the ancients used the whole plant and its parts. Stems, branches, roots, leaves, and flowers were used in decoctions, infusions, plasters, oil or wine extractions, and condensates. Decoctions of branches were applied to stop diarrhea, dye hair, prevent vaginal discharge, and as an antivenom for snakebites. Leaves were chewed to strengthen gums and plastered to constrain shingles, head scurf, prolapsed eyes, and hemorrhoids. Flowers triturated with oil reduced eye inflammations and cooled skin rashes; infusions with water or wine aided stomach ailments. Greeks and Romans recorded female applications, whereas the Chinese described uses in male disorders. The fruits of R. chingii are combined in a yang tonic called fu pen zi, “overturned fruit bowl,” and prescribed for infertility, impotence, low backache, poor eyesight, and bedwetting or frequent urination. The Leechbook of Bald described the use of brambles against dysentery, combining ancient medicinal knowledge with pagan superstition and herb lore. Medicinal properties of Rubus continue in Renaissance and modern herbals, sanctioning leaf infusions as a gargle for sore mouth, throat cankers, and as a wash for wounds; the bark, containing tannin, was a tonic for diarrhea; and root extract, a cathartic and emetic. Recent research has measured high ellagic acid, anthocyanin, total phenolics, and total antioxidant content in Rubus fruits. Fruit extracts have been used as colorants and are now being tested as anticarcinogenic, antiviral, antiallergenic, and cosmetic moisturizing compounds. From ancient traditions through conventional folk medicines to the scientific confirmation of health-promoting compounds, Rubus is associated with health-inducing properties.
Reclaimed Water as an Alternative Water Source for Crop Irrigation
Authors: Parsons Lawrence R. , Sheikh Bahman , Holden Robert , York David W.
Published: February 2019

Reclaimed water has been safely and successfully used for more than 40 years in Florida and California. Reclaimed water in these states is regulated with restrictions more stringent than World Health Organization guidelines. In the United States, Florida is currently the largest producer and California is the second largest producer of reclaimed water. Reclaimed water is more highly tested than other sources of irrigation water, and the safety of this water has been demonstrated in these and other states. Very high application rates of reclaimed water to citrus on well-drained Florida sands increased tree growth and fruit production. Although reclaimed water contains some nutrient elements, there is usually insufficient macronutrient content to meet plant nutritional requirements. Most reclaimed waters do not have high salinity levels although they are slightly more salty than the potable waters from which they originated. With an adequate leaching fraction, salts in reclaimed water can be handled with appropriate irrigation management. Use of reclaimed water has steadily increased in Florida since 1992, but other entities besides agricultural irrigation are now competing for its use. Public acceptance of reclaimed water has also increased, and crops grown with reclaimed water in Florida and California have been marketed without a negative public reaction. Recent issues of food safety have caused some to question reclaimed water, but there is no evidence of food safety problems with its use. Although reclaimed water in Florida was initially promoted as a way to improve surface water quality, it has now become an important alternate source of water to help meet water shortages and urban demand. In California, reclaimed water has become a necessary part of statewide water management.
Comparison of Stem Diameter Variations in Three Small Ornamental Shrubs under Water Stress
Authors: Miralles-Crespo Julián , Sánchez-Blanco María J. , Navarro G. Alejandra , Martínez-Sánchez Juan J. , Franco L. Jose A. , Bañón A. Sebastián
Published: February 2019

The dendrometer has been proposed as a sensitive plant water indicator based on stem growth. However, studies including dendrometers have been mainly focused on fruit trees and less attention has been paid to ornamental shrubs (small plants). In the study described here, stem dendrometers were used to ascertain whether there is any relationship between water status and dendrometric indices in potted ornamental shrubs (1 to 2 cm diameter). For this purpose, three Mediterranean shrubs (Pittosporum tobira, Callistemon citrinus, and Rhamnus alaternus) were studied under water stress recovery conditions in winter, spring, and early summer. At the end of the experiment, an extreme water stress treatment, which resulted in plant death (August) was also studied. Stem diameter variations [maximum and minimum daily stem values (MXDS and MNDS, respectively), maximum daily shrinkage (MDS), and stem growth rate (SGR)], daily evapotranspiration (daily plant ET), and leaf water potential (Ψleaf) parameters were considered throughout the experiment. A regression analysis between dendrometric indices and daily plant ET showed that MXDS and MNDS were sensitive under water stress recovery conditions, especially in severe environmental conditions (spring and summer). The SGR in C. citrinus, the MDS in P. tobira, and both indices in R. alaternus were seen to be sensitive during the stress to death period. Although more studies are needed, the results confirm that the use of dendrometers in small plants may be useful to provide continuous and automated registers of the plant water status under different substrate water content and climatic conditions. However, the response of these indices may imply moderate water stress.
Changes in Prooxidant and Antioxidant Enzymes and Reduction of Chilling Injury Symptoms during Low-temperature Storage of ‘Fuyu’ Persimmon Treated with 1-Methylcyclopropene
Authors: Zhang Zhengke , Zhang Yu , Huber Donald J. , Rao Jingping , Sun Yunjing , Li Shanshan
Published: February 2019

‘Fuyu’ perisimmon fruit were treated with 500 nL·L−1 1-methylcyclopropene (1-MCP) for 24 h at 20 °C and then stored at 4 °C for 45 days to investigate the effects of 1-MCP on chilling injury (CI) during storage at 4 °C. Persimmon fruit developed CI, manifested as rapid softening and external and internal browning. Injury symptoms were reduced by 1-MCP treatment. 1-MCP also delayed increases in respiration and ethylene production. Compared with control fruit, 1-MCP-treated fruit exhibited increased superoxide dismutase and catalase activities within the initial storage period and lower membrane permeability, malondialdehyde content, and peroxidase and polyphenol oxidase activities throughout the entire storage period. These results suggest that reduction of CI symptoms in persimmon fruit in response to 1-MCP treatment may be attributed to altered oxidative status.
Effects of Preconditioning and Fruit Maturity on the Occurrence of Soft Scald and Soggy Breakdown in ‘Honeycrisp’ Apples
Authors: Moran Renae E. , DeEll Jennifer R. , Murr Dennis P.
Published: February 2019

Preconditioning, holding fruit at 10, 17.5, or 21 °C temperatures for up to 7 days before placement in cold storage, was inconsistent in its effect on soft scald and soggy breakdown in ‘Honeycrisp’ apples in Maine and Ontario. In Ontario, 4 days of preconditioning at 21 °C increased soft scald in 1 year but had no effect in the next year. Five d of preconditioning at 10 °C reduced soft scald and had no effect on soggy breakdown in 1 year but reduced it the next year. In Maine, 5 days preconditioning at 17.5 °C was effective in reducing soft scald and/or soggy breakdown in 2002 to 2007 when starch index at harvest was 5.9 to 7.2. Seven days of preconditioning at 17.5 °C increased soggy breakdown with an early harvest in two orchards but only in one of two orchards with a later harvest. This same preconditioning had no effect on soft scald with the first harvest but reduced it with the second. In the next year, the same preconditioning treatment increased soft scald and soggy breakdown with an early maturity but had no effect with a later maturity in one orchard but not in fruit from another. Conditions during preconditioning and subsequent cold storage temperatures varied from previous recommendations, and this may be why preconditioning was not consistent in our studies and in some cases increased chilling disorders.
Use of a Nitrogen Budget to Predict Nitrogen Losses in Processing Butternut Squash with Different Nitrogen Fertilization Strategies
Authors: Van Eerd Laura L.
Published: February 2019

With rising input costs and environmental concerns, growers are seeking methods to minimize nitrogen (N) inputs and off-field N losses while maintaining crop yields. Field studies on processing butternut squash (Cucurbita moschata Duchesne ex Poir.) were conducted in 2004–2007 at 11 locations in Ontario, Canada, to determine the optimal N rate and estimate potential N losses. Preplant broadcast ammonium nitrate was applied at five rates between 0 and 220 kg N/ha. In contrasting years (i.e., cool/wet versus warm/dry versus average), 64% of sites were nonresponsive to N fertilizer as indicated by no differences in marketable squash yield. In responsive sites, the most economical rate of N (MERN) was between 105 and 129 kg N/ha of N fertilizer, indicating that the Ontario-recommended rate of 110 kg N/ha seems appropriate for responsive sites. At 110 kg N/ha, no yield advantage resulted from using a controlled-release N (CRN) or split-applying ammonium nitrate at preplant and vine elongation at 65 + 45 kg N/ha, respectively, compared with the same amount applied preplant. Apparent N losses (N inputs – N outputs) at harvest were 83 and 29 kg N/ha greater at a fertilizer application rate of 220 kg N/ha than at 0 and 110 kg N/ha, respectively. At 110 kg N/ha, crop removal balance and apparent N loss calculations suggest relatively low risk of N loss from the field during the growing season and after harvest, respectively. However, environmental and economical risks would be minimized if nonresponsive sites could be identified before N fertilizer application.
Planting Depth at Onset of Container Production and Subsequent Root Ball Remediation at Transplanting Affects Pin Oak and Littleleaf Linden
Authors: Harris J. Roger , Day Susan D.
Published: February 2019

Root flares of landscape trees are increasingly found to be much deeper than their forest counterparts, indicating that their root systems have been situated deeper in the soil. Planting deeply in production containers contributes to this phenomenon, yet the consequences of deep planting in production containers or the consequences of any adjustments made to planting depth at the time of transplant on growth in the landscape have not been reported for many species. Container-grown (11.4 L) liners of Tilia cordata Mill. (littleleaf linden) and Quercus palustris Münchh. (pin oak) were planted in 50-L containers with the first main lateral roots (structural roots) at substrate-surface grade or 10 cm or 20 cm below grade (deep planting). Trees were grown in the 50-L containers for two growing seasons and in a simulated landscape for three additional seasons after transplanting with the top of the container substrate at soil level or with some roots and substrate removed such that the original structural roots were just below the soil surface (remediated). Deep planting pin oak, but not littleleaf linden, slowed growth during container production; however, the effect did not persist after transplanting. Remediation of the 20-cm-deep pin oaks slowed growth during all three post-transplant years. Littleleaf linden remediation slowed growth for the first season after transplanting to a simulated landscape for 10-cm-deep trees and for the first two seasons for 20-cm-deep trees. Evaluation of pin oak root systems 3 years after transplanting revealed vigorous growth of non-deflected adventitious roots that had formed on the trunks of deep trees, and these roots appeared to be developing into main structural roots. No adventitious roots were present on littleleaf linden; instead, deflected roots grew and produced deformed root systems. Deep planting of linden reduced suckering; however, we conclude that remediation of deep-planted littleleaf linden is warranted as a result of potential hazards from trunk-girdling roots. In some species such as pin oak, non-deflected, strong adventitious root systems may assume the role of structural roots and diminish the effect of deflected and circling roots systems formed during container production. Remediation of these trees is likely not as critical as for species without abundant adventitious roots.
Diurnal Fluctuation in Tissue Nitrate Concentration of Field-grown Leafy Greens at Two Latitudes
Authors: Neely Haly L. , Koenig Richard T. , Miles Carol A. , Koenig Teresa C. , Karlsson Meriam G.
Published: February 2019

Tissue nitrate (NO3) concentration (TNC) in leafy greens generally decreases with increasing light intensity and photoperiod in controlled environment studies. Harvesting late in the day has been recommended as a way to produce leafy greens with lower TNC, although data from field research do not support this recommendation. This study investigated the effect of time of day of harvest on TNC in lettuce (Lactuca sativa L.) and spinach (Spinacia oleracea L.) grown in the field during the summer at Pullman, WA (lat. 46° N) and Fairbanks, AK (lat. 64° N). Whole plants were sampled every 2 h on three separate, 24-h harvest dates at each latitude. Plants were dried, ground, and analyzed for NO3-N. At the high-latitude location, TNC decreased linearly during the day (1000 to 2300 hr) on all three dates for spinach and one for lettuce. At the low-latitude location, TNC decreased linearly during the day (1000 to 1900 hr) on one date and increased linearly during the night (2000 to 0400 hr) on two dates for lettuce. The TNC (average 287 to 607 mg NO3-N/kg fresh weight for lettuce and 141 to 189 mg NO3-N/kg fresh weight for spinach) and magnitude of diurnal fluctuation (generally less than 25%) should not pose a human health risk regardless of when plants are harvested.
Bounce® Fabric Softener Dryer Sheets Repel Fungus Gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), Adults
Authors: Cloyd Raymond A. , Marley Karen A. , Larson Richard A. , Arieli Bari
Published: February 2019

This study was conducted to assess the repellency of Bounce® original brand fabric softener dryer sheets against fungus gnat, Bradysia sp. nr. coprophila (Diptera: Sciaridae), adults. For all five experiments conducted under laboratory conditions, fungus gnat adults collected in the sample compartments that included Bounce® original brand fabric softener dryer sheets ranged between 12% and 18% compared with the mean proportion of fungus gnat adults recovered from sample compartments that excluded dryer sheets, ranging in mean proportion from 33% to 48%. Chemical analysis using a steam distillation procedure to isolate volatile constituents found linalool as one of the major volatiles detected in the Bounce® original brand fabric softener dryer sheets. Additional constituents isolated were benzyl acetate, beta-citronellol, and hedione. Based on the results from our study, under laboratory conditions, Bounce® fabric softener dryer sheets do in fact repel B. sp. nr. coprophila adults.
Growth and Yield Responses to Mulches and Cover Crops under Low Potassium Conditions in Drip-irrigated Apple Orchards on Coarse Soils
Authors: Hogue Eugene J. , Cline John A. , Neilsen Gerry , Neilsen Denise
Published: February 2019

Fertigated ‘Gala’ apple trees on M.9 (Malus domestica Borkh.) rootstock, planted in 1998, were grown on a coarse soil for 6 years (1998 to 2003) and exposed to eight orchard floor vegetation management treatments within the tree row. These consisted of a glyphosate control; three waste paper mulch treatments [spray-on mulch paper mulch (SM), SM incorporated with dichlobenil, SM applied over uniformly spread shredded office paper (SOP)]; and four living cover crop mulch treatments [dwarf white clover (WC), sweet clover (SC), hairy vetch (HV), and annual rye]. There were no significant treatment effects on leaf nitrogen (N) and phosphorus (P) status; however, leaf potassium (K) levels were negatively affected by the living mulch treatments in 2 of 5 years. Tree vigor was diminished by several of the orchard floor vegetation management systems in 5 of 6 years. Trees receiving an SM treatment grew more rapidly than trees receiving the ground cover treatments and trees receiving a glyphosate treatment had relatively poor but comparable growth to several of the cover crop treatments. Growth response in trees receiving SM were observed in all production years. After 6 years, cumulative yields were highest from trees receiving any of the three SM or glyphosate treatments and significantly less for any of the ground cover treatments. Weed growth within the rye cover crop was significantly reduced in comparison with the other living mulches; however, it remained sufficiently competitive to contribute to diminished overall yield and tree growth in comparison with the SM and gylphosate control treatments. Overall, response of leaf K concentration to mulch treatments was insufficient to prevent low K levels after 5 years. The addition of K through the organic mulches or recycling of K by cover crops was insufficient to avoid the development of low leaf K levels. Annual fertigation of K, in addition to N and P, appears necessary to maintain adequate vigor and yield when using mulches or cover crops in intensive, drip-irrigated apple orchards grown on coarse soils.
Salinity Tolerance of Ryegrass Turf Cultivars
Authors: Marcum Kenneth B. , Pessarakli Mohammad
Published: February 2019

Relative salinity tolerance of 32 perennial (Lolium perenne L.) and three intermediate (Lolium ×hybridum Hausskn.) ryegrass turf cultivars was determined by measuring turf leaf clipping dry weight, root weight, rooting depth, and percent green leaf canopy area relative to control (non-salinized) plants. After gradual acclimation, grasses were exposed to moderate salinity stress (6 dS·m−1) for 6 weeks through solution culture in a controlled environment greenhouse. Shoot parameters were highly correlated, being mutually effective predictors of salinity tolerance. After 6 weeks of salinity stress, percent green leaf canopy area (GL) was correlated with relative (to control) final week leaf clipping weight (LWREL) (r = 0.90) and with linear slope of decline of weekly leaf clipping weight over the 6-week exposure to salinity (LWSLOPE) (r = 0.66). Rooting parameters root dry weight (RW) and rooting depth (RD), although significantly correlated with all shoot parameters, were only moderately effective in predicting relative salinity tolerance. ‘Paragon’ was the most salt-tolerant as indicated by all parameters. Other salt-tolerant cultivars included Divine and Williamsburg. Intermediate ryegrass cultivars (Froghair, Midway, and Transist) were invariably found within the most salt-sensitive category for all parameters.
BseGI Restriction of the Polymerase Chain Reaction Amplicon Th444 Is Required to Distinguish Biotypes of Trichoderma aggressivum Causing Serious Losses in Mushroom (Agaricus bisporus) Production
Authors: Staniaszek Mirosława , Szajko Katarzyna , Uliński Zbigniew , Szczech Magdalena , Marczewski Waldemar
Published: February 2019

Green mold is a serious disease of the cultivated mushroom causing losses in production of economical importance. In the present study, digestion of a Th444 amplicon with endonuclease BseGI was useful to discriminate Trichoderma aggressivum f. aggressivum (T.a.f.a) from the T. aggressivum f. europeanum (T.a.f.e.). The informative restriction fragments of 260 and 300 bp were revealed in the corresponding reference strains T.a.f.a. and T.a.f.e. The 300-bp marker was found in all 28 Polish mushroom isolates tested.
Light Exposure and Shade Effects on Growth, Flowering, and Leaf Morphology of Spiraea alba Du Roi and Spiraea tomentosa L
Authors: Stanton Kelly M. , Weeks Sally S. , Dana Michael N. , Mickelbart Michael V.
Published: February 2019

Two native shrubs, Spiraea alba (meadowsweet) and Spiraea tomentosa (hardhack or steeplebush), have potential as landscape plants, but little is known about light requirements for these species. The performance of plants from four geographical seed sources of each species was evaluated in the field under six different light treatments: full sun; morning full sun; afternoon full sun; and 40%, 60%, and 80% shade. Provenance differences did exist for height, flowering, and leaf greenness. Growth, flowering, and canopy density were greater in full sun and 40% shade and least in 80% shade. Both species responded to shade with increased individual leaf area and higher specific leaf area. Relative leaf greenness decreased with shade in S. tomentosa but did not change in S. alba. Plants grown in morning or afternoon shade were shorter and smaller and had fewer inflorescences than did the full-sun plants. These species can survive in deep shade, but based on growth and appearance, they are best suited to full sun or light shade in the landscape.
Ploidy Variation and Genetic Diversity in Dichroa
Authors: Rinehart Timothy A. , Scheffler Brian E. , Reed Sandra M.
Published: February 2019

Recent evidence suggests a close genetic relationship between Hydrangea macrophylla (Thunb.) Ser. and D. febrifuga Lour., which supports previous morphological and DNA sequence data. This relationship was confirmed by the production of fertile intergeneric hybrids. We characterize the genetic diversity of available D. febrifuga plants, both cultivars and wild-collected taxa, as breeding material to improve H. macrophylla. Relatively high genetic diversity is seen among D. febrifuga, which splits into two main clusters. We also document considerable differences in genome size when compared with previously characterized D. febrifuga. Dichroa versicolor (Fortune) D.R. Hunt plants were also included and data suggest that D. versicolor could be a hybrid between H. macrophylla and D. febrifuga, similar to the intergeneric hybrids produced by recent breeding efforts. Because native H. macrophylla plants do not overlap extensively with D. febrifuga populations, we tested Hydrangea indochinensis Merr. as a possible parent because endemic H. indochinensis populations overlap regions where D. febrifuga and D. versicolor have been collected. However, results suggest that H. indochinensis does not share a genetic background with D. versicolor. Taxonomic revision of Dichroa is warranted, especially because we document several more intergeneric hybrids from self-sown, open-pollinated sources.
Growth and Water Use of Petunia as Affected by Substrate Water Content and Daily Light Integral
Authors: Van Iersel Marc W. , Dove Sue , Kang Jong-Goo , Burnett Stephanie E.
Published: February 2019

More efficient irrigation practices are needed in ornamental plant production to reduce the amount of water used for production as well as runoff of fertilizers and pesticides. The objective of this study was to determine how different substrate volumetric water contents (θ) affected petunia (Petunia ×hybrida) growth and to quantify the daily water use of the plants. A soil moisture sensor-controlled irrigation system was used to maintain θ within ≈0.02 m3·m−3 of the θ threshold values for irrigation, which ranged from 0.05 to 0.40 m3·m−3. Shoot dry weight increased as the θ threshold increased from 0.05 to 0.25 m3·m−3 and was correlated with the total amount of irrigation water applied over the 3-week course of the experiment. The daily water use of the petunias grown with a θ threshold of 0.40 m3·m−3 was 12 to 44 mL/plant and was positively correlated with both plant age and daily light integral. Lower θ thresholds resulted in a decrease in both leaf water (ψ) and osmotic potential (ψS). A decrease in turgor pressure (P) at lower θ was seen at 11, but not 20 days after the start of the treatments. There were no significant effects of θ on ψ, ψS, or P on fully rehydrated plants at the end of the study. Plants were able to survive and grow at all θs, although water at a θ less than 0.20 m3·m−3 is generally considered to be unavailable to the plants. Results show that it is possible to automatically irrigate plants with the use of soil moisture sensors, and this approach to irrigation may have applications in controlling the growth of ornamental plants.
Capsaicinoids Are Absent in Habanero Pepper Vegetative Organs (Capsicum chinense Jacq.)
Authors: Ruiz-Lau Nancy , Medina-Lara Fátima , Minero-García Yereni , Torres-Tapia Luis W. , Peraza-Sánchez Sergio R. , Martínez-Estévez Manuel
Published: February 2019

Capsaicinoids, the chemical compounds that confer the pungency trait to peppers, are accumulated at different levels in all species of the genus Capsicum. There is much evidence suggesting that the synthesis of capsaicinoids occurs in the placenta interlocular septum of pepper fruits; however, the exact localization of the capsaicinoids biosynthesis accumulation pathways is still under debate. Thus, the aim of the present work was to evaluate whether pepper plants synthesize or accumulate capsaicinoids in vegetative organs as an indirect way to elucidate the systemic regulation of the capsaicinoid biosynthesis. For that purpose, we studied habanero pepper grown in the Yucatan Peninsula, which is among the hottest pepper worldwide. Our results, obtained by chromatographic and enzymatic measurements, provide solid evidence that habanero pepper plants do not accumulate capsaicinoids in the vegetative organs analyzed, even under water stress conditions. Thus, it is probable that the accumulation of capsaicinoids is restricted to reproductive organs.
Determining the Optimal Timing of Fruit Harvest in Transgenic Tomato Expressing F1-V, a Candidate Subunit Vaccine against Plague
Authors: Matsuda Ryo , Kubota Chieri , Alvarez M. Lucrecia , Cardineau Guy A.
Published: February 2019

Changes in the amounts of F1-V, an antigen fusion protein and a candidate subunit vaccine against plague, and total soluble protein (TSP) in green fruit of transgenic tomato plants were investigated to identify the optimum harvest timing to maximize the F1-V yields. Two T2 progenies of the transgenic plant, ‘22.11.21’ and ‘22.11.5’, were grown. The F1-V concentration rapidly decreased at the beginning of the green stage and decreased to less than 5% of the initial concentration at the late green stage in ‘22.11.21’. The F1-V concentration also decreased as fruit size increased in ‘22.11.5’, but the pattern of the decrease was linear and different from that in ‘22.11.21’. The concentration of TSP also decreased with fruit growing in both plants. When calculated on a whole fruit basis, the F1-V content linearly decreased with increasing fruit size in ‘22.11.21’. In ‘22.11.5’, the F1-V content per fruit also tended to decrease from the middle to late green stage. Based on these observations, collecting small green fruits without pruning was proposed as a harvest practice that may maximize the F1-V yields. Thus, the optimum protocols for harvesting and pruning for plant-made pharmaceutical production may be substantially different from those currently used in commercial hydroponic greenhouses for fresh market tomato.
Temperature and Photoperiod Influence Flowering and Morphology of Four Petunia spp.
Authors: Warner Ryan M.
Published: February 2019

Flowering and morphology of four Petunia Juss. spp. [P. axillaris (Lam.) Britton et al., P. exserta Stehmann, P. integrifolia (Hook.) Schinz & Thell., and P. ×hybrida Vilm.] were evaluated in response to photoperiod and temperature. Photoperiod responses were evaluated under 9-h short days (SD), 9-h photoperiod plus 4-h night-interruption lighting (NI), or a 16-h photoperiod supplemented with high-pressure sodium lamps (16-h HPS). All species flowered earlier under NI than SD and were classified as facultative (quantitative) long-day plants. Increasing the daily light integral within long-day treatments increased flower bud number for P. axillaris only. In a second experiment, crop timing and quality were evaluated in the temperature range of 14 to 26 °C under 16-h HPS. The rate of progress toward flowering for each species increased as temperature increased from 14 to 26 °C, suggesting the optimal temperature for development is at least 26 °C. The calculated base temperature for progress to flowering varied from 0.1 °C for P. exserta to 5.3 °C for P. integrifolia. Flowering of P. axillaris and P. integrifolia was delayed developmentally (i.e., increased node number below the first flower) at 14 °C and 17 °C or less, respectively, compared with higher temperatures. Petunia axillaris and P. integrifolia flower bud numbers decreased as temperature increased, whereas P. ×hybrida flower bud number was similar at all temperatures. The differences in crop timing and quality traits observed for these species suggest that they may be useful sources of variability for petunia breeding programs.
Relative Rooting Depths of Native Grasses and Amenity Grasses with Potential for Use on Roadsides in New England
Authors: Brown Rebecca Nelson , Percivalle Cynthia , Narkiewicz Sophia , DeCuollo Samantha
Published: February 2019

Erosion is a significant problem on highway embankments in Rhode Island. At present, a mixture of red fescue (Festuca rubra L.), perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) is planted to stabilize the soil. However, only the red fescue survives long term on slopes. Red fescue is shallow-rooted, leading to sod sloughing after heavy rains. The objective of this study was to compare the rooting depth, plant height, and adaptation to roadside conditions of 16 native grasses and five amenity grasses with red fescue to identify species that could be used to reduce sod sloughing. Research was conducted from May 2006 through Aug. 2009 in the greenhouse at the University of Rhode Island in Kingston and on the shoulder of state Route 4 in North Kingstown, RI. The cool-season grasses smooth brome (Bromus inermis Leyss. ssp. inermis), Pumpelly's brome [Bromus inermis Leyss. ssp. pumpellianus (Scribn.) Wagnon], Canadian wildrye (Elymus canadensis L.), Virginia wildrye (Elymus virginicus L.), silky wildrye (Elymus villosus Muhl. ex Wild.), eastern bottlebrush (Elymus hystrix L.), perennial ryegrass, and tall fescue (Festuca arundinacea L.) and the warm-season grasses little bluestem [Schizachyrium scoparium (Michx.) Nash] and purple lovegrass [Eragrostis spectabilis (Pursh.) Steud.] were similar in height to red fescue while rooting significantly more deeply. Of these 10 species, little bluestem, purple lovegrass, and tall fescue showed the best survival on the roadside.
Abscisic Acid Application Enhances Drought Stress Tolerance in Bedding Plants
Authors: Waterland Nicole L. , Campbell Craig A. , Finer John J. , Jones Michelle L.
Published: February 2019

Drought stress is a major cause of postproduction decline in bedding plants. The plant hormone abscisic acid (ABA) regulates drought stress responses by mediating stomatal closure, thereby reducing transpirational water loss. Exogenous ABA applications delay wilting and allow plants to survive short periods of severe drought. The effectiveness of the ABA biochemical, s-ABA (ConTego™; Valent BioSciences Corp., Libertyville, IL), at delaying wilting and extending shelf life during drought stress was evaluated in six bedding plant species. Spray and drench applications of 0 or 500 mg·L−1 s-ABA were applied to Impatiens walleriana (impatiens), Pelargonium ×hortorum (seed geranium), Petunia ×hybrida (petunia), Tagetes patula (marigold), Salvia splendens (salvia), and Viola ×wittrockiana (pansy). Water was subsequently withheld and wilting symptoms were compared between treated and control plants. s-ABA applications delayed wilting in all crops by 1.7 to 4.3 days. Leaf chlorosis was observed after s-ABA application in drought-stressed seed geraniums, marigolds, and pansies. In seed geraniums and marigolds, the drought stress itself resulted in leaf chlorosis that was equivalent to or more severe than the s-ABA application alone. In pansies, s-ABA applications induced leaf chlorosis that was more severe than the drought treatment. Overall, s-ABA was consistently effective at reducing water loss and extending shelf life for all species treated. Applications of s-ABA to bedding plants before shipping and retailing would allow plants to maintain marketability even under severe drought stress conditions.
Preharvest 1-Methylcyclopropene Treatment Reduces Soft Scald in ‘Honeycrisp’ Apples during Storage
Authors: DeEll Jennifer R. , Ehsani-Moghaddam Behrouz
Published: February 2019

The main objective of this study was to investigate the effectiveness of preharvest 1-methylcyclopropene (1-MCP) treatment on the development of soft scald in ‘Honeycrisp’ apples. In addition, the effects of preharvest 1-MCP on fruit quality at harvest and after storage were examined. For two consecutive years of study, ‘Honeycrisp’ trees were sprayed preharvest with 1-MCP and fruit were harvested twice during each year. Preharvest 1-MCP treatments had little consistent effect on fruit maturity at the time of harvest. In both years of study, preharvest 1-MCP reduced the incidence of soft scald in ‘Honeycrisp’ apples after air storage at 0 or 3 °C for 5 or 6 months. Soggy breakdown developed only in the second year of study and high incidences were reduced by preharvest 1-MCP treatments. Preharvest 1-MCP often reduced flesh firmness loss in ‘Honeycrisp’ during storage, especially during the second year of study, and with 1-MCP application closer to harvest. Malic acid content was often higher in apples with the preharvest 1-MCP spray closer to harvest. Overall, the most important benefit of preharvest 1-MCP treatments on ‘Honeycrisp’ apples was the reduction in soft scald development. Due to the high potential for substantial fruit losses from this disorder, the use of preharvest 1-MCP sprays on ‘Honeycrisp’ apples could be very advantageous.
A Leaf Lamina Compression Method for Estimating Turgor Pressure
Authors: Calbo Adonai Gimenez , Ferreira Marcos David , Cruz Pessoa José Dalton
Published: February 2019

A portable wiltmeter instrument to estimate leaf turgor pressure according to an adaptation of the flattening method was developed. In the instrument, a flexible inflating membrane presses the leaf against a flattening plate having small orifices surrounded by a finely engraved network of obtuse indentations through which air flow is delivered. During a measurement, as the compression builds up, the leaf is progressively molded against the flattening plate, and as a consequence, the air flow (x) crossing the plate is reduced toward zero. The smallest leaf compression (p0) that blocks the air passage is an estimate of the leaf turgor. Wiltmeter measurements were compared with pressure probe measurements of cell turgor pressure in detached leaves of lettuce (Lactuca sativa L.), kale (Brassica oleracea L. var. Acephala), and chicory (Chichorium endivia L.), which were allowed to suffer diverse levels of wilting caused by transpiration. Such observed wiltmeter readings were a little lower than the cell turgor pressure measured with a pressure probe; the regression coefficients between these methods were: 1.156 for lettuce, 1.13 for kale, and 1.036 for chicory. This portable quantitative procedure to measure leaf firmness has potentially valuable applications related to postharvest and field plant physiology studies.
Chromosome Number and Karyotype Variation in Codiaeum variegatum Cultivars
Authors: Deng Min , Chen Jianjun , Henny Richard J. , Li Qiansheng
Published: February 2019

Codiaeum variegatum (L.) Blume is one of the most popular ornamental foliage plants. It encompasses more than 300 recognized cultivars valued by their wide range of leaf shapes and vivid foliage colors. Thus far, only limited information is available regarding the genetic basis of their leaf morphological variation. This study investigated the chromosome numbers and karyotypes of seven phenotypically diverse cultivars. Root-tip cells were fixed, mounted, and observed under light microscopy. Results showed that chromosome numbers in the mitotic metaphase of the seven cultivars were high and variable and ranged from 2n = 66, 70, 72, 76, 80, 82, 84, to 2n = 96, indicating that the cultivars are polyploid and some could be aneuploid. Genetic mosaics occurred in one of the seven cultivars. Additionally, each cultivar had its own karyotype. There were no relationships between chromosome numbers or karyotypes and leaf morphology. Results from this study suggest that the morphological diversity among cultivars of this species could be in part attributed to high variation in chromosome numbers and karyotypes.
Effect of Saline Irrigation Water on Antioxidants in Three Hydroponically Grown Leafy Vegetables: Diplotaxis tenuifolia, Eruca sativa, and Lepidium sativum
Authors: Hamilton Jeffrey M. , Fonseca Jorge M.
Published: February 2019

Our study evaluated changes in nutritional content of leafy vegetables at harvest and during postharvest in response to nutrient solutions of increasing salinity using a recirculating ebb and flow irrigation system within a controlled environment (CE). Two antioxidants, ascorbic acid (AsA) and total phenolics (TP), were used as proxies for nutrition as determined by the 2,6-dichloroindolphenol titrimetric and the Folin-Ciocalteu methods, respectively. Two arugulas, Diplotaxis tenuifolia (L.) DC cv. Sylvetta and Eruca sativa (P. Mill.) Thell. cv. Astro, and a garden cress, Lepidium sativum L. cv. Presto, were grown with five salinity levels ranging from 1.5 to 9.5 dS·m−1 electrical conductivity (EC) during two trials. We observed no difference in TP at harvest in response to salinity treatments in Trial 1 for all species collectively evaluated; however, during Trial 2, the TP at harvest responded to salinity treatments. In contrast, we observed a response in AsA at harvest to salinity treatments during both trials. The response of both TP and AsA to treatments was characterized by variability, both increases and decreases, when contrasting species and trials. We concluded that the variability in the nutritional content of the specific crucifers evaluated might reflect both individual species responses and the modest CE microclimate changes we recorded between trials. In addition, our research suggests that salinity levels greater that an EC of 9.5 dS·m−1 may be required to define the salinity tolerance of these specific crucifers within a CE.
The Appeal of Biodegradable Packaging to Floral Consumers
Authors: Hall Charles R. , Campbell Benjamin L. , Behe Bridget K. , Yue Chengyan , Lopez Roberto G. , Dennis Jennifer H.
Published: February 2019

Currently, one of the most widely discussed topics in the green industry, which is promulgated by consumers exhibiting greater degrees of environmental awareness, is the issue of environmental sustainability. This has led to a desire for products that not only solve the needs of consumers, but are also produced and marketed using sustainable production and business practices. Consumers increasingly place a greater emphasis on product packaging and this has carried over to the grower sector in the form of biodegradable pots. Although various forms of these eco-friendly pots have been available for several years, their marketing appeal was limited as a result of their less-than-satisfying appearance. With the recent availability of more attractive biodegradable plant containers, a renewed interest in their suitability in the green industry and their consumer acceptance has emerged. The objective of this study was to determine the characteristics of biodegradable pots that consumers deem most desirable and to identify distinct consumer segments, thus allowing producers/businesses to more efficiently use their resources to offer specific product attributes to those who value them the most. We conducted a conjoint analysis through Internet surveys with 535 valid observations from Texas, Michigan, Minnesota, and Indiana. Our results show that on average, consumers like rice hull pots the most followed by straw pots. Our analysis identified seven market segments and corresponding consumer profiles: “Rice Hull Likers,” “Straw Likers,” “Price Conscious,” “Environmentally Conscious,” “Carbon Sensitive,” “Non-discriminating.” Idiosyncratic marketing strategies should be implemented by industry firms to market biodegradable containers to the identified consumer segments.
Germination and Early Seedling Growth of Rare Zamia spp. in Organic and Inorganic Substrates: Advancing Ex Situ Conservation Horticulture
Authors: Calonje Claudia , Husby Chad , Calonje Michael
Published: February 2019

Improved propagation methods greatly benefit conservation of rare cycads. Appropriate substrate conditions, especially excellent root aeration, are crucial to successful cultivation of most cycads. Typical cycad substrates include substantial portions of organic materials that will decompose over time, reducing drainage and increasing water retention. In this study, two inorganic substrates, arcillite (Turface® MVP®) and coarse silica sand, and one mixed cycad substrate (with organic and inorganic components) were evaluated for germination and growth of three rare Zamia species: Z. fairchildiana L.D. Gómez, Z. cunaria Dressler & D.W. Stev., and Z. aff. portoricensis Urb. over a period of 14 months from seed sowing. Substrate type affected leaves per seedling and leaf length. These factors also varied by species as did taproot length and germination rate. There were also significant interactions between substrate and species for caudex diameter and leaf variables, likely reflecting ecological differences among the species, two of which are from rainforest habitats and one from dry forest. All three substrates performed adequately for germination, survival, and growth of Zamia. Turface® and possibly the silica sand likely require additional watering to improve their performance as cycad substrates.
Effects of Various Plant Growth Regulators on the Traffic Tolerance of ‘Riviera’ Bermudagrass (Cynodon dactylon L.)
Authors: Brosnan James T. , Thoms Adam W. , Breeden Gregory K. , Sorochan John C.
Published: February 2019

Data describing effects of plant growth regulator (PGR) applications on bermudagrass (Cynodon spp.) traffic tolerance are limited. A 2-year study was conducted evaluating effects of several PGRs on ‘Riviera’ bermudagrass (Cynodon dactylon L.) traffic tolerance. Treatments included 1) ethephon at 3.8 kg·ha−1; 2) trinexapac-ethyl (TE) at 0.096 kg·ha−1; 3) paclobutrazol at 0.28 kg·ha−1; 4) flurprimidol at 0.0014 kg·ha−1; 5) flurprimidol + TE at 0.0014 kg·ha−1 + 0.096 kg·ha−1, respectively; 6) ethephon + TE at 3.8 kg·ha−1 + 0.096 kg·ha−1, respectively; and 7) untreated control. All treatments were applied three times on a 21-d interval before trafficking. Plots were subjected to three simulated football games per week with the Cady Traffic Simulator. Traffic began 2 weeks after the last sequential application of each PGR. Turfgrass color, quality, and cover were quantified weekly using digital image analysis. Turfgrass cover measurements were used to assess traffic tolerance. Improvements in turfgrass color, quality, and cover were observed with applications of TE, ethephon + TE, and flurprimidol + TE. Turfgrass color, quality, and cover were enhanced for ethephon + TE and flurprimidol +TE compared with applications of ethephon and flurprimidol alone. Considering that no differences in turfgrass color, quality, or cover were detected among TE, ethephon + TE, and flurprimidol + TE at any time in the study, the responses observed suggest that TE may have a greater impact than other PGRs on ‘Riviera’ bermudagrass athletic field turf when applied before traffic stress. Chemical names used: rthephon (2-chloroethyl)phosphonic acid; glurprimidol {α-(1-methylethyl)-α-[4-(trifluoro-methoxy) phenyl] 5-pyrimidine-methanol}; paclobutrazol, (+/−)-(R*,R*)-β-[(4-chlorophenyl) methyl]-α-(1–1-dimethyl)-1H-1,2,4,-triazole-1-ethanol; trinexapac-ethyl [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester].
Screening and Morphological Characterization of Melons for Resistance to Fusarium oxysporum f.sp. melonis Race 1.2
Authors: Chikh-Rouhou Hela , González-Torres Rafael , Alvarez José María , Oumouloud Ali
Published: February 2019

A total of 110 melon accessions with different geographical origins (18 countries) were screened for resistance to Fusarium oxysporum f.sp. melonis race 1.2 (pathotypes 1.2Y and 1.2W) using two artificial inoculation procedures. Twelve accessions showed some resistance to one or both strains. Three Japanese accessions, Shiro Uri Okayama (var. conomon), Kogane Nashi Makuwa, and C-211 (var. makuwa), and a Portuguese accession, BG-5384 (var. cantalupensis), showed the highest levels of resistance to both strains. The remaining eight accessions (all var. inodorus) had some level of partial resistance to 1.2W only. To our knowledge, this is the first time a high level of resistance to F. oxysporum f.sp. melonis race 1.2 has been identified in melon accessions of Western origin. The morphological traits of the 12 accessions that showed partial resistance were characterized to assess their suitability as resistance sources in melon breeding programs. Because most of the Western commercial cultivars belong to the cantalupensis, reticulatus, or inodorus botanical varieties, the resistant accessions from these varieties seem to be the most useful sources of resistance in breeding programs for developing melon cultivars of these types resistant to fusarium wilt race 1.2. The Portuguese accession BG-5384 had a high level of resistance within the Western types, and its morphological characteristics were fairly similar to some of the Western commercial cultivars.