bluuebunny/crossref_metadata_2025 huggingface dataset:
Acceleration of Begonia × semperflorens-cultorum Growth Using Supplemental Irradiance
Authors: Kessler Raymond , Armitage Allan M. , Koranski David S.
Published: February 2019

Plug flats of Begonia × semperflorens-cultorum Hort. `Pizzazz Red', Vodka', and `Viva' were provided 0, 50, 125, or 200 μmol·s-1·m-2 metal-halide supplemental irradiance in the greenhouse for 0, 2, 4, 6, or 8 weeks. Treatments were initiated when seedlings were in the first true leaf stage (2 weeks after sowing). Plug-grown begonias reached transplantable dry weight and leaf area after 4 weeks of 125 μmol·s-1·m-2 supplemental exposure, while those under O and 50 μmol·s-1·m-2 required 6 to 8 weeks. Fewest number of days to visible bud and anthesis and the fewest number of nodes for all cultivars occurred after 2 weeks of 125 μmol·s-1·m-2 supplemental exposure. The same conditions achieved the greatest final leaf area and plant height; however, final dry weight was unaffected. Additional supplemental irradiance and/or exposure time did not accelerate flowering or improve vegetative growth of finished plants.
Postharvest Factors Governing the Development of Peteca Rind Pitting on `Meyer' Lemons
Authors: Wild B.L.
Published: February 2019

The postharvest development of peteca rind pitting in `Meyer' lemons [Citrus meyeri (Y.) Tan] was aggravated by citrus wax application and fruit brushing. Increasing brushing time increased the incidence of the disorder. Polyethylene-based waxes induced more peteca than carnauba-based wax formulations. Ethylene degreening and/or storage before waxing decreased fruit susceptibility, while application of the fungicide guazatine did not increase peteca incidence. Storage between 10 and 25C had no effect on injury levels. Chemical name used: bis(8-guanidino-octyl) amine (guazatine).
Growth Regulator and Axillary Bud Position Effects on in Vitro Establishment of Vitis rotundifolia
Authors: Sudarsono  , Goldy Ronald G.
Published: February 2019

Four muscadine grape (Vitis rotundifolia Michx.) cultivars (Carlos, Noble, Regale, and Tarheel) were evaluated for their ability to be cultured in vitro. Axillary buds were placed on Murashige and Skoog medium as modified by Chee. Different levels of benzylaminopurine [(BA) 0.5 to 10.0 μm], kinetin [(KIN) 0.5 to 5.0 μm], and thidiazuron [(TDZ) 0.5 to 11.3 μm], and different explant positions were evaluated for their effect on in vitro explant establishment and shoot production. Thidiazuron (2.3 to 4.5 μm) alone or in combination with BA (1.0 to 5.0 μm) or KIN (1.0 or 5.0 μm) was effective for establishing axillary buds. Similar levels were also effective for promoting shoot proliferation. Explants originating from the 10 basal nodes of a shoot with at least 25 nodes gave better shoot proliferation than explants originating from the 10 distal nodes. Chemical names used: 6-benzylaminopurine, 6-furfurylaminopu. rine (kinetin):N -phenyl-N'-l,2,3 -thiadiazol-5-y lurea (thidiazuron).
Phosphorus Application Constraints Limit Profitability of Sweet Corn and Lettuce Production
Authors: Alvarez Jose , Sanchez C.A.
Published: February 2019

The economics of producing sweet corn (Zea mays L.) and head lettuce (Lactuca sativa L.) on Florida Histosols were analyzed with and without P application constraints based upon quadratic response functions derived from two experiments with each crop. At the lower end of the historical price range, production of both crops is unprofitable, especially when P is constrained. At higher prices, net returns for sweet corn under P constraints are relatively small compared with the capital invested; net returns are higher for lettuce. However, an analysis of historical monthly prices showed that those high prices rarely occur. Values for the marginal contribution of the last unit of P show that constraints greatly limit net returns. Many sweet corn and head lettuce producers may be forced out of business if P fertilization rates are arbitrarily lowered below the economic optimal rate.
Omission of Lime Reduces Mouse-ear Symptoms in Container-grown Pecan Trees
Authors: Goff William D. , Keever Gary J.
Published: February 2019

Container-grown pecan [Carya illinoensis (Wangenh.) C. Koch] trees with “mouse-ear” symptoms, characterized by small, rounded, cupped, and slightly wrinkled leaflets, were repotted into two types of media amended with three rates of dolomitic limestone (0, 5.4, or 10.7 kg·m-3). In both media [4 milled pine bark: 1 sand; 1 soil: 1 peat: 1 perlite (by volume)], mouse-ear symptoms in the season following repotting were dramatically reduced at the lower lime application rates. Medium Fe, Ca, Cu, and Mn and foliar Ca, Mg, Mn, Zn, and B were affected by lime rate 10 months after repotting in one or both media. Medium pH increased quadratically as lime rate increased. Greatest plant recovery occurred when no lime was added, resulting in a pH of 3.9 in the bark-sand medium and 4.2 in the soil-peat-perlite medium.
Quality Changes in Asparagus Spears Stored in a Flow-through CA System or in Consumer Packages
Authors: Baxter Lawford , Waters Luther
Published: February 2019

Asparagus spears (Asparagus officinalis L.) stored 28 days at 2C in air, a flow-through controlled-atmosphere (CA) system, or 14 days in polymeric film consumer packages were evaluated in respect to compositional and quality changes. CA-stored spears retained more sugars, organic acids, and soluble proteins than spears stored in air. Spears stored in vented consumer packages had a useful life of 14 days, whereas those in nonvented packages started to break down after 8 days. Spears from vented packages lost more weight but retained more sugars and organic acids than those from nonvented packages.
Inheritance of Resistance to the Florida Strain of Zucchini Yellow Mosaic Virus in Watermelon
Authors: Provvidenti R.
Published: February 2019

A high level of resistance to zucchini yellow mosaic virus (ZYMV) was found in four landraces of Citrullus lanatus (Thunb.) MatSum. & Nakai (PI 482322, PI 482299, PI 482261, and PI 482308) originally collected in Zimbabwe. This resistance is specific to the Florida strain of the virus (ZYMV-FL), which prevails in the United States. Inheritance studies were conducted by using a single-plant selection (PP261-I) of PI 48226I and the ZYMV-susceptible watermelon cultivar New Hampshire Midget. In F1, F2, and reciprocal backcross populations, resistance was conferred by a single recessive gene to which the symbol zym is assigned. There was no linkage between zym and one of the three homodimer bands of the isozyme phosphoglucoisomerase (Pgi-2b), which was found in PP261-1, and in other ZYMV-FL resistant plants.
EFFECT OF SEED SIZE AND CULTIVAR ON EMERGENCE OF BROCCOLI IN CRUSTED SOIL
Authors: Heather Douglas W. , Sieczka Joseph B.
Published: February 2019

Greenhouse and field experiments were conducted in 1988 and 1989 to determine the effect of seed size and cultivar on seedling emergence through crusted soil for several hybrid broccoli cultivars (Brassica oleracea ssp. italica). Seed was separated into four sizes (2.0, 1.8, 1.6 and 1.4 mm diameter) for the greenhouse investigations and soil crusting was achieved with a chemical resin. In 1989, field experiments using three seed sizes (small=1.4-1.6, medium=1.7-1.9 and large=2.0-2.2 mm diameter) were planted at the Long Island Horticultural Research Laboratory in a Riverhead sandy loam which crusted readily after rainfall. Seedling emergence data from both greenhouse and field studies indicate that both seed size and cultivar significantly affect stand establishment. Seedling stand, dry weight and final yield significantly increased as seed size increased for both cultivars in the field experiments. The emergence of `Mariner' was generally found to be significantly greater than that of `Greenlady' for each seed size. Emergence was also influenced by seed weight.
A RAPID METHOD FOR EVALUATING α-FARNESENE, TRIENE AND ANTIOXIDANT LEVELS IN APPLE SCALD PHYSIOLOGY STUDIES
Authors: D'Souza Mervyn C. , Ingle Morris
Published: February 2019

Superficial scald on apples is effectively controlled by the currently registered inhibitors, diphenylamine and ethoxyquin. However, the availability of these chemicals as scald inhibitors in the future is uncertain. There is renewed interest and need for scald research to develop prediction systems and non-chemical control measures. Scald is believed to be caused by the oxidation of α-farnesene into trienes. The reaction is partially inhibited by the presence of antioxidants in the peel.

We have developed a new method to evaluate scald reaction compounds. This method was used to show that differences exist in reaction compound concentrations between the blushed and nonblushed sides and scalded and normal portions of `Rome' apples. The benefits of this method over the conventional method will also be presented.
PROPAGATION OF JUNIPERUS SCOPULORUM `WICHITA BLUE' BY GRAFT-CUTTING
Authors: Duchesne Isabelle , Rioux Jacques-André
Published: February 2019

The main objective of this research was to determine the propagation potential of Juniperus scopulorum `Wichita Blue' through grafted cuttings while using Juniperus chinensis `Hetzii' and Juniperus Sabina `Blue Danube' as a rootstock. The experiment took place in a glass greenhouse, the propagation material was either placed under a polyethylene film or intermittent mist. In each of these growth conditions the graft union was either wax coated or buried in a humid substrate. Grafting method was a side veneer graft. Each treatment was repeated three times and the experimental unit was made up of ten specimens.

Best results were obtained from the experimental trial covering the period of february to may (12 weeks). During this trial period we observed a similar rate of successful graft union whether grafted cuttings or conventional graft was used with J. S. `Blue Danube', while grafted cuttings was more successful with J. c. 'Hetzii'. Grafted cutting obtained the best results with J. S. `Blue Danube' when graft union was buried in perlite and placed under an intermittent mist. Rooting quality of rootstock cuttings was slightly inferieur to conventional cuttings for J. S. `Blue Danube' this difference was more prononced in the case of J. c. `Hetzii'
RELATION OF AMMONIUM ACCUMULATION AND ETHYLENE BIOSYNTHESIS IN EXPRESSION OF PHYSIOLOGICAL STRESS IN PLANTS
Authors: Barker Allen V. , Ready Kathleen M. , Feng Jinan
Published: February 2019

Several factors inducing physiological stress in plants were investigated for their effects on foliar ammonium accumulation and ethylene evolution in tomato (Lycopersicon esculentum Mill.). Plants grown on ammonium nutrition (0.015M NH4+) in solution culture had elevated rates of ammonium accumulation and ethylene evolution relative to plants grown on nitrate nutrition at the same molar concentration. Inhibitors of ethylene action (0.001 mM Ag+) or synthesis (0.01 mM amino-oxyacetic acid) restricted ammonium accumulation and ethylene evolution relative to rates by untreated controls receiving ammonium nutrition. The inhibitors lessened the expression of ammonium toxicity. Stress from salinity, drought, or flooding in soil increased ammonium accumulation and ethylene evolution. Plants infected with root-knot nematode had variable rates of ethylene evolution in response to variations in ammonium accumulation. Ammonium accumulation and ethylene evolution appear to be factors in the expression of physiological stress.
HORTICULTURE RESEARCH CENTER AT LAVAL UNIVERSITY (CRH)
Authors: Dansereau Blanche , Gosselin André
Published: February 2019

The CRH consists of 20 professors and researchers as well as more than 50 graduate students enrolled at the master or doctorate level in the various departments of the Faculty of Agriculture and Food. The scientific program of the CRH is articulated around the theme of quality and availability of Quebec horticultural products. This multi-disciplinary program comprises: production systems, plant pathology, in vitro culture and somatic hybridization, bio-climatology, and engineering of these processes as well as post-harvest technology and marketing of horticultural products. Our goals are evidently to improve production systems but they are also aimed at the quality and innocuity of horticultural products as well as using environment-friendly technologies.
HORT 2001: INTERACTIVE VIDEO COURSEWARE
Authors: White John , Beattie David , Clark Yvonne
Published: February 2019

Information storage technologies are changing, so this project is focused on the future and the use of new videodisc technology. A model plant science inquiry-learning tool was developed for vocational agriculture students using advanced video and computer technology. The interactive videodisc lesson, which focuses on plant identification, was designed to increase learning and allow teachers to spend more time with students.
INFLUENCE OF R:FR RATIO ON CHRYSANTHEMUM GROWTH
Authors: Rajapakse Nihal C. , Kelly John W.
Published: February 2019

The response of chrysanthemum plants to varying R:FR ratios and phytochrome photoequilibrium values (Ø = Pfr/Ptot) was evaluated by growing plants under 6%, or 40% CuSO4 and water spectral filters. Using a narrow band-width (R = 655-665 and FR = 725-735 nm) and a broad bandwidth (R = 600-700 and FR = 700-800 nm) for R:FR calculation, 6% CUSO4 filter transmitted light with greater R:FR (3.9) and grater Ø (0.81) than 40% CuSO4 or water filters. Light transmitted through 40% CuSO4 and water filters had a similar narrow band R:FR ratio (1.2), but the broad band R:FR ratio (2.1) of 40% CuSO4 filter was higher than water filter. Estimated Ø value was similar for both water and 40% CuSO4 filters. Final height of plants grown in CuSO4 chambers was about 30% less than the plants in control chambers. The results suggest that broad band R:FR ratio correlated more closely to plant response than the narrow band R:FR ratio.
WATER RELATIONS IN SWEETPOTATO
Authors: Quarrels Jesse R. , Thompson Paul G.
Published: February 2019

An experiment was conducted to determine the rate and frequency of irrigation needed for optimum yield in sweetpotato (Ipomoea batatas (L.)Lam). A line source irrigation system was used to provide continuously increasing amounts of water at each irrigation. The physiological responses of sweetpotato to water application were measured. There was an increase in leaf water potential with increasing rates of irrigation. Leaf diffusive resistance decreased as total water rate increased to 76% of pan evaporation (Epan) and then increased with higher rates of irrigation. Marketable yields increased as total water rate increased to 76% of Epan and then decreased rapidly with higher irrigation rates. Water relations measurements indicated that reduction in yield with higher amounts of water application was due to low soil oxygen content.
EVALUATING SWEETPOTATOES FOR RESISTANCE TO THREE PATHOGENS SIMULTANEOUSLY
Authors: Hurley R. Mark , Thompson Paul G. , Lawrence Gary W.
Published: February 2019

A factorial test was conducted to evaluate the potential of screening sweetpotato plants to three pathogens simultaneously. The pathogens were Meloidogyne incognita, Fusarium oxysporum, and Streptomyces ipomoea. The test also involved six sweetpotato cultivars and three evaluation times. Evaluation times were 3, 6, and 9 weeks post inoculation. The symptoms evaluated were vascular necrosis, fibrous root necrosis, and gall and egg mass production. For each of the three pathogens, the ability to separate cultivars with intermediate levels of resistance from those with low levels of resistance decreased as post Inoculation time increased. Simultaneous screening was practical if the goal was to select plants with resistance to all three pathogens. Resistances to individual pathogens could not be identified in plants inoculated with all three pathogens.
EVOLUTIONARY BIOLOGY OF THE SWEET POTATO AND ITS RELATIVES: OPPORTUNITIES FOR MOLECULAR GENETICSTUDIES
Authors: Varadarajan G. S. , Prakash C. S.
Published: February 2019

The sweet potato (Ipomoea batatas) and its relatives (the batatas complex) appear to have evolved in the New World and radiated over several geographic centers in the tropics and subtropics. Traditional studies on taxonomy, cytogenetics, and reproductive biology of the batatas complex have enabled us to investigate certain evolutionary aspects. We conclude that this complex is a monophytetic, “polyploid pillar”, evolved by chromosome doubling (euploidy) and interspecific hybridization. We apply molecular genetic techniques to detect variation [restriction fragment length polymorphism (RFLP) and DNA fingerprinting analyses] to reexamine some of the evolutionary issues that could not be satisfactorily addressed by the conventional approaches, e. g., phylogenetic history of the batatas group, the diploid ancestors of the polyploid members, homology/diversity of genome(s) within the entire group. We find DNA variation in the hypervariable or multiple copy regions of the genome in Ipomoea species. In addition, we are investigating polymorphism in unique/low copy regions using a battery of DNA sequences from homologous as well as heterologous sources. The success of this study will hopefully shed a new light on the subject of evolutionary biology and may also have potential applications in the sweet potato breeding.
WEED CONTROL IN SWEET POTATOES WITH OXYFLUORFEN
Authors: Porter Wayne C.
Published: February 2019

Oxyfluorfen was evaluated for weed control in sweet potatoes. In 1989, applications were made overtop transplants immediately after transplanting. The 1990 applications were made just prior to transplanting. Oxyfluorfen applied post-transplant at 0.38 lb ai/A and greater rates caused a significant reduction in crop vigor. A 1.0 lb ai/A rate of oxyfluorfen reduced crop vigor when applied pretransplant. All rates of oxyfluorfen controlled Brachiaria platyphylla, Digitaria sanguinalis, Cyperus iria, and Sesbania exaltata. Oxyfluorfen rates of 0.5 lb ai/A and greater were needed to consistently control Sida spinosa and Echinochloa crus-galli. Mollugo verticillata was controlled at all rates in 1989 but not controlled at all in 1990. Yields of all grades of sweet potato roots from plots treated with oxyfluorfen were not different from yields from plots treated with currently labeled herbicides. However, in 1989 yields from all oxyfluorfen-treated plots were lower than yields from the hoed check. In 1990, plots treated with oxyfluorfen at 0.25 or 0.38 lb ai/A had lower yields of No. 1 grade roots than the hoed check.
EFFECT OF FOUR ROW COVER SYSTEMS ON PRODUCTION OF SOLANUM TUBEROSUM IN SOUTHEAST MISSOURI
Authors: Wilson Mack A. , Aide Michael T.
Published: February 2019

`Norchip' and `Atlantic' potatoes grown at Blodgett and Dielstadt, Missouri on 2 sandy, well drained entisols were evaluated using four row covers. The row covers were spunbonded polyester, insolar slitted, clear slitted polyethylene and VisPore. Row covers increased the mean afternoon soil temperature from 62° to 108°. The mean plant heights were significantly different among treatments for the cultivar `Norchip' but were not different for `Atlantic'. Data for average and total plant heights were significantly different between the bare soil control and all row covers. The grade a marketable weights and numbers in Kg and nos/Ha of `Norchip' and `Atlantic' potatoes had a significant contrast at the 0.01 level of probability with cultivars.
WESTERN FLOWER THRIPS: IDENTIFICATION OF RESISTANCE IN PEPPER
Authors: Fery R. L. , Schalk J. M.
Published: February 2019

A greenhouse study was conducted to confirm the availability of resistance in pepper (Capsicum annuum L.) to western flower thrips [Frankliniella occidentalis Pergande)]. Host plant resistance ratings confirmed earlier observations that there is a considerable amount of variability within pepper germplasm for reaction to F. doccidentalis. Plants of `California Wonder', `Keystone Resistant Giant', `Mississippi Nemaheart', `Sweet Banana' and `Yolo Wonder L' were resistant to the insect and exhibited only mild injury. Plants of `Bohemian Chili', `Carolina Cayenne', and `Santaka', however, exhibited the symptoms of severe thrips injury, i.e., poorly expanded, deformed and distorted leaves, greatly shortened internodes, and severe chlorosis. The resistance in pepper to F. occidentalis appears to be due to tolerance mechanisms, not nonpreference or antibiosis mechanisms. The levels of resistance identified in this study are sufficiently high to justify the initiation of breeding efforts to transfer F. doccidentalis resistance into susceptible pepper cultivars.
KUDZU IN THE SOUTH: AN OLD ALTERNATIVE CROP
Authors: Small Tanya , Rhoden E. G. , Woldeghebriel A. , Carver G.W.
Published: February 2019

Kudzu (Pueraria lobata) has become a pervasive weed in the southeast US. It has been receiving much attention recently and a study was initiated to evaluate the plant as an alternative food and feed source. Kudzu vines were sectioned into; 0-25, 25-50, 50-75 and 75-100 cm and analysed for acid detergent fiber (ADF), neutral detergent fiber (NDF), ash and crude protein content. Leaf ash content of kudzu increased while stem ash content decreased as the vine was sampled from the growing tip. Stem NDF increased from 44.4% at the 0-25 cm section to 57.83% at the 75-100 cm section of the vine, while leaf NDF declined from 52.23 to 39.01% for the same sections. The trend was reversed for ADF in the kudzu leaf and stem. Crude protein content of kudzu ranged from 18.45% at the 0-25 cm section for leaves to 7.42% for stem sections at 75-100 cm. The high crude protein content of kudzu as well as its abundance in the Southeast makes it a good feed source and a potential food source. However, further studies are needed to determine the vitamin content and digestion coefficient to ascertain its suitability as a food and feed source.
EVALUATION OF THE NITROGEN FIXING CAPABILITIES OF PHASEOLUS VULGARIS LINES, DEVELOPED FOR THE CARIBBEAN BASIN
Authors: Hanning Paige , Marsh Dyremple B. , Dkhili Mohsen
Published: February 2019

Chemically fixed nitrogen is a costly import for Caribbean Basin Countries. Increased cost of fertilizer only serves to reduce crop yields in these areas. This greenhouse research was undertaken to evaluate the N2 fixing capabilities and yield potential of several Phaseolus vulgaris lines developed for use in Caribbean Basin countries. Ten common bean lines from breeding programs at the Universities of Puerto Rico and Wisconsin and two efficient Rhizobium phaseoli strains were used for the study. Plants treated with Rhizobium UMR 1899 and UMR 1632 had significantly higher stem and leaf dry weight than the control plants. Bean lines WBR 22-34, WBR 22-50, WBR 22-55, PR9056-98B and the cultivar Coxstone showed increased dry matter accumulation over that of the control plants. Plants treated with the Rhizobium strain UMR 1899 had the highest stem and leaf dry matter accumulation. Nodulation was significantly higher when plants were treated with UMR 1632. The lines WBR 22-34 and PR 9056-98B produced more nodules than the other lines used. Pod yield as measured by number of immature pods was highest for PR 9056-98B when inoculated with Rhizobium UMR 1899.
GROWTH INHIBITION AND ENHANCED FLOWERING OF CAMELLIA HIEMALIS `SHISHI-GASHIRA' WITH UNICONAZOLE
Authors: Keever Gary J. , McGuire John A.
Published: February 2019

Container grown `Shishi-Gashira' camellias received a single foliar spray of 0, 5, 10, 15, 20, 40, or 60 mg a.i. liter uniconazole on 26 May 1989. Growth indices were determined about every 4 weeks during the 1989 growing season and following the spring 1990 growth flush. Flowering was also monitored. Growth was suppressed linearly or quadratically over the duration of the test, with growth inhibition 12 months after treatment ranging-l from 3.7% (5 mg a.i. liter-1) to 20.6% (60 mg a.i. liter-1) relative to the control Flower number increased from 52.6% (5 mg a.i. liter-1) to 100% (60 mg a.i. liter-1) compared to the control. Time to flower was not affected by 5 to 20 mg a.i. liter-1 uniconazol but increased 4 to 7 days with the 40 and 60 mg a.i. liter-1 rates. Uniconazole rate did not affect flower diameter.
VERTICILLIUM WILT INFECTION IN CERCIS CANADENSIS.
Authors: Spafford Michael R. , Kling Gary J.
Published: February 2019

Cercis canadensis, Eastern Redbud, is very Cercis canadensis, Eastern Redbud, is very susceptible to infection by Verticillium Wilt caused bysusceotible to infection by Verticillium Wilt caused by the common soil-borne fungi Verticillium albo-atrum and Verticillium dahliae. Little is known about the inoculum levels, the time required for natural infection to occur and how fast the pathogen travels inside the host species. One-year-old Cercis canadensis seedlings were planted in 7.6 liter (2-gallon) containers with a 1:1:2 soil/sand/perlite mix inoculated with five levels (0, 10, 100, 500, and 1000 microsclerotia/g soil) of V. dahliae prior to planting. At the end of the first growing season, half of the plants were removed from the containers, surface sterilized, dissected and root sections plated out on a Verticillium selective media. The remaining plants were grown for a second season. Infection first occurred in plants which received 100, 500 or 1000 ms/g at the end of the first season. The infection had spread at least 5 cm during the first growing season.
OVI POSITIONAL ANTIXENOSIS-BASED HOST RESISTANCE TO THE PEAR PSYLLA IN PYRUS GERMPLASM OF EAST EUROPEAN ORIGIN
Authors: Bell Richard L.
Published: February 2019

A collection of 60 genotypes-of pear (Pyrus sp.) from East Europe were assayed for ovipositional antixenosis in no-choice cage tests. Five single plant replicates of each genotype, 'Bartlett' (P. communis L.), a susceptible and NY10352 (P. ussuriensis × P. communis BC1 hybrid)' as a resistant control, were stripped to the 6 youngest, but fully expanded leaves, and enclosed in single-plant cages. Four mating pairs of summer-morph adult pear psylla were introduced into each cage. The number of eggs laid on each plant was counted after 5 days. Egg hatch was determined 7 days later, and leaf area was measured. Twelve genotypes, 8 of which are P. communis, were found to be highly resistant to oviposition. These same genotypes had previously been found to exhibit high levels of nymphal feeding antixenosis and antibiosis. The results will be discussed in light of ovipositional cues and host acceptance-related behavior of the pear psylla.
ESTABLISHMENT OF ROOT CULTURES FROM CEPHALOTAXUS HARRINGTONIA CALLUS
Authors: Wickremesinhe Enaksha R. , Arteca Richard N.
Published: February 2019

Cephalotaxus harringtonia plants produce alkaloid compounds possessing antitumor properties, the major one being homoharringtonine. The purpose of this study was to produce roots from callus cultures developed earlier. Fast growing callus cultures were placed on MS basal salt medium with B-5 vitamins, 2% sucrose, 10 μM kinetin, 0.45 μM 2,4-D and 0.2% Gelrite. Upon subculture onto basal medium without hormones, we observed organogenesis of both shoots and roots. Roots were excised and established on basal medium without hormones. By subculturing two 2-inch root tips containing numerous visible laterals in liquid medium we were able to harvest 30 g of roots/250 ml flask after 3 weeks and 50 g/250 ml flask after 6 weeks. A 20-fold increase in fresh weight was achieved within 3 weeks when 15 grams of roots were initially seeded into a 3 liter air-sparged bioreactor. However, most of these roots appeared to be fleshy/swollen while root cultures established from half inch root tips grew slower but were normal in appearance. We arc currently in the process of establishing growth characteristics for these roots and assaying roots for the presence of these alkaloids.
COMPARISON OF JUVENILITY IN TWO GENERA OF THE ASTERACEAE
Authors: Damann Peggy , Lyons Robert E.
Published: February 2019

Chrysanthemum × superbum, Coreopsis lanceolata, and Coreopsis grandiflora are LD flowering perennial plants. The end of juvenility could be defined as the minimum expanded leaf number required for fastest flowering once placed in LD. This research was conducted to compare juvenility and flowering requirements in dwarf and standard cultivars of these species. Plants were maintained under SD and transferred to LD upon reaching true leaf stages beginning with 0 (cotyledons only) and progressing at 2 or 3 leaf intervals to the 24 leaf stage. Coreopsis `Sunray' and Chrysanthemum `G. Marconi' were relatively unresponsive to LD whereas LD induced flowering in 70-100% of the plants in each leaf number treatment in Coreopsis `Early Sunrise'. Plants transferred at the 15 leaf stage required the least number of LD to reach anthesis. LD promoted complete flowering in Chrysanthemum × superbum `Snow Lady' plants and 90% of the SD control plants flowered as well. SD control plants from the other 3 cultivars remained vegetative. Effects of vernalization will also be presented.
GENE EXPRESSION IN PECAN SOMATIC EMBRYOS
Authors: Levi Amnon , Wetzstein Hazel Y. , Galau Glen A.
Published: February 2019

Repetitive somatic embryogenic lines of pecan (Carya illinoensis) were obtained and subcultured on basal WPM, following a one week induction of zygotic embryo tissue on modified WPM with 6 mg/L NAA. Gene expression of somatic embryos has been studied and compared with that occurring in zygotic embryos. Somatic embryos simultaneously expressed mRNA classes that are specific to each of the zygotic embryo cotyledon (Cot), maturation (Mat), and post abscission stages (Late embryogenesis, Lea). Somatic embryos exhibiting such multiple, nonregulated gene expression patterns have a low germination rate. Treatments found to enhance embryo germination (cold and desiccation) may be effective in part, by modifying gene expression patterns. Some of the Cot and Mat mRNA classes decreased following such treatments, while Lea mRNAs were not effected. Cold and desiccation treatments appear to coordinate gene expression in pecan somatic embryos, which might be associated with embryo germination.
INVESTIGATION OF ATTITUDES OF WHOLESALE FLORICULTURE GREENHOUSE GROWERS TOWARD COMPUTER USAGE FOR MARKETING PURPOSES
Authors: Kippen Laura Sue , Rhodus W. Timothy
Published: February 2019

A focus group was conducted to ascertain the attitudes and behaviors of wholesale floriculture greenhouse growers toward the use of computers for marketing purposes. The focus group consisted of nine individuals from nine different wholesale greenhouses in the Greater Cleveland - Lorain area. The greenhouses were selected according to their sizes which ranged from one-half acre of production under cover up to 70 acres. Each individual was either the owner of the greenhouse operation or charged with the marketing function in that company. The study was conducted for the purposes of identifying possible factors related to the speed of adoption of computer technology for marketing purposes and its possible future course within the wholesale greenhouse industry. Variables that were identified from the focus group study were tested using a national survey.
POTATO RESPONSES TO FERTILIZER AND INDIGENOUS SOIL PHOSPHOROUS
Authors: Evans W.B. , Warncke D.D.
Published: February 2019

Single-plant microplots of `Russet Norkotah' potatoes (Solanum tuberosum L.) were grown outdoors in a 5 × 5 factorial RCBD of indigenous phosphorous level (200, 325, 450, 575, 700 kg·ha-1 Bray-Kurtz Pl extractable; McBride sandy loam) and banded triple super phosphate (0, 50, 100, 150, 200 kg P2O5/ha). Disease in the low P soil that was used to create the four lower P soil blends completely confounds response of the plants across indigenous P levels and might have accentuated responses within levels. Plants responded to fertilizer P with tuber yield increases of 100, 70, 40, and 10 percent within the 200, 325, 450, and 575 indigenous P levels, respectively. Fertilizer P also increased marketable yield and tuber P concentration. Neither indigenous nor fertilizer P altered tuber specific gravity.

Companion studies compare the responses of corn (Zea mays L.) and potato to indigenous soil P levels and quantify P uptake among potato cultivars in solution culture.
ALTERNATIVE GROUNDCOVER MANAGEMENT SYSTEMS AFFECT ORCHARD SOIL FERTILITY AND APPLE LEAF NUTRIENT CONTENT.
Authors: Merwin I.A. , Stiles W. C.
Published: February 2019

Eight groundcover management systems (GMS) have been evaluated since 1986 in an apple orchard replant site. Tree-row GMS have included post-emergence herbicide (glyphosate) “killed sods,” pre-emergence herbicide (norflurazon + diuron) strips, a crownvetch “living mulch,” hay-straw mulch, monthly cultivation, a close-mowed sod, and an unmowed, chemically growth-regulated (maleic hydrazide + 2,4-D) sodgrass. Soil organ&matter content, surface aggregate structure, and water infiltration have improved under vegetative groundcovers relative to herbicide treatments. Extractable soil N, K, P and B have increased under straw mulch. Except for K, foliar nutrient content (dry wt basis) has not been closely coupled with soil nutrient content. Leaf K, P and B contents have increased, while leaf N, Mg and Zn, have decreased in trees in sodgrass relative to herbicide GMS.
“NATIVE PLANTS OF INDIANA”: VIDEOS FOR INSTRUCTION AND EXTENSION
Authors: Dana Michael N.
Published: February 2019

Interest in native plant species for general landscape planting, mitigation of environmental impact and ecological restoration plantings continues to expand with public awareness of environmental quality. An expanding area of opportunity exists for the landscape horticulture industry to supply non-traditional plant materials to support landscape planting with native species. To capitalize on the opportunity, horticulture and landscape architecture students and practitioners must become knowledgeable of species native to their region. Video is a useful medium for increasing such knowledge. This presentation will review the development, production, distribution and content of six video programs that survey the native herbaceous flora of Indiana prairies and woodlands. Each program is less than 30 minutes in length, to facilitate classroom use and presentation in broadcast formats. Botanically correct nomenclature is presented graphically as each species is introduced. The narration includes botanical, ecological and horticultural information, but emphasizes plant lore to increase interest for general audiences and provide memory clues for those attempting to learn the plants. This project, supported by the Indiana Association of Nurserymen, provides a good example of how horticultural industries can become leaders as the public expands its demand for improved environmental quality.
THE ROLE OF SPUR AND BOURSE LEAVES OF THREE APPLE CULTIVARS ON FRUIT SET AND GROWTH AND CALCIUM CONTENT
Authors: Proctor J.T.A , Palmer J.W.
Published: February 2019

The development of a complete and healthy early season canopy of spur leaves, and later addition of bourse leaves, is essential for fruit set, fruit growth and quality in apple. The present study was undertaken to evaluate the temporal role of spur leaves and bourse shoots on fruit set, growth and return bloom in three apple cultivars and fruit Ca Level at harvest in two cultivars.

Individual flowering spurs on mature wood of “Cox's Orange Pippin”, “Golden Delicious” and “Crispin” apple trees were modified by removing the spur leaves, the bourse shoot, or both, at full bloom and two, four and eight weeks afterwards. Leaf removal reduced fruit set, yield (as fruit number and not size), fruit calcium level at harvest, and return bloom. Defoliationhad its greatest effect on fruit calcium level when done early in the season and plots of this against treatment time suggested a curvilinear relationship. Return bloom was dependent on the presence of the bourse shoots on the spur but not on spur leaves. Return bloom of all three cultivars declined with the number of fruitlets per spur four weeks after full bloom.
DEVELOPMENTAL CHANGES IN CELLULAR COMPONENTS OF FRUIT SIZE IN STRAWBERRY.
Authors: Cheng G.W. , Breen P.J.
Published: February 2019

Number of cells and mean cell volume of strawberry receptacles were determined throughout the development of secondary fruit of three day-neutral cultivars grown in a greenhouse. Receptacle tissue was digested with pectinase and cellulase and number of cells determined with a Batch counting chamber. Cultivars differed in fruit size throughout development. The size of ripe fruit was small (3.8 g) in `Tillikum', medium (11.6 g) in `TriStar', and large (15.6 g) in `Selva'. Cell division continued in all cultivars for 15 days after anthesis (DAA) and was exponential during the first 10 days. The number of cell per fruit after 15 DAA averaged 0.71, 1.96, and 2.94×106 for `Tillikum', `TriStar', and `Selva' respectively. Mean cell volume, as estimated from number of cells and volume of receptacle tissue, increased rapidly between 10 and 25 DAA. Cells of the pith were larger than those of the cortex during early fruit development. Mean cell volume of mature fruit was approximately 6×106 μm3 in the three cultivars. Genotypic variation in fruit size was primarily due to the difference in number of receptacle cells.
PRESERVATION OF PHENOTYPES VS. GENOTYPES?GENES
Authors: Baker Larry R.
Published: February 2019

Key examples of germplasm use to resolve industry varietal problems will be reviewed. The pros and cons of preserving phenotypes and genotypes will be presented with a view to the future from a private breeder viewpoint.
DOES SEED VIGOR INFLUENCE CROP YIELD?
Authors: TeKrony Dennis M. , Egli Dennis B.
Published: February 2019

Both seed viability and vigor directly affect the performance of seeds planted to regenerate the crop. Although seed quality can influence many aspects of performance (e.g., total emergence, rate of emergence), this presentation will primarily examine the relationship of seed vigor to one aspect of performance - crop yield. Reductions in yield can be indirectly related to low seed vigor if the low vigor seed results in plant populations that are below a critical level. Thus, we investigated the direct effects of seed vigor on yield in the absence of population differences for annual crops that are harvested at three stages; during vegetative growth, early reproductive growth or at full reproductive maturity. Seed vigor affects vegetative growth and is frequently related to yield in crops that are harvested during vegetative growth or during early reproductive growth. However, there is usually no relationship between vigor and yield in crops harvested at full reproductive maturity because seed yields at full reproductive maturity are usually not closely associated with vegetative growth. The use of high vigor planting seed can be justified for all crops; however, to insure adequate plant populations over the wide range of field conditions which occur during emergence.
Wear Tolerance of Kentucky Bluegrass and Creeping Bentgrass Following Nitrogen and Potassium Application
Authors: Carroll Mark J. , Petrovic A. Martin
Published: February 2019

Nitrogen (96 and 192 kg·ha-1·year-1) and K (0, 48, 96, and 192 kg·ha-1·year-1) were applied in factorial combination over 4 years to two creeping bentgrass (Agrostis palustris Huds.) and one Kentucky bluegrass (Poa pratensis L.) field plot locations. Turfgrass wear tolerance and recovery from wear were evaluated in the 3rd and 4th years of N and K application by visually estimating the percentage of unworn turf present at the wheel track of a wear simulator or by determining the fresh weight of turfgrass tissue collected from cores removed within, and outside the simulator wheel track. Increasing the supply of N improved creeping bentgrass wear tolerance in the 4th year, but had no effect on Kentucky bluegrass wear tolerance. Nitrogen did not influence recovery from the wear of either species over 8 to 14 days of evaluation following the imposition of wear. Potassium did not affect the wear tolerance or recovery from wear injury in either species.
High-temperature Conditioning to Delay Internal Breakdown Development in Peaches and Nectarines
Authors: Nanos George D. , Mitchell F. Gordon
Published: February 2019

Storage at 0C of `O'Henry' and `Fairtime' peaches and `Red Jim' and `September Grand' nectarines (Prunus persica L. Batsch) resulted in significantly longer postharvest life than did storage at 5C, due to differences in the development of internal breakdown (IB) symptoms. Conditioning at 20C for 2 days before storage at 0 or 5C generally prolonged the storage life of fruit of these cultivars. The use of elevated CO2 during conditioning helped maintain fruit firmness. Addition of 5% CO2 to air gave the best results in maintaining fruit firmness and freedom from IB symptoms for up to 6 weeks. Reducing the O2 content kept flesh firmness high after storage but did not delay the appearance of IB. Conditioning at 30C using various atmospheres was less effective than conditioning at 20C.
Bound versus Free Water in Dormant Apple Buds—A Theory for Endodormancy
Authors: Faust Miklos , Liu Dehua , Millard Merle M. , Stutte G.W.
Published: February 2019

Intact apple (Malus domestica Borkh.) buds were examined by magnetic resonance imaging (MRI). MRI did not excite water in unchilled apple buds and could not image it. When chilling was satisfied, images were produced. We interpret this difference to mean that water is in bound and/or structured form in dormant apple leaf buds before the chilling requirement is satisfied. Conversion of bound to free water occurred equally in the low-chilling-requirement cultivar Anna and the high-chillingrequirement cultivar Northern Spy only after 600 and 4000 hours of chilling, respectively. It appears that processes involved in satisfying chilling requirement are also converting water in buds from bound to free form. Absence of free water in dormant buds during the winter signifies endodormancy, whereas when the water is in free form, buds are ecodormant. Thidiazuron, a dormancy-breaking agent, applied to partially chilled buds is instrumental in converting water to the free form within 24 hours. Summer-dormant buds contain free water, and they could be classified only as paradormant. Based on proton profiles, ecodormant and paradormant buds cannot be distinguished but endodormant buds can be readily identified.
A Continuously Ventilated Natural-light Growth Chamber Complex for Greenhouse Environmental Studies
Authors: Buxton Jack W. , Walker John N.
Published: February 2019

Natural-light growth chambers constructed within a greenhouse compartment were equipped with a ventilation/circulation system, two stages of heating, and evaporative cooling. Air drawn from the greenhouse compartment continuously ventilated the chambers; the air was heated or cooled to the set-point temperature. A computer-controlled environmental system maintained uniform temperatures within the chambers and maintained the temperature within ±1C of the set point at night and during periods of low solar radiation; during higher solar radiation periods, control was not as precise. Carbon dioxide concentration was accurately maintained, and the photosynthetic photon flux from supplemental high-pressure sodium lamps was ≈200 μmol·m-2·s-1. The natural-light growth chambers provide a means for studying the interactive effects of temperature, light, and other environmental variables in experiments to increase production efficiency.
Effect of Sowing Dates, Temperatures on Germination, Flowering, and Yield of Cucumis metuliferus
Authors: Benzioni A. , Mendlinger S. , Ventura M. , Huyskens S.
Published: February 2019

Seed germination, growth, flowering, and yields of Cucumis metuliferus Mey. were examined in several seasons and conditions in the northern Negev, Israel. Germination was optimal between 20 and 35C. Germination was delayed at 12C, totally inhibited at SC, and greatly inhibited above 35C. Salinity increased the time required for full germination. Plants sown in mid-March set fruit in mid-May and gave a higher yield of export-quality fruits than plants sown in mid-April, which set fruit normally but produced a large proportion of small (<200 g) fruits. Plants sown in June did not flower until October. C. metuliferus sown in a greenhouse on three dates in October and November developed very slowly during the cold months and leaves were chlorotic; however, fast growth and development resumed in the spring and high yields were eventually achieved.
Resistance in Pepper (Capsicum annuum L.) to Western Flower Thrips [Frankliniella occidentalis (Pergande)]
Authors: Fery Richard L. , Schalk James M.
Published: February 2019

A replicated greenhouse study was conducted to confirm the availability of resistance to western Rower thrips in pepper germplasm. Host-plant resistance ratings confirmed earlier observations that there is a considerable amount of variability within pepper germplasm for reaction to F. occidentalis. Plants of `Keystone Resistant Giant', `Yolo Wonder L', `Mississippi Nemaheart', `Sweet Banana', and `California Wonder' were resistant to the insect and exhibited only mild symptoms of damage. Plants of `Carolina Cayenne', `Santaka', and `Bohemian Chili', however, exhibited the symptoms of severe thrips damage, i.e., poorly expanded, deformed, and distorted leaves; greatly shortened internodes; and severe chlorosis. The resistance to F. occidentalis in pepper appears to be due to tolerance mechanisms, not antixenosis (nonpreference) or antibiosis mechanisms. Thrips-resistant cultivars could be used as a cornerstone in an integrated pest management program for greenhouse pepper production.
Early and Late-season Blossom-end Rot of Tomato following Mulching
Authors: Elmer Wade H. , Ferrandino Francis J.
Published: February 2019

Paper mulch and black plastic mulch were compared with no mulch on tomatoes (Lycopersicon esculentum Mill. `Better Boy' and `San Marzano') for incidence of blossom-end rot (BER) in the field during 1988–90. Early season (late July to late August) harvest had more BER than in later pickings. Black plastic mulch significantly increased early season BER in `Better Boy' relative to paper or no mulch. Late-season BER in `San Marzano' was decreased with paper or black plastic mulch relative to no mulch.
Influence of Rootstock, Scion, and Water Deficits on Growth of `Colt' and `Meteor' Cherry Trees
Authors: Ranney Thomas G. , Bassuk Nina L. , Whitlow Thomas H.
Published: February 2019

Growth and physiological characteristics were evaluated in autografted and reciprocally grafted plants of Prunus avium L. ×pseudocerasus Lindl. `Colt' and Prunus cerasus L. `Meteor'. Containerized plants were grown for 150 days in a greenhouse under either well-watered or water-stressed conditions. Both the scion and rootstock influenced growth (relative growth rate, R̄), morphological [leaf area : root surface area (LARSA) and specific leaf area (SLA)], and physiological (mean net assimilation rate, Ē) characteristics of grafted plants. Regardless of the watering regime, plants with `Meteor' scions and `Colt' rootstocks maintained higher R̄ than plants with `Colt' scions and `Meteor' rootstocks. This enhanced growth occurred as a result of higher Ē. Measurements on water-stressed plants also showed that the graft combination of `Meteor' on `Colt' had the lowest LARSA, while the reciprocal combination of `Colt' on `Meteor' had the highest. Differences in LARSA among water-stressed plants primarily reflected changes in SLA, as influenced by both rootstock and scion, and not in partitioning of dry weight between these organs.