bluuebunny/crossref_metadata_2025 huggingface dataset:
COLD HARDENING VS ABA AS A PRETREATMENT FOR MERISTEM CRYOPRESERVATION
Authors: Reed Barbara M.
Published: February 2019

Cold hardening is an effective method for conditioning meristems for cryopreservation. ABA plays a role in hardening and produces increased hardiness in suspension cultured cells. This study was designed to determine if growth, in vitro, on ABA (5×10-5 M) for one week, would substitute for one week of cold hardening, and if ABA would provide additional conditioning when added in combination with cold hardening treatments. In vitro plantlets of Rubus spp. were grown for one week with or without cold hardening and with or without ABA. Meristems from these plants were frozen at 0.8C* min-1 to -35 C, then plunged into LN2, thawed, and plated on recovery medium. One month after thawing, cold-hardened plants with and without ABA treatment had recovery rates of up to 83%. Survival of plants grown at room temperature ranged from zero to 8% and zero to 28% for plants grown on ABA at room temperature. At the rates tested, ABA is less effective than cold hardening in conditioning apical meristems of in vitro Rubus plants for cryopreservation and provides no additional protection to cold-hardened meristems.
INFLUENCE OF PRODUCTION NITROGEN LEVEL AND BENZYLADENINE ON POSTHARVEST CHARACTERISTICS OF Rosa × hybrida `Meijikatar'
Authors: Clark David G. , Kelly John W.
Published: February 2019

Rosa × hybrida `Meijikatar' plants were fertilized on weekdays with Hoagland's solution at 100, 200, or 300 mg·liter-1 nitrogen. Prior to simulated shipping, plants were treated with benzyladenine at 0, 25, 50, or 100 mg a.i.·liter-1. Plants were subsequently paper sleeved and stored in cardboard boxes in darkness at 16 C for 5 days.

On the day of harvest, plant height and number of flowers per plant were not affected by production nitrogen level. After removal from simulated shipping, total chlorophyll was increased in the lower leaves of plants grown at higher nitrogen rates and treated with higher rates of benzyladenine. Three and five days after removal from simulated shipping, the least percent leaf chlorosis was observed on plants treated with higher rates of cytokinin, but there was no effect of production nitrogen regime.
GERMINATION OF THREE WILDFLOWER SPECIES AFTER SEED PRIMING
Authors: McClure G. B. , Sundstrom F. J. , Robbins N. S.
Published: February 2019

Wildflower species are being used for highway median vegetation, land restoration programs, and revegetation of industrial sites. Rapid, uniform germination is critical to establishment of new stands Seed priming techniques may increase the potential for successful establishment under adverse environmental conditions. The influence of seed priming of Gaillardia puchella, Monarda citriodora, and Coreopsis tinctoria on germination at 10° and 25° C was investigated. Seeds of the three species were placed in five levels of oxygenated KNO3 (3.5, 3.25, 3.0, 2.75, and 2.5%) solutions, or a control of oxygenated distilled water for 144 hr. Germination percentage and rate of germination (MRG) were improved for Gaillardia and Coreopsis at 10° and 25°C. Germination percentage and MRG for Monarda were not effected by priming at 25°C, but both were significantly improved at 10°C, The optimum concentration of KNO3 for greatest rapid germination was dependent on the seed variety, These results suggest that in most cases wildflower germination percentage and rates ware improved by the priming procedure.
CHARACTERIZATION OF ICE FORMATION IN BLUEBERRY FLOWER BUDS
Authors: Flinn Cindy L. , Ashworth Edward N.
Published: February 2019

Examination of both frozen specimens and -5C freeze-fixed buds showed that ice crystals were not uniformly distributed in blueberry flower buds. Localized freezing was also evidenced by detection of multiple freezing events using differential thermal analysis (DTA). Upon cooling, an initial exotherm occurred just below 0C and coincided with ice formation in adjacent woody tissue. Multiple low temperature exotherms (LTE), which have been reported to correspond with the freezing of individual blueberry florets (Bierman, et al. 1979. ASHS, 104(4):444-449), occurred between -7C and -28C. The presence and temperature of LTEs was influenced by cooling rates and whether buds were excised. LTE temperatures did not correlate with hardiness of buds frozen under field-like conditions. Results suggested that DTA of excised buds was not an appropriate method for determining hardiness.
CHRYSANTHEMUM RESPONSE TO TIMING OF PACLOBUTRAZOL AND UNICONAZOLE SPRAY APPLICATION
Authors: Gilbertz David A.
Published: February 2019

Spray applications of uniconazole (UC) or paclobutrazol (PB) were applied 0, 2, or 4 weeks after pinching Dendranthema grandiflora (Tzvelev). `Bright Golden Anne' cuttings planted 4 per 15 cm pot. Cuttings were controlled to 3 shoots each, averaging 5.4 and 14.9 cm at 2 and 4 weeks, respectively.

Final height was affected interactively by week of application and chemical treatment. Treatment at pinch caused less stem elongation than later treatments, probably due to persistence of PB and UC activity until flowering. At week 4, 67% of stem elongation had already occurred and, therefore, less retardation was possible. Of the 4 triazole treatments, PB at 30 mg 1-1 (20 ml per pot) applied at pinch produced heights similar to daminozide 5000 mg 1-1 applied at 2 weeks. PB at 60 mg 1-1 gave similar height control as UC 15 mg 1-1. UC 30 mg 1-1 treated plants were shortest regardless of treatment timing, averaging 16.9 cm applied week 2.

Other growth data was pooled for week of application and for chemical treatment since there was no interaction. Flowering was delayd 2 days and flower dry weight was reduced up to 26% by treatment at pinch compared to later treatments. Flower diameter was only minimally affected by treatments.
FACTORS INDUCING DESICCATION TOLERANCE IN CELERY SOMATIC EMBRYOS
Authors: Saranga Yehoshua , Rhodes David , Janick Jules
Published: February 2019

Desiccation tolerance of somatic embryos is a key factor for production of dry synthetic seeds. In celery (Apium graveolens L.) desiccation tolerance can be enhanced by optimization of culture duration, ABA application, or sucrose concentration in the embryo production medium. Morphologically mature embryos cultured for 10 days have shown higher desiccation tolerance then those cultured for 8 days, indicating that biochemical changes occur without any noticeable morphological changes. Application of ABA (1 μM) for the last two days of the embryo production cycle was critical for inducing desiccation tolerance; ABA application for the last four days had some additional beneficial effect. Desiccation tolerance was further enhanced by increasing the sucrose concentration of the embryo production media from 3% to 7% for the last two days. Increased desiccation tolerance achieved with optimal harvest timing and ABA application were associated with increased endogenous proline and aminobutyrate, and reduced glutamine.
CHILLING OF PEACH SEEDS, SEEDLINGS AND CUTTINGS
Authors: Frisby James W. , Seeley Schuyler D.
Published: February 2019

Correlations were made between the responses of seeds, physiologically dwarfed seedlings and dormant cuttings to similar chilling treatments. Seed germination correlated highly with growth of physiologically dwarfed seedlings and shoot growth of dormant cuttings. Emergence and seedling growth correlated poorly with germination, growth of physiologically dwarfed seedlings and shoot growth of dormant cuttings. Thus, germination was a better seed predictor of the mature peach chilling response than emergence or seedling growth. Growth of dwarfed seedlings correlated highly with shoot growth of dormant cuttings. The anomalous leaf condition of peach seedlings may have confounded seedling growth after seed chilling, but was not a problem when the chilling treatment was provided to physiologically dwarfed seedlings. The dormancy release mechanisms that promoted seed germination, growth of physiologically dwarfed seedlings and growth of dormant cuttings were similar.
WHOLE PLANT MECHANISMS OF AMMONIUM INDUCED INCREASES IN WATER STRESS AND SENSITIVITY OF MUSKMELON TO NaCl
Authors: Adler Paul R. , Wilcox Gerald E.
Published: February 2019

Two mechanisms that reduce water and salt stress, respectively, are an increase in root hydraulic conductivity (LP) and reduction in Na and Cl absorption and transport to the leaf. NH4+-N decreased muskmelon LP 55-70% while under 100 mM NaCl stress and 40-50% in the absence of NaCl stress. A decrease in LP increases the rate of water stress development as the transpiration rate increases. Although dry weight decreased about 70%, with NO-3-N, muskmelon remained healthy green, while with NH+4-N they became chlorotic and necrotic with a 100% and 25% increase in leaf blade Na and Cl compared to NO-3-N, respectively. Further investigation indicated that NH+4-N increased muskmelon sensitivity to NaCl through both an increased rate of net Na influx and transport of Na to the leaf. Since Na influx partitioning is controlled by mechanisms K/Na selectivity and exchange across membranes, the NH+4-N inhibition of K absorption may impair K/Na exchange mechanisms. Reduced K/Na selectivity or Na efflux are implicated as the source of the increased net Na influx with NH+4-N. The importance of K in preventing Na partitioning to the leaf was confined through removal of K from the nutrient solution thereby simulating the NH+4-N-induced gradual K depletion in muskmelon. Our work indicates that at a given level of water or NaCl stress, NO-3-N reduces the level of stress experienced by muskmelon through increasing LP and reducing the net rate of Na influx and transport to the sensitive leaf blade. This avoidance mechanism should enable muskmelon plants fertilized with NO-3-N to tolerate greater levels of stress.
IMPROVED HIGH TEMPERATURE SEED GERMINATION OF PANSY WITH SEED PRIMING
Authors: Cushman K. E. , Pemberton H. B. , Cobb B. G. , Roberson W. E.
Published: February 2019

Viola tricolor seed were exposed to aerated solutions of water or 300 or 400 mM NaCl for 0, 2, 4, 6, or 8 days. After priming treatments, seed were air dried, placed on moist filter paper in petri dishes, and set in dark growth chambers at 18 or 30°C for germination. priming for 6 days in water increased germination of `Crystal Bowl Yellow' seed from 80 to 88% when germinated at 30 °. Untreated seed germination was 92% at 18°. Priming for 6 days in 300 mM NaCl improved germination of `Majestic Giant Blue' seed from 57 to 76% when germinated at 30°. Untreated seed germination was 80% at 18°. These data indicate that seed priming could be used to improve summer germination of a cool season annual. Priming increased germination at the higher than optimum temperature (30°) to levels similar to that for the optimum temperature (18°). However, the best priming solution depended on the cultivar.
FLOWER DEVELOPMENT OF MINIATURE POTTED ROSE PLANTS DURING SIMULATED SHIPPING
Authors: Cushman L. C. , Pemberton H. B. , Kelly J. W.
Published: February 2019

Orange end Red Sunblaze miniature rose plants were forced. to flower in a glasshouse in 10 cm pots. At harvest, flower stage (FST) 1 (tight bud), 2 (reflexed calyx), and 3 (petals starting to reflex) flowers were designated and tagged. The plants were then stored at 4, 16 or 28°C for 2, 4, or 6 days. Subsequent to the simulated shipping treatments, plants were evaluated in a simulated home interior environment (21° with 30 μmoles M-2 sec-1 cool-white fluorescent light). After summer forcing, flowers of both cultivars developed at least 1 FST during simulated shipping. Flower development increased as storage duration increased for FST 1 and 2, but storage duration did not affect development of FST 3 flowers. The higher the temperature the faster flowers developed, but development was less than 1 FST at 4°. After winter forcing, flowers developed less than 1 FST during simulated shipping. Flower development increased with increasing temperature. In summer, plants with FST 2 flowers could be shipped at up to 16°, but plants with FST 3 flowers should be shipped at 4°. In winter, plants can be shipped at up to 16° with FST 3 flowers.
MICROPROPAGATION OF WHITE EASTERN REDBUD (CERCIS CANADENSIS VAR. ALBA.
Authors: Yusnita S. , Geneve Robert L. , Kester Sharon T.
Published: February 2019

In vitro shoot multiplication of white Eastern redbud was successful using two-node mature explants from the initial spring flush on a woody plant medium (WPM) supplemented with benzylaminopurine (BAP). Optimal shoot proliferation was obtained at 10-15 μM BAP. Treatment with thidiazuron produced fasciated (stunted) adventitious shoots which failed to elongate. Successive subcultures increased the ability of explants to form shoots. However, shoot tip necrosis became a problem after 7-8 subcultures. Shoot tip necrosis is being studied by comparing shoot multiplication on bacto-agar vs. gelrite, increasing the Ca concentration in WPM and by trying to reduce the phenolic exudate by the explants with PVP or activated charcoal. Microshoots >3 cm long were rooted by pulse treatment on half strength WPM containing 300 μM IBA or NAA before being moved to hormone free WPM. There was a different morphology between IBA and NAA induced roots, although the number of roots were comparable. IBA treated microcuttings developed branched, fine roots, whereas NAA treated plants produced unbranched, coarse roots. Rooted microshoots were successfully acclimated to greenhouse condition.
CHANGES IN ENZYMES AND PROTEINS IN SALT-SHOCKED VS. GRADIENT INCREASES IN NACL IN `POINSETT' CUCUMBER ROOTS
Authors: Hurley Anne K. , Cobb B. Greg
Published: February 2019

Cucumis sativus, L., `Poinsett' seedlings were grown under artificial light in 40% modified Hoagland's solution until an average plant plastochron index of 4.73 was reached. Plants were then placed in solutions of (1) 0 mM NaCl, (2) 80 mM NaCl (salt-shock), or (3) placed in a dropwise gradient solution of NaCl and Hoagland's until the final concentration of 80 mM NaCl was reached at 41 hours. Leaves of the 80 mM shock treatment wilted immediately, but recovered turgor within 6 hours. Leaves of 80 mM gradient did not wilt at anytime. The control and gradient treatments had relative growth rates which were similar to each other, but RGR decreased in the shock treatment. Invertase activity was measured in the roots at 24, 41, and 48 hours after initial treatment. Invertase activity of shock treatment increased significantly over the controls at 24 hours. The 80mM gradient was not significantly different than either treatment. Four isozymes of α– galactosidase were detected. The relative intensities of the bands varied with time and treatment. One invertase band was resolved in roots on 8% native acrylamide gels. SDS gels indicated increases in proteins in the gradient treatment compared to the control and the 80 mM shock treatment.
CONTROLLED-RELEASE FERTILIZER REGIMES INFLUENCE PRODUCTION AND POSTPRODUCTION QUALITY OF POTTED CHRYSANTHEMUMS
Authors: Prince T.L. , Tayama H.K. , Prince T.A. , Bhat N.R. , Carver S.A.
Published: February 2019

Controlled-release fertilizers (CRF), Nutricote 14N–6.2P-11.6K or Osmocote 14N-6.2P-11.6K, at the recommended rate (1×) and at half that rate (0.5×) plus 200 mg/l N of Peter's 20N-4.4P-16.6K water soluble fertilizer at every irrigation were applied to potted chrysanthemums cv. `Bright Golden Anne' and `Torch'. Production and postproduction quality was evaluated. CRF applications (1×) resulted in reductions of plant height (-10%), plant diameter (-17%), leaf area (-35%), and leaf dry weight (-47%), but did not affect number of flowers compared to plants receiving only water soluble fertilizer. Application of water soluble fertilizer with CRF (0.5×) increased foliar nutrient levels above water soluble fertilizer application alone, or above either CRF (1×). CRF applications (1×) resulted in improved floral longevity (up to +8 days) and flower color rating (up to +54%), and less foliar senescence (up to -45%) than the water soluble fertilizer application alone, or either of the CRFS (0.5×) used with water soluble fertilizer.
SHORT TERM STORAGE OF PLUG-GROWN BEDDING PLANT SEEDLINGS.
Authors: Kaczperski M. P. , Armitage A. M.
Published: February 2019

The effects of differing storage conditions prior to transplanting were examined for Salvia splendens `Red Hot Sally', Impatiens wallerana `Super Elfin White', Viola × wittrockiana `Universal Beaconsfield' and Petunia × hybrida `Supercascade Lilac'. Plug-grown seedlings were stored for 0, 1, 2 or 3 weeks at 5C or 10C and irradiance levels from incandescent bulbs at 0, 2 or 12 μmol s-1 m-2. A second group of plants were stored at 18C and irradiance from fluorescent bulbs at 105 μmol s-1 m-2 for the same time period. Temperature was more important than irradiance in maintaining plant quality over the storage period. Impatiens and salvia could be stored successfully for a minimum of 2 weeks at 5 or 10C with no appreciable loss of quality, petunia and pansy up to 3 weeks. Seedlings of all species showed diminished quality when stored longer than 1 week at 18C. After storage, petunias stored at 18C flowered sooner than those stored at 5 or 10C. However, these plants were single stemmed, with long internodes and few flowers while those plants stored at 5 or 10C developed multiple branching and a short, compact growth habit at flowering.
EFFECT OF HYDROPHILIC POLYMER AND IRRIGATION REGIME ON GROWTH AND CUTTING PRODUCTION OF GOLDEN TORCH CACTI
Authors: Crosswhite Frank S. , Feldman William R.
Published: February 2019

Golden Torch Cactus (Trichocereus spachianus) from Argentina is a handsome, cold-hardy, columnar cactus with excellent landscape potential. Hydrophilic polymer in combination with 5 watering regimes has been tested to determine the optimal water cost-effective manner to produce these cacti. The hydrophilic polymer is a highly absorbent polyacrylamide compound. The summer water regimes tested were: rainfall only, irrigation twice per week, once per week, twice per month, and monthly. The study was evaluated at 16 and 36 months. Amendment with polyacrylamide resulted in significant depression in total cuttings and total length of cuttings as of 16 months, but this effect had disappeared as of 36 months. There were no significant interactions between the polyacrylamide and irrigation regime variables. Irrigation regime significantly affected performance throughout the course of the study. Weekly irrigation (summer) resulted in the greatest cost benefits in terms of production as a function of water applied. Cultivation under ambient rainfall resulted in 100% survival and modest production, as compared with irrigated plants.
AN APPARENT INCREASE IN SYMPLASTIC WATER CONTRIBUTES TO GREATER TURGOR IN MY CORRHIZAL ROOTS OF DROUGHTED ROSA PLANTS
Authors: Augé Robert , Stodola Ann
Published: February 2019

Using psychrometric pressure-volume analysis, root water relations following drought were characterized in Rosa hybrida L. plants colonized by the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith. Measurements were also made on uncolonized plants of similar size and adequate phosphorus nutrition. Under well-watered conditions mycorrhizal colonization resulted in lower solute concentrations in root symplasm, and hence lower root turgors. Following drought, however, mycorrhizal roots maintained greater turgor across a range of tissue hydration. This effect was apparently not due to increased osmotic adjustment (full turgor osmotic potentials were similar in mycorrhizal and nonmycorrhizal roots after drought) or to altered elasticity but to an increased partitioning of water into the symplast. Symplast osmolality at full turgor was equivalent in mycorrhizal and nonmycorrhizal roots but because of higher symplastic water percentages mycorrhizal roots had greater absolute numbers of osmotic (symplastic) solutes. Drought-induced osmotic potential changes were observed only in mycorrhizal roots, where a 0.4 megapascal decrease (relative to well-watered controls) brought full turgor osmotic potential of mycorrhizae to the same level as nonmycorrhizal roots under either moisture treatment.
PVCURVE: A COMPUTER SPREADSHEET TEMPLATE FOR EVALUATING PRESSURE-VOLUME CURVES
Authors: Augé Robert
Published: February 2019

The determination of tissue water potential components is important for understanding plant growth and response to the environment. Pressure-volume (PV) analysis is often considered to give the most accurate estimate of symplastic osmotic potential. Additional information about tissue water relations can also be computed from PV curves estimates of bulk cell wall elasticity, symplastic water volume, and turgor potential at various states of tissue water content. The generation of PV curves is a time-consuming procedure, however, and involves considerable computation. This presentation describes a computer spreadsheet template for traditional evaluation of a PV curve through linear regression of the zero turgor segment. The template allows real-time plotting of the inverse ψ/ water loss relating, provides estimates of most commonly calculated PV characteristics and permits instant graphic visualizations of changes in water potential components and elasticity with changes in water potential, total tissue water and symplastic water content. The advantages of spreadsheet analysis of PV curves are simplicity, consistency, thoroughness and speed. A fleeting acquaintance with spreadsheet software and a thorough understanding of pressure-volume theory on the part of the user is assumed.
EFFECT OF GREENHOUSE SHADING ON `DOUGLAS' AND `MOTO' STRAWBERRY YIELD DISTRIBUTION IN A SUBTROPICAL CLIMATE
Authors: Rubeiz Ibrahim G. , Khoury Ramzy Y.
Published: February 2019

Strawberry (Fragaria ananassa Duch.) fruiting period lasts several months around the Mediterranean coast. Greenhouses in these locations will enhance earliness, however, from mid spring and on, the greenhouse inside becomes very hot, thus fruiting will be retarded; plants start forming runners, and fruiting stops earlier than in field-grown strawberry. Shading with white cloth for 1 hr (1h) or 2 hr (2h) at sunrise and sunset and unshaded treatments (0h) were studied as they would affect yield distribution and duration of `Douglas' and `Moto' cv. grown on mulched beds inside a polyethylene covered greenhouse. Douglas shading delayed first fruit harvest by 1 or 2 weeks under 1h or 2h, respectively in comparison to 0h. Harvest season ended in late May for all treatments, about 15 weeks long. Total yield was highest under 1h (11 tons/ha) followed by 2h (10.6 t/ha) and 0h (10.1 t/ha}. Moto shading delayed first fruit harvest by 1 or 2 weeks in 1h and 2h, respectively in comparison to 0h. Harvest season ended in early June, about 18 weeks long. Total yield was comparable between 1h and 0h (31.8 t/ha), and the 2h yielded least (31.1 t/ha). In conclusion, shading may enhance slightly late production, but the economic returns are higher for an early season crop, thus shading should not be practiced.
EFFECT OF HARDWOOD BARK MULCH ON THE WINTER SURVIVAL OF EIGHT CULTIVARS OF GARDEN CHRYSANTHEMUMS
Authors: Hayslett William F. , Thangudu P. R. , Shaw Sabrina
Published: February 2019

A field study was conducted at Tennessee State University's research station to evaluate the effect of hardwood bark mulch on the winter survival of garden mums. A randomized complete block design was used. Cultivars used were adorn, encore, grandchild, jackpot, legend, minnautumn, minnwhite and triump. At the end of the flowering season the tops were removed leaving a four inch stubble in the mulch. The number of mum plants that resumed growth the following spring were counted for each cultivar. There was a difference in the winter survival of the different cultivars as well as a significant difference in the mulch treated and the control. Grandchild and jackpot were most cold hardy followed by encore, minnwhite, minnautumn, triump, legend, and adorn. Grandchild and jackpot with four inches of hardwood bark mulch had an 88 percent survival while the control had a 44 percent survival. Adorn. had a 51 percent survival with four inches of mulch and a 20 percent survival in the control. This data shows that hardwood bark mulch holds a great potential for providing excellent winter protection for garden mums.
IDENTIFICATION OF BACTERIA INFECTING MUNG BEAN SEEDLINGS USED IN ROOTING BIOASSAYS
Authors: Tripepi Robert R. , George Mary W.
Published: February 2019

Mung bean (Vigna radiata (L.) R. Wilcz.) cuttings are used in rooting bioassays, and nonexperimental variability must be rigorously controlled to obtain meaningful results. This study was conducted to document bacterial disease problems of mung bean and identify the causal organisms. `Berken' seeds were surfaced sterilized and aerated 24 hr before sowing. Nine-day-old seedlings were used in rooting bioassays. Up to 10% of the seedlings and 17% of the cuttings had collapsed stems or wilted leaves. A white and two yellow (Y1 and Y2) bacteria were isolated from diseased cuttings and used in subsequent pathogenicity tests. The Y2 isolate was nonpathogenic. Stems of healthy mung beans inoculated with the white isolate turned brown and collapsed 2 days after inoculation, whereas leaves of plants inoculated with the yellow isolate wilted after 7 days. Standard biochemical and physiological tests revealed that the white isolate was Pseudomonas syringue pv. syringae van Hall and the yellow isolate was Curtobacterium flaccumfaciens subsp. flaccumfaciens (Hedges) Collins and Jones. This research is the first report of a disease in mung bean caused by P.s. pv. syringae. These results demonstrate the need or disease-free seeds being used in bioassays since both pathogens were seed-borne.
INFLUENCE OF IN VITRO CONDITIONS ON GROWTH OF IMMATURE EMBRYOS OF PEACH (P. persica (L.) Batsch).
Authors: Pinto Alberto C. O. , Byrne David H. , Rogers Suzanne M. D.
Published: February 2019

SH and MS media, sucrose concentrations (6% and 10%) and types of support (0.25% Gelrite, vermiculite and filter paper bridge) were compared in a factorial experiment to determine the effects on growth of immature embryos from peach cultivar B611505. Embryos were measured at the beginning of the experiment (control) and all treatments were kept in the dark at room temperature, for 40 days. Although gelrite, over all media treatments, increased embryos wet weight by 66%, the embryos were soft and succulent and their dry weight increased only 37%. Vermiculite support, on the other hand, increased wet and dry weights by 63% and 79%, respectively. Less embryo growth occurred with MS medium and filter paper bridge. Except for vermiculite and SH medium, 10% sucrose was more effective than 6% in increasing embryo growth.
DORMANCY EVALUATION UNDER THE SUBTROPICAL CONDITIONS OF NORTHERN MEXICO
Authors: del Real-Laborde Jose Ignacio , Anderson J. LaMar
Published: February 2019

Mild. winter conditions vary greatly from year to year, and models to evaluate dormancy development have to separate between years to make accurate predictions for rest breaking purposes. The Utah Chill Unit model has been revised to incorporate time in the definition of chill units. A Chill Unit is redefined as equivalent to one hour at the optimal chilling temperature during the optimal chilling time. Mexico has 50,000 ha of apple trees that require rest breaking practices. Winter conditions of three contrasting years at two Mexican locations were analyzed by the original and revised Utah Chill Unit models. The original Utah model tends to overestimate chill unit accumulation under Mexican mild winter conditions. The revised model increased prediction accuracy of leaf development ten days after full bloom by 10% to within 1-2% of the observed values.
EVALUATION OF DRIS-DERIVED CRITICAL LEVELS IN OREGON CRANBERRIES
Authors: Wilder Kris L. , Righetti Timothy L. , Poole Arthur
Published: February 2019

Cranberry (Vaccinium macrocarpon Ait.) is an important crop in Oregon. However, nutrient critical levels have not been established. Since developing nutrient critical levels usually requires time-consuming and expensive field trials, we chose to use the Diagnosis and Recommendation Integrated System (DRIS), which can use survey data to determine critical levels. We analyzed 139 cranberry samples collected from the southern Oregon coastal area over a three-year period. Leaf concentrations for N, P, K, S, Ca, Mg, Mn, Fe, Cu, B, and Zn in bearing uprights collected in mid-August were matched with the corresponding yields. DRIS was employed to obtain norms and critical levels from this survey data. To test our DRIS norms and critical levels, we evaluated two published experiments (Torio and Eck, 1969 and Medappa and Dana, 1969) where fertility treatments altered mineral concentrations and affected yield. Both ratio-based and critical concentration diagnoses were useful. Changes in the Nutrient Imbalance Index was a good predictor of yield response.
IN VITRO NUTRITION OF ALSTROEMERIA
Authors: Smith Mark A. , Bridgen Mark P.
Published: February 2019

In vitro growth and development of Alstroemeria `Cornell Pink' were evaluated on media containing different amounts of CaCl2, MgS O4, FeSO4, NO3, or NH4. Six levels of calcium chloride were originally examined (from 0 to 75 mM); the low levels proved to be most beneficial. Subsequent experiments used CaCl2 levels from 0 to 3.0 mM. Again, the low levels were most productive. Two experiments, with different gelling agents, were designed for MgSO4. The levels ranged from 0 to 15 mM. The 15 mM level produced explants with the greatest fresh weight. Three experiments were used to study the effect of FeSO4. The range was the same in all of the experiments (0 to 1 mM), but the increments and the gelling agents differed. In all three experiments, the 1 mM level proved to be toxic. The group with treatments from 0.01 to 0.5 mM had the best response over time. Both experiments with nitrogen found no response to different NO3:NH4 ratios. A positive linear response to rate was found within the range studied (20 to 80 mM).
ASEXUAL EMBRYOGENESIS AND PLANT REGENERATION FROM MALE CATKINS OF QUERCUS
Authors: Gingas V.M.
Published: February 2019

Partially expanded male catkins at the pre-pollen shedding stage of Quercus rubra L. and Quercus bicolor Willd. were cultured on MS medium supplemented with BA or 2,4D Explants on 2,4D produced a yellow embryogenic callus, seeming to originate from the pedicels. Subsequent transfers to BA and then, MS without growth regulators, resulted in callus proliferation. After ten weeks in culture, white embryoids developed from the callus of Q. bicolor. Separated and individually cultured embryoids underwent direct, repetitive embryogenesis. Upon transfer to ½-strength MS, embryoid germination and plant regeneration occurred, Callus of Q. rubra degenerated after five months in culture, failing to produce embryogenic structures.
EFFECT OF FOLIAR FERTILIZATION AND SOME GROWTH REGULATORS ON GROWTH OF CROTON PLANTS
Authors: Shedeed Mahmoud R. , El-Gamassy Khairy M. , Hashim Mahmoud E. , Almulla Alaa M.
Published: February 2019

The experiment was designed to investigate the effect of Fulifertil at levels 0,2 and 4 gm/L and growth regulators GA3 at 0,100,200 and 300 ppm also kinetin at 0,25,50 and 75 ppm and their combination on croton plants. The results indicate that there were increases in the plant height, leaves, number, leaf area and fresh and dry weight of vegetative growth. Spraying plants with 4 gm/L Fulifertil or 200 ppm GA3 or 50 ppm kinetin gave the best results specially with combined treatments.
IN VITRO PROPAGATION OF VIRGINIA PINE FROM COTYLEDONS
Authors: Saravitz Carole H. , Blazich Frank A. , Amerson Henry V.
Published: February 2019

Adventitious shoots developed on cotyledons of Virginia pine (Pinus virginiana Mill.) excised from seeds germinated for 3, 6, or 9 days and cultured on media containing 0.5 to 10 mg/liter benzyladenine (BA). Shoot regeneration was greatest (46 shoots per embryo) on cotyledons from seeds germinated for 6 days and placed on medium containing 10 mg/liter BA. Shoots were excised and elongated on medium lacking BA. Following elongation, shoots were placed on media containing 0 to 40 mg/liter indolebutyric acid (IBA) for 14 days followed by transfer to the same medium lacking auxin. Without IBA treatment, percent rooting was 3% and increased to 50% for concentrations of 5 to 40 mg/liter. Rooted shoots averaged 2.0 roots per shoot without auxin treatment, 3.3 roots when treated with 5 mg/liter IBA and root number increased linearly with increased IBA concentration up to 40 mg/liter (4.5 roots). Plant lets were transferred to growing medium and acclimated successfully to greenhouse conditions.
HISTOLOGICAL EXAMINATION OF IN VITRO ADVENTITIOUS BUD DEVELOPMENT ON HYPOCOTYLS OF FRASER FIR
Authors: Saravitz Carole H. , Blazich Frank A. , Amerson Henry V.
Published: February 2019

Hypocotyls of Fraser fir (Abies fraseri (Pursh) Poir.) were excised from seeds germination 9 days and placed on bud induction medium containing 10 mg/liter benzyladenine (BA) and 0.01 mg/liter naphthaleneacetic acid (NAA) or medium without growth regulators. After 3 days on medium containing growth regulators, cell divisions were localized in epidermal and subepidermal layers of the hypocotyl while similar cell divisions were not observed in control-treated hypocotyls. Cell clusters consisting of two to five cells were present after 7 days in hypocotyls placed on bud induction medium. In control-treated hypocotyls, stomata continued to develop and cells within the cortex became vacuolated during the first 2 weeks in culture. All hypocotyls were transferred to secondary medium after 3 weeks. Cell clusters continued to enlarge into meristemoids in hypocotyls initially placed on bud induction medium. Gradually, meristemoids developed into buds and cataphylls were observed covering bud meristems.
EFFECT OF PLANTING DATE AND SOIL APPLICATIONS OF FUNGICIDE AND TRICHODERMA ON FLOWERING AND YIELD OF TWO STANDARD CARNATION CULTIVARS
Authors: Lee Chi Won , Liang Benjamin , Goldsberry Kenneth L. , Baker Ralph R. , Chapman Phillip L.
Published: February 2019

This study was carried out to determine the influences of planting date (June, July) and soil applications of Trichoderma harzianum (strain T-95) and a fungicide containing ethazole + thiophanate (BanrotR) on flower production of standard carnation cvs. Improved White and Tanga. The one-year production data showed that the fungicide treatment increased flower yield by 7.3% (33.5 flowers/m2) and 4.8% (23.3 flowers/m2) in Improved White and Tanga, respectively, for June planting. Improved White produced more flowers and fancy grades when planted in July as compared to June planting. Planting date did not influence either the yield or the flower quality in Tanga. The effectiveness of Trichoderma as a biological control agent on flower yield and quality was not evident. The patterns of weekly flower production for the two cultivars were determined and graphically illustrated.
PETUNIA SEEDLING GROWTH - FLOWERING RESPONSE
Authors: Healy Will , Graper David
Published: February 2019

Petunia `Red Flash' seedlings were grown under HPS (175 μmol m-2 s-1) photoperiod treatments of 10, 12, 14 or 16 hr at 20C soil temperature in a shaded glasshouse where the maximum peak PPF was reduced to 150 μmolm-2s-1. Seedling were transplanted after they had unfolded a specific number of leaves and grown under natural days or placed under photoperiod treatments which consisted of an 8 hr natural day with incandescent day extension treatments of 1 to 6 hours.

A 16 hr HPS treatment decreased the days to transplant (DTT) by more than 4 days and reduced the days from transplant to flower (DTF) by more than 5 days. The total reduction in days from sowing to flower (DSTF) was at least 8 days. When compared to unlighted controls, the reduction in DSTF was 26 days. The longer the seedlings remained under the HPS treatments, the shorter the DTF and DSTF. Premature shifting of plants to natural days resulted in up to a 9 day delay in DSTF. At photoperiods greater than 13 hr, the number of nodes subtending the inflorescence becomes constant regardless of number of leaves at transplant.
PETUNIA SEEDLING GROWTH - HPS PHOTOPERIOD STUDY
Authors: Healy Will , Graper David
Published: February 2019

Petunia `Red Flash' seedling were grown under HPS (175 μmolm-2 s-1) photoperiod treatments of 10, 12, 14 or 16 hr at 20C soil temperature in a shaded glasshouse where the maximum peak PPF was reduced to 150 μmolm-2s-1. Seedling dry weight and individual leaf area were determined daily. The photosynthetic rate was determined when seedlings reached the second true leaf stage.

The dry weight response to increasing photoperiod durations was cubic with a peak at 14 hr. Seedling dry weight increased slowly during days 5 through 10 then increased rapidly during the next 7 to 10 days. This increase coincided with the unfolding of leaves one through four. The total leaf area showed a cubic response to the photoperiod treatments. The leaf area increased slowly then began an exponential increase after day 10. The photosynthetic rate per gram dry weight was increased by the 10 hr photoperiod treatment when compared to the 16 hr treatment. The increased photosynthetic rate was not observed when the data was calculated on a fresh weight or leaf area basis.
AIR LAYERING FOR CLONAL PROPAGATION OF PROSOPIS CHILENSIS AND OTHER WOODY DESERT LEGUMES
Authors: Hagen Randall H. , Palzkill David A.
Published: February 2019

Woody legumes used for landscape plants in the desert southwest are extremely variable when propagated from seed. Three Prosopis chilensis trees were air layered in early April, 1989. Stems diameters of 0,5 and 1.0 cm and IBA levels of 5,000 and 15,000 ppm IBA were compared. Except when mechanical damage occurred during the wounding stage or from wind, 100% of the layers at both 5,000 and 15,000 ppm IBA rooted. The 0.5 cm branches were more susceptible to mechanical damage from wounding than the 1.0 cm branches.

A second study begun in mid-August, 1989, compared 0 and 5,000 ppm IBA on the same three genotypes. After eight weeks, IBA treated layers had 83% and untreated layers only 13% rooting. Layers with IBA had thicker and more numerous roots.

Air layers of Cercidium, Parkinsonia, and other species of Prosopis were also successfully rooted.
TOLERANCE OF ORNAMENTAL GRASSES TO POSTEMERGENCE GRASS HERBICIDES
Authors: Hubbard Joanna , Whitwell Ted
Published: February 2019

Ornamental grasses are popular landscape plants and often encounter turf encroachment or other grass weed problems. Several postemergence grass herbicides are available for use in turf and ornamentals and herbicide tolerance information is needed for ornamental grass species. Fifteen ornamental grasses including species from the genera Calamagrostis, Cortaderia, Eragrostis, Erianthus, Miscanthus, Sorghastrum, Spartina, Panicum and Pennisetum were field planted in Clemson, SC in May 1989 and Festuca species in November, 1989. Herbicide treatments were fenoxaprop-ethyl, fluazifop-P and sethoxydim at 0.4 kg a.i.·ha-1 applied 4 weeks after planting and an untreated control. Height and injury evaluations were taken at weekly intervals and plants were harvested 10 weeks after treatment. Fenoxaprop-ethyl treated Calamagrostis and Festuca species treated with all herbicides were the only treatments that were the same as untreated controls in terms of % injury, height and dry weight. Three ornamental Calamagrostis species were evaluated in a greenhouse study to determine the level of tolerance to fenoxaprop-ethyl at 0.4, 0.8, 1.6 and 3.2 kg a.i.·ha-1. No visual injury symptoms were seen on any treatments as compared to untreated controls but growth rates of the youngest leaves did vary among species shortly after treatment.
DIURNAL CHANGES IN LEAF CONDUCTANCE AND WATER RELATIONS IN FRAGARIA CHILOENSIS AND F. VIRGINIANA FOLLOWING WATER DEFICIT STRESS
Authors: Zhang Baolin , Archbold Douglas D.
Published: February 2019

Plants of F. chiloensis cv. BSP14 (FC) and F. virginiana cv. NCC85-13V (FV) were stressed until wilting, then watered for 2 days prior to measurement. Diurnal measurements of leaf conductance and water relations were conducted. Leaf conductance of stressed FC plants was generally lower, than that of controls at most times, but there wee no difference between the two in FV. Leaf conductance and transpiration rates had not fully recovered to pre-stress levels within this recovery period, Leaf wafer potential declined from predawn to midday, more in stressed than control plants of both species. Leaf osmotic potential averaged 0.4 and 0.2 MPa lower in stressed than control FC and FV plants, respectively, Greater differences occurred at midday than predawn. Leaf pressure potential of stressed plants was higher predawn than midday, 1.4 vs. 0.7 MPa, in FC; it was not different for FV at most times. The difference in water relations between these two species may be explained by a greater residual effect from the osmotic adjustment in FC es compared to FV that occurred during prior water deficit stress.
RESPONSE OF FIVE BEDDING PLANT SPECIES TO PACLOBUTRAZOL AND THREE COMMERCIAL GROWTH RETARDANTS
Authors: Carter Johnny , Mathews Edwin K.
Published: February 2019

Paclobutrazol and three commercial growth retardants (B-nine, Cycocel and A-rest) were compared for their effectiveness in controlling the growth of five bedding plant species ('Yellow Boy' marigold, `Blue Blazer' ageratum, `Dreamland Orange' zinnia, `Better Boy' tomato and `Black Beauty' eggplant). Results showed that growth suppression depended on the treatment and species tested. All of the growth retardants suppressed the growth of `Yellow Boy' marigold. Growth of `Blue Blazer' ageratum was suppressed by all the treatments except for Cycocel. With `Dreamland Orange' zinnia, B-nine and Cycocel suppressed growth while Paclobutrazol and A-rest did not have any effect. All of the treatments except A-rest suppressed the growth of `Better Boy' tomato and `Black Beauty' eggplant.
BLUEBERRY-BUNCHBERRY INTERACTIONS IN LOWBUSH BLUEBERRY FIELDS.
Authors: Yarborough D.E. , Bhowmik P.C.
Published: February 2019

Bunchberry (Cornus canadensis L.) is increasing in density and distribution in lowbush blueberry fields (Vaccinium angustifolium Ait.) in Maine and Nova Scota. Replacement series experiments to assess competitive effects of bunchberry were established on native stands of blueberries at Blueberry Hill Farm in Jonesboro, ME in 1986 and 1987. Ten 0.42 M2 quadrats were established on prune and crop fields with cover ratings where c=crop, blueberry and w=weed, bunchberry at 100c/0w, 75c/25w, 50c/50w, 25c/75w, 0c/100w. Dormant blueberry and bunchberry plugs from prune fields were transplanted into five, 0.42 M2 boxes at 16 plugs/box in the above proportions in April 1987 and grown in the greenhouse over the summer in Orono, ME. Regression of individual vs associate yield indicates blueberry and bunchberry equivalent in competitive ability. Blueberries are competitive with bunchberry but in native fields open areas among clones allow faster growing bunchberry to spread without competition.
ARTIFICIALLY DRYING EARLY HARVESTED PECANS AND ITS EFFECTS ON KERNEL TASTE
Authors: Herrera Esteban
Published: February 2019

Pecan growers are interested in harvesting pecans early because of better prices available early in' the harvest season. Random samples from previously tagged nuts were taken each week for 7 weeks in 1985, and for 8 weeks in 1986. A 50-nut sample was weekly harvested for each of the following treatments: 1) fresh sample, 2) oven-dried for 24 hours at 29.4°C 3) oven-dried for 24 hours at 35°C, 4) oven-dried for 30 hours at 29.4°C, 5) oven-dried for 30 hours at 35°C, 6) dried at room temperature for 72 hours and 7) the control. At the start of the experiment, kernel moisture was about 14%. Some treatments brought kernel moisture below 5% the first week of the experiment. Drying nuts at room temperature reduced kernel moisture as effectively as other treatments. Kernel taste was evaluated after 3 months of cold storage. Judging by taste and moisture content, most treatments could have been harvested 4 weeks before normal harvest in 1985 and 5 weeks before in 1986. It seems that pecans can be harvested early and artificially dried, beginning around 4 weeks before normal harvest, without affecting quality.
EFFECTS OF FOLIAR CALCIUM SPRAYS ON ALUMINUM TOXICITY OF PEACH
Authors: Graham Charles J. , Reighard Gregorv L.
Published: February 2019

Peaches are often grown on sandy, low pH soils which may predispose plants to aluminum (Al) toxicity. Previous research has shown that peach (Prunus persica, L. Batsch) is not tolerant to Al and toxicity may be associated with occurence of peach tree short life syndrome. Current recommendations to control PTSL include soil calcium (Ca) applications to reduce soil acidity and Al availability. However, these applications often result in inconsistent responses. Objectives of this study were to determine if Ca would ameliorate the effects of Al toxicity and whether different Ca compounds would provide different responses.

Rootstock were grown in sand culture supplied with Hoagland's solution containing 16.7 mM aluminum Trees received weekly foliar sprays containing 12.5 uM calcium and 0.1% Chevron X-77 as a spreading agent. Calcium compounds tested included calcium chloride, formate, lactate, nitrate, phosphate, and sulfate. Stem dry weights were significantly increased by Ca lactate and sulfate, leaf dry weight by Ca lactate, and Ca formate significantly increased leaf retention. Nutrient concentrations and interactions in leaves, stems, and roots will be discussed.
RESEARCH TO PRODUCTION: LABORATORY SCALE-UP WITH MICROPROPAGATED ACER SACCHARINUM L.
Authors: Preece John E. , Huetteman Carl A. , Ashby W. C. , Roth Paul L.
Published: February 2019

During the research phase, a system was developed to clonally micropropagate silver maple. Explant performance was best on DKW medium with 10 nM thidiazuron, and explants commonly developed 1 7 shoots after three months and over 60 shoots that could be rooted after four months in vitro. Plants were rooted (>90%) and acclimatized under intermittent mist and transplanted to an outdoor nursery bed. However, results were different during the production phase when 90 clones were propagated. Shoot proliferation rates were lower, differences in clonal response and worker efficiency were apparent, mass rooting under mist was inconsistent and acclimatization problems arose. The mean rooting was 46% under mist because of uneven coverage. Only 56% of rooted plantlets acclimatized which resulted in an overall efficiency of 26%. Partial solutions included root initiation in vitro, and use of fog for acclimatization.
PICLORAM-INDUCED ETHYLENE PRODUCTION BY BROOM SNAKEWEED
Authors: Lownds Norman K. , Sterling Tracy M.
Published: February 2019

Broom snakeweed [Gutierrezia sarothrae (Pursh) Britt. & Rusby] is a suffrutescent shrub that is a problem in rangeland production areas because it interferes with forage growth and is potentially dangerous to livestock. Picloram, an auxin-like herbicide, is used for broom snakeweed control. Picloram-induced ethylene production may be important to its efficacy, therefore, studies were conducted to characterize ethylene production and phytotoxicity. Picloram, applied as individual drops, induced a linear increase in ethylene production (r= 0.738***) between 0 and 72 hr after treatment. When plants were sprayed with 0.125, 0.25 and 0.50 lb ae/A, ethylene production increased linearly through 120 hr then leveled off and began to decrease for all three concentrations. The highest rate of ethylene production was induced by 0.25 lb ae/A followed by 0.50 and 0.125, respectively. Epinasty was evident 24 hr after treatment and chlorosis 3 to 4 days after treatment. Both were more severe with increasing picloram concentration. It appears that picloram-induced ethylene production is an important component in picloram activity.