bluuebunny/crossref_metadata_2025 huggingface dataset:
Dead Prunus Flower-bud Primordia Retain Deep-supercooling Properties
Authors: Kadir Sorkel A. , Proebsting Ed L.
Published: February 2019

Differential thermal analysis (DTA) was used to measure deep supercooling in flower buds of Prunus dulcis Mill., P. armeniaca L., P. davidiana (Carr.) Franch, P. persica (L.) Batsch, three sweet cherry (P. avium L.) selections, and `Bing' cherries (P. avium L.) during Winter 1990-91 and 1991-92. Low temperatures in Dec. 1990 killed many flower buds. After the freeze, dead flower primordia continued to produce low-temperature exotherms (LTEs) at temperatures near those of living primordia for >2 weeks. In Feb. 1992, cherry buds that had been killed by cooling to -33C again produced LTEs when refrozen the next day. As buds swelled, the median LTE (LTE50) of dead buds increased relative to that of living buds, and the number of dead buds that produced LTEs decreased. LTE artifacts from dead flower priimordia must be recognized when DTA is used to estimate LTE50 of field-collected samples.
Embryo Cap Removal and High-temperature Exposure -Stimulate Rapid Germination of Needle Palm Seeds
Authors: Carpenter William J. , Ostmark Eric R. , Cornell John A.
Published: February 2019

High synchrony, rate, and germination of needle palm [Rhapidophyllum hystrix (Pursh) H.A. Wendle & Drude] seeds were achieved only after removing the sclerotesta and embryo cap, which imposed physical dormancy. After scarification, recently harvested seeds or seeds stored for 12 months at 5C and 100% relative humidity had 96% and 98% final germination (G), with 9 to 11 days required to achieve 50% of final germination (T50) at 30C. Germination temperature controlled G, T50, and days between 10% and 90% of final germination (T90 - T10) of scarified seeds, with respective values of 98%) 9 days, and 5 days at 30C, and 18%, 31 days, and 12 days at 15C. Seeds with 36% moisture at harvest had no reduction in G until moisture was <14%. Germination of seeds with 19% moisture declined from 80% if stored at 0C to 33% if stored at -l0C; no seeds germinated after storage at less than -l0C.
Irrigation Schedules and Annual Ryegrass as a Ground Cover to Conserve Water and Control Peach Tree Growth
Authors: Huslig Susan M. , Smith Michael W. , Brusewitz Gerald H.
Published: February 2019

Irrigation schedules were evaluated on `Cresthaven' peach [Prunus persica (L.) Batsch.] to determine if water application could he reduced or omitted without affecting fruit size or yield. Tensiometers were used to schedule trickle irrigation during 1984-M. Treatments were no irrigation or irrigation when soil pressure potential at a 30-cm depth reached 40 or 60 kPa, respectively. When production began in 1986, trees were either irrigated until harvest (1-7 Aug.) or until October. Beginning in 1989, class A pan evaporation was used to schedule irrigation by replacing 60% of evaporation. Trees were irrigated from budbreak to harvest or October, from beginning of stage III fruit growth until harvest or October, or trees were not irrigated. The irrigation treatments were in factorial combination using sod middles, with annual ryegrass (Lolium multiforum Lam.) seeded under the trees or a sod-herbicide strip. The ryegrass was seeded in October, then killed at the onset of stage III fruit growth. Water application was reduced 32% to 57% when irrigation was discontinued after harvest compared to irrigation until October. Irrigation before stage III fruit growth did not affect fruit yield, size, or pruning weights compared to trees irrigated at the onset of stage III fruit growth. Trunk size was increased by irrigation; however, there were no differences in trunk size among irrigation treatments. Irrigation occasionally increased fruit size and yield compared to no irrigation. There were few differences in flower bud density, fruit set, yield, or fruit size among trees with reduced irrigation schedules compared to trees receiving irrigation from budbreak until October. Annual ryegrass decreased shoot growth in 1990 and flower bud density in 1991; however, fruit set was not affected. Annual ryegrass depleted excess soil moisture during the spring in some years, then conserved soil moisture after it was killed. Using sod with annual ryegrass under the trees may be a viable alternative to management with sodherbicide strips.
Ion Leakage as a Criterion for Viability of Lily Bulb Scales after Storage at –2C for 0.5, 1.5, and 2.5 Years
Authors: Bonnier Frans J.M. , Keurentjes Joost , van Tuyl Jaap M.
Published: February 2019

The viability of `Avignon' and `Esther' (Asiatic hybrids), `Star Gazer' (Oriental hybrid), and `Snow Queen' lily bulb scales (L. longiflorum Thunb.) was determined after storage at –2C for 0.5, 1.5, and 2.5 years. Ion leakage, the percentage of scales that formed bulblets, and the number and weight of these bulblets were determined on scales from the inner, middle, and outer part of bulbs. During storage, the outer scales of all cultivars and the inner and middle scales of `Snow Queen' showed increased ion leakage accompanied by a decreased ability to form scale bulblets during storage. Concurrently, the percentage of scales forming bulblets declined, and more and smaller scale bulblets were formed per regenerative scale. Thus, ion leakage is a useful criterion to measure viability of lily scales.
Vesicular–Arbuscular Mycorrhizae Colonization of Redwood and Incense Cedar Seedlings following Storage
Authors: Afek U. , Lippet L.A. , Adams D. , Menge J.A. , Pond E.
Published: February 2019

Vesicular–arbuscular mycorrhizal inoculum consisting of a mixture of roots of coast redwood [Sequoia sempervirens (D. Don)], soil, and spores of Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappe was tested for viability and efficacy following storage for 4 or 8 weeks at 4, 9, 15, or 24C and moisture contents of 0%, 6%, 12%, or 17%. Storage regimes did not have any effect on the number of spores of Glomus mosseae recovered after storage. However, germinability of the spores decreased from 35% before storage to 10% to 31% during storage, especially under typical ambient room conditions (17% moisture at 24C). Maximum colonization of coast redwood, sierra redwood [Sequoiadendrom giganteum (Lindl.) Buchh.], and incense cedar (Libocedrous decurrens Torr.) was achieved after inoculation with 1 inoculum: 1 potting mix dilution (w/w). However, plant fresh weight was highest following inoculation with a 1 inoculum: 5 potting mix dilution (w/w). Dried inoculum was effective when stored at 24C, or below 10C when moist.
STUDIES OF LIQUID FERTILIZATION OF ANTHURIUM
Authors: Sakai William S. , Hanohano Trudy
Published: February 2019

Anthuriums appear to be very salt sensitive. Small plants of Anthurium andraeunum `Marian Seefurth' were fertilized daily with 25, 50, 75, 100, and 125 ppm N of 12N-16P-30K + micros (75% nitrate-25% ammonium) liquid fertilizer corresponding to 0.50, 0.74, 0.98, 1.22, 1.45, and 1.69 mS·cm-1 of electrical conductivity (EC). After 1 year, flower production was greatest [5.2 flowers per plant (fl/pl)] at 0.50 mS·cm-1 (25 ppm N). Flower production decreased gradually with increasing EC to 3.9 fl/pl at 1.45 mS·cm-1 (125 ppm N), then dropped to 1.8 fl/pl at 1.69 mS·cm-1 (150 ppm N). Flower stem length and flower size followed the same pattern. With larger `Ellison Onizuka' plants, the number of flowers, flower stem length, and flower size all peaked at 0.74 mS·cm-1 (75 ppm N). A drop was again observed at 1.69 mS·cm-1 (125 ppm N). Other workers recommend 0.60 to 0.80 mS·c m-1 for anthurium production. Our findings are in agreement. However, for smaller plants, 0.50 mS·cm-1 would produce better growth.
Development and Testing of Preliminary Foliar DRIS Norms for Onions
Authors: Caldwell Jordan O'N , Sumner Malcolm E. , Vavrina Charles S.
Published: February 2019

The Diagnosis and Recommendation Integrated System (DRIS) was developed to incorporate the importance of nutrient balance into plant analysis. Yield and plant analysis data from five fertilizer trials conducted in the field during 2 years, using `Granex 33' onions (Allium cepa L.), were entered into a data bank. The trials consisting of a N4 × P4 × K4 × S4, a N4 × P4 × K4 × plant density4, two N4 × P4 × K4, and a 4N × 6S factorial were conducted on sandy Ultisols in Georgia. Significant yield responses resulted from the addition of P and N. Leaf samples were analyzed for N, P, K, S, Ca, Mg, Mn, Zn, Cu, and B. Nutrient data were expressed in ratio form, and the population with yields >45 Mg·ha–1 were used to calculate the DRIS norms. The proposed norms for N, P, K, Mg, and Cu were tested using published data from independently conducted field and greenhouse studies. By accurately diagnosing the most limiting nutrients, these norms successfully predicted yield responses to treatment. Preliminary norms for S, Ca, Mn, Zn, and B were determined but not tested.
Cyclic Irrigation Reduces Container Leachate Nitrate-nitrogen Concentration
Authors: Fare Donna C. , Gilliam Charles H. , Keever Gary J. , Olive John W.
Published: February 2019

Two experiments were conducted to evaluate the effects of cyclic irrigation on leachate NO3-N concentration, container leachate volume, total effluent volume, and growth of Ilex crenata Thunb. `Compacta'. In Expt. 1, container leachate volume was reduced 34% when 13 mm of water was applied in three cycles compared to continuous irrigation of 13 mm per unit time. Forty-nine percent less container leachate volume was collected from a continuous application of 8 mm than from that of 13 mm water. In Expt. 2, container leachate volume was reduced 71% when 6 mm was applied in a single application over 30 minutes compared to 13 mm applied continuously for 1 hour. Total effluent was reduced by 14% and 10% in Expts. 1 and 2, respectively, when 13-mm irrigation was applied in three cycles compared to one continuous irrigation. Container leachate NO3-N concentrations from cyclic irrigation were generally less than leachate NO3-N concentrations from continuous irrigation treatments. The percentage of applied N leached as NO3-N ranged from 46% when 13-mm irrigation was applied in three cycles to 63% when 13-mm irrigation was applied in a single cycle. Leachate NO3-N concentration was reduced as irrigation volume was reduced from 13 to 6 mm in Expt. 2. Percentage of applied N leached as NO3-N was 63%, 56%, and 47% when 13-mm irrigation was applied in one, two, and three cycles, respectively, compared to 19%, 16%, and 15% when 6-mm irrigation was applied in one, two, and three cycles, respectively. `Compacta' holly shoot and root growth were minimally affected by cyclic irrigation or irrigation volume.
Postharvest Quality of `Valencia' Orange after Exposure to Hot, Moist, Forced Air for Fruit Fly Disinfestation
Authors: Shellie Krista C. , Mangan Robert L.
Published: February 2019

`Valencia' oranges [Citrus sinensis (L.) Osbeck] were exposed to moist, forced air (MFA) at 46, 47, or 50C for 1, 2, 3, or 4 hours to identify the maximum temperature and duration of exposure for which there was no detectable reduction in fruit quality. The flavor of oranges exposed to MFA at 47 or 50C was rated significantly inferior to that of oranges exposed to 46C. The degree minutes that accumulated in the center of the fruit between 2 and 4 hours and the maximum fruit center temperature during the heat treatment were associated with inferior fruit flavor. Oranges exposed to MFA at 46C for up to 4 hours could not be distinguished from the nonheated fruit. MFA at 46C is a promising quarantine treatment for `Valencia' oranges.
Supplemental Carbon Dioxide and Light Improved Tomato and Pepper Seedling Growth and Yield
Authors: Fierro Alejandro , Gosselin André , Tremblay Nicolas
Published: February 2019

The experiment was conducted to determine the effects of CO, enrichment (900 μl·liter-1, 8 hours/day) in combination with supplementary lighting of 100 μmol·s-1·m-2(16-h photoperiod) on tomato (Lycopersicon esculentum Mill.) and sweet pepper (Capsicum annuum L.) seedling growth in the greenhouse and subsequent yield in the field. Enrichment with CO2 and supplementary lighting for ≈ 3 weeks before transplanting increased accumulation of dry matter in shoots by ≈ 50% compared with the control, while root dry weight increased 49% for tomato and 6270 for pepper. Early yields increased by =1570 and 11% for tomato and pepper, respectively.
Kernel Protein Concentration in sugary-1 and shrunken-2 Sweet Corn
Authors: Goldman I.L. , Tracy W.F.
Published: February 2019

Changes in endosperm type used for commercial sweet corn (Zea mays L.) production may affect corn protein levels. The two most widely used endosperm types are sugary-1 (su1) and shrunken-2 (sh2). To determine the effects of endosperm type on protein concentration, we calculated kernel N concentrations of dry mature kernels of seven inbreds near-isogenic for su1 and sh2 and of four samples of commercially canned su1 and sh2 sweet corn. Nitrogen values were converted to protein values using a standard conversion factor for maize. For the dry kernels and the canned samples, significant differences were detected between endosperm types for kernel protein concentration when measured on a weight basis. Averaged overall inbreds, the sh2 dry kernels had 30% more protein than su1 kernels. On a weight basis, the sh2 canned samples averaged 22% more protein than the su1 samples. When compared on a kernel basis, protein concentration of the two endosperm types did not differ. Thus, sh2 sweet corn marketed as a frozen or canned product may be identified as a higher protein product when the serving size is based on weight or calories.
FLESH COLOR AS A PEACH MATURITY INDEX
Authors: Boswell Walter , Bible Bernard , Singha Suman
Published: February 2019

Flesh color has been proposed as a maturity index for peaches. The objective of the present study was to determine the effectiveness of this parameter in `Loring', `Jersey Dawn', `Madison', and `Raritan Rose' peach (Prunus persica L. Batsch). Fruit were picked at weekly intervals at three or four harvest dates, with five fruit per cultivar being picked from each of three trees. Flesh firmness and soluble solids were measured immediately following harvest, and CIELAB coordinates (L*a*b*) of blush and flesh color were determined with a Minolta CR-200b calorimeter. There was a highly significant correlation (P < 0.001) between firmness and flesh hue angle for all four cultivars and with flesh chroma especially for the white-fleshed `Raritan Rose'. The correlation values between firmness and blush hue angle were consistently lower. Soluble solids did not consistently correlate with flesh or blush color. Even though blush color influences consumer preference, it was not as good an indicator of maturity as flesh color for the cultivars that we tested.
COLD HARDINESS OF CORNUS ALBA `ARGENTEO-MARGINATA' AND WEIGELA FLORIDA `RUMBA' UNDER DIFFERENT FALL FERTILIZER TREATMENTS
Authors: Duchesne Isabelle , Rioux Jacques-André , Beaudry Michèle
Published: February 2019

Effects of fall fertilization programs on cold hardiness of young Cornus alba `Argenteo-marginata' and Weigela florida `Rumba' plants were examined. At the end of Summer 1992, four fertilization programs were applied to 1-year-old woody plants that were propagated in 1991 by cuttings. Fertilization treatments were as follows: 1) discontinuation of liquid fertilizer treatments on 30 Aug., 2) decreasing N concentration (100 to 0 mg·liter-1 of 20N–20P–20K) from 15 Aug. to 30 Sept., 3) constant N concentration (100 mg·liter-1 of 20N–20P–20K) from 15 Aug. to 30 Sept., and 4) high K concentration (110 mg·liter-1 of 7N–11P–27K) from 15 Aug. to 30 Sept. Whole plants were then removed from pots and roots were cleaned. Plants were then placed under freezing temperatures from 0 to –20C at 2C intervals, with plant samplings done three times during fall—at the end of September, October, and November. After the freezing test, plants were stored at –2C and repotted in May 1993 for winter injury evaluation. Preliminary results indicated that the four fertilization programs did not induce a significant effect on cold hardiness of the two species. However, it was clear that the degree of cold hardiness was different for each species: Weigela was ≈10 degrees less hardy compared to Cornus in September and October. In November, species demonstrated hardiness at temperatures less than –20C. Cornus also showed cold hardiness at less than –20C in October.
BREADFRUIT SHELF-LIFE EXTENSION BY CACL2 TREATMENT
Authors: Bernardin Jeanne , Willemot Claude , Sankat Clement K.
Published: February 2019

The effect of Ca on breadfruit (Artocarpus altilis) postharvest storage was investigated. Mature-green breadfruits were hand-harvested in Blanchisseuse, Trinidad, dipped in 0%, 2%, 5%, and 10% CaCl2-2H2O solutions for 0.5, 1.0, 3.0, 6.0, and 12.0 hours, and stored at 16C for 9 days. Calcium content was shown to increase in both peel and pulp with increasing concentration and length of treatment. The 5% and 10% Ca treatment had a detrimental effect on color and texture as determined by sensory evaluation. The 2% treatment delayed fruit softening, particularly for 3-, 6-, and 12-hour dips. At the end of storage, total soluble solids content was affected little by the treatments, while pectin solubilization was delayed. Breadfruit shelf life was extended from 4 to 9 days with 2% treatments. Peel browning remains the limiting factor for storage.
SELECTING PREDATORS FOR BIOLOGICAL CONTROL OF TOMATO RUSSET MITE
Authors: Brodeur Jacques , Bouaicha M'hammed , Bouchard André
Published: February 2019

In recent years, the tomato russet mite (TRM) [Aculops lycopersici (Acarina: Eriophyidae)] has become one of the more important pests of greenhouse tomatoes in northeastern North America. As a first step toward developing a biological control strategy for the TRM, our objective has been to test the potential of already commercialized mite predators. In laboratory experiments, voracity of Chrysopa carnea (Neuroptera: Chrysopidae), Phytoseiulus persimilis (Acarina: Phytoseiidae), and Amblyseius cucumeris (Acarina: Phytoseiidae) was determined for egg, immature, and adult stages of the TRM. The first two predator species did not prey on TRM, whereas A. cucumeris fed on each of the life stages of the eriophyid mite. Further experiments showed that A. cucumeris was able to develop and reproduce when feeding on TRM. Implication of these results for controlling TRM in greenhouses is discussed with respect to predator specificity and prey suitability.
Somatic Embryogenesis and Plant Regeneration in Cucumber
Authors: Lou H. , Kako S.
Published: February 2019

The embryogenic capacity of seven cucumber (Cucumis sativus L.) cultivars was examined by tissue culture of cotyledon, young first-leaf, and internode explants. Somatic embryogenesis frequencies differed significantly among the tested cultivars, and `Fushinarimidori' produced the highest number of embryos from either cotyledons or young first leaves. Cotyledon- and first-leaf-derived calluses produced more embryos than calluses from internodes. Somatic embryos were induced from `Aonaga F1' internodes. With relatively high sucrose levels (6% and 9%) in the initiation medium, the frequency of embryogenic callus formation from `Fushinarimidori' cotyledon explants was >90%. The highest yield of somatic embryos occurred in cultures initiated with high sucrose levels (9% or 12%), although 12% sucrose inhibited callus formation and growth. Somatic embryos germinated in a basal liquid medium supplemented with 0.5% activated charcoal, and they developed into well-shaped, healthy plantlets on semisolid medium with 1% sucrose.
Changes in Amylose and Total Starch Content in `Fuji' Apples during Maturation
Authors: Fan X. , Mattheis J.P. , Patterson M.E. , Fellman J.K.
Published: February 2019

Total starch and amylose (AM) concentration and a starch index (SI) were determined in `Fuji' apple (Malus domestica Borkh.) fruit from weekly harvests in 1990 and 1991. As apples matured, SI scores increased and total starch and amylose content decreased. The percentage of AM in the total starch decreased as the apples matured. Because KI solutions interact efficiently only with AM, the SI is less reliable in representing total starch during later stages of `Fuji' apple maturation.
A Novel Method for Rapid Micropropagation of Pineapple
Authors: Kiss E. , Kiss J. , Gyulai G. , Heszky L.E.
Published: February 2019

A novel micropropagation method for pineapple (Ananas comosus L.), based on shoot elongation induced in vitro, was demonstrated for two cultivars. Decapitated in vitro plantlets were used as explants. Shoot etiolation was induced by placing explants in a Murashige and Skoog (MS) medium containing NAA (10 μm) and incubating in darkness at 28C for 30 to 40 days. The mean number of the regenerated etiolated shoots per explant was 2.6 ± 0.29. The etiolated shoots were placed into N6 medium supplemented with kinetin or BA (25 or 20 μm, respectively). After 4 to 6 weeks, shoots regenerated along the nodes. The highest regeneration rate was 15 and 13 plantlets per node with 25 μm kinetin and 20 mm BA, respectively. Regenerated plantlets were rooted on a growth-regulator-free MS medium. Residual shoots of the initial explants could be recycled by rooting on a growth-regulator-free MS medium. This procedure enables the regeneration of several thousand plantlets per year. Chemical names used: naphthaleneacetic acid (NAA); benzyladenine (BA).
ROLE OF CALCIUM IN REDUCING POSTHARVEST CELL WALL DEGRADATION IN `GOLDEN DELICIOUS' APPLE FRUIT
Authors: Roy S. , Conway W.S. , Watada A.E. , Gillen G. , Wergin W.P.
Published: February 2019

Calcium is an important constituent of the cell wall and plays roles in maintaining firmness of fruit and reducing postharvest decay. The modification of the cell wall is believed to be influenced by calcium that interacts with acidic pectic polymers to form cross-bridges. Infiltrating apples with CaCl2 has been suggested as an effective postharvest treatment for increasing the calcium content. Three different methodologies were used to analyze the effects of calcium on the cell walls: 1) nickel staining of polygalacturonate on free-hand sections, 2) cationic gold labeling of anionic binding sites in the cell walls, and 3) analytical detection of calcium ions (40Ca, 44Ca) using a secondary ion mass spectrometry. The combination of these methods allowed us to directly visualize the cellular features associated with the infiltration of calcium. Treatment resulted in significant enrichment in the cell wall of the pericarp, transformed the acidic pectins in calcium pectates, and resulted in new calcium cross-bridges. Evidence now suggests that exogenously applied calcium affects the cell wall by enhancing its strength and reinforcing adhesion between neighbor cells; therefore, calcium infiltration delays fruit degradation.
Establishment, Growth, and Foliar Nutrient Content of Plum Trees on Various Rootstocks
Authors: Boyhan G.E. , Norton J.D. , Pitts J.A.
Published: February 2019

The dwarfing characteristics of St. Julien and Pixy rootstocks, measured by shoot growth, were evident with `AU-Amber' and `AU-Producer' plum (Prunus salicina Lindl.) scions. Dwarfing did not occur with `AU-Rubrum'. Trunk cross-sectional area (TCA) was reduced with `AU-Amber', `AU-Producer', and `AU-Rubrum' scions on St. Julien and Pixy rootstocks. After 3 years, tree survival was 94% for Lovell; 89%, Halford; 57%, Nemaguard; 75%, Nemared; 83%, St. Julien; and 47%, Pixy. Tree survivability was significantly lower on Nemaguard and Pixy rootstocks than on Lovell and Halford. Multiple regression of total shoot growth, TCA, and survivability against foliar nutrient content resulted in the following significant equations: 0.460Mg - 0.210Mn, 0.236B - 0.487Mn, and 0.359N + 0.398Ca - 0.267P - 0.360Fe for each, respectively. Growth, survivability, and foliar nutrient content are significantly affected by rootstock in plum production.
Ground Covers Affect Raspberry Yield, Photosynthesis, and Nitrogen Nutrition of Primocanes
Authors: Bowen Pat , Freyman Stan
Published: February 2019

Raspberries (Rubus idaeus L.) were grown for 5 years with three floor management treatments: clean cultivation (CC) and ground covers of white clover (Trifolium repens L.) (WC) and perennial ryegrass (Lolium perenne L.) (PR). Primocane growth was strongest with WC and weakest with PR. Fruit production did not differ between WC and CC treatments and was higher than with PR. On 22 Aug. and 10 Sept. in the last year, primocanes grown with WC were taller, had more nodes and a higher dry weight, contained more N, and had retained more leaves than those grown with PR. Net CO2 assimilation per unit leaf area was higher with WC than with PR, and the difference was greater at the more proximal position. The estimated net CO2 assimilation rate per primocane was more than twice as high with WC than with PR.
Shoot and Root Responses of Eight Subtropical Species Grown in Cupric Hydroxide-treated Containers
Authors: Svenson Sven E. , Johnston Diane L. , Coy Bonnie L.
Published: February 2019

The effect of Cu(OH)2 applied to interior container surfaces on shoot and root responses was evaluated on eight species cultivated in subtropical regions. Species studied were Cedrela odorata L.; Eriobotrya japonica (Thunb.) Lindl.; Leea coccinea Planch.; Peperomia serpens (Swartz.) Loud.; Peperomia obtusifolia (L.) A. Dietr.; Radermachera sinica (Hance) Hensl.; Schefflera actinophylla (Endl.) Harms; and Swietenia mahagoni (L.) Jacq. No foliar Cu toxicity symptoms developed on any species during the study. Swietenia mahagoni seedlings grew faster in height and had larger shoot: root ratios when grown in Cu(OH)2-treated containers than in nontreated containers. Leea coccinea seedlings were taller and produced more shoot dry weight when grown in Cu(OH)2-treated than in control containers. Applying Cu(OH)2 did not influence shoot growth of the other six species studied. Root coverage reduction on the exterior of the rootball in Cu(OH)2-treated containers was excellent for all species studied, and coverage was completely eliminated in three species. Shoot and root responses to Cu(OH)2-treated containers varied among subtropical species, which is consistent with shoot and root responses among temperate species.
Correcting Loss of the Terminal Bud in Fraser Fir Christmas Trees
Authors: Hinesley L. Eric , Snelling Layne K.
Published: February 2019

Various pruning treatments were evaluated to determine the best procedure to correct terminal bud loss in Fraser fir [Abies fraseri (Pursh) Poir.]. Removing the top node (expanding terminal and subterminal buds) soon after budbreak combined with light pruning of the major branches in the next two lower whorls best restored a normal leader. This procedure allowed one or more shoots just below the cut to become orthotropic leaders in the first growing season. All but one of these shoots were removed, and only a single leader was retained after growth matured in late August or September.
Comparison of Four Methods for Estimating Total Light Interception by Apple Trees of Varying Forms
Authors: Wünsche Jens N. , Lakso Alan N. , Robinson Terence L.
Published: February 2019

Four methods of estimating daily light interception (fisheye photography with image analysis, multiple-light sensors, ceptometer, and point grid) were compared using various apple (Malus domestica Borkh.) tree forms: slender spindle, Y- and T-trellises, and vertical palmette. Interactions of tree form, time of day, and atmospheric conditions with light interception estimates were examined. All methods were highly correlated to each other (r2 > 0.92) for estimated daily mean percent total light interception by the various tree forms, except that the point grid method values were slightly lower. Interactions were found among tree form, time of day, and diffuse/direct radiation balance on estimated light interception, suggesting that several readings over the day are needed under clear skies, especially in upright canopies. The similar results obtained by using the point grid method (counting shaded/exposed points on a grid under the canopy) on clear days may allow rapid, simple, and inexpensive estimates of orchard light interception.
PEROXIDASE ACTIVITY DIFFERS IN SWEET CORN GENOTYPES
Authors: Collins J.K. , Biles C. , Wann E.V. , Perkins-Veazie P.
Published: February 2019

Increased peroxidase activity is used to predict development of off-flavor in frozen sweet corn. However, peroxidase activity was not indicative of flavor changes in frozen supersweet (sh2) or sugar enhanced (sul/se) sweet corn genotypes. These results suggested an inactivation or absence of certain peroxidase isozymes. Frozen `Florida Staysweet' (sh2), `Merit' (sul), and `Bodacious' (sul/se) kernels were cut from cobs after 0 and 12 months of storage. Proteins extracted from acetone powders were separated by isoelectric focusing (IEF) and Native-PAGE. Banding patterns differed according to cultivar and storage duration. All cultivars contained a peroxidase isozyme having a molecular weight of 99 kD and pI of 4.5. The sul/se and su2 cultivars expressed an additional peroxidase band of 17.9 kD. An additional peroxidase isozyme (pI 5.0) appeared after 12 months of storage in the sul cultivar. This isozyme did not appear in sul/se or sh2 and is a possible marker for predicting off-flavor in corn. This isozyme may also catalyze off-flavor reactions in sul corn genotypes. Although changes in total peroxidase activity may not predict flavor loss in all genotypes, certain peroxidase isozymes may be useful in predicting and catalyzing off-flavor reactions in sul corn cultivars.
LOW-TEMPERATURE STORAGE OF MICROPROPAGATED PLANTLETS UNDER SELECTED LMHT SPECTRA
Authors: Kubota Chieri , Rajapakse Nihal C. , Young Roy E.
Published: February 2019

`Green Duke' broccoli plantlets, which were ready for transplanting after 2 weeks of photoautotrophic (sugar free) culture under the conditions of 1100 μmol·mol–l CO2 (outside the vessel), 22 + 4C air temperature, and 140 μmol·m–2·s–1 photosynthetic photon flux (PPF), were stored for 6 weeks at 5C in darkness or in white, red, or blue light at 2 μmol·m–2·s–l PPF (light compensation point at 5C). Photoperiod was set at 24 hour/day during storage. Spectral quality significantly affected plantlet quality: stem length was longer and chlorophyll concentration of leaves was lower in red or in blue light than in white light or in darkness after 6 weeks in storage. Regardless of the spectral quality, light in storage maintained plantlet dry weight at a level comparable to that before storage; dry weight was reduced significantly in dark-stored plantlets. Spectral quality did not significantly affect the photosynthetic and regrowth potential of plantlets. All plantlets stored in light, regardless of light spectra, grew preferably and had similar dry weight and stem length after 9 weeks of transplanting to the greenhouse under natural light.
PHOTOSYNTHETIC RATES AND YIELD COMPONENTS OF EIGHT VEGETABLE AMARANTHUS GENOTYPES
Authors: Whitehead Wayne F. , Singh Bharat P.
Published: February 2019

Over 2 years, eight vegetable amaranth (Amaranthus spp.) genotypes were grown in a yield trial. Data on yield and gas exchange rates were obtained. On 16 July 1993 and 27 June 1994, all genotypes (Hinchoy VL & GL, RRC numbers 389, 701, 843, 1034, 1186, & PI349553) were planted in a randomized complete-block design with four replications. Plants were harvested ≈44 days after planting. Net photosynthesis (Pn), transpiration (E), green yield (GYLD), and leaf fresh weight (LFW) are discussed. Significant variation (P < 0.01) existed across and within years for all treatments. Higher GYLD and LFW were found in 1994, and Pn and E were higher in 1993. Over both years, GYLDs were highest for RRC 843 (10.4 Mg·ha–1) and RRC 1034 (l0.0 Mg·ha–1); RRC 1034 had the highest LFW (64.4 g/plant). The highest E rate (8.9 mmol·m–2·s–1 was in RRC 843 and RRC 1034. Genotype RRC 843 showed highest Pn (27.5 μmol CO2/m2 per second). In general, RRC 843 and RRC 1034 outperformed other genotypes.
SCREENING SWEETPOTATO GERMPLASM FOR SODIUM TOLERANCE IN HYDROPONIC CULTURE
Authors: Pitts M.L. , David P.P. , Riley S.
Published: February 2019

Four sweetpotato breeding lines were tested for their sodium tolerance in sand culture. All plants were grown in the greenhouse in sterilized sand and watered daily with a modified half-Hoagland solution (N: K-1:2:4). Four sodium levels (0, 35, 70, and 105 ppm) were applied to the breeding lines in a split-plot design with four replications. Soil leachate was collected every 2 days and was measured for P, Na concentration, and electrical conductivity. Plants were grown for 60 days. Preliminary results from analysis of soil leachate showed an increase in EC as sodium concentration increased 5 days after treatments were initiated. Potassium and Na concentration varied with each breeding line tested. Storage root fresh and dry weight were significantly affected by Na levels (i.e., lines tested were tolerant ≤70 ppm Na).
SWEETPOTATO WEEVIL RESISTANCE IN U.S. PLANT INTRODUCTIONS
Authors: Thompson Paul G. , Schneider John C. , Graves Boyett
Published: February 2019

One hundred plant introductions (PIs) were evaluated for sweetpotato-weevil resistance in experiment station field trials for 2 years in Beaumont, Miss. Weevil infestation was accomplished by applying adult weevils in year 1 and weevil infested roots in year 2. The percentage of uninjured roots ranged from 38% in `Centennial', the susceptible control, to 93% in PI538288. Severity of root and stem injury were measured in year 2. Stem injury ratings on a scale of 0, for no injury, to 4, for severe injury, ranged from 1.2 in PI564113 to 3.7 in `Beauregard'. Root injury ratings on a scale of 0 to 5 ranged from 0.1 in PI538288 to 4.2 in `Beauregard' (susceptible control). Thirty-five PIs had lower root injury values than `Regal' (resistant control), and the percentage of uninjured roots was higher in 45 PIs than in `Regal'. These results suggest that genes are available in PIs for increased levels of weevil resistance in sweetpotato.
EFFECT OF CANOPY TYPE ON WEED COMPETITION IN SWEETPOTATOES
Authors: La Bonte D.R. , Harrison H.F. , Motsenbocker C.E.
Published: February 2019

The objective of this study was to identify a sweetpotato canopy type ideally suited to suppress weed growth. With this knowledge, breeders could select sweetpotatoes that require less weed control. Diverse canopy types, ranging from upright, short-internode bunch types to long-internode trailing types, were compared in a split-plot design (hand-weeded and weed treatments). We also included lines with deeply lobed leaves (palmate) and more entire-leaf types. Our results show no significant differences between lines for total ground surface area covered after 6 weeks of growth, no differences in weed dry weight at harvest and few differences in canopy dry weight at harvest. Total ground surface area covered correlated positively with total yield, and weed dry weight correlated negatively to total yield. We were unable to identify individual lines that yield better when pressured with weeds compared to the hand-weeded control, but we were able to identify lines that yield poorly when pressured with weeds compared to the hand-weeded control. These results demonstrate the difficulty in categorically identifying a superior canopy.
COMMUNICATING COMPOSTING TO THE PUBLIC.
Authors: Balch Sandra A. , Auld Dick L.
Published: February 2019

As the public becomes more aware of environmental concerns, there has been a renewed interest in composting. Municipalities are promoting composting as a way to save diminishing landfill space. Although there are many successful composting programs, many would-be composters are thwarted by a lack of expertise, information, and follow-up support. Brochures, videos, and slide presentations present visual information, but hands-on instruction and active involvement in on-going programs has increased the likelihood of success. Integrating composting into established programs, such as community gardens, institutional programs, education curriculum, and demonstration sites, has proven an effective method of conveying composting information to the public.
Temperature Influences Flowering of Pakalana (Telosma cordata Merrill) under Long Days
Authors: Criley Richard A.
Published: February 2019

The flowers of pakalana are initiated under long days (LD) at 18C or above. At 21 and 24C, inflorescence initiation occurs after 3 weeks of LD, and the clusters grow to 6 mm in another 2 weeks, but at 18C, about 12 weeks are required to achieve the 6-mm length. This length is critical, as a shorter stage often fails to develop further. From a length of 6 mm, clusters develop to anthesis in 3 to 4 weeks at 24C, 4 to 5 weeks at 21C, and 6 to 7 weeks at 18C. This work is important to the production of pakalana flowers for Hawaii's winter lei flower trade.
Effect of Fruit Maturity on Bitter Rot of Apple
Authors: Shi Y. , Rom C. , Correll J.C.
Published: February 2019

The susceptibility of five apple cultivars to bitter rot was examined by inoculating fruit with multiple isolates of Colletotrichum gloeosporioides and C. acutatum. Fruit were inoculated at three maturity dates in 1994. Fruit maturity was analyzed for firmness, soluble solids, and acidity. `Smoothee' and `Red Rome' were wounded-inoculated by placing 0.1 ml of inoculum (106 conidia/ml) into wounds while `Granny Smith', `Golden Delicious', and `Red Delicious' were inoculated by spraying unwounded fruit with inoculum until runoff. Free moisture was maintained on fruit for 15 h by enclosing fruit in a plastic bag. Bitter rot was quantified by counting lesion number and measuring lesion diameter. In general, more-mature fruit had a higher number and larger lesions than younger fruit. Lesion diameter was highly correlated with increased fruit soluble solids (r = 0.76) and decreased firmness (r = –0.77). The results indicate that fruit susceptibility increases as fruit ages. Differences in susceptibility were observed among apple cultivars and differences in virulence were observed among bitter rot pathogens.
Effect of Spray Additives on Cuticular Transfer of NAA
Authors: Fader Royal G. , Luque Patricia , Bukovac Martin J.
Published: February 2019

Foliar application of plant growth regulators (PGR) is an established horticultural practice. We are using a finite dose system to examine diffusion of 14C-labeled PGRs, primarily napththaleneacetic acid (NAA), from aqueous droplets and deposits through enzymatically isolated plant cuticles (CM) as affected by spray adjuvant chemistry, solution pH, and epicuticular wax. Recent studies have focused on a nonbuffered aqueous medium, which approximates field application conditions. Despite the negligible buffering capacity of the spray solution, there were significant differences in NAA diffusion with solution pH. At pH 3.2, NAA (pKa = 4.2) diffusion was two-fold greater than at pH 5.2. Additives (surfactants, urea, and urea:NH4NO3, 1:1 mixture) in the spray solutions increased the initial rate and absolute amount of NAA diffused. The polyethoxalated octylphenol surfactant (Triton-X) TX-45 (EO 5.5) enhanced rate and quantity of NAA diffusion. This enhancement was observed with CM, but not after removal of the epicuticular waxes, implicating an interaction between surfactant and waxes. Urea, over a four-fold concentration range, increased NAA diffusion 5% to 31% after 144 h. The urea:NH4NO3 mixture increased NAA diffusion to a greater extent at pH 5.2 (+136%) than at pH 3.2 (+8.4%) after 144 h.
Vapor Pressure Deficit (VPD) Effects on the Physiology and Yield of Greenhouse Tomato
Authors: Iraqi Driss , Gagnon Serge , Dubé Sylvain , Gosselin André
Published: February 2019

Tomato production represents >70% of all greenhouse vegetables produced in Quebec, Canada. To obtain high yields and high quality fruit, an adequate control of greenhouse environmental characteristics, including the vapor pressure deficit (VPD), is necessary. Our study examines four VPD treatments (0.5 kPa day and night, 0.8 kPa day and night, 0.8 kPa day 0.5 kPa night, and automatic VPD management according to transpiration) and three photoperiods [12 h, 14 h, and variable-12 h (summer) 16 h (winter)] on growth, yield, and photosynthetic capacity of tomato plants. Greenhouse temperature was maintained at 22C day/18C night. Pure CO2 was injected into the greenhouse to maintain a constant atmospheric concentration of 800 ppm throughout the experiment. Growth, yield, and leaf mineral composition were determined monthly for each treatment during the experiment. The photosynthetic rate of the 5th and 10th leaves also were measured in addition to the content of chlorophyll a and b. Our results indicated an increase in total yield and photosynthetic rate under a VPD of 0.8 kPa during day and night. An increase in leaf mineral concentration also was noted in plants grown under high VPD. Differences in yield and photosynthetic capacity were not found between the three photoperiods studied. However, there was a tendency to have higher yields under longer photoperiods.
Essential Oils of Boronia megastigma—Selection of Improved Genotypes
Authors: Plummer J.A. , Wann J. , Considine J.A. , Spadek Z.
Published: February 2019

Boronia megastigma is cultivated or picked from natural stands in Western Australia for the production of essential oil. Boronia absolute is extracted from the highly perfumed flowers. It is currently valued at between US$4000 and US$7000 per kilogram, and world consumption for perfumery is about 1 tonne. The variation in essential oil composition within and between populations has indicated considerable variation in oil components. Some individuals have high β-ionone and low levels of pinenes. Principle components analysis indicated that the content of β-ionone and dodecyl acetate were tightly linked, as were the monoterpenes, α-pinene, β-pinene, and, to a lesser extent, limonene. Separate linkages between the desirable oil components (β-ionone and dodecyl acetate) and the undesirable components (α-pinene, β-pinene, and limonene) will facilitate selection of plants to be used in oil production.
Preharvest Calcium Sprays Do Not Improve Highbush Blueberry (Vaccinium corymbosum L.) Quality
Authors: Hanson Eric J.
Published: February 2019

Calcium sprays were applied to `Bluecrop' highbush blueberry bushes between petal fall and fruit harvest. In 1992, bushes received five sprays between 18 June and 16 July that totaled 0, 1.0, 1.9 or 3.8 kg Ca/ha. Calcium was applied as CaCl2 at spray concentrations of 0.08% to 0.2% Ca. Treatments in 1993 consisted of a control; 12.1 and 24.2 kg Ca/ha as CaCl2; and 12.1 kg Ca/ha as the commercial product Nutrical. Calcium was applied in seven sprays between 4 June and 16 July using spray concentrations of 0.1% to 0.4% Ca. Berry samples were hand-picked, stored for 3 to 20 days, and evaluated. Treatments had no effect on the percentage of soft or rotten berries, berry firmness, or berry Ca concentrations during either year. Calcium applications increased leaf Ca concentrations. Chemical names used: calcium trihydroxyglutarate (Nutrical).
Mechanical Harvesting of Peaches—Limited Potential
Authors: Glenn D.M. , Peterson D.L. , Miller S.S.
Published: February 2019

This study evaluated the total and marketable yield of three peach cultivars [Prunus persica (L.) Batsch. `Autumnglo', `Harvester', and `Redhaven'] when mechanical pruning and harvesting systems were used and trees were grown under three irrigation regimes. All cultivars were trunk-shaken using an experimental inertial shaker on an over-the-row (OTR) shake–catch harvester. `Autumnglo' also was hand-harvested at all irrigation regimes. Fruit damage was not significantly affected by irrigation. A significant source of fruit damage was pruning debris that remained in the canopy after hedging and became lodged in the fruit-conveying system, resulting in cultivar effects on fruit damage. Total yield of firm-ripe fruit was similar among cultivars in 1987 and 1988. However, `Autumnglo' trees had a higher percentage of marketable fruit than `Redhaven' or `Harvester' in 1987 and 1991. Mechanical harvesting appeared to accelerate the decline of `Autumnglo' as shown by tree deaths and greater symptom expression of Prunus necrotic ringspot virus. The potential for a single mechanical harvest of peaches is limited because of the difficulty in managing the ripening window, the high potential for fruit damage, and the possibility of accelerated tree decline for disease-susceptible cultivars.
Yield of Indeterminate, Small-vine Cowpea Cultivars Unaffected by Uniformity of Within-row Spacing
Authors: Kahn Brian A. , Stoffella Peter J. , Leskovar Daniel I. , Cooksey James R.
Published: February 2019

Cowpea [Vigna unguiculata (L.) Walp.] planters can produce variable within-row seed spacing. We determined whether precision planting of cowpea would produce a yield advantage over more random planting at the same rate. Studies were conducted from May 1992 to Feb. 1993 at three locations: Uvalde, Texas; Bixby, Okla.; and Fort Pierce, Fla. Seeds of the indeterminate, small-vine cowpea cultivars Mississippi Silver and Pinkeye Purplehull BVR were hand-planted at 42 per 3.15 m of row. Seeds within rows were either spaced uniformly at 7.5 cm [control, with sd = 0] or in one of two random sequences (sd = 4.8). At harvest, in Oklahoma and Florida, mean within-row spacings were similar, but sd values of random-sequence plots remained greater than those of control plots. Control plots averaged four more plants at harvest than random-sequence plots in Texas. However, seed yield (seed dry weight per hectare) and harvest index were unaffected by uniformity of within-row spacing at all three locations. Thus, precision seeding of indeterminate, small-vine cowpea cultivars seems unlikely to produce a yield advantage over more random planting at the same rate.
Soil Bedding Treatments Improve Pepper Plant Anchorage
Authors: McCullough Michael D. , Motes James E. , Kahn Brian A.
Published: February 2019

Two problems associated with machine harvesting of peppers (Capsicum annuum L.) are plant lodging during growth and uprooting. Factorial combinations of four bedding treatments and two N rates were compared for effects on lodging, uprooting, and fruit yield of chile and paprika-type peppers in Fort Cobb and Bixby, Okla. Bedding treatments were 1) no bed (T1); 2) no bed with 5 cm of soil hilled to the plant bases (T2); 3) bedded preplant, but bed not sustained (i.e., allowed to erode) during the growing season (T3); and 4) bedded preplant and bed sustained during the growing season (T4). All plots received preplant N at 45 kg·ha–1. In 1992, one-half of the plots were sidedressed with 45 kg N/ha. In 1993, one-half of the plots were sidedressed with N at 45 and 90 kg·ha–1 for paprika and chile, respectively. The higher N rates consistently produced larger and higher-yielding chile plants and generally increased yield and stem and leaf weights of paprika plants. The force required to uproot plants was not significantly affected by N rates. Plant lodging was significantly worse at the higher N rates in only one of five studies. Bedding treatments did not have a consistent influence on fruit yield. The force required to uproot plants was greater with T2 and 4 compared to T1 and 3 in three of four studies. Plant lodging was not influenced by the bedding treatments.