bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Gardening Activities on Consumer Perceptions of Life Satisfaction
Authors: Waliczek T.M. , Zajicek J.M. , Lineberger R.D.
Published: February 2019

A survey based on the Life Satisfaction Inventory A (LSIA) was used to investigate gardeners' and nongardeners' perceptions of life satisfaction. The LSIA was developed in 1961 by Neugarten and measures five components of quality of life including zest for life, resolution and fortitude, congruence between desired and achieved goals, high physical, psychological and social self-concept, and a happy optimistic mood tone. The survey was posted for four months on one of the largest online resources for Texas Master Gardeners within the Aggie Horticulture network, the Texas Master Gardener Web page (http:aggie-horticulture.tamu.edu/mastergd/mg.html). During the 4 months, 402 responses were gathered. Additionally, identical `paper/pencil' format surveys were distributed to garden, church, social and community groups with about 400 responses received. In each group of participants, respondents differentiated themselves as gardeners or nongardeners by responding positively or negatively to the survey question, Do you garden? Results indicated statistically significant differences in comparisons of the overall life satisfaction scores with gardeners receiving higher mean scores indicating more positive results on the LSIA. When responses to individual statements were analyzed, results indicated statistically significant differences on 20% of the statements. Differences were detected on statements relating to energy levels, optimism, zest for life, and physical self-concept with gardeners answering more positively on all statements when compared to nongardeners' responses. Additionally, gardeners rated their overall health and their physical activity levels higher than did nongardeners.
Composted Chicken Manure as a Medium for the Production and Delivery of Trichoderma virens for Weed Control
Authors: Héraux Farah MG , Hallett Steven G. , Ragothama K.G. , Weller Stephen C.
Published: February 2019

Trichoderma virens (Gliocladium virens) (Miller et al.) von Arx is a soilborne fungus with a high degree of rhizosphere competence that produces a potent herbicidal compound, viridiol, and therefore has potential for development as a bioherbicide. We investigated the possibility of using composted chicken manure (CCM) as a medium for the production and deployment of T. virens. We chose CCM since the safe disposal of chicken manure presents significant logistic problems, and composted manures, as well as serving as an organic source of nitrogen, have been shown to support the activity of other biological control agents. Composted chicken manure supported the growth of T. virens and the rapid production of high concentrations of viridiol, but only when it was supplemented with large quantities of nutrients, including sucrose (16% w/w). Viridiol was not stable when stored in CCM, with a rapid decline in viridiol concentrations observed in T. virens-inoculated CCM cultures. Clearly, a cheaper alternative to sucrose is required as a carbon source for T. virens in CCM or similar media, and effective storage methods would need to be found for a T. virens-based bioherbicide product. Importantly, CCM did not need to be sterilized to support the growth of T. virens and its concomitant production of viridiol, suggesting that on-farm production systems may be feasible. Trichoderma virens-colonized CCM reduced the emergence and seedling growth of redroot pigweed (Amaranthus retroflexus L.) in a greenhouse experiment and dramatically reduced the emergence of a mixed community of broadleaf weeds in the field.
Comparative Response of Strawberries to Conidial Root-dip Inoculations and Infection by Soilborne Microsclerotia of Verticillium dahliae Kleb.
Authors: Gordon Thomas R. , Shaw Douglas V. , Larson Kirk D.
Published: February 2019

Previous studies have demonstrated significant genetic variation for susceptibility to verticillium wilt, caused by Verticillium dahliae, among strawberry (Fragaria ×ananassa Duch.) genotypes adapted to California growing conditions. These evaluations have been conducted using a conidial root-dip inoculation procedure; valid application of this method in a breeding program assumes the reaction of inoculated plants will be predictive of their response to infection by more natural means. To test this expectation, we evaluated the responses of plants representing eight strawberry genotypes that were either root-dip inoculated prior to being transplanted into a fruit production field or were transplanted into soil artificially infested with pathogen propagules (microsclerotia). Both inoculation methods revealed significant variation among genotypes in all 3 years that tests were conducted and the absence of significant genotype × treatment interactions demonstrate similar rankings of genotypes with both methods. However, based on statistical repeatability, the root-dip inoculation method was more consistent over time (R = 0.759) than the soil inoculation method (R = 0.510).
Chemical Changes during Storage of 'Barhi' Dates under Controlled Atmosphere Conditions
Authors: Al-Redhaiman K.N.
Published: February 2019

Mature 'Barhi' dates (Phoenix dactylifera L.) were stored in air or under controlled atmosphere (CA) storage conditions with 5%, 10%, or 20% carbon dioxide concentrations (balance air) during storage at 0 °C. CA conditions extended date storability by maintaining fruit quality. Fruit quality was maintained for 26 weeks when stored in 20% CO2, 17 weeks in both 5% and 10% CO2, and 7 weeks in air. Treatment with 20% CO2 maintained fruit color, firmness, SSC%, total sugar content, and total tannins. CO2 treatment also reduced degradation of caffeoylshikimic acid (CSA), which is one of the major phenolic compound of date fruit. This study indicates that 'Barhi' dates could be stored under CA conditions in cold storage with good eating quality for 17 to 26 weeks.
Mist Level Influences Vapor Pressure Deficit and Gas Exchange During Rooting of Juvenile Stem Cuttings of Loblolly Pine
Authors: LeBude Anthony V. , Goldfarb Barry , Blazich Frank A. , Frampton John , Wise Farrell C.
Published: February 2019

Two experiments were conducted during which juvenile hardwood or softwood stem cuttings of loblolly pine (Pinus taeda L.) were rooted under six mist regimes in a polyethylene-covered greenhouse to investigate the effect of mist level on vapor pressure deficit (VPD) and cutting water potential (Ψcut), and to determine the relationships between these variables and rooting percentage. In addition, net photosynthesis at ambient conditions (Aambient) and stomatal conductance (gs) were measured in stem cuttings during adventitious root formation to determine their relationship to rooting percentage. Hardwood stem cuttings rooted ≥80% when mean daily VPD between 1000 and 1800 hr ranged from 0.60 to 0.85 kPa. Although rooting percentage was related to Ψcut, and Aambient was related to Ψcut, rooting percentage of softwood stem cuttings was not related to Aambient of stem cuttings. Using VPD as a control mechanism for mist application during adventitious rooting of stem cuttings of loblolly pine might increase rooting percentages across a variety of rooting environments.
Observation of High-frequency Occurrence of Chimeral Adventitious Shoots in Tissue Culture from the Chimeral Tissues of Pelargonium zonale
Authors: Li Ming-yin
Published: February 2019

In Pelargonium, the plastid mutation in three independent cell layers L1, L2, and L3, can produce plastid chimeras with visible shoot colour difference such as GWG (green-white-green) and GGW (green-green-white). Chimera can be used to trace the relationship between the cell layers of different genotypes during shoot development and the effect of the mutated genes on shoot development. In this study, we have obtained different adventitious shoots with GGG, GWG, GGW, and WWW combinations of cell layers through tissue culture of petioles and internodes from GGW and GWG chimeras of Pelargonium zonale `Mrs Pollock'. Much higher percentage (14.9%) of chimeral adventitious shoots was obtained from GGW tissues than from GWG tissues (4.2%). Of the 10.8% chimeral adventitious shoots regenerated in this experiment, 8.6% are different from the original type of explants. This result indicated that cells at least in both L2 and L3 of the explants were involved in the regeneration of the adventitious shoots. The number of shoot types regenerated is likely dependent on the number and the type of cells that were in direct contact with the culture medium. It is suggested that the mixed cells can be used to produce the chimera by tissue culture. Three possible ways to form the chimeras in vitro culture were discussed. Chemical names used: TDZ =1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (Thidiazuron); IAA = Indole-3-acetic acid; PVP = polyvinylpyrrolidone.
Optimizing a Protocol for Sterilization and in vitro Establishment of Vegetative Buds from Mature Douglas Fir Trees
Authors: Traore Abdoulaye , Xing Zizhuo , Bonser Amy , Carlson John
Published: February 2019

A successful tissue culture initiation step often begins with effective explant sterilization. To improve douglas fir bud culture initiation, five sterilization treatments (20% bleach, 100% bleach, 3 second flaming, 5 second flaming, and self-extinguishing flaming) were evaluated for their effectiveness on winter and spring bud sterilization. The 20% and 100% bleach treatments resulted in the highest percentage of healthy bud cultures (>90% for winter buds). Spring buds showed a higher level of contamination with 20% bleach sterilization (36%) than did winter buds (1%). Successful sterilization was also achieved by flaming, but bud injury was observed. Increased flaming time caused a decrease in the percentage of healthy actively growing buds. The percentage of healthy bud cultures after 3 second flaming, 5 second flaming and self-extinguishing-flaming (9 to 14 s) were 66%, 59%, and 10% respectively. In addition, sterilization by either approach required subsequent bud dissection to remove the outer scales; otherwise most buds were lost to contamination. When sterilization was followed by bud dissection, contamination rates for winter buds were <2% for all treatments. After successful sterilization and culture initiation, bud expansion was the highest (50% to 98%) in the presence of low concentrations of BA (0 to 0.045 μmol·L–1), while high concentrations of BA (0.448 to 4.527 μmol·L–1) reduced bud expansion (0% to 60%), but promoted bud multiplication.
Micropropagation of Endemic and Endangered Mexican Species of Ponytail Palms
Authors: Osorio-Rosales María Luisa , Mata-Rosas Martín
Published: February 2019

Experiments were conducted to establish an efficient protocol of micropropagation of Beaucarnea gracilis and B. recurvata two endemic and endangered Mexican species. Multiple shoots were induced by direct organogenesis from in vitro seedlings and longitudinal sections of seedlings in both species. The highest formation of shoots per explant, both B. gracilis and B. recurvata, was obtained from longitudinal sections of seedlings on Murashige and Skoog (MS) medium supplemented with 22.2 μm 6-benzylaminopurine, induced 8.2 and 11.1 shoots per explant respectively. In vitro rooting was readily achieved on MS medium with 1 g/l activated charcoal without growth regulators. According to initial treatment and depending on where the shoots come from, the rooting rates were 61% to 100% for B. gracilis, and 83% to 100% for B. recurvata. Survival rates in greenhouse conditions for both species were 80% to 100% after 3 months. These results indicate that the micropropagation of these species of Beaucarnea is technically feasible, and that in vitro culture is a useful option for the conservation and propagation of these important endangered species.
Response of Woodland-planted Ramps to Surface-applied Calcium, Planting Density, and Bulb Preparation
Authors: Ritchey K. Dale , Schumann Carol M.
Published: February 2019

Concern about over-harvesting wild populations of ramps (Allium tricoccum Ait.) has led to interest in planting ramps as an under-story agroforestry crop. To see if ramps would respond to Ca amendments in an acidic site, we planted three types of ramps bulbs and broadcast slaked lime (3316 kg·ha–1) or gypsum (7704 kg·ha–1) on a Rayne silt loam (fine-loamy, mixed, mesic Typic Hapludults). After 3 years, surface-applied slaked lime raised Ca levels as deep as the 22.5 to 30 cm layer, which showed an increase of 0.34 cmolc·kg–1, and increased pH in the 2.5 to 5.0 cm layer from 3.96 to 4.67. Gypsum application raised Ca concentration in the 22.5 to 30 cm layer from 0.2 in the control to 0.7 cmolc·kg–1, but had little effect on pH anywhere in the profile. In plots harvested after 2 years, both amendments increased plant survival and per-plant weight, compared to controls. In plots harvested after 3 years, ramps grown in the slaked lime treatment were heavier than in the gypsum treatment indicating that slaked lime, which raised pH as well as supplied Ca, was probably the better amendment. Single or joined bulbs survived better than bulbs obtained by breaking joined bulbs in two. While more research is needed to overcome limitations to commercial planting of ramps in acidic sites, our data show that Ca application is beneficial to growth and survival of ramps.
Growth of Container-grown Pin Oak and Japanese Maple as Influenced by Sulfur and Sulfated Micronutrients
Authors: Browder Jake F. , Niemiera Alexander X. , Harris J. Roger , Wright Robert D.
Published: February 2019

Substrates of container-grown plants are commonly preplant amended with sulfated micronutrients to supply micronutrients. However, the cause for the increased growth may be due to micronutrient addition or other factors such as S addition or substrate acidification. Container-grown pin oak (Quercus palustris Müench) and japanese maple (Acer palmatum Thunb.) seedlings were grown in a 100% pine bark substrate and amended (or not) with one of the following treatments: control (no amendment), Micromax, K2SO4, H2SO4, HCl, chelated micronutrients, elemental S, or CaSO4. After 11 weeks, dry weights of plants in all treatments supplying S were higher than plants receiving no S. Dry weights of plants in all experiments receiving the chelate treatment were not higher than dry weights for control plants. These data indicate that S, not micronutrient application, is a primary cause of increased growth from the addition of sulfated micronutrients. However, it was demonstrated that there are conditions such as higher substrate solution pH (4.1 vs. 5.4), where Micromax may prove advantageous over sulfur alone since it would supply micronutrients as well as S.
Growth Response of Container-grown Pin Oak and Japanese Maple Seedlings to Sulfur Fertilization
Authors: Browder Jake F. , Niemiera Alexander X. , Harris J. Roger , Wright Robert D.
Published: February 2019

Sulfur (S) is essential to the growth of higher plants; however, research on S fertilizer requirements for container-grown nursery tree species has not been established. The purpose of this study was to determine the substrate solution S concentration that maximizes the growth of container-grown pin oak (Quercus palustris Münchh) (pin oak–K2SO4 experiment) and japanese maple (Acer palmatum Thunb.) (japanese maple–K2SO4 experiment) in a pine bark (PB) substrate. Both species were fertilized with solutions supplying a range of S concentrations (0, 1, 2, 5, 10, 20, 40, or 80 mg·L–1) using K2SO4. Regression analysis revealed that dry weights of both species were near maximum at the predicted application concentration of 30 mg·L–1 S, which corresponded to about 15 and 7 mg·L–1 S in substrate solution for pin oak and japanese maple, respectively. In a Micromax, FeSO4, lime experiment, S was supplied to pin oak via a preplant micronutrient sulfate fertilizer or FeSO4 in limed or unlimed PB. When the PB pH was relatively low (4.5, unlimed), FeSO4 and the preplant micronutrient fertilizer were effective in supplying ample S. However, when the PB pH was relatively high (6.1, limed), the preplant micronutrient fertilizer with micronutrients in a sulfate form was more effective in supplying S and micronutrients than FeSO4.
Cool-season Turfgrass Response to Bispyribac-Sodium
Authors: Lycan Darren W. , Hart Stephen E.
Published: February 2019

Previous research has demonstrated that bispyribac-sodium can selectively control established annual bluegrass (Poa annua L.) in creeping bentgrass (Agrostis stolonifera L.). Annual bluegrass is also a problematic weed in other cool-season turfgrass species. However, the relative tolerance of other cool-season turfgrass species to bispyribac is not known. Field experiments were conducted at Adelphia, N.J., in 2002 and 2003 to gain understanding of the phytotoxic effects that bispyribac may have on kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea (L.) Schreb.), and chewings fine fescue (Festuca rubra L. subsp. commutata Gaud.). Single applications of bispyribac at 37 to 296 g·ha–1 were applied to mature stands of each species on 11 June, 2002 and 10 June, 2003. Visual injury was evaluated and clippings were collected 35 and 70 days after treatment (DAT). Visual injury at 35 DAT increased as bispyribac rate increased. Kentucky bluegrass was least tolerant to bispyribac with up to 28% injury when applied at 296 g·ha–1. Injury on other species did not exceed 20%. Initial injury on perennial ryegrass, tall fescue, and chewings fine fescue was primarily in the form of chlorosis, while kentucky bluegrass exhibited more severe stunting and thinning symptoms. Bispyribac at rates from 74 to 296 g·ha–1 reduced kentucky bluegrass clipping weights by 19% to 35%, respectively, as compared to the untreated control at 35 DAT in 2002. Initial visual injury on perennial ryegrass, tall fescue, and chewings fine fescue dissipated to ≤5% by 70 DAT. However, recovery of kentucky bluegrass was less complete. These studies suggest that bispyribac-sodium has potential to severely injure kentucky bluegrass. Injury on perennial ryegrass, tall fescue, and chewings fine fescue appears to be less severe and persistent; therefore, bispyribac can be used for weed control in these species. Chemical names used: 2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoic acid (bispyribac-sodium).
'Hannah's Choice' Highbush Blueberry
Authors: Ehlenfeldt Mark K. , Stretch Allan W. , Vorsa Nicholi , Draper Arlen D.
Published: February 2019

'Hannah's Choice' is an early-ripening, tetraploid, highbush blueberry (Vaccinium corymbosum L.) that was developed by the cooperative breeding program of the Agricultural Research Service of the U.S. Department of Agriculture (USDA) and the New Jersey Agricultural Experiment Station (NJAES). It was named because it represents an improvement in sweetness, firmness, and flavor over currently grown early cultivars.
Cycad Toxins and Neurological Diseases in Guam: Defining Theoretical and Experimental Standards for Correlating Human Disease with Environmental Toxins
Authors: Marler Thomas E. , Lee Vivian , Shaw Christopher A.
Published: February 2019

Consumption of Cycas micronesica seed tissue has been associated with the amyotrophic lateral sclerosis–parkinsonism dementia complex (ALS–PDC) of the Western Pacific. However, failures to document vital plant and neighborhood descriptors and pronounced variability in toxin concentrations noted within and among studies obfuscate decades of research on this subject. We discuss the theoretical and experimental constraints of plant tissue sampling in relation to human disease research. Comparisons are made between this approach and methods used throughout the history of ALS–PDC research, most notably very recent reports concerning β-methyl-amino-alanine. Methods for studying possible plant neurotoxins need to be standardized and must follow rigorous criteria to be valid in principle. Our discussions reveal why these criteria are essential and highlight the impact that natural variations have on environmental toxin quantification and interpretation. Past research on cycad toxins is deficient on experimental and theoretical grounds, and interpretation of published data is dominated by ambiguities. This area of study as conventionally conceived and carried out needs transforming. We argue that future empirical studies should honor appropriate plant science standards concomitantly with medical science standards. This dual focus will ensure appropriate sampling scheme, sample size, and reporting of background plant and community factors known to influence phenotypic plasticity.
Spatial Variation of Steryl Glucosides in Cycas micronesica Plants: Within- and Among-plant Sampling Procedures
Authors: Marler Thomas E. , Lee Vivian , Shaw Christopher A.
Published: February 2019

Amyotrophic lateral sclerosis–parkinsonism dementia complex (ALS–PDC) of the Western Pacific has been linked to the consumption of washed Cycas micronesica seed tissue. The search for a causal toxin in the seed tissue has generated decades of research, yet none of the published reports include an adequate description of sampling methods. We set out to design and conduct a study to serve as a model for future research. We used three populations of plants with similar recent plant life history, size, shade, seed load, and co-occurring species to determine intra- and interplant variation of four steryl glucoside variants. Variation was greatest among tissue types within seeds, intermediate among plants, and least among locations within plants. Results demonstrate the need of adhering to appropriate sampling protocols in cycad biochemistry research. Uses of appropriate sampling scheme and sample size are clearly required to avoid artifacts as this important area of research progresses.
Endemic Wild Ornamental Plants from Northwestern Yunnan, China
Authors: Li Xiao-Xian , Zhou Zhe-Kun
Published: February 2019

Northwestern Yunnan is situated in the southern part of the Hengduan Mountains, which is a complex and varied natural environment. Consequently, this region supports a great diversity of endemic plants. Using field investigation in combination with analysis of relevant literature and available data, this paper presents a regional ethnobotanical study of this area. Results indicated that northwestern Yunnan has an abundance of wild ornamental plants: this study identified 262 endemic species (belonging to 64 genera and 28 families) with potential ornamental value. The distinguishing features of these wild plants, their characteristics and habitats are analyzed; the ornamental potential of most plants stems from their wildflowers, but some species also have ornamental fruits and foliage. Among the endemic genera, Pedicularis and Rhododendron have particularly high numbers of ornamental wild species, while Aconitum, Gentiana, Corydalis, Silene, Delphinium, Cremanthodium, and Saussurea also contain significant numbers of wild ornamental species. It is suggested that cultivation of these species may be beneficial, both commercially and to help conserve endangered endemic plant species.
Resistance Sources to Xanthomonas fragariae in Non-octoploid Strawberry Species
Authors: Xue Shiming , Bors Robert H. , Strelkov Stephen E.
Published: February 2019

Forty-three accessions from 11 strawberry species were screened in the greenhouse for resistance to three strains of Xanthomonas fragariae Kennedy and King. Among the accessions tested, Pen-5 of Fragaria pentaphylla Losink expressed either no symptoms or a hypersensitive reaction, while accessions Pen-2 and Pen-4 developed either no symptoms or restricted water-soaked lesions. Two accessions of F. moschata Duch were characterized by reduced translucency at the inoculation site in the course of symptom development. These accessions, representing three resistance types, were classified as highly resistant, resistant, and moderately resistant, respectively, based on mean separation of disease severity ratings. The classifications proved to be consistent with the results from measurements of bacterial populations on inoculated leaves of those genotypes. The study suggests that species of F. pentaphylla and F. moschata harbour diversified sources of resistance. Resistant genotypes were not detected in F. nilgerrensis Schlect, F. daltoniana J. Gay, F. nubicola Lindl, F. gracilis Losinsk, F. iinumae Makino, F. vesca L., F. viridis Duch, or F. orientalis Losinsk.
Genetic Variation in Jerusalem Artichoke (Helianthus tuberosus L.) Flowering Date and Duration
Authors: Kays Stanley J. , Kultur F.
Published: February 2019

Increased interest in the Jerusalem artichoke (Helianthus tuberosus L.) stems from the high level of inulin, a straight chain fructan, found in the tubers that has a number of current and potential industrial applications. Deficiencies in existing cultivars have underscored the need for a pragmatic breeding program. Since synchronization of flowering has a pronounced influence on genetic crosses that can be made, we assessed the flowering date and duration of 190 clones with selected clones similarly monitored for two additional growing seasons. Substantial genetic variation in the date and the duration of flowering were found with the onset of flowering ranging from 69 to 174 days after planting (DAP). Flowering duration ranged from 21 to 126 days. The onset of flowering was substantially affected by planting date and to a lesser extent by location. The results suggest that at lower latitudes flowering date for some clones can be manipulated by planting date; at higher latitudes, growth under controlled conditions may be required to synchronize flowering of some clones.
Improving Productivity of Open-pollinated Processing Tomato Cultivars
Authors: Duman Ibrahim , Düzyaman Eftal , Esiyok Dursun , Vural Hüseyin , Erkan Semih
Published: February 2019

In contrast to developed countries open-pollinated (OP) processing tomato cultivars still have a certain market value in Turkey. A total of 26 subpopulations of 6 different OP cultivars (9 of Rio Grande, 5 of Rio Fuego, and 3 of each of C-37, Interpeel, T2 Improved, and VF 6203) were evaluated in two experimental sites in Marmara Region and Aegean Region. A high degree of phenotypic variance for yield (kg/plant) was found for most subpopulations which revealed the variation for yield amongst individuals, and hence the possibility to select for superior plants. Eighteen populations were developed by two cycles of mass selection conducted within the initial populations in both regions. Most progeny populations significantly exceeded their source cultivars in yield. Heritability estimates occurred generally parallel to that of yield increases of the progenies, which were slightly higher in the Karacabey trial (Marmara Region) as compared to the Muradiye trial (Aegean Region). Results were discussed from the point of view of the resource-poor farmers conducting low-input agriculture.
Genotypic Variation in Flower Induction and Development in Hydrangea macrophylla
Authors: Orozco-Obando Warner , Hirsch Gwen N. , Wetzstein Hazel Y.
Published: February 2019

The general doctrine of flowering in Hydrangea macrophylla (Thunb.) Ser. is that floral induction occurs during the fall months with the flower appearing the following spring or summer. However, hydrangea cultivars differ widely in their relative abundance and duration of flower production. The objective of this study was to determine how developmental flowering patterns compared among different hydrangea genotypes. Flowering was characterized in 18 cultivars by assessing flower initiation in dormant buds of 1-year-old stems that received natural outdoor inductive conditions. Terminal and lateral buds were dissected and floral developmental stage categorized microscopically. In terminal buds, flower development was very consistent and occurred in 100% of buds for all cultivars except `Ayesha' (33%). In contrast, lateral buds showed a wide variation in flower induction among genotypes. `Ayesha', `Blushing Pink', `Freudenstein', and `Nigra' had 10% or fewer lateral buds with floral initials. `All Summer Beauty', `David Ramsey', `Masja', `Nightingale', and `Penny Mac' showed high levels of floral induction (>92%). Within a cultivar, flower development was more advanced in terminal than lateral buds. In several cultivars, a significant correlation between bud size (length) and floral stage was found. However, low r-square values indicated that flower stage was explained largely due to factors other than bud length. This study shows that floral induction patterns vary markedly among hydrangea cultivars and provides insight into why cultivars differ in the extent and reliability of seasonal blooming. Genotypes that possess floral primordia in lateral buds would be amenable to cultural practices that enhance lateral budbreak and recurrent blooming.
Effects of Light, Temperature, Defoliation, and Fruiting on Carbon Assimilation and Partitioning in Potted Cranberry
Authors: Vanden Heuvel Justine E. , Davenport Joan R.
Published: February 2019

Carbohydrate supply has been hypothesized to limit fruit set in cranberry (Vaccinium macrocarpon Ait.), however the limitations to carbon gain throughout the season are currently unknown. These experiments investigated the effects of light, temperature, fruit presence, and defoliation on carbon production and partitioning in potted cranberry. Fruiting and vegetative uprights (short vertical stems which bear fruit biennially) reached similar asymptotes with respect to light response, but fruiting uprights reached saturation at a lower light intensity than vegetative uprights. Runners (diageotropic vegetative stems) had a lower asymptote, higher light compensation point, and greater rate of dark respiration than uprights. Temperature had little effect on net carbon exchange rate of uprights or runners. Before new growth, defoliation did not affect the concentration of total nonstructural carbohydrates in the vegetative uprights, or the partitioning of soluble carbohydrates to starch, even though uprights with lower leaf areas had higher net CO2 assimilation. At fruit set and again at fruit maturity, defoliation reduced total nonstructural carbohydrate concentration, while net CO2 assimilation was not affected. Carbohydrate production and partitioning within an upright was unaffected by the presence of a single fruit throughout the experiment.
Pollination Potential of the Bee Osmia aglaia for Cultivated Red Raspberries and Blackberries (Rubus: Rosaceae)
Authors: Cane James H.
Published: February 2019

A manageable cavity-nesting bee, Osmia aglaia Sandhouse (Apiformes: Megachilidae), was evaluated as a pollinator for cultivated red raspberry and blackberries. Floral visits by free-flying honey bees or by less numerous caged O. aglaia yielded red raspberry fruit (`Canby' and `K81-6') of equivalent size. These fruit were 30% larger (1.9 g, 70 drupelets) than fruit from unvisited flowers. Female O. aglaia readily visited flowers of all eight diverse blackberry cultivars observed. For all of these cultivated Rubus, female O. aglaia were observed to invariably collect pollen while pivoting atop the brush of pistils, maximizing opportunities for pollen transfer. Within its native geographic range in western Oregon and California, this effective native pollinator could be a sustainably managed, economical bee for cultivated cane fruit.
Alternatives to Methyl Bromide for Strawberry Runner Plant Production
Authors: Kabir Zahangir , Fennimore Steven A. , Duniway John M. , Martin Frank N. , Browne Gregory T. , Winterbottom Christopher Q. , Ajwa Husein A. , Westerdahl Becky B. , Goodhue Rachael E. , Haar Milton J.
Published: February 2019

For years, strawberry (Fragaria ×ananassa L.) runner plant nurseries have relied on methyl bromide (MB) fumigation of soil to produce healthy transplants. Methyl bromide, however, has been phased out due to its environmental risks. The potential for alternative fumigants to replace MB was evaluated at low and high elevation strawberry nurseries in California. The alternative fumigant iodomethane plus chloropicrin (IMPic) and a nonfumigated control (NF) were compared to methyl bromide plus chloropicrin (MBPic) at a low elevation nursery (LEN) and at a high elevation nursery (HEN) near Susanville, Calif. At a HEN near Macdoel, Calif., MBPic was compared to alternative fumigants IMPic, 1,3-dichloropropene plus chloropicrin mixture (Telone C35) followed by dazomet, chloropicrin (Pic) followed by dazomet and NF. Plants produced at the LEN were transplanted at the Macdoel HEN to measure the effects of soil fumigant history on plant health and runner plant production. Plants produced at both high elevation nurseries were evaluated for fruit yield and quality at two commercial fruit production sites in soils previously fumigated with MBPic or Pic. Runner plant production at the nurseries was similar in plots fumigated with either MBPic or alternative fumigants. All fumigation treatments had higher runner plant production than plants produced for two production cycles on NF soils. Generally, fruit yields from nursery plants produced on soils fumigated with IMPic, Pic followed by dazomet, or Telone C35 followed by dazomet, were similar to fruit yields from plants produced on MBPic fumigated soils. Overall, our results indicate that preplant soil treatments with IMPic, Pic followed by dazomet, and Telone C35 followed by dazomet, are potential alternatives to MBPic fumigation for strawberry runner plant nurseries. Fruit yields by plants in MBPic and Pic fumigated soils were comparable; however, they were more variable in Pic fumigated soils. Chemical names used: 1,3-dichloropropene (1,3-D), methyl bromide, methyl iodide (iodomethane), trichloronitromethane (chloropicrin), tetrahydro-3, 5-dimethyl-2 H-1,3,5-thiadiazine-2-thione (dazomet).
Time of Interseeding of Lana Vetch and Winter Rye Cover Strips Determines Competitive Impact on Pumpkins Grown Using Organic Practices
Authors: Vanek Steven , Wien H.C. , Rangarajan Anu
Published: February 2019

Growing a main vegetable crop for harvest and a cover crop for residue return to soil in the same growing season is a promising strategy to sustain soil quality in vegetable rotations. Our research evaluated cover crop strips interseeded between pumpkins (Cucurbita pepo L.) as a way to implement such a strategy. Cover crop types were lana vetch (Vicia villosa ssp. dasycarpa Ten.) and a lana vetch–winter rye (Secale cereale L.) mix, interseeded before, at the same time, or after pumpkins. The competitive impact of different cover crop strips was assessed using pumpkin yield, cover strip biomass, crop nitrogen status, soil nitrate status, and soil water potential. Cover strips were also assessed for competitiveness with native weeds. Seeding date affected the competitiveness of cover strips with pumpkins, while cover type did not. Cover crops seeded before pumpkins or at the same time reduced pumpkin yield in proportion to biomass produced by the cover strips early in pumpkin growth. Cover strips seeded after pumpkins did not reduce yield. Tilling in a before-seeded cover strip at 30 days after pumpkin seeding gave higher pumpkin yield than before-seeded cover strips that were not tilled. At three of four sites, after-seeded cover strips had the lowest percent weed biomass in strips, and at two sites with moderate weed pressure vetch–rye strips were more effective than vetch alone in suppressing weeds. Cover strips seeded before or at the same time as pumpkins reduced pumpkin yield by taking up resources that were otherwise available to pumpkins. At a high-rainfall site, competition for soil nitrate by cover crop strips was the dominant factor in reducing pumpkin yield. At a low-rainfall site, the dominant factor was competition for water. Because of effective weed suppression and lack of pumpkin yield reduction, interseeding vetch–rye strips after pumpkins was a promising practice, as was tilling in preexistent cover strips at an interval <30 days after pumpkin seeding. Good previous weed management and rye–vetch mixes at high seeding rates are necessary to allow interseeded cover strips to outcompete weeds.
Effects of Kaolin Particle Film and Rootstock on Tree Performance and Fruit Quality in 'Doyenne du Comice' Pear
Authors: Sugar David , Hilton Richard J. , VanBuskirk Philip D.
Published: February 2019

Tree growth and productivity in 'Doyenne du Comice' ('Comice') pear were not affected by kaolin (Surround WP) treatment programs consisting of applications at 30 or 60 g·L–1 of water applied either three or six times per growing season and repeated for 3 years. In 2 of 3 years, kaolin treatment programs reduced the extent of russet on the fruit surface, although the comparative effectiveness of different concentrations or numbers of applications was not consistent. It appears that kaolin treatment programs can be used in 'Comice' pear production without adverse effects on tree growth and performance. In a relatively high density planting (1098 trees/ha), 'Comice' pear trees growing on Pyrus calleryana rootstock were less yield-efficient and had lower bloom and crop density and fruit set than trees growing on Quince A (Cydonia oblonga) rootstock. Fruit from trees growing on P. calleryana were generally smaller and had less surface russet than did fruit from trees growing on Quince A.
Allyl Isothiocyanate and Carbon Dioxide Produced during Degradation of Brassica juncea Tissue in Different Soil Conditions
Authors: Price Andrew J. , Charron Craig S. , Saxton Arnold M. , Sams Carl E.
Published: February 2019

A study was conducted to quantify volatiles generated from Indian mustard (Brassica juncea L. Czerniak) tissue incorporated into soils under controlled conditions. Mustard residues were incorporated into noncovered and covered soils that varied by texture, temperature, moisture, pH, or sterility (autoclaved or nonautoclaved). Sandy loam soil had 38% more allyl isothiocyanate (AITC) than clay loam soil. AITC concentration in 45 °C soil was 81% higher than in soil at 15 °C, and 56% higher in covered compared to noncovered treatments. The microbial catabolism of AITC was suggested by the result that AITC concentration in autoclaved soils was over three times that measured in nonautoclaved soils. The highest AITC level detected (1.71 μmol·L–1) occurred in the autoclaved covered soil. Several factors also influenced CO2 evolution. At 30 or 45 °C, CO2 concentration was at least 64% higher than at 15°C. The covered soil had over twice the CO2 found in the noncovered soil, and the nonautoclaved soil treatment yielded twice the CO2 measured in the autoclaved soil. There were no main effect differences among soil moisture, soil pH, and soil texture treatments for CO2 concentrations. This information could be helpful in defining ideal soil conditions for field scale experiments. Additionally, this study demonstrates a sampling technique for testing fumigation potential of biofumigation and solarization systems that may have the potential to replace methyl bromide.
Survival and Growth of Wildflowers with Buffalo Grass or Blue Grama Grass
Authors: Lindgren Dale T. , Schaaf Daniel
Published: February 2019

Two studies in west-central Nebraska to determine the survival of wildflowers planted with buffalo grass [Buchloe dactyloides (Nutt.) Engelm.] and blue grama grass [Bouteloua gracilis (H.B.K.) Lag. ex Steud.)] were conducted in 6 and 10 year studies. In total, 19 forbs and 1 grass were transplanted with `Texoka' buffalo grass in the first study, and 16 forbs were planted in a split-plot design into 3 buffalo grass selections, blue grama or a clean cultivated plot in the second study. Survival between transplants in both studies varied significantly. In the first study, survival was significantly higher for little bluestem (Schizachyrium scoparium Michx.) (85%), bouncing bet (Saponaria officinalis L.) (100%), and stiff goldenrod (Solidago rigida L.) (100%) over the 6 years of the study. In the second study, there were significant differences between species for survival, with grayhead prairie coneflower [Ratibida pinnata (Vent.) Barnh.] (85%) and pitcher sage (Salvia azurea Lam.) (80%) having the highest survival at the end of the 10-year study. There were significant differences in height and number of flower stalks within S. rigida, R. pinnata, and S. azurea between years and between main plots. This study demonstrates differences in survival and growth of wildflowers when planted in conjunction with buffalo grass and blue grama grass.
Cross-sensitivity in Sweet Corn to Nicosulfuron and Mesotrione Applied Postemergence
Authors: Williams Martin M. , Pataky Jerald K. , Nordby Jonathan N. , Riechers Dean E. , Sprague Christy L. , Masiunas John B.
Published: February 2019

Nicosulfuron and mesotrione are herbicides from different chemical families with different modes of action. An association between the sensitivity of sweet corn (Zea mays L.) to nicosulfuron and mesotrione was observed when hybrids, inbreds, and S1 families (S2 plants) were evaluated for herbicide sensitivity in field trials. In 2003 and 2004, 50% and 53% of mesotrione-sensitive hybrids were sensitive to nicosulfuron compared with only 6% and 1% of mesotrione-tolerant hybrids that were sensitive to nicosulfuron. In trials with inbreds in 2003 and 2004, 88% and 78% of nicosulfuron-sensitive inbreds had some injury from mesotrione but 0% and 5% of nicosulfuron-tolerant inbreds were injured by mesotrione. Among S1 families, 77% of the mesotrione-sensitive families were nicosulfuron-sensitive but only 5% of the mesotrione-tolerant families were sensitive to nicosulfuron. Segregation of S1 families for response to mesotrione was not significantly different from a 1:2:1 pattern of sensitive: segregating: tolerant families (chi square value = 2.25, P = 0.324) which would be expected if sensitivity was conditioned by a single recessive gene. Segregation of S1 families for response to nicosulfuron was 15:23:26 (sensitive: segregating: tolerant) which was slightly different from an expected 1:2:1 ratio (chi square value = 8.84, P = 0.012). Segregation of S1 families probably was affected by the relatively small number of S2 plants sampled from each family. Similar responses of the S1 families to nicosulfuron and mesotrione lead us to hypothesize that the same recessive gene is conditioning sensitivity to both herbicides. Possibly, this gene is common in the inbreds and hybrids that were sensitive in these trials. These hypotheses will be tested by examining segregation in S2 families and other segregating generations and by conducting tests of allelism among sensitive inbreds and inbred parents of sensitive hybrids. Chemical names: 2-(4-mesyl-2-nitrobenzoyl)-3-hydroxycyclohex-2-enone, (mesotrione); 2-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide, (nicosulfuron).
Chlorophyll Fluorescence Imaging Allows Early Detection and Localization of Lemon Rind Injury following Hot Water Treatment
Authors: Obenland David , Neipp Paul
Published: February 2019

Green lemons (Citrus limon (L.) Burm.) were imaged for chlorophyll fluorescence (CF) 30 minutes after immersion of the fruit into 55 °C water for 5 minutes to determine if CF could be used to identify areas of hot water-induced rind injury before the appearance of visible symptoms. Fluorescence was variable in intensity over the surface of the rind with defined areas of enhanced fluorescence being present that corresponded in shape and location with visible injury that later developed during 24 hours of storage. Images showing minimum fluorescence (F0) and maximal fluorescence (Fm) provided the best image contrast between injured and noninjured areas of the rind. Total F0 present in the image was closely correlated (r2 = 0.87) with the area of rind injury present following storage. Holding the fruit under conditions of low humidity for 24 h before hot water treatment prevented both the formation of areas of enhanced fluorescence and the corresponding rind injury. Imaging of CF has potential as a means to identify areas of incipient rind injury in citrus to facilitate study of the causal mechanisms of postharvest rind disorders.
Propagation Techniques for a Spineless Acacia wrightii
Authors: Bryan Donita L. , Arnold Michael A. , Lineberger R. Daniel , Watson W. Todd
Published: February 2019

Three spineless phenotypes of Acacia wrightii G. Bentham ex A. Gray were identified with aesthetic landscape potential. Experiments in seed, cutting, grafting, and tissue culture propagation were undertaken to perpetuate this desired spineless phenotype. Germination percentages for mechanically scarified seeds ranged from 33% to 94%, however yield of spineless seedlings was low (0% to 34%). Sulfuric acid scarification for 10, 20, 30, or 60 minutes hastened and unified germination compared to nontreated seeds by 7 to 8 days. Vegetative propagation was successful for softwood cuttings. Rooting measures increased with auxin (2:1 indole butyric acid to naphthalene acetic acid) concentrations from 0 to 15000 mg·L–1, with maximum rooting percentage (70%), root number (9.2), and root length (12.4 cm) per softwood cutting at 15000 mg·L–1 auxin 8 weeks after treatment. Rooting was not successful for semi-hardwood or hardwood cuttings. Whip-and-tongue or T-bud grafting was not successful. Tissue culture of shoots from in vitro germinated seedlings indicated that shoot proliferation was greatest in Murashige and Skoog (MS) medium with 15 μm zeatin. The number of shoots that rooted in vitro increased with increasing concentrations of indole-3-butyric acid from 0 to 25 μm.
Seed Germination of Dirca (Leatherwood): Pretreatments and Interspecific Comparisons
Authors: Schrader James A. , Graves William R.
Published: February 2019

The genus Dirca L. (Thymelaeaceae) consists of three species of understory shrubs. Dirca palustris L. is sparsely distributed across eastern North America, D. occidentalis Gray is endemic near the San Francisco Bay, and D. mexicana Nesom & Mayfield is known only in one population in northeastern Mexico. Despite interest in the horticultural use of Dirca, plants seldom are marketed. Difficult propagation impedes production of Dirca. We sought to define protocols that promote uniform seed germination of all three Dirca spp. Endodormancy and paradormancy cause sporadic germination over several years under natural conditions, but endocarp removal, cold stratification, and treatment with GA3 increased germination percentage, speed, and uniformity. Dirca occidentalis was most responsive; up to 94% of seeds germinated after endocarp removal, 24 hours in GA3 at 50 mg·L–1, and stratification at 4 °C for 30 days. Treatments also were effective for D. palustris (up to 68% germination), but seeds of D. mexicana were unresponsive and germinated at 25% or less. Seed treatments should facilitate production of D. occidentalis and D. palustris, but further research is needed to define methods to propagate D. mexicana for horticultural use and for conserving this rare species in the wild.
The Effect of Preplant Monoammonium Phosphate Fertilizer and Compost on the Growth and Yield of 'Macoun' Apple Trees
Authors: Moran Renae E. , Schupp James R.
Published: February 2019

'Macoun'/B.9 apple (Malus ×domestica Borkh.) trees were planted in May 1998 in ± compost or ± monoammonium phosphate (MAP) for a total of four preplant treatments: 1) 90 g phosphorus (P) per tree, 2) 128 kg compost per tree, 3) 90 g P and 128 kg compost per tree, and 4) and an untreated control. MAP did not increase tree growth or yield in any year of the study. Compost increased canopy width into the sixth year after planting, and increased tree height and trunk cross-sectional area (TCA) into the seventh year. Annual yield was increased by compost in the fifth and seventh years, but not fourth or sixth year after planting. Compost increased cumulative yield in the sixth and seventh years.