bluuebunny/crossref_metadata_2025 huggingface dataset:
025 MICROPROPAGATION OF HESPERALOE PARVIFLORA
Authors: Richwine A. M. , Tipton J. , Thompson G.
Published: February 2019

Hesperaloe parviflora is a useful xeric landscape plant. Two methods of shoot culture initiation were developed. Shoots were initiated indirectly through the use of callus derived from pieces of young inflorescences. Callus was initiated on modified Murashige and Skoog medium with 4.52 μM 2,4-dichlorophenoxyacetic acid and 2.32 μM kinetin. Callus produced shoots when placed on modified MS medium with 6.0 μM zeatin riboside. Direct initiation of shoots was also accomplished using the bottom four floral buds of young inflorescences. Buds were placed on modified MS media containing either benzylaminopurine or kinetin at 0.1, 1.0, or 10.0 μM or zeatin riboside at 6.0 μM. The most shoots were produced by the medium containing 6.0 μM zeatin riboside. Preliminary results indicate optimum shoot production with 2.0 to 4.0 μM BA or 6.0 μM zeatin riboside.Hesperaloe parviflora micro-shoots were rooted on one quarter strength MS medium and ex vitro.
026 MICROPROPAGATION OF BUTTERNUT, JUGLANS CINEREA
Authors: Pijut Paula M.
Published: February 2019

Butternut (Juglans cinerea L.), a native hardwood to the northeastern United States, is a valuable species for its wood and edible nuts. Butternut is becoming endangered in its native range as a result of a virulent fungal (perennial canker) pathogen, Sirococcus clavigignenti - juglandacearum. Micropropagation techniques are being developed to clone disease-resistant specimens. Axillary buds, obtained from 2-3-month old seedlings, were induced to break buds in vitro and form a single shoot when cultured on Murashige and Skoog (MS) medium supplemented with 200 mg/l casein hydrolysate, 3% sucrose, and 2 mg/l 6-benzylaminopurine. Roots were initiated on microshoots when cultured on half-strength MS medium containing 100 mg/l casein hydrolysate, 1.5% sucrose, and 0.5 mg/l indole-3-butyric acid for seven days in the dark. Adventitious roots elongated when shoots were placed in the light on the same medium, but with 2% sucrose, and no growth regulators. Rooted plantlets were successfully acclimated ex vitro. These results provide a basis for the development of techniques to micropropagate selected, mature, disease-resistant butternut germ plasm.
030 GENOTYPIC AND PHENOTYPIC FIELD GROWTH CORRELATIONS OF MICROPROPAGATED SILVER MAPLE
Authors: Preece John E. , Huetteman Carl A. , Ashby W. Clark , Roth Paul L. , Adams Richard G.
Published: February 2019

Sixty clones (four clones from each of 15 provenances) were micropropagated and planted in replicated plots in lowland and upland sites in Carbondale, IL in 1991. Data were collected on tree growth, including basal caliper, height, branching, crown volume, dates of bud break, bud set, and leaf fall. There were significant and strong positive genotypic and phenotypic correlations between tree height and basal caliper throughout the three years of growth. During 1993, bud break was not significantly correlated with any growth parameters. After three years in the field, tree height was significantly negatively correlated with the amount of callus that had formed after one month during the in vitro micropropagation phase. However, all shoots that formed in vitro were of axillary origin.
031 EFFECT OF BLANCHING, IBA CONCENTRATION, AND PLANT GROWTH REGULATORS ON GROWTH AND OVERWINTER SURVIVAL OF CUTTING-PROPAGATED ORNAMENTALS
Authors: Bassuk Anna Perkins Nina
Published: February 2019

Budbreak inhibition and poor overwinter survival (OS) limit successful cutting propagation of Acer rubrum October Glory, A. rubrum Red Sunset, Hamamelis vernalis, H. virginiana and Stewartia pseudocamellia. Localized blanching (banding) of the cutting on the stock plant; a range of 3 IBA concentrations, and foliar spray application of: 1% silver thiosulfate(STS), STS followed ten days later by Gibberellin, GA4/7:250ppm(STS GA),50ppm thidiazuron (TDZ) and TDZ followed by GA4/7 (TDZ GA)were tested for increasing growth and overwinter survival.. Carbohydrates were analyzed in cuttings which did and didn't grow. A. rubrum October Glory*, and Hamamelis spp all had increased OS for cuttings which grew. A. rubrum Red Sunset demonstrated a similar trend. Hamamelis spp. had significant increase in carbohydrates for cuttings which grew. A. rubrum October Glory' exhibited the same trend. S. pseudocamellia did not have increased OS with growth. and showed no increases in carbohydrates with growth, but the cuttings that didn't grow had at least 93 % more carbohydrates than the other species analyzed. All species had higher OS when stored in the 3° C cooler, than in the fluctuating cold frame. Banding increased growth of A. rubrum October Glory, and H. virginiana. IBA concentration affected growth of all species. STS increased growth of H. virginiana and S. pseudocamellia. GA4/7 increased growth of all cuttings except A. rubrum October Glory.
052 GENETICS OF FLORAL LONGEVITY IN PETUNIA
Authors: Krahl Kimberly H. , Randle William M.
Published: February 2019

Ornamental plant breeding has focused almost exclusively on floral prolificacy rather than floral longevity. The importance of floral longevity is obvious in any ornamental crop grown primarily for floral display. This study was undertaken to determine the genetic basis of floral longevity in an important ornamental crop, petunia.

Four parental lines representing the extremes for floral longevity were used to generate 6 F1 families which were selfed to generate F2 families and backcrossed to create 12 backcross families. Generation means analysis was utilizied to determine estimates of additive. dominance, and epistatic genetic variance for floral longevity in petunia.
053 CLONAL DECLINE IN HORTICULTURAL CROPS DUE TO MULLER'S RATCHET
Authors: Anderson Neil O. , Ascher Peter D.
Published: February 2019

It should be possible to maintain horticultural clones unchanged forever through asexual generations, as commercial propagators and clonal repositories maintain clonal integrity, disease-free stock plants, or remove mutations. However, unintentional selection for nonhorticultural traits could still be occurring. Accumulations of such traits would be due to the operation of Muller's ratchet and include fertility losses, increases in virus titer, and stunted growth habit. In chrysanthemums, Dendranthema grandiflora. clones separated from sexual cycles for generations become increasingly sterile. Seed set across years, using coefficients of crossability (FCC/MCC), was examined for garden clones (forced through sexual cycles annually) and greenhouse clones (asexual cycles only). Garden clones 40 years old (54-101-11) had only depressed levels of fertility. In other cases (77-AM 3-17), the ratchet was reversed >1 sexual cycle. Greenhouse clones were often completely sterile since their propagation is primarily asexual.
063 IMPLEMENTING WRITING ACROSS THE CURRICULUM IN HORTICULTURE COURSES
Authors: McKenney Cynthia B.
Published: February 2019

Writing Across the Curriculum (WAC) programs are viewed as a plausible solution to poor student communication skills. These programs are further justified on the premise that writing fosters and reinforces learning in any discipline.

WAC programs integrate easily into horticulture. Traditional writing opportunities frequently utilized in horticulture include essays, papers, presentation critiques, lab reports, field trip summaries, business proposals, and cropping schedules. New opportunities might include microthemes and target audience writings.

WAC programs have their own share of pitfalls: increased grading time, reduced course content, ill-equipped faculty to teach language arts, and unrecognized objectives. Ultimately, the success or failure of a WAC program hinges on the commitment of faculty in the discipline who should have the best understanding of the language and style needed to communicate effectively in their field.
072 MITES AND CROP DENSITY INFLUENCE `DELICIOUS' APPLES
Authors: Marini Richard P. , Pfeiffer Douglas G.
Published: February 2019

`Campbell Redchief Delicious' trees were treated with a factorial combination of five European red mite (ERM) populations (range = 0 to 3000 cumulative mite-days per leaf (CMD)), and four crop densities (CD) (range = 2 to 12 fruit · cm-2 trunk cross sectional-area) during two growing seasons. Yield was related positively to CD and negatively to CMD. In general, fruit weight, fruit surface red color, and fruit soluble solids concentration declined with increasing levels of CMD and CD. For most response variables, there was a significant CMD by CD interaction. Fruit were graded into six size categories and crop value was calculated. Crop value generally increased with increasing CD and declined with increasing CMD, mite feeding reduced crop value most at high CD. Crop value estimates were used to calculate economic injury levels. We propose economic injury levels of 1000, 500, and 300 CMD, respectively for spur `Delicious' trees with light, moderate, and heavy crop loads.
091 PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES OF GRAPEVINES TO METHANOL
Authors: Dami Imed , Stushnoff Cecil , Hamman Richard
Published: February 2019

The response of grapevines to methanol was investigated at the Orchard Mesa Research Center in Grand Junction, CO. Optimum sublethal methanol dose levels, based on visual assessments, were 90% for leaves and 100% for trunks for 10 cultivars. Total soluble sugars (TSS) of the berries, monitored every week until harvest, showed significant differences with Muscat Blanc during veraison. Berries from the methanol-treated vines had higher TSS (16.4 °Brix) than controls (15 °Brix). However, no significant differences were observed later in the season when approaching fruit maturity. At harvest, data on yields as estimated by cluster weight, berry weight and berry size showed no differences between the two treatments. Methanol did not enhance cold hardiness of bud tissues. measured by differential thermal analysis. It was concluded that, although methanol has been reported to improve several physiological features of C3 crops, our study suggested that it has little or no practical effect on grapes. More data on the determination of sugars in berries by HPLC will be discussed.
113 ESTIMATING SOIL. POTASSIUM SUPPLY TO MEET PROCESSING TOMATO REQUIREMENTS
Authors: Hartz T. K.
Published: February 2019

A 1993 survey of 50 commercial processing tomato fields in California revealed widespread potassium deficiency, as determined by tissue K levels below existing sufficiency standards and the occurrence of vine necrosis consistent with K deficiency. Soils from these fields were analyzed for exchangeable K by ammonium acetate extraction, and for K release rate by a 7 day incubation procedure (1:10 soil:. 01 M CaCl2 at 25°). Soil K release rate was more highly correlated with tissue K at midseason than was exchangeable K. These soils were further examined for K fixation capacity. Three g soil was blended with 3 ml 10 meq K as KNO3, allowed to dry, incubated for 7 days in a 1:10 soil: H2O solution, then extracted in 1 N NH4Cl; added K not recovered was considered fixed. Percent K fixation ranged from 0 to 82%. These data suggest that the inconsistent response of processing tomato to K application in numerous California trials may be related to a) the reliance on extractable K analysis to characterize soil K supply and b) no consideration of soil K fixation capacity in determining K application timing and method.
119 PHOTOSYNTHESIS AND RESPIRATION OF APPLE PLANTS AT DIFFERENT CARBON DIOXIDE CONCENTRATIONS
Authors: Pan Qiyuan , Quebedeaux Bruno
Published: February 2019

Low CO2 concentrations ([CO2]) frequently occur in dense crop canopy. To determine plant performance under sub-atmospheric [CO2], young `Gala' apple plants were phytotron-grown at 928 mmole m-2s-1 light intensity. Whole-plant photosynthesis and respiration under [CO2] between 0 and the ambient level (382 to 460 ml 1-1) were measured by monitoring [CO2] of the air entering and coming out of a 38-1 clear plexiglass gas exchange chamber at either 3.4 or 6.2 1 min-1. The chamber seals two plants of up to 77 cm height for long-term experiments. There was a linear relationship between [CO2] and net photosynthesis (Pn), with the R2 being as high as 0.99. The increase of Pn with increased [CO2] was 51% greater for the high air flow than for the low air flow. At the ambient CO2 level Pn at the high flow rate was 49% higher than that at the low flow rate. CO2 compensation points were 57.6 and 58.5 ml 1-1 at the high and low flow rates, respectively. The relationship between [CO2] and dark respiration was linear. Dark respiration decreased by 20% on average as the [CO2] increased from 0 to the ambient level, and it was 11% higher at the high flow rate than at the low flow rate. These results suggest that wind may act to reduce Pn depression in dense crop canopy by both reducing leaf resistance and atmospheric [CO2] gradient outside the boundary layer.
158 Effects of supplemental lighting and cluster pruning on yield, photosynthesis, and sugar accumulation of greenhouse tomato plants
Authors: Dafiri Mohammed , Gosselin André
Published: February 2019

Tomato plants were submitted to three photosynthetic photon fluxes (PPF) of 50, 100, and 150 μmol. m-2s-1 and cluster-pruned according to different scenarios. The highest PPF combined with severe cluster pruning produced the highest yield and the best fruit quality. The highest PPF increased growth, photosynthesis and leaf sugar content. Severe cluster pruning increased the average fruit weight, leaf sucrose and glucose content, but reduced photosynthesis. Data will be discussed in relation to crop management and efficiency.
160 TOMATO PRODUCTION IN KUWAIT
Authors: Abdal Mahdi S. , Basham Charles
Published: February 2019

Tomatoes are the leading vegetable crop in Kuwait and are produced in both open field agriculture (OFA) and protected environment agriculture (PEA). Prior to the invasion by Iraq there were 1018 ha of tomatoes in OFA and 76 ha in PEA. We project that nearly 90% of the pre-invasion PEA area and more than 50% of the OFA area will be restored to production in the 1994 season.

Most of the PEA structures currently in production are simple structures of bent pipe frames with plastic film covers. Some multi-span, rigid-cover structures have been restored. Fan and pad cooling systems are used although many of the structures are uncooled and produce only a winter crop.

PEA production uses desalinated sea water (DW) for irrigation and a mixture of DW and brackish water (BW) for cooling. OFA uses a mixture of DW and BW for irrigation, usually applied with drip systems.

Pest problems include whitefly, spider mite, aphid, root knot nematode and a number of diseases including tomato yellow leaf curl.
165 VESICULAR-ARBUSCULAR MYCORRHIZAE DECREASE DAYS TO FLOWERING AND INCREASE INFLORESCENCE NUMBER OF GERANIUM `SPRINTER SCARLET' GROWN IN THREE SOILLESS MEDIA.
Authors: Shaw Peter M. , Hummel Rita
Published: February 2019

The effects of vesicular-arbuscular mycorrhizae (VAM) on the growth and flowering of Geranium `Sprinter Scarlet' in three greenhouse soilless media were investigated. All media proved to be well suited for geranium growth and VAM had no significant effect on most vegetative parameters. However, VAM significantly reduced the number of days to flowering of plants grown in Mycori-Mix and Sunshine Aggregate #4 by 6.4 and 6.6 days respectively. Plants grown in Mycori-Mix with VAM flowered 99.4 days after sowing, significantly sooner than those grown in the other media with VAM. Mycorrhizal plants in Mycori-Mix and Metro Mix had a greater number of lateral branches >5 cm in length than non-mycorrhizal in the same media. Regardless of VAM treatment, plants grown in Mycori-Mix had a greater number of visible inflorescences at harvest than the other two media.
170 DRIP IRRIGATION OF PLASTIC-MULCHED STRAWBERRY USING CARBONATED WATER-A GREENHOUSE STUDY
Authors: Shore Margaret L. , Hughes Harrison G. , Moore Frank D. , Smith Danny H.
Published: February 2019

Carbonated water (CW) application has enhanced yields of tomato. However, little is known about the mechanism of this response. Our objectives were to determine if strawberry would respond to CW application and the effect of soil pH modification on the expression of a yield response. Two different soils were used; a calcareous soil (5% CaCO3, pH 7.9), with a Zn content 0.8 ppm and a non-calcareous soil (< 1% CaCO3, pH 6.5) with a Zn content 8.8 ppm. The carbonated water temporarily lowered the pH of the calcareous soil to 6.7 and the non-calcareous soil to 5.9, at both extremes of the optimal range (6.0-6.7) for strawberry. Application of carbonated water increased production of marketable fruit as compared to the tap water control on both soils, and the magnitude of the response to CW was similar for both soils. Soil and water treatment effects on leaf tissue Zn levels will also be discussed.
172 STRAW MULCH INCREASES YIELD OF THORNLESS BLACKBERRY CULTIVARS
Authors: Funt Richard C. , Bartholomew Henry M. , Schmittgen Mark C. , Golden John C.
Published: February 2019

Annual yields of thornless blackberries may be inconsistent due to low winter or early spring temperatures. Under ideal conditions thornless blackberries can produce two or three times more berries per acre and ripen over a longer period of time than the erect, thorny type.

Yields of several thornless blackberry cultivars were improved by using straw mulch. In experiment one standard cultivars were compared to numbered clones. In experiment two Chester, Black Satin, Dirksen and C-65 were compared. Over a six year period, straw increased yields from 1670 to 8300 pounds per acre. Straw mulch appeared to be effective during years where low temperatures did not affect bearing surface.
188 DEVELOPMENT OF A FORECAST SYSTEM FOR GROWTH REGULATOR (HYDROGEN CYANAMIDE) APPLICATION ON PEACHES USING A COMPUTERIZED AGRICULTURAL WEATHER PROGRAM
Authors: Powell Arlie A. , Harker Karl , Getz Roger , Simpson Eugene H.
Published: February 2019

In order to provide timely weather information to county agents (CEA) and growers, a sophisticated user friendly weather information program was developed that provides over 900 weather files daily to users. This program uses a 420 Sun Server that automatically downloads files from the NWS office on the AU campus and makes them instantly available to CEA offices via the Extension Network. Growers may obtain information from CEAS or use their personal computers to access a “Weather Board”. A chilling/growing degree hour (GDH) model (mod. 45) has been developed for peaches that provides a good estimate of when rest is completed and allows prediction of phenological stages through flowering. This information assists growers with orchard management decisions. Studies with peaches were conducted using the chilling/GDH model to properly apply hydrogen cyanamide (Dormex) to replace lack of chilling. This work resulted in an effective application timing based on chilling accumulation and allowed development of a forecast model for grower use.
190 EFFECTS OF DORMANT APPLICATION OF SOYBEAN OIL ON PEACH TREES
Authors: Myers R. E. , Deyton D. E. , Sams C. E.
Published: February 2019

`Redhaven' peach trees at the Knoxville Experiment Station were sprayed to runoff on 3 February 1993 with single applications of 0, 2.5, 5.0, 10.0, or 15.0% (v/v) degummed soybean oil with 0.6% Latron AG 44M emulsifier. Treatments were arranged in a randomized complete block design with 6 single tree replications. The internal CO2 concentration of treated twigs was elevated the first day and continued to be significantly higher than the control through the fifth day following treatment. Respiration rates of soybean oil treated buds-twigs were lower than the control for the first eight days after treatment. Flower bud and bloom development were delayed by treatment of trees with 5.0 to 15.0% soybean oil. Treatment with 5.0% oil delayed bloom approximately 4 days. The greatest delay (approximately 6 days) occurred after treatment with 10.0 or 15.0% oil. Yield was reduced and fruit size increased as the concentration of soybean oil was increased. Optimum fruit size was achieved with the 5.0% soybean oil treatment.
193 COLD HARDINESS OF CORNUS ALBA `ARGENTEA MARGINATA' AND WEIGELA FLORIDA `RUMBA' GROWN UNDER DIFFERENT FALL FERTILIZATION PROGRAMS.
Authors: Duchesne Isabelle , Rioux Jacques-André , Beaudry Michèle
Published: February 2019

Effects of fall fertilization programs on cold hardiness if young Cornus alba `Argenteo-Marginata' and Weigela florida `Rumba' plants, were examined. In August 1992, four fertilization programs were applied to one year old woody plants, propagated by cuttings in 1991. Fertilization treatments were as follows: 1. discontinuation of fertigation treatments on August 30; 2. gradual decreasing nitrogen concentration (100 to 0 mg/l of 20-20-20) from August 15 to September 30; 3. constant nitrogen concentration (100 mg/l of 20-20-20) from August 15 to September 30; and 4. high potassium concentration (110 mg/l of 7-11-27) from August 15 to September 30. Whole plants were the” removed from pots and roots cleaned. They were placed under freezing temperatures ranging from 0 to -20°C at 2°C intervals. Sampling were taken at the end of September, October and November. After the freezing test, the plants were stored at -2°C. re-potted in May 1993, and evaluated for winter injury in August 1993. Results indicate that none of the four fertilization programs induced positive or negative effects on cold hardiness in both species. However, the signs of cold hardiness are observable in October at different degrees in each species. Plants of Weigela died at -12°C, while all plants of Cornus survived down to -20°C. Furthermore, a 25% loss of growth of stems and roots was found at -9°C for Weigela, while for Cornus it was -17 and -15°C stems and roots respectively.
197 ENERGY BALANCE OF URBAN SURFACES AFFECTS GAS EXCHANGE OF CRABAPPLE AND NORWAY MAPLE
Authors: Kjelgren Roger , Montague Thayne , Rupp Larry
Published: February 2019

We investigated gas-exchange response of norway maple and crabapple to the energy balance of turf, bark-mulch, and asphalt surfaces. In each surface stomatal conductance, leaf temperature (T1), and photosynthesis, were measured during two dawn-to-dusk studies concurrent with soil (To), top surface (Ta), and air temperature (Ta) measurements. Different properties affected the energy balance of each surface. Turf transpiration moderated To and Ts while low thermal conductivity of the mulch resulted in To similar to turf but Ts23C higher. Higher thermal conductivity of the asphalt resulted in higher To but Ts intermediate to mulch and turf surfaces. We did not detect differences in Ta, probably due to close proximity to one another that allowed substantial air mixing between treatments. Higher Ts increased longwave radiation flux that raised midday T1 of trees in the mulch and asphalt 3 to 8C higher than trees in the turf. Differences in T1 between the asphalt and mulch were minimal. Stomatal conductance declined with increasing leaf-to-air vapor pressure gradient in all trees, and was consistently lower for trees in the mulch and asphalt through the day due to larger gradients induced by higher T1. Midday photosynthesis was highest for trees in the turf and lowest for those in the mulch. Foliar interception of higher energy fluxes from mulch and asphalt surfaces apparently limited gas exchange in both species due to over-optimal leaf temperatures as compared to trees in the turf
198 EVALUATION OF DROUGHT TOLERANCE OF Fragaria chiloensis CLONES WITH POTENTIAL AS LOW-MAINTENANCE ORNAMENTAL GROUNDCOVERS
Authors: VanDerZanden Ann Marie , Cameron J. Scott
Published: February 2019

Fragaria chiloensis (Linnaeus) Is a viable. low maintenance alternative to groundcovers currently available in the ornamental landscape industry. There is considerable genetic variability within this specks for leaf morphology, growth and flowering habits as well as drought tolerance. Clones collected from 11 coastal sites in CA and OR were compared for drought tolerance after two Imposed water stress\recovery cycles. Predawn water potential, gas exchange, chlorophyll (chl) content, fourth derivative spectroscopy, carbon isotope discrimination, and total biomass production were evaluated and significant clonal differences were observed.

Predawn water potentials after the first stress cycle ranged from -35.0 MPa to -6.5 MPa. Clones I05, DNT and G19 had highest predawn water potentials and gas exchange rates after both stress cycles. In the control group, I05 and DNT had higher levels of chl a, chl b, total chl and chl a\b. After the first stress cycle, clones DNT and I05 had the highest chl a\b ratio, however, after the second stress event there were no differences In any chl parameters. Varying adaptive abilities observed may suggest differential use in the landscape.
202 THE USE OF RYE, WHEAT, AND CRIMSON CLOVER FOR WEED SUPPRESSION IN `CARDINAL' STRAWBERRIES
Authors: Whitworth Julia
Published: February 2019

Rye, wheat, and crimson clover were planted in separate pots outdoors in the fall of 1992 and 1993 Control pots had media without plants in them. There were 4 replications in 1992 and 9 in 1993. In early spring. the rye, wheat, and crimson clover were killed, using tillage in 1992 and glyphosate in 1993. In 1992. the residues were tilled into the media. In 1993, the residues were left on the surface. `Cardinal' strawberries, yellow nutsedge nutlets, crabgrass seeds, or bermudagrass rhizomes were planted into pots with the various residues, and also into the control pots. In July of 1992 and August-September of 1993, the weeds and strawberry plants were removed from the pots. Various growth measurements were taken on the plants. None of the tilled residues affected the growth of nutsedge or crabgrass, but tilled rye and wheat residues increased the growth of strawberry plants and decreased the growth of bermudagrass. None of the residues left on the surface significantly affected the growth of crabgrass. Clover residues suppressed nutsedge growth Both strawberry and bermudagrass growth was greatly reduced by all surface residues
208 EXTENSION SERVICES LINK INDUSTRY TO RESEARCH
Authors: Beck Nancy , Kerr Jim
Published: February 2019

The restructuring of government research and extension organisations within New Zealand provides a rare opportunity to reshape our approach to technology transfer. This paper describes the approaches which HortResearch is taking to develop its technology transfer activities and extension services to New Zealand's horticultural industries.

Research is without purpose if the resultant technology is not transferred from scientists to growers and other industry groups and vice versa. Effective research planning in HortResearch and the provision of decision support information to growers, will depend on good working links between researchers and other key industry players. Rapid development of this linkage is crucial due to the loss of the traditional free extension service in the restructuring process.

A working party assessed the industry's needs and concepts of technology transfer. A workshop to discuss technology transfer option was held with key people from the horticultural industry; this was followed later by an in-house workshop. Proposals for the Institute to establish link teams for each horticultural sector were the outcome.
213 A COMPARISON OF STRATEGIES FOR SCHEDULING IRRIGATION OF VEGETABLES
Authors: Simonne Eric H. , Kemble Joseph M. , Smittle Doyle A.
Published: February 2019

The effect of irrigation scheduling method (variable crop factor, 1; constant crop factor, 2; empirical, 3), soil water tension (25, 50, 75kPa SWT), tillage (disc arrow, DA, moldboard plow, MP) and planting dates (PD) on total irrigation (TI), number of irrigations (NI), useful (UR) and lost rainfall (LR) was studied using a Pascal program that simulated water budgets of 720 crops of snap bean over 10 years. NI and TI were significantly (p<0.01) lower with met.1. Met.3 had the lowest LR and highest UR, but did not allow the complete calculation of the water balance. TI was significantly higher at 25kPa. MP tillage requested fewer NI and less TI, had lower LR and higher UR. Early PD requested fewer NI and TI, and had higher LR. Hence, when water supply was not limiting and weather data were available, a combination of Met.1, MP at any PD provided a continuous supply of water to the crop while controlling water deficit.
226 USING CD-ROM COMPUTER TECHNOLOGY TO TEACH PLANT MATERIALS
Authors: Gilman Edward F.
Published: February 2019

Due to the high cost of color separations, few plant materials texts have photographs and line drawings showing each plant at different times of the year and at different ages. CD-ROM computer technology allows the user ready access to this information at a reasonable cost. Horticulturists at the University of Florida have developed three CD-ROM discs for use throughout the U.S. The discs contain more than 3000 pages of text, extensive morphological characteristics and plant use suggestions, in addition to more than 2000 line drawings and nearly 3600 photographs of more than 1,800 plant species. Software developed for DOS and Windows allows the student to generate customized plant lists for landscape sites. Lists can be created to match specific site characteristics, desirable ornamental attributes, or both. Students can also use the programs to help identify unknown plant specimens. Other features allow viewing of insect and disease problems and access to up-to-date control recommendations.
235 ELECTRONIC SENSING OF AROMATIC VOLATILE!? FOR QUALITY SORTING IN BLUEBERRIES
Authors: Benady Meny , Hetzroni Amots , Simon James E. , Bordelon Bruce
Published: February 2019

We have developed an electronic sensor (“sniffer”) that measures fruit ripeness rapidly and nondestructively by measuring the aromatic volatiles that are naturally emitted by ripening fruit. In this study, we evaluated the potential of using the fruit ripeness sniffer in the quality sorting of blueberries. Blueberries were first visually classified into four distinct ripeness classes: unripe; half-ripe; ripe; and over-ripe and quantitatively measured for color, firmness, TSS, and sugar acid ratio. Ripeness classification accuracy with the sniffer matched or exceeded that of all other ripeness indices. The sniffer differentiated unripe, ripe and over-ripe berries within one second, but could not distinguish between the unripe and half-ripe class. Detection of l-2 damaged or 1-2 soft fruit spiked within a large container of 24-37 high quality ripe fruit was also achieved, but required a response time of 10 seconds. Electronic sensing of aromatic volatiles may be a useful new technique in the grading and sorting of blueberries.
243 VOLATILE EMISSIONS FROM LETTUCE GROWN UNDER DIFFERENT TEMPERATURES, LIGHT INTENSITIES, AND PHOTOPERIODS
Authors: Charron Graig S. , Cantliffe Daniel J.
Published: February 2019

The National Aeronautics and Space Administration (NASA) is developing a Controlled Ecological Life Support System (CELSS) for long-term space exploration in which plants would be one major component. Volatile emissions from these plants may disrupt the proper functioning of CELSS. This research investigated how environmental factors alter the volatile emissions from hydroponically-grown `Waldmann's Green' leaf lettuce. A growth chamber was modified to allow the injection of purified air into a glass enclosure positioned over individual lettuce plants. Air samples from the enclosure were analyzed by gas chromatography-mass spectrometry (GC-MS). The lipoxygenase pathway products (Z)-3-hexenal, (Z)-3-hexenol, and (Z)3-hexenyl acetate were emitted following the end of the light period. Mechanical damage also stimulated the release of these same compounds. The design of toxin management systems in CELSS may need to incorporate these findings. Additionally, lipoxygenase pathway products have been previously demonstrated to influence insect behavior and pathogen growth, and may indicate future directions for plant breeding.
245 EFFECTS OF PLANT AGE AND CONSTANT NUTRIENT SUPPLY ON POTATO LEAF ELEMENTAL COMPOSITION
Authors: Berry W.L. , Wheeler R.M. , Mackowiak C.L. , Stutte G.W. , Sager J.C.
Published: February 2019

Critical levels of nutrients in leaf tissue are influenced by plant metabolism, environment, and nutrient availability. In this study, we measured the elemental concentrations in fully expanded, upper canopy potato (Solunum tuberosum cv. Norland) leaves throughout growth and development in a controlled environment. Plants were grown hydroponically (NFT) in NASA's Biomass Production Chamber using a complete nutrient solution with the electrical conductivity maintained continuously at 0.12 S m-1. Photoperiod and air and root zone temperatures were changed midseason to promote tuberization, while CO2 levels were maintained at 1000 μmol mol-1 throughout growth. During vegetative growth, leaf nutrient concentrations remained relatively constant, except for a decline in Ca. During tuber enlargement and plant maturation, overall nutrient uptake decreased. Concentrations of the less mobile nutrients such as Ca, Mg, and B increased in the leaf tissue during mature growth, but somewhat surprisingly, highly mobile K also increased. Leaf concentrations of P, Zn, and Cu decreased during maturation.
248 COMPARISON OF MEDIUM, TISSUE TYPE AND GENOTYPE ON IN VITRO PLANT REGENERATION OF TOMATO
Authors: Vallejo Roger L. , Polston Jane E.
Published: February 2019

Cultured cotyledon and leaf pieces of five cultivars of Lycopersicon esculentum Mill. were tested in six culture media for their ability to produce shoots for transformation studies. The no. of tissue pieces with callus/total tissue pieces, quality of callus (size and vigor), no. of tissue pieces with shoots/total tissue pieces, and shoot quality (size and vigor) were measured. Cultivars tested were `Campbell 28', `Flora-Dade', `UC82b', and two breeding lines, Fla.7171 and Fla.7324. The six media used were Murashige and Skoog medium supplemented with six combinations of indole acetic acid (IAA) and cytokinins: A) 1 mg/l IAA + 1 mg/l kinetin, B) 0.5 mg/l IAA + 2 mg/l kinetin, C) 0.02 mg/l IAA + 1 mg/l zeatin, D) 0.2 mg/l IAA + 2 mg/l zestin, E) 1 mg/l IAA + 2.5 mg/l BAP (6-benzyl amino purine), and F) 0.2 mg/l IAA + 1 mg/l BAP. Standard procedures were followed for culturing 4 - 5 mm pieces of cotyledon and leaves. Callus and shoot regeneration were greater, less variable and faster, in cotyledon than in leaf pieces. Media C and F gave the highest rates of callus and shoot production, respectively, in cotyledon tissue. Medium E gave the highest rate for both callus and shoot production in leaf discs. The best rates of shoot production were achieved with cotyledon tissue from cultivar UC82b cultured on media C (85.3%) and F (77.2%).
249 REGENERATION OF GARLIC, Allium sativum L., AND ITS IMPLICATION FOR TRANSFORMATION
Authors: Myers J. Michele , Simon Philipp W.
Published: February 2019

Garlic callus derived from young basal plate explants of one genotype was evaluated for regeneration. Callus was initiated on a modified B5 medium supplemented with 2.4-D for 10 weeks and then subcultured on medium with picloram + 2iP for 10 weeks. This friable callus was used in regenerating plants. Callus was transferred to a modified B5 medium with 10 hormonal combinations of auxins and cytokinins in a complete factorial design. Four pieces of callus about 1.0 cm square were transferred to a petri plate with four replications per treatment Callus was subcultured monthly to ensure optimum growth and data was collected after three months in culture. The best regeneration frequency occurred on medium supplemented with picloram + BA. Regenerated lines were then transferred to medium with no hormones for evaluation of single plants. The genetic stability of these regenerated lines was tested using polyacrlyamind gel elcctrophoresis (PAGE) and six isozyme systems. This regeneration system will be very useful in the production of regenerated putative transformed lines from callus.
252 STUDIES ON ADVENTITIOUS REGENERATION IN COCOYAM
Authors: Nyochembeng Leopold M. , Garton Stephen
Published: February 2019

Studies were conducted to determine the response of cocoyam shoot tips, petioles, cotyledons and hypocotyls in various media for callus formation, adventitious shoot development and somatic embryogenesis. In all experiments, B5 basal medium or low N B5 were supplemented with various growth regulators.

High frequency adventitious shoot proliferation was obtained using cotyledons and hypocotyls in medium supplemented with 1 mg/l IBA and 0.5 mg/l TDZ. Embryogenic callus was obtained using shoot tips in media containing 1 mg/l Dicamba, hile somatic embryos were observed in media containing 0.3 mg/l 2, 4 - D and 1 mg/l Kinetin, using hypocotyl and petiole explants. The impact of these results on micropropagation of cocoyam is discussed.
260 NITROGEN PARTITIONING IN APPLE IS AFFECTED BY TIMING AND TREE GROWTH HABIT
Authors: Khemira Habib , Righetti Timothy L. , Azarenko Anita N.
Published: February 2019

Young bearing spur (Red-Spur Delicious) and standard (Top-Red Delicious) type apple trees were given one of the following treatments: 120g N applied to the ground in spring (SG), 120g N applied to the ground one month before harvest (PG), 60g N sprayed on the foliage after harvest (FF), 60g N SG and 60g N PG, or 60g N SG and 60g N FE Urea and NH4NO3 depleted in 15N (0.01 atom percentage 15N) were used for foliar and ground applications, respectively. Very little labeled N was present in leaves and fruit with PG applications, but roots, bark, and buds contained substantial amounts of it. Nitrogen from the FF sprays was effectively translocated to buds and bark. Percentage of N from the fertilizer in Sept leaves from spur-type trees that had only 60 g of N in spring was 56% higher than that found in standard-type trees. This figure rose to 180% with 120 g N spring application. Mature fruit showed the same trend. Spur-type trees appeared more responsive to N management practices. In contrast to the above ground structure, small roots of standard-type trees showed more label than those of spur-type trees. The difference was bigger with SG applications. Partitioning of N in the roots was apparently affected by the scion.
266 NITROGEN EFFECT ON GROWTH OF YOUNG `HAMLIN' ORANGE/`SWINGLE' CITRUMELO TREES IN THE NURSERY
Authors: Guazzelli L. , Davies F.S. , Ferguson J.J.
Published: February 2019

Two experiments were conducted with containerized `Hamlin' orange trees (Citrus sinensis [L.] Osb.) on `Swingle' citrumelo (C. paradisi Macf. × Poncirus trifoliata [L.] Raf.) rootstock to study the effects of N rate on growth of plants in the nursery. Treatments consisted of the following N rates: 12, 50, 100 and 200 mg·liter-1 applied once a week through drip irrigation. In Expt. 1, fertilization at the 200 mg·liter-1 rate resulted in greater scion growth, trunk diameter and total leaf dry weight as compared to the other rates. In Expt. 2, application of 100 and 200 mg·liter-1 rates resulted in greater scion growth and trunk diameter as compared to lower rates, but no differences were seen between the two highest rates. Trees receiving the 12 and 50 mg·liter-1 rates were stunted and leaves were chlorotic. Therefore, the optimum N rate for trees on `Swingle' citrumelo rootstock is between 100 and 200 mg·liter-1, although the 200 mg·liter-1 rate may not be economically justified. Moreover, the N rate for nursery plants growing on `Swingle' citrumelo rootstock in commercial medium may be higher than for other rootstocks, where rates less than 50 mg·liter-1 produce optimum growth.
268 DARK BROWNING AND ITS CONTROL OF `NIITAKA' JAPANESE PEARS DURING STORAGE
Authors: Kim Wol Soo , Kim Seong Bong , Song Nam Hyun , Lee Han Chan
Published: February 2019

Dark browning of fruit skin of Japanese pear `Niitaka' (Pyrus pyriforia) is a physiological disorder during storage. Very higher rates of dark browning were observed in bagged pears, and in the orchards under higher humidity during the maturing season. Also the factors, such as higher humidity and lower temperature in storage room increase the dark browning. Dark browning is a different physiological disorder with the sugerficial scold of apples, which associated with conjugated trienes, oxidation products of alpha-farnesenes. The dark browning was controlled by dipping the harvested pears into 1,000 ppm diphenylamine (DPA) solution for 5 seconds before storage.
276 INHERITANCE OF SOME CHARACTERS IN OKRA
Authors: El-Hak Seif H. Gad , Saved H. Mahmoud , Abobakr Mohamed A. , Aiv Ragab M.
Published: February 2019

Inheritance of plant height, leaf lobing index, internode length, and number of fruits per plant was studied. Four crosses (Pusa Swani × White Velvet and its reciprocal; Pusa Swani × Emerald: White Velvet × Emerald) were used in this investigation. The parents, F1. F2. and the first backcrosses populations were grown. The inheritance of all the studied characters was found to be quantitative. The proper statistical methods were followed for the analysis of all recorded data. It could be generally concludes that the narrow sense heritability in plant height ranged from 37.18 to 59.13%. leaf lobing index ranged from 26.35 to 77.73%: internode length ranged from 50.06 to 56.52%. and number of fruits per plant varied from 23.22 to 44.26%.
284 EVALUATION OF THREE DISEASE FORECASTING SYSTEMS FOR CON-l-ROLLING EARLY BLIGHT ON STAKED OR GROUND CULTURE TOMATOES IN NEW JERSEY
Authors: Maletta M.H. , Cowgill W.P. , Tietjen W. , Nitzsche P. , Johnston S.A.
Published: February 2019

Since 1990, FAST - Pennsylvania State University, CUFAST - Cornell University. and TOM-CAST - Ridgetown College, Ontario, three systems for forecasting early blight, have been field tested at The Snyder Research and Extension Farm in northwestern New Jersey for their potential use in fresh market tomato production in that area of the state. In 1993, the number of fungicide applications for tomato early blight control required by the three forecast systems was less than the number required following a weekly schedule. FAST and CUFAST scheduled applications of chlorothalonil, 1.5 lb per acre, reduced disease severity, hut TOM-CAST scheduled applications did not reduce disease severiety compared to the untreated control. Culture did not affect disease control results hut did affect disease incidence and post-harvest losses. Total and marketable yields were not affected by fungicide application schedule. Potential cost savings of $270 or $465 per acre, resulting from reduced numbers of fungicide applications following CUFAST or FAST. were estimated. Chemical name used: tetrachloroisophtalonitrile (chlorothalonil).
293 INFLUENCE OF TEMPERATURE ON FRUITLET GROWTH OF APPLE
Authors: Warrington Ian J. , Schnell Tina A. , O'Brien Iona E.
Published: February 2019

The early growth responses of apple fruit to temperature were studied under controlled environment conditions. Growth of fruit on young trees of `Fuji'/M.9 `Golden Delicious'/M.9, and `Harold Red Delicious'/M.9 was frequently measured, over a 30-day period commencing 10 days after full bloom, under daily maximum/minimum temperatures of 22/12, 19/9, 16/6 and 13/3C. All other environmental conditions were maintained constant across all temperature treatments. Fruitlet diameter growth rate was approximately constant over the treatment period within each temperature regime and ranged from 0.24 mm day-1 at 13/3C to 0.85 mm day-1 at 22/12C. The growth responses to temperature were similar among cultivars but expansion rates were highest for `Fuji' and lowest for `Golden Delicious'. Cell division rates and durations, using flow cytometry, were measured over the treatment period and could be related to diameter growth rates. The impacts of temperature-induced differences in early fruit growth rates on final fruit sire will be described.
297 EFFECTS OF NAA ON FRUIT SIZE OF `DELICIOUS' APPLES
Authors: Black Brent L. , Bukovac Martin J. , Hull Jerome
Published: February 2019

Post-bloom fruit thinning of spur-type `Delicious' with NAA may occasionally result in excessive small fruit (50 - 67 mm) not correlated with crop load. We evaluated the effect of carrier volume and time of application on incidence of small fruit over three growing seasons. A constant dose of NAA (30 g·ha-1) was applied in 230 to 2100 liter·ha-1 at about 10 mm king fruit diameter (KFD). Amount of NAA-induced small fruit differed from year to year, but there was no significant effect of carrier volume in any given year. NAA (15 mg·liter-1) was applied as a dilute spray at 5 to 22 mm KFD. Time of application influenced fruit size distribution at harvest in only one of three years. The incidence of small fruit appeared more closely related to temperature during spray application than to carrier volume or time of application. The effect of NAA on growth rate of king fruit with minimal competition (branches hand thinned, no lateral fruit) was determined over the first month after thinning. There was no pronounced effect of NAA on post-treatment growth rate. In a related study, NAA caused a significant decrease in fruit size when two or more fruit were competing on the same spur, while fruit size in the absence of intra-spur competition was not significantly reduced.
298 CHALCONE SYNTHASE AND UDPG GLUCOSYL-TRANSFERASE REGULATE ANTHOCYANIN SYNTHESIS IN APPLE
Authors: Ju Zhiguo
Published: February 2019

Delicious apples were harvested and analyzed every 7 days from the start of fruit coloration to commercial harvest. Chalcone synthase (CS) activity increased from 521 to 4120 fkat/g protein during 30 days, while UDPG glucosyltransferase (UDPGTF) activity increased from 0 to 6570 fkat/g protein. These changes significantly correlated with anthocyanin synthesis in fruit skin. Ethephon enhanced activities of both enzymes for 25 days after application, but not beyond. Cycloheximide inhibited CS and UDPGTF activities by 57% and 72%, respectively, and this could not be overcome by ethephon treatment. Bagging prevented fruit from coloring, and removing bags before maturation promoted it. Activity of both enzymes was nil in bagged fruit, and increased dramatically after bag removal. Cycloheximide applied at bag removal reduced CS and UDPGTF activities 74% and 91%, respectively, and decreased anthocyanin synthesis by 82%. The results showed that both CS and UDPGTF were positively correlated with anthocyanin formation and both required de novo synthesis during fruit coloring, although CS had existed before that.
300 UV-B INDUCED CHANGES IN PHENYLALANINE AMMONIALYASE (PAL) ACTIVITY AND UV-ABSORBING COMPOUNDS IN COTTON AND CUCUMBER SEEDLINGS
Authors: Krizek Donald T. , Upadhyaya Abha , Mirecki Roman M.
Published: February 2019

UV-B (UV) induced changes in PAL activity and UV-absorbing compounds were followed in cotton after 1 to 9 days and in cucumber after 1 to 14 days. UV increased PAL activity in the lower hypocotyl (LH) of cotton but had no effect on the upper portion. In general, PAL decreased with time, but UV treatment slowed that decline in the LH portion. Anthocyanin concentration declined with time in both portions. In cucumber cotyledons, UV had no effect on PAL. In cucumber leaves, there was no overall effect of UV; but there were significant interactions with time. In both cotyledons and in leaves, PAL decreased with time. As in LH cotton tissue, UV slowed the rate of decline of PAL in cucumber leaves. In leaves, UV absorbing compounds (at 330 nm) were increased by UV; in cotyledons, the increase in absorption was greater in controls than in UV-B irradiated seedlings. In cotton, changes in anthocyanins mirrored those in PAL, this was not the case for UV absorbing compounds in either species.