bluuebunny/crossref_metadata_2025 huggingface dataset:
Municipal Solid Waste Heavy Fraction for Production of Turfgrass Sod
Authors: Flanagan M.S. , Schmidt R.E. , Reneau R.B.
Published: February 2019

The “heavy fraction” portion of a municipal solid waste separation process was evaluated in field experiments as a soil amendment for producing turfgrass sod. Soil organic matter and concentrations of extractable NO3-N, P, K, Ca, and Zn in the soil increased with addition of heavy fraction. Soil incorporation of heavy fraction resulted in greater air, water, and total porosity and lower bulk density of a loamy sandy soil. .Sod strength measurements taken 8.5 and 9.5 months after seeding were higher for Kentucky bluegrass (Poaprutensis L.) grown in heavy-fraction-amended topsoil than for turf grown in topsoil only. The use of this by-product may reduce the time required to produce a marketable sod. Soil incorporation of heavy fraction did not influence post-transplant rooting of Kentucky bluegrass sod but enhanced rooting of bermudagrass [Cynodon dactylon (L.) Pers.] sod at the highest rate evaluated. Results of these studies suggest that the use of heavy fraction for sod production may provide cultural benefits in addition to reducing the volume of solid waste deposited in landfills.
Water Relations of Various Peach Cultivars in Relation to Peach Canker Disease
Authors: Biggs A.R.
Published: February 2019

Whole-shoot water potential, osmotic potential of the xylem fluid, and bark water potential were examined from late winter through early spring for six peach [Prunus persica (L.) Batsch.] cultivars varying in relative susceptibility to Leucostoma canker. There were significant differences among cultivars for whole-shoot water potential on all 11 dates tested in 1986, but not in 1985. The date effect was not consistent among cultivars, although when averaged across dates, the whole-shoot water potential of `Loring' was significantly more negative than that of `Candor' or `Garnet Beauty'. There were significant differences among cultivars for xylem fluid osmotic potential on one of five dates tested in 1985 and three of 11 dates tested in 1986, although cultivar differences were not consistent between years. Cultivars exhibited differences in bark water potential on three of five dates tested in 1985, with `Loring' exhibiting the least negative values when averaged across dates. There were only occasional significant correlations of the water status characteristics with relative susceptibility to Leucostoma canker or suberin accumulation. Measurements of plant water status among cultivars or genotypes in peach do not appear to be reliable indicators of susceptibility to Leucostoma spp. or wound response.
Maturity and Storage Performance of `Bartlett' and `Sensation Red Bartlett' Pears
Authors: Sugar David , Powers Kate A.
Published: February 2019

A study was conducted to determine whether or not the practice of harvesting `Sensation Red Bartlett' (SRB) pear (Pyres communis L.) fruit later than `Bartlett' fruit results in a higher risk of core breakdown development in SRB fruit. Over a range of harvest dates in 2 years of study, incidence of core breakdown in SRB fruit was lower than in `Bartlett' fruit from the same orchard. The disorder increased in both cultivars with longer storage periods, but was usually less in SRB than in `Bartlett'. Core breakdown in both cultivars was more severe in the second year of the study, when lower summer temperatures prevailed. SRB maintained higher fruit firmness on the tree than did `Bartlett'. Accordingly, harvesting SRB later than `Bartlett' appears to be an acceptable practice.
Comparison of Seed-quality Indices Resulting from Single-seed Electroconductivity Measurements
Authors: Davidson K.G.V. , Moore F.D. , Roos E.E. , Nath S. , Sowa S.
Published: February 2019

Five seed-quality indices based on individual seed electrolyte leakage tests were evaluated. Zea mays L. seeds were soaked for 6 hours, and individual seed leachate conductivity values were obtained. A total of 100 cells were scanned, one seed per cell, at 5-minute intervals for the first 30 minutes, followed by 15-minute intervals for the remaining 330 minutes. Seeds were allowed to dry for 5 to 7 days at room temperature and then were tested for germinability at 25C for 7 days. Radicle lengths were measured after 72 hours. The Richards function was fitted to cumulative frequency distributions of μAmps to obtain internal slope (IS), mean μAmp, and median μAmp values for each scan. Initial leach rate (ILR) was estimated after fitting hyperbolic functions to μAmp vs. soak time data. Average leach rate (ALR) was also derived from fitting the Richards function to μAmp vs. soak time data. Linear regression of seed quality on IS, mean, and median μAmp values after 5 hours of imbibition yielded r2 values of 0.91, 0.81, and 0.86 for predicting viability and 0.56, 0.46, 0.52 for predicting radicle length. Thus, IS was the best seed quality predictor, followed closely by median and mean μAmp values. ILR and ALR were not correlated with seed quality.
Biocompatibility of Wheat and Tomato in a Dual Culture Hydroponic System
Authors: Schuerger Andrew C. , Laible Philip D.
Published: February 2019

`Yecora Rojo' Wheat (Triticum Aestivum L.) And `Florida Petite' Tomato (Lycoper-Sicon Esculentum Mill.) Plants Were Grown In Monocultured Or Intercropped Recirculating Hydroponic Systems To Determine Whether Plant Growth Or Yield Would Be Affected By Intercropping. Mean Fruit Weight Was Slightly Lower (12%) For Intercropped Than For Monocultured Tomato Plants. The Number Of Tillers Per Plant Was Slightly Lower (7%) For Wheat, And Grain Dry Weight Per Plant And Mean Seed Dry Weight Were Slightly Higher (14% And 15%, Respectively) For Intercropped Than For Monocultured Plants. A Lettuce Seedling Bioassay Showed No Evidence Of Allelopathic Compound Accumulation In Monocultured Or Intercropped Hydroponic Systems.
Heat-treating `Sharwil' Avocado for Cold Tolerance in Quarantine Cold Treatments
Authors: Sanxter Suzanne S. , Nishijima Kate A. , Chan Harvey T.
Published: February 2019

Chilling injury symptoms were reduced when `Sharwil' avocados (Persea americana Mill.) were held at 37 to 38C for 17 to 18 hours and then air-cooled at 20C for 4 hours before storage at 1.1C for ≥14 days. In contrast, nonheated fruit developed severe surface discoloration and pitting. Chilling injury symptoms were reduced further when the heated fruit were stored in perforated polyethylene bags during 1.1C storage. No treatment equaled or surpassed the quality of fruit in nontreated controls.
Irrigation Regimes Affect Fruit Soluble Solids Concentration and Rate of Water Loss of `O'Henry' Peaches
Authors: Crisosto Carlos H. , Johnson R. Scott , Luza Juvenal G. , Crisosto Gayle M.
Published: February 2019

The effect of irrigation management strategies on the quality and storage performance of `O'Henry' peaches [Prunus persica (L.) Batsch] was studied for two seasons. The deficit irrigation treatment induced a higher fruit soluble solids concentration and lower fruit weight. The excess irrigation treatment, compared to the optimum treatment, increased the rate of fruit water loss without altering fruit quality and storage performance. Scanning electron microscope observations indicated a higher density of trichomes on fruit from the deficit and optimum irrigation treatments than from the excess irrigation treatment. Light microscopy studies indicated that fruit from deficit and optimum irrigation had a continuous and much thicker cuticle than fruit from the excess irrigation treatment. These differences in exodermis structure may explain the high percentage of water loss from fruit from the excess irrigation treatment compared to the deficit and optimum irrigation treatments.
Plant Water Status and Fruit Quality in `Braeburn' Apples
Authors: Mills T.M. , Behboudian M.H. , Tan P.Y. , Clothier B.E.
Published: February 2019

Five-year-old `Braeburn' apple trees (Malus domestica Borkh.) on MM.106 rootstock were studied to determine plant and fruit quality responses to reduced plant water status late in the season. Trees were irrigated or not irrigated. Those not irrigated developed reduced xylem water potential and stomatal conductance from 110 and 132 days after full bloom (DAFB), respectively. However, they showed no reduction in photosynthetic rates. Fruit were harvested at stage 1 (S1), starting 167 DAFB, or stage 2 (S2), starting 180 DAFB. At S1, fruit had higher soluble solids concentrations, enhanced red skin pigmentation, and a tendency for higher sorbitol concentrations. Total soluble sugar concentrations at final harvest showed no difference between treatments, but fruit from the nonirrigated trees showed earlier sugar accumulation during the season. Such fruit also had reduced Ca+2 concentrations at S1 and S2 relative to those on plants that were irrigated. No incidence of any disorder was found in fruit from either treatment at harvest or after 12 weeks of 0C storage.
Root Growth and Water Status of Container-grown Photinia ×fraiseri Dress Transplanted into a Landscape
Authors: Beeson R.C.
Published: February 2019

Photinia plants produced in 11.4-liter polyethylene containers using a pine bark-based medium were transplanted into a well-drained sand and irrigated on alternate days. Polyethylene barriers were placed under half the root balls at transplanting to limit gravitational water loss. Plant water potential was measured diurnally between irrigations, and root growth was determined at 4-month intervals. Plants with barriers averaged higher cumulative daily water stress than control plants over the year, although predawn and minimum water potentials were similar. Growth index and trunk diameter were similar for the plants over barriers and controls, but the former were taller after 1 year. Plants with barriers had twice the horizontal root growth into the landscape site as control plants, resulting in twice the root mass in the landscape after 1 year.
Seedling Growth of Catawba Rhododendron. I. Temperature Optima, Leaf Area, and Dry Weight Distribution
Authors: Rowe D. Bradley , Warren Stuart L. , Blazich Frank A.
Published: February 2019

Catawba rhododendron (Rhododendron catawbiense Michx.) seedlings of two provenances, Johnston County, N.C. (35°45′N, 78°12′W, elevation = 67 m), and Yancey County, N.C. (35°45′N, 82°16′W, elevation = 1954 m), were grown in controlled-environment chambers for 18 weeks with days at 18, 22, 26, or 30C in factorial combination with nights at 14, 18, 22, or 26C. Shoot and root dry weights and total leaf areas of seedlings of the Yancey County provenance (high elevation) exceeded (P ≤ 0.05) those of the Johnston County (low elevation) provenance at all temperature combinations. Leaf area was maximal at 22/22C, 18/26C, and 22/26C and minimal at 30/14C (day/night). Shoot dry weight responded similarly. Root dry weight decreased linearly with increasing day temperature, but showed a quadratic response to night temperature. Leaf weight ratio (leaf dry weight: total plant dry weight) increased, while root weight ratio (root dry weight: total plant dry weight) decreased with increasing day temperature. Leaf weight ratio was consistently higher than either stem or root weight ratios. Day/night cycles of 22 to 26/22C appear optimal for seedling growth.
Nitrogen Supply during Production of Tomato Transplants Affects Preference by Colorado Potato Beetle
Authors: Hunt D.W.A. , Liptay A. , Drury C.F.
Published: February 2019

Host plant selection by Colorado potato beetle [Leptinotarsa decemlineata (Say)] was examined on tomato [Lycopersicon esculentum Mill.] transplants fertilized with varying N, P, and K concentrations during greenhouse production. In choice tests conducted with beetles in the field and the greenhouse, the insect preference for plants increased with increasing leaf tissue N concentration, but P and K concentrations had no effect. Five-day, seedling acclimatization to outdoor spring temperatures before planting reduced the insect preference for plants.
Somatic Embryogenesis of Carrot in Bioreactor Culture Systems
Authors: Teng Whei-Lan , Liu Yann-Jiun , Tsai Yu-Ching , Soong Tai-Sen
Published: February 2019

A bioreactor was used to establish a scale-up system for somatic embryogenesis in `Scarlet' carrot (Daucus carota L.). At a cell density of 1–2 × 106 cells/ml, mature and germinating embryos could be observed within 4 to 5 weeks. As cell density exceeded 2 × 106 cells/ml, the culture turned darker yellow, and embryo development was inhibited. Cell densities below 106 cells/ml resulted in abnormal embryos. Bioreactor design had a critical impact on somatic embryogenesis due to various types and the strength of shear forces generated. In this study, an air-lift bioreactor was selected from three different types (spinner flask, screen column bioreactor, and air lift) because it resulted in the highest biomass production and somatic embryogenesis. Foaming was eliminated by preculture of embryogenic cells in flasks; cells were then sieved on a 60-μm polyester screen and thoroughly rinsed with distilled water before being transferred to the bioreactor. Such preculture for at least 10 days significantly increased the regeneration of somatic embryos. During somatic embryogenesis, dissolved O2 concentrations decreased to 33% of saturation, and then increased up to 80% when embryo development approached maturity and mature embryos germinated. Bioreactor-cultured embryos germinated with relatively short cotyledons and long roots, whereas flask-cultured embryos germinated with relatively long cotyledons and short roots.
Plant Regeneration in Coreopsis lanceolata L. from Leaf Tissue Cultures
Authors: Lee Chiwon W. , Nichols Joel T. , Wang Lijuan , Ke Shanqiang
Published: February 2019

Excised leaf sections of lance coreopsis cultured on Murashige Skoog (MS) medium produced adventitious shoots in response to BA. When the combinations of 0, 0.5, 1, or 2 μm NAA with 0, 5, 10, 20, or 40 μm BA were tested, shoots were induced by any of the four BA concentrations used in the medium, regardless of the presence of NAA. The average number of shoots formed per leaf section ranged from 1.4 to 4.3 seven weeks after culture initiation. Roots were induced at the base of individual shoots on the same regeneration medium when cultures were kept longer than 7 weeks. The rooted plants were transferred successfully into soil. The regenerated plants had the same growth and flowering characteristics as the seed-grown plants. Chemical names used: benzyladenine (BA); naphthaleneacetic acid (NAA).
Carbon Dioxide Enrichment in `Virosa' Tomato Plant: Responses to Enrichment Duration and to Temperature
Authors: Behboudian M. Hossein , Lai Robert
Published: February 2019

Responses of the tomato (Lycopersicon esculentum Mill. cv. Virosa) plant to elevated CO2 concentrations applied throughout the photoperiod or part of it were studied under two temperature regimes. Plants were exposed to CO2 at 340 (control), 700, and 1000 μl·liter–1. The highest concentration was applied only at 22/16C (day/night) and 700 μl·liter–1 at 22/16C and 25/16C. Transpiration rates were lower and photosynthetic rates were higher under elevated CO2 than at the ambient level. Biomass production was higher only for plants grown at 700 μl·liter–1 and 25/16C. Concentrations of macronutrients were lower in plants exposed to 1000 μl CO2/liter than in the control plants. Intermittent CO2 was applied using two timing methods. In method 1, plants were exposed to 4- or 8-hour high-CO2 concentrations during their 12-hour photoperiod. In method 2, plants were exposed for 3.5 days of each week to 700 μl CO2/liter. Only two of the 8-hour exposures resulted in greater growth than the controls. The lack of higher growth for CO2-enriched plants at 22/16C was attributed to a higher dark respiration rate and to a lack of efficient transport of photosynthates out of leaves.
Branch Inducement in Apple Stoolbed Shoots by Summer Leaf Removal and Tipping
Authors: Ouellette David R. , Young Eric
Published: February 2019

The ability of various leaf removal treatments or shoot tipping to induce lateral shoot development on current-season stoolbed shoots of MM.106 EMLA and M.26 EMLA apple (Malus domestica Borkh.) rootstocks was investigated. Removal of the five uppermost immature leaves or shoot tipping after every 20 to 25 cm of terminal growth produced more lateral budbreak than occurred on nontreated shoots. Shoot tipping resulted in the highest number of branches (≥5 cm) and greatest total branch length. Only tipping consistently induced lateral budbreak higher than 30 cm up the shoot. Removal of the 10 uppermost leaves and tipping resulted in the shortest terminal shoots. MM.106 shoots had more lateral budbreak, branches, and total branch length than did M.26 shoots.
Calcium Source Affects Calcium Content, Firmness, and Degree of Injury of Apples during Storage
Authors: Beavers William B. , Sams Carl E. , Conway William S. , Brown George A.
Published: February 2019

Fruit from five apple (Malus domestica Borkh.) cultivars were pressure-infiltrated at 103 kPa for 6 min with a 0%, 0.73%, 1.46%, 2.91%, or 5.82% (w/v) Ca-equivalent solution of CaCl2, Ca EDTA chelate, or buffered CaCl2 solution (Stopit). The fruit were stored at 0 ± 1C for 18 weeks and then evaluated for Ca content, firmness, and injury. Fruit treated with Ca chelate had no increase in fruit Ca content and were injured at all treatment levels. No significant differences occurred in fruit Ca levels between CaCl2 and Stopit treatments across all cultivars tested. Apples treated with Stopit were firmer than apples treated with CaCl2, when averaged across cultivars. Fruit Ca levels, firmness, and incidence of injury were positively correlated with concentrations of CaCl2 and Stopit for all cultivars.
A New Source of Resistance to Anthracnose (Race 2) in Watermelon
Authors: Boyhan G.E. , Norton J.D. , Abrahams B.R. , Wen H.H.
Published: February 2019

In an anthracnose [Colletotricum obiculare (Berk. & Mont.) Arx.] screening test of 76 plant introductions (PIs), commercial Chinese watermelons [Citrullus lanatus (Thunb.) Matsum. & Nakai], and `Crimson Sweet', PI 512385 had the highest disease resistance with a mean rating of 4.5 (1= resistant, 9 = susceptible). In a second test with PI 512385, which included material with previously reported resistance (PIs 270550,326515, 271775,271779,203551, 299379, and 189225), and `Crimson Sweet' (susceptible control), PI 512385 had significantly higher resistance than `Crimson Sweet' but was not significantly more resistant than the other PIs evaluated. PI 512385 had a mean rating of 2.2 in the second test.
Production Temperatures Influence Growth and Physiology of Leatherleaf Fern
Authors: Stamps Robert H. , Nell Terril A. , Barrett James E.
Published: February 2019

Leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] fronds produced under a high-temperature regime (HTR, 30 day/25C night) grew faster and produced sori earlier than those in a low-temperature regime (LTR, 20 day/15C night). Abaxial diffusive conductance was lower for HTR-grown fronds. Light-saturated net CO2 assimilation rates (Pn) and dark respiration were lower for HTR fronds, but light-saturated Pn efficiencies (chlorophyll basis); light compensation points; and soluble sugars, starch, and nonstructural carbohydrate levels were similar for the two regimes. Transpiration and water-use efficiency (mass basis) at light saturation were similar for fronds from both temperature treatments. Comparison of physiological characteristics of fronds from the two temperature regimes revealed no differences that might account for reduced postharvest longevity of fronds produced at the higher temperatures.
Time, Temperature, and Calcium Interact in Scald Reduction and Firmness Retention in Heated Apples
Authors: Klein Joshua D. , Lurie Susan
Published: February 2019

Apple (Malus domestica Borkh. `Grand Alexander') fruit were stored immediately at 0C after harvest or after being held at 38,42, or 46C for 72,24, or 12 h, respectively. Half of each fruit lot was dipped in 1.5 % CaCl before storage. Heating did not appreciably affect Ca uptake into epidermal or cortical tissue. Calcium and heat treatments acted synergistically in reducing the severity of superficial scald and in retaining fruit firmness after 5 months of storage, relative to nontreated or nonheated Ca-dipped fruit.
Polyamine Uptake Does Not Affect Floral Longevity in Miniature Potted Roses
Authors: Serek Margrethe , Andersen Arne Skytt
Published: February 2019

Postharvest life of Rosa hybrids L. `Elegance Parade' was increased by 0.2 mm silver thiosulfate and decreased by ethephon at 500 μl·liter-1. In contrast, spraying the plants with various polyamine (PA) concentrations (spermine, spermidine, or putrescine) or the PA-synthesis inhibitor methylglyoxal-guanylhydrazone did not affect postharvest life. Investigation of PA-uptake patterns showed that the compounds were entering the petal tissue.
Adventitious Shoot Organogenesis and Plant Regeneration from Cotyledons of Tetraploid Watermelon
Authors: Compton Michael E. , Gray D.J.
Published: February 2019

Cotyledon explants of four watermelon [Citrullus lanatus (Thunb.) Mataum. & Nakai] breeding lines (F92U8, SP90-1, SP90-2, and SP90-4) were prepared from mature seed or from 2-, 4-, 6-, 8-, or 10-day-old seedlings. Explants were incubated on shoot regeneration medium for 8 weeks followed by 4 weeks on shoot elongation medium. The four genotypes differed in their ability to produce shoots at each explant age. The highest frequency with which F92U8 (66%) and SP90-2 (60%) explants produced shoots was for 2-day-old seedlings. Fewer explants formed shoots when established from mature seed or seedlings older than 2 days. In contrast, the percentage of SP90-4 explants that produced shoots was highest when cotyledons were obtained from 4-day-old seedlings (40%), but the response was less than the optimum for F92U8 and SP90-2. SP90-1 cotyledon explants exhibited the poorest response of the four breeding lines (<11% produced shoots), with little difference in response among the explant ages tested. The number of shoots per responding explant also depended on the age of the explant source. Explants from 2- to 4-day-old seedlings produced the most shoots. Fewer shoots formed on cotyledons from mature seed or seedlings older than 4 days.
In Vitro Propagation of Citrus reticulata Blanco and Citrus limon Burm.f.
Authors: Singh S. , Ray B.K. , Bhattacharyya S. , Deka P.C.
Published: February 2019

Multiple shoots were obtained from shoot tips (2 to 3 mm) derived from mature plants (5 to 6 years old) of Citrus reticulata Blanco cv. Khasi mandarin and C. limon Burm.f. cv. Assam lemon when cultured on Murashige and Skoog (MS) medium, supplemented with (mg·liter-1) 1.0 BAP, 0.5 kinetin, and 0.5 NAA. Root induction was observed when 7-week-old single shoots (≈ 2 cm long) of both Citrus species were cultured on MS medium supplemented with (mg·liter-1) 0.25 BAP, 0.5 NAA, and 0.5 IBA. These plantlets were successfully established in the soil. Chemical names used: naphthalene acetic acid (NAA), indole 3-butyric acid (IBA), and benzylamino purine (BAP).
INHERITANCE AND HERITABILITY OF SEED SIZE IN HULLLESS SEEDED STRAINS OF CUCURBITA PEPO
Authors: Carle R. Bruce , Loy J. Brent
Published: February 2019

Genetic experiments were initiated to assess the potential for combining large seed size from PI 285611, a large-fruited, hullless seeded accession, with small fruit size from a hullless seeded breeding line (NH29-13-5-4). An F2 population and parental line were field-grown during Summer 1993 to determine inheritance and heritability of large seed size and the relation between fruit and seed size. Seed size variables of weight, width, length, and thickness were regressed against fruit weight. There was a moderate, positive correlation between large fruit and seed length (R2 = 0.46). However, seed thickness, a major determinant of seed weight, was not correlated with fruit size. In an F2 population of ≈450 plants, there was a small number of plant selections with fruit under 1.5 kg and seed size approaching that of PI 285611.
FIELD EVALUATION OF FACTORS CONTRIBUTING TO STRAWBERRY BLACK ROOT ROT DISEASE
Authors: Wing Katherine B. , Pritts Marvin P.
Published: February 2019

Black root rot is a devastating, poorly understood disease complex affecting strawberries in temperate regions. The objective of the study was to conduct a comprehensive field survey of environmental, cultural, and pathological factors contributing to black root rot disease of strawberries as it occurs in New York. In Spring 1992, growers were visited to collect information on cultural practices, field measurements, and plant and soil samples from healthy and infected fields. Plants were scored for root health and measurements were made for nematode densities, soil compaction, soil texture, soil nutrients, and plant dry weights. Variables significantly correlated with poor root health were soil compaction, fine soil texture, absence of raised beds, high rates of terbacil (Sinbar) use, advanced age of planting, and many cumulative years of strawberry culture.
EFFECTS OF SOIL MANAGEMENT ON TREE GROWTH, FRUIT SET, YIELD, AND FRUIT QUALITY OF SPARTAN APPLES ON M.9 ROOTSTOCK
Authors: Paré Martin , Buszard Deborah
Published: February 2019

Four soil management treatments were applied from 1991 to 1993 to `Spartan'/M.9 apple trees planted in 1987. Geotextile, straw mulch, composted manure mulch, and grass sod were used to control weed growth in a 1-m-wide band under the trees. The experiment was a randomized complete block design with two blocks and seven trees per treatment; data was taken from the five inner trees in each plot. Trees in straw mulch showed the largest increase in trunk cross-sectional area (+45.6%) over the three years; those in the geotextile showed the second largest (40.7%). Straw mulch also resulted in the largest yield 2 years out of 3. Fruit set and fruit quality were also assessed, and trees in manure mulch and grass sod set the least fruit in each season. Fruit from the grass sod treatment remained harder in storage, and both straw mulch and grass sod have a higher proportion of grade A fruit (57 of total fruit).
WOODY ORNAMENTAL TRIAL NETWORK IN QUEBEC
Authors: Richer-Leclerc C. , Rioux J.A.
Published: February 2019

The “Reseau d' Essai de Plantes Ligneuses Ornementales du Québec” (REPLOQ) is a research project created in 1982 with a principal mandate to elaborate, develop, and coordinate with specialists on a cooperative research project to evaluate the winter hardiness of ornamental plants throughout the province of Quebec.
COMPARISON OF NEAR-INFRARED REFLECTANCE SPECTROSCOPY AND WET CHEMICAL ANALYSIS ON THATCH COMPOSITION
Authors: Couillard Andree-Anne , Turgeon A.J. , Shenk J.S. , Westerhaus M.O.
Published: February 2019

The ability to predict thatch composition with the use of near-infrared reflectance spectroscopy (NIRS) was investigated. This study compared a new quick test for evaluating different thatch components using NIRS with the Van Soest wet chemical analysis. Creeping bentgrass (Agrostis palustris Huds.) thatch samples were taken from an experimental golf green at the Valentine Turfgrass Research Center at Penn State Univ. Fresh and dried ground samples were scanned from 400 to 2500 nm with a near-infrared monochromator. Dried ground samples were analyzed in four replicates using the Van Soest procedures for the acid detergent fiber, cellulose, and lignin. Moisture and organic matter contents were also evaluated in the laboratory. Preliminary comparisons between predicted NIRS values and laboratory results were encouraging. NIRS analysis of thatch could become a convenient, rapid, and inexpensive alternative to wet chemical analysis for thatch assessment.
POTENTIAL OF PROTEINASE INHIBITORS FOR THE PRODUCTION OF TRANSGENIC PLANTS TOLERANT TO INSECT PESTS. I. FUNCTIONAL ASPECTS
Authors: Michaud Dominique , Overney Serge , Nguyen-Quoc Binh , Yelle Serge
Published: February 2019

In the past few years, transformation of plant genomes with proteinase inhibitor (PI) genes has been proposed as an effective way to produce insect-tolerant plants. For such a control approach, however, biochemical studies are necessary to assess the effect of PIs on not only insect digestive proteinases (target enzymes) but also plant endogenous proteinases (nontarget enzymes). As an example, transformation of potato (Solanum tuberosum L.) with oryzacystatin (OC) genes, two cysteine PIs, was considered for controlling Colorado potato beetle (CPB; Leptinotarsa decemlineata Say). The use of electrophoretic approaches and standard assays showed that CPB uses at least 14 cysteine proteinases for protein digestion throughout its development. Proteinases of the same class were also detected in sprouting potato tuber extracts, suggesting a potential interference of cPIs in transgenic plants. While OCs inhibit a significant fraction of CPB digestive proteinases, no inactivation of potato proteinases was detected. This apparent absence of direct interference suggests the real potential of OCs for producing CPB-tolerant transgenic potato plants.
QUEBEC SMALL-FRUIT RESEARCH AND DEVELOPMENT—A NEW APPROACH WITH THE GARD-PF
Authors: Bégin Serge , Garneau Alain , Roy Michèle , Thibodeau Pierre O.
Published: February 2019

Consequent to the propositions of the Québec Agriculture Summit concerning suggestions to increase research efforts and technological transfer and market awareness, members of the research division of the provincial ministry of agriculture have established an animation team in small-fruit research and development. This group will be composed of scientists whose mandate will be to lead and rally the small-fruit sector into regrouping, to provide adequate tools necessary for research and development (bibliography, periodicals, etc.), to counsel and plan research and development projects, and to give advice on actions and means of development in a particular sector.
INFLUENCE OF NITROGEN, POTASSIUM, AND MAGNESIUM FERTILIZATION ON DAY-NEUTRAL STRAWBERRIES IN QUEBEC
Authors: Lamarre M. , Lareau M.J.
Published: February 2019

From June to Sept. 1993, the day-neutral strawberry cultivar Tribute was subjected to two N fertilization rates (50 and 100 kg/ha), four K fertilization rates (0, 60, 120, and 180 kg/ha), and three Mg fertilization rates (0, 25, and 50 kg/ha) through trickle irrigation. The N and K treatments had no significant influence on yield and fruit size. The Mg treatments increased fruit size and did not affect yield.
EFFECT OF NUTRIENT SOURCE ON THE GROWTH OF PHYSOCARPUS OPULIFOLIUS `NANUS', WEIGELA FLORIDA `RUMBA', AND SPIRAEA × BUMALDA `GOLDFLAME'
Authors: Duchesne Isabelle , Rioux Jacques-André , Gosselin André
Published: February 2019

Six fertilization programs were applied to three woody plants: Physocarpus opulifolius `Nanus', Spiraea × bumalda `Gold flame', and Weigela florida `Rumba'. The objective of this study was to determine fertilization programs best adapted to container woodyplant production. Treatments were: 1) Nutricote (5 g/liter of growth medium) + weekly fertigation of 20N–20P–20K (300 mg N/liter); 2) Coïc-LeSaint solution for each irrigation; 3) Nutricote + weekly fertigation of liquid 9N-9P–9K (300 mg N/liter); 4) fertigation with complete nutrient solution (125 mg N/liter); 5) Polyon + weekly fertigation of 20N–20P–20K (300 mg N/liter); and 6) Nutralene + weekly fertigation of 20N–20P–20K (300 mg N/liter). The experiment took place between 25 June 1991 and 15 Aug. 1992. Results show that, independent of species, plants given fertilization program 4 had lower plant height (57 cm) and stem dry weight (97 g) than plants under other treatments, the average for each parameter being 72 cm and 127 g, respectively. Plant height was highest in Physocarpus with treatment programs 2, 4, 5, and 6. Weigela had greater growth under program 2, while Spiraea had more growth with programs 1, 3, and 6. Consequently, differences exist between optimum fertilization programs used for each species studied.
CHANGES IN SUGAR CONTENT IN CUT ONION DURING STORAGE
Authors: Blanchard Mylène , Castaigne Francois , Makhlouf Joseph
Published: February 2019

Our purpose was to study the impact of controlled atmosphere (CA) on respiration of and changes in sugar content of diced onions. The onions were peeled, diced, washed, disinfected, and centrifuged before storage for 12 days under gas mixtures of 21% O2 and 0% CO2 (air), 2% O2 and 0% CO2, and 2% O2 and 10% CO2. Every 4 days, respiration rate and sugar content (total, sucrose, fructose, and glucose) were determined. Carbon dioxide-enriched atmosphere limited respiration rate and sucrose depletion, whereas the mere reduction of O2 had no effect. Reducing sugar contents remained constant during storage regardless of the treatment.
CONTROL OF THE COLORADO POTATO BEETLE WITH AUGMENTATIVE RELEASES OF THE STINKBUG PERILLUS BIOCULATUS
Authors: Cloutier Conrad
Published: February 2019

Tests in experimental plots over two seasons have shown that it is possible to obtain excellent control of eggs and larvae of the Colorado potato beetle (CPB) (Leptinotarsa decemlineata) under Quebec growing conditions by augmentative releases of a generalist predator, the twospotted stinkbug P. bioculatus. The stinkbugs were mass-reared on CPB eggs and larvae in the laboratory, and were released as second or third instar nymphs at the time of peak beetle oviposition. They were introduced manually at ratios of 2-4 predators : beetle egg mass in plots comprising ≈1000 `Kennebec' potato plants. Short-interval sampling after introduction indicated good rates of establishment and survival of the released P. bioculatus nymphs. Analysis of CPB egg recruitment and mortality indicated high rates of destruction of CPB eggs by the stinkbug. Egg destruction was followed by significant predation of late-instar bugs on CPB larvae, resulting in significant reductions of CPB prepupal and adult densities, and excellent foliage protection in treated plots compared to untreated controls. The results will be discussed with reference to traits of P. bioculatus that make it a good candidate for biocontrol of the CPB, and to problems yet to be resolved before augmentative releases of the predator can be used as an integrated pest management tactic in larger scale potato production.
Luffa Sponge Gourd Production Practices for Temperate Climates
Authors: Davis Jeanine M.
Published: February 2019

The objective of 2 years of field studies was to begin development of a luffa sponge gourd (Luffa aegyptiaca Mill.) production system for a cool, temperate climate by studying the effects of planting date, planting method, in-row spacing (30.5, 61, and 91 cm), and pruning techniques on yield and quality of luffa sponge gourds. High yields of mature gourds were obtained when transplants were field-set as soon as the danger of frost had past. Highest marketable yields were obtained when plants were spaced 30.5 cm apart in the row and the first four lateral shoots were removed. Plants spaced 91 cm apart produced gourds with the largest diameter, whereas plants with 30.5-cm in-row spacing produced the highest yields of gourds with bath sponge diameters (5.1-7.6 cm). Plants spaced 91 cm apart and topped at node six obtained high fiber density, strong fibers, and excellent visual appeal, but low yields. Yields were competitive with yields obtained in warmer climates.
Maximizing Nitrogen-use Efficiency in Relation to the Growth and Development of Poinsettia
Authors: Rose Mary Ann , White John W. , Rose Mark A.
Published: February 2019

`Celebrate 2' poinsettias (Euphorbia pulcherrima Willd.) received either a constant application rate of 200 mg N/liter or a variable rate that was linked to the N accumulation pattern of the crop. At final harvest, shoot N content, N concentration, dry weight, leaf area, and quality were similar for the treatments. However, N recovery efficiency of the variable treatment was greater (58% vs. 38%), and 41% less total N was applied compared to the constant-rate treatment. Growth analysis revealed that N accumulation rates for both treatments increased rapidly as side branches developed, reaching a maximum 50 to 60 days after potting, and decreased throughout bract development. The decrease in N accumulation rates after day 60 reflected a shift in N allocation from leaves to bracts, a tissue with a lower N concentration.
Reduction of Postproduction Quality Loss in Potted Miniature Roses
Authors: Tjosvold Steven A. , Wu Meng-Jen , Reid Michael S.
Published: February 2019

Potted miniature roses (Rosa × hybrids L. `Belle Sunblaze') held after production in simulated home conditions (21C, continuous fluorescent light) yellowed prematurely, flower buds and leaves abscised, and flower buds failed to open. These symptoms were accelerated when the plants were exposed to low concentrations (1 μl·liter-1) of ethylene in the absence of inhibitors. Spray application of 100 μl BA/liter reduced leaf yellowing but had no significant effect on flower opening or bud abscission. Spray application of 1 mm silver thiosulfate (STS) strongly promoted flower display but did not prevent leaf yellowing. A combined BA and STS treatment greatly improved the postproduction quality of rose plants, particularly if applied 1 day before harvest. Chemical name used: benzyladenine (BA).
Low-temperature Scanning Electron Microscopy of Frozen Hydrated Apple Tissues and Surface Organisms
Authors: Roy Stéphane , Watada Alley E. , Conway William S. , Erbe Eric F. , Wergin William P.
Published: February 2019

Frozen hydrated buds and epicarp of `Golden Delicious' apple (Malus domestica Borkh.) were observed with a low-temperature, field emission scanning electron microscope (SEM). In addition to observing surface features of these specimens, holders were modified to observe fractured specimens. A modified hinged holder retained both halves of a fractured specimen for examination of the complementary faces of frozen hydrated tissues. Low-temperature SEM avoided artifacts, such as extraction, solubilization, and shrinkage, which are normally encountered with chemical fixation, dehydration, and drying, respectively. The technique allowed observations of well-preserved frozen hydrated structures, such as the platelets of epicuticular wax; loosely associated organisms on plant surfaces, such as spider-mite eggs; delicate structures, such as fungal hyphae; and partially hydrated tissues, such as fruit epicarp and winter bud scales.
Unique Organic Acid Profile of Rabbiteye vs. Highbush Blueberries
Authors: Ehlenfeldt Mark K. , Meredith Filmore I. , Ballington James R.
Published: February 2019

The fruit of six highbush (Vaccinium corymbosum L.) cultivars and eight rabbiteye (V. ashei Reade) cultivars and selections were evaluated by high-performance liquid chromatography for levels of the commonly found organic acids, citric, malic, succinic, and quinic. The two cultivar groups possessed distinctive patterns of relative organic acid proportions that could unambiguously separate pure rabbiteye and highbush clones in a principal component analysis. Highbush clones were characterized by high citric acid content, with percentages averaging 75% (range 38% to 90%). Succinic acid was the second most plentiful acid, averaging 17%. In contrast, rabbiteye cultivars and selections contained 10% citric acid, and no clone had >22%. Succinic acid and malic acid were found in greater quantities than in highbush, averaging 50% and 34%, respectively. Analysis of the fruit of seven albino-fruited highbush selections exhibited a profile similar to standard highbush cultivars, but with a citric acid average of <50%, and proportionally greater amounts of succinic and quinic acids. Given the differences in sensory quality of these four acids, it is likely that acid partitioning patterns can largely account for some of the perceived flavor differences between rabbiteye and highbush blueberries. Because several current breeding efforts involve hybridization between highbush and rabbiteye blueberries, a consideration of acid composition of breeding parents maybe worthwhile.
003 SYSTEMIC IMPACTS OF NON-CROP RESIDUES ON PEST MANAGEMENT IN SNAP BEAN PRODUCTION
Authors: Peachey Ed , William Ray
Published: February 2019

Altering the physical or chemical nature of the crop production environment through introduction of cover crops or other non-crop vegetation may amend the impact of various pests on vegetable crops. Current work is focused on the interaction of cereal cover crops and respective management systems with weed emergence and growth, white mold (Sclerotinia sclerotiorum) incidence, symphylan (Scutigerella immaculata) population dynamics, soil food-web structure, and crop yield in snap bean production systems. Research has demonstrated the potential of cover crop residues, tillage, and a single broadcast application of a postemergence herbicide to control summer annual weeds. Additionally, white mold incidence was significantly decreased by both reduced tillage conditions and flailed barley cover crop residues in one year of research. Two years of research indicate that symphylan density can be reduced by flailing spring-planted cereals before crop planting.
032 EFFECT OF STRATIFICATION AND GIBBERELLIC ACID ON SEED GERMINATION OF NATIVE PLANTS
Authors: Bohnen Julia L. , Hanchek Anne M.
Published: February 2019

The Legislative Commission on Minnesota's Resources funded a two year research project to promote expansion of the native wildflower and grass seed industry in Minnesota. Production of seeds and plants for landscaping and restoration is a growing sector of the horticultural industry, yet documentation of production techniques is sketchy due in part to the large number of species. The species Lilium philadelphicum (wood lily), Phlox pilosa (prairie phlox), and Spartina pectinata (prairie cordgrass) were selected for further analysis of germination requirements. These species were noted by producers as having poor and/or unreliable germination. Cold moist stratification and gibberellic acid (GA) treatments were applied Total percent germination and mean days to germination were calculated and analyzed after 30 days under greenhouse growing conditions. Stratification improved total percent and mean days to germination in L. philadelphicum. P. pilosa responded to treatment by both stratification and GA. Four weeks of stratification may be the best method for decreasing mean days to germination while obtaining adequate total percent germination for S. pectinata.
034 INCORPORATION OF USEFUL TRAITS FROM NATIVE ALMOND SPECIES INTO CULTIVATED ALMOND VARIETIES
Authors: Kester Dale E. , Gradziel Thomas M.
Published: February 2019

Approximately twenty native almond species have been described. Representative germplasm from seven of these are present in UC collections and have been used in crossing. Three specific breeding lines utilizing these species are described. One (1980 series) involved increasing yield potential through selection of high blossom density following gene introgression from Prunus fenzliana. A second involved incorporation of self-fertility, late bloom, smaller tree size, early maturity, high blossom density, and desirable nut characters from Prunus webbii into commercial breeding lines. A self-fertile selection resembling `Nonpareil' has been obtained from this material. The third line involves transmission of a unique thin, netted-surfaced, hard-shell phenotype from Prunus argentea.
040 EFFECT OF VARIOUS HORMONES ON THE GROWTH AND GERMINATION OF WALNUT SOMATIC EMBRYOS
Authors: Sutter Ellen G. , Ahmadi Hamid
Published: February 2019

Somatic embryos of Juglans regia transformed with Agrobacterium rhizogenes Rol B gene and non-transgenic lines were proliferated on basal DKW medium. They were then transferred to media containing different concentrations of ABA, IBA and BA to increase the rate of proliferation and maturation. Transgenic embryos required 50 μM ABA and 40 μM IBA whereas non-transgenic embryos required 40μM ABA and 10 μM IBA. Neither kind of embryos required BA. Roots were. induced by drying embryos at 75% for 2-3 weeks until they lost about 30% fresh weight and then transferring them to basal DKW medium for an additional 2 weeks in the dark. Over 50% of the somatic embryos grown on medium containing both ABA and IBA developed well defined root systems compared to less than 15% of embryos grown on basal medium. A combination of 27 μM GA, and 9 μM BA was needed for development of shoot systems and germination of both transgenic and non-transgenic rooted embryos. Anatomical studies followed to characterize the extent of development at each stage.
056 EFFECT OF HYDROPONIC SOLUTION NITROGEN CONCENTRATION ON `CHANDLER STRAWBERRIES
Authors: Himelrick David G. , Dozier W. A.
Published: February 2019

`Chandler' strawberry plants were grown in a nutrient flow hydroponic systems with six solution N treatments (35, 70, 140, 210, 280, 350 ppm). Total N was determined in leaf blade and petiole samples using Kjeldahl procedure and by LECO CHN analyzer. Nitrate-N was extracted with KCl and analyzed using a LACHAT ion analyzer. Correlations for total N in leaf blades with hydroponic N levels were r7 = 0.79 for Kjeldahl, r2 = 0.25 for LECO, and r2 = 0.60 for LACHAT while petiole samples were r* = 0.57 for Kjeldahl, r2 = 0.55 for LECO and r2 = 0.41 for LACHAT. Vegetative characteristics of the plants were affected with the 210 ppm treatment producing both the most crowns and runners and 350 ppm the least.
064 OFFERING A CAPSTONE COURSE IN HORTICULTURE
Authors: Rhodus Tim
Published: February 2019

Capstone courses generally target students who are nearing completion of their studies, are designed to build on skills acquired in earlier courses, and emphasize realistic situations and challenges that exist in the “real world”. Specific learning goals and course objectives are found to vary across disciplines but most capstone courses provide an opportunity for students to demonstrate a range of professional competencies and communication skills. By incorporating computer simulations, case studies, or research projects, students are better able to develop critical thinking and problem solving skills, a learning goal frequently adopted following curriculum review. The goals and organization of “Quality, Ethics, and the Global Environment,” the capstone course in Horticulture at The Ohio State University will be compared to other capstone courses.
066 A MODEL FOR REFORM OF UNDERGRADUATE HORTICULTURE EDUCATION: THE WASHINGTON TREE FRUIT PROGRAM
Authors: Mullinix Mark K. , Tvergyak Paul
Published: February 2019

Horticulture departments have been experiencing a decline of students studying pomology and the tree fruit industry suffers from a shortage of horticulturists. Wenatchee Valley College responded to the tree fruit industry's request to develop an undergraduate pomology program. The program has an industry advisory committee, is industry oriented and emphasizes the art and the science of deciduous tree fruit production. Industry and field-based instruction is a significant component of the curriculum. The fruit industry funded the development of two laboratory orchards totaling 53 acres. Industry satisfaction and student placement is high. Wenatchee Valley College's success motivated the industry to encourage the Washington State University Dept. of Horticulture and Wenatchee Valley College to join in an educational partnership. The Washington Tree Fruit Program was implemented in 1993. It is the state's first educational program cooperatively developed by two state institutions of higher education and boasts 55 degree-seeking students. The articulated curriculum has many innovations and represents a significant departure from traditional undergraduate pomology curricula.