bluuebunny/crossref_metadata_2025 huggingface dataset:
IDENTIFICATION OF ROSE CULTIVARS BY RESTRICTION FRAGMENT LENGTH POLYMORPHISMS
Authors: Rajapakse Sriyani , Hubbard Mark , Abbott Albert , Ballard Robert , Kelly John
Published: February 2019

Restriction Fragment Length Polymorphisms (RFLPs) were investigated in rose cultivars as a means of reliable cultivar identification. A random genomic DNA library was generated by shotgun cloning HindIII digested fragments of DNA extracted from rose cultivar Confection into pUC8 plasmid of Escherichia coli strain JM 83. Compared to genomic clones carrying low or highly repeated sequences, clones with moderately repeated sequences were most effective in cultivar identification. These clones were identified by hybridizing rose DNA fragments from the library with genomic DNA from `Confection'. Clones with moderately repeated copy sequences were used as probes to detect the presence of RFLPs by Southern hybridization of EcoRI digested genomic DNA of various rose cultivars. Several of these probes have revealed RFLPs useful in cultivar identification. By using a combination of two or more of these probes most of the rose cultivars compared at this time can be identified. A dichotomous key useful in identification of rose cultivars was prepared from RFLPs displayed by 3A9 probe.
AMMONIA AND NITRATE FLUCTUATIONS IN STORED WATER SAMPLES
Authors: Fare D.C. , Gilliam C.H. , Keever G.J. , Touchton J.T.
Published: February 2019

Water samples containing 0, 2.5, 10.0, or 20.0 ppm nitrate and ammonia were evaluated under 3 temperatures (0, 6, 20C) plus or minus sulfuric acid (36N) for changes in concentration. Ammonia and nitrate levels were measured 0, 1, 2, 4, 8, 16, 24, and 32 weeks after storing. Response to storage conditions was the same regardless of acid or concentration of ammonia or nitrate. Nitrate concentrations in the storage locations were similar for the first 2 weeks. Afterwards, treatments stored at room temperature fluctuated from initial standards. With ammonia, frozen samples had the greatest deviation from initial standards during the first 4 weeks. By week 24, ammonia samples stored at room temperature had exceeded acceptable deviations from the standards. Nitrate and ammonia samples held in refrigeration had the least fluctuation during the 32 week storage period.
A COMPARISON OF 12- TO 14- MONTH SLOW RELEASE FERTILIZERS IN AZALEA PRODUCTION
Authors: Eakes Joseph , Olive John W.
Published: February 2019

Five 12- to 14- month slow release fertilizers (Osmocote 17-7-12, Sierra 16-6-10, High-N 24-4-7, Sierrablend 17-7-10, and Nutricote 16-10-10 Type 360) were incorporated into a 3:1 pine bark: peat moss potting medium at one of 4 rates (0.9, 1.2, 1.5, and 1.8 kg N/m3). Plant growth of 3 azale a species, `Coral Bells' (Kurume), `Formosa' (Southern Indica), and `Pink Gumpo' (Satsuki), and monthly medium solution electrical conductivity (EC) were determined. Growth indices 180 days after applying fertilizer were greatest for plants receiving the Sierrablend and Osmocote fertilizers regardless of azalea species. Plant growth indices increased as N rate increased for the 3 azaleas, regardless of the fertilizer product. The highest media solution EC readings occurred during the first 90 days after fertilizer application for all fertilizer treatments and declined thereafter.
CHEMICAL ROOT PRUNING OF SAWTOOTH OAK WITH COPPER SULFATE
Authors: Flanagan Phillip C. , Witte W.T.
Published: February 2019

Interior surfaces of tube trays were painted with white exterior acrylic latex paint and white interior latex paint containing 0, 50, or 300 gm/1 copper sulfate. Germinated Quercus acutissima seedlings were used to study chemical root pruning effects and subsequent root regeneration. After 16 weeks, only 0.73 roots per seedling continued growth after being deflected by the tubewall painted with 100gm/1 compared with 3.67 for the control. Fibrous roots were reduced when in contact with cu treated surfaces. Height and caliper were not affected at any treatment level. Three weeks after transplanting to larger untreated containers, height and caliper were still unaffected by any cu treatment. Time required for regeneration of new roots was not affected by cu treatments.
INTEGRATING CADD INTO HORTICULTURE CURRICULUMS - OPPORTUNITY OR HEADACHE?
Authors: Creech David L.
Published: February 2019

Nationwide, horticulture enrollments have fallen from the peak in the late 1970's. For instance, Stephen F. Austin State University enjoyed a maximum horticulture enrollment of 99 undergraduates in 1977. By fall 1990, that enrollment had fallen to 30. The absence of CADD (computer-assisted drafting or design) on SFASU's campus suggested an opportunity for horticulture to fill a void. This paper will discuss the decision-making process and costs involved in setting up a ten-station AutoCad lab with good plotting capability. A successful marketing effort has resulted in easy-to-fill sections with wide appeal across campus. CADD courses make sense in horticulture if the resource is not available in other departments, technical support is available, and the tool has value to related projects in the horticulture program.
ADVANCED APPLE SELECTIONS IN THE ARKANSAS APPLE BREEDING PROGRAM: FRUITS FOR THE MID-SOUTH
Authors: Rom Curt R. , Rom Roy C. , Moore James N.
Published: February 2019

The Arkansas apple breeding program began in 1966 with objectives to develop high quality, dual purpose, adapted cultivars with a range of harvest dates and resistance to spring diseases. The program has two goals: 1) to develop red colored apples which are large, tart, firm and ripen between June and August; and, 2) develop yellow apples as a replacement for `Golden Delicious' which are large, typey, without russet and with a range of maturities from July through September. Apples with commercial potential are AA-18 (red, ripens 1-July), AA-44 (red, ripens 15-July), AA-58 (yellow, ripens 29-Aug.), AA-65 (yellow, ripens 11-Sept.) and AA-62 (yellow, ripens 15-Sept.). Data on time of bloom, harvest, fruit size, and fruit storage tests will be presented.
A RAINFALL CAPTURE SYSTEM FOR DRYLAND CANTALOUPE PRODUCTION
Authors: Bender David A. , Dainello Frank J.
Published: February 2019

A system for collecting winter rainfall and storing it for crop use during the growing season was developed and tested for three seasons for non-irrigated cantaloupe production. In early fall raised beds on 2-m centers were shaped with two trenches ca. 30 cm wide and 10 cm deep spaced 50 cm apart. Black plastic mulch was applied over the beds, with small mounds of soil placed on the plastic over the trenches to conform the mulch to the shape of the beds. Slits 15 cm long were made in the bottom of the trenches at 1 m intervals. Fifty kg/ha of a polyacrylamide gel was incorporated into the top 10 cm of some beds prior to shaping. Precipitation falling prior to spring planting was channelled into the beds through the trenches and prevented from evaporating by the mulch. Cantaloupes were seeded through the plastic in the spring and grown without irrigation. The rainfall capture system increased soil moisture in the surface 15 cm by 50% and in the top 60 cm by over 20%. Plant stands were increased from <10% in uncovered plots to nearly 70% under the system. Under drought conditions in two of the three seasons, yields were significantly higher in the rainfall capture plots than in uncovered plots, although not commercially acceptable. In a wet season, similar differences were noted and good commercial yields were obtained with the system. The rainfall capture system in conjunction with supplemental irrigation has the potential to allow excellent cucurbit production with limited water.
NUTRIENT UPTAKE OF SWEETPOTATO CULTIVARS
Authors: Niyonsaba E. , Rhoden E. G. , Biswas P. K.
Published: February 2019

The uptake of nutrients by sweetpotato (Ipomoea batatas) is critical in determining crop yield. Research was conducted to assess the effects of gypsum application on the nutrient uptake in three sweetpotato cultivars; `Carver II', `Georgia Jet' and `Jewel'. Gypsum application did not influence leaf P content of sweetpotato. However application of 3 tons per acre of gypsum increased leaf N and K content in `Carver II' and `Jewel' at 60 and 90 days after planting. There was a similar increase observed in Ca and Mg content of the leaf. While rate of gypsum did not influence nutrient uptake, date of sampling significantly influenced leaf nutrient concentration. It was noted that leaf K for `Jewel' and Ca for `Carver II' were greatest at 60 days after planting. Overall, Mg content was decreased following the application of gypsum in both `Carver II' and `Georgia Jet' cultivars.
THE EFFECTS OF WATER STRESS ON PLANT WATER STATUS AND GROWTH OF SELECTED SWEETPOTATO GENOTYPES
Authors: Thongket Thammasak , Garner James O.
Published: February 2019

Responses of four sweetpotato genotypes (`Centennial', `Travis', `Vardaman' and `MS 21-2') to water stress were studied. Two irrigation regimes (irrigation vs non-irrigation) were imposed on five-week old cuttings grown in a greenhouse environment. Transpiration and leaf diffusive resistance (LDR) were measured with a steady state porometer and mid-day total leaf water potentials were determined with a thermocouple psychrometer. Leaf growth was inhibited earlier than root growth. Water stress caused a reduction of leaf size in Centennial and in leaf number in the other three. Storage root number of Vardaman was not inhibited by limited soil moisture but development of storage roots was retarded by water stress. Total growth under non-irrigation of MS 21-2 was inhibited more than Vardaman. Mid-day leaf water potential did not show promise as a good indicator of water status. Genotypic differences in the water stress sensitivity as measured by LDR, were observed.
ALTERNATIVE MARKETING AND CULTURE SYSTEMS FOR TEXAS HIGH PLAINS ONIONS
Authors: Roberts Roland , Bender David , Field Samuel
Published: February 2019

Extension-research teamwork supports Texas High Plains onion grower-shippers in transition from unprofitable labor intensive marketing and culture to profitable mechanical systems that are less stressful to workers. System comparisons include machine harvest vs. lifting and hand clipping; stationary seed grading and bagging vs. mobile field grading and bagging; transplant vs. fall seeding, spring seeding and dry set production. Old marketing systems cost growers $4.30/50-lb. sack, and the innovative system costs $2.59 to $3.00/sack. Old transplant systems average $450 to $500/acre and direct seeding costs $200/acre. Net increase in return to grower management from adoption of new systems range from $1,300 to $1,700. Extension and research conduct economic analysis, cultivar performance trials, seeding technique studies and on-farm demonstrations.
RELATIONSHIP BETWEEN SWEETPOTATO FIBROUS ROOT GROWTH AND NUTRIENT UPTAKE IN FRITTED CLAY MEDIA.
Authors: Rhoden E. G. , Ndolo P. J. , Carver G. W.
Published: February 2019

A greenhouse study was conducted to investigate the ability of sweetpotato (Ipomoea batatas), cv. `Centennial', `Rojo Blanco', `Georgia Jet' and `TI-82-155', fibrous roots to accumulate N, P, K, Ca and Mg. Sweetpotato plants were grown in a fritted clay medium and harvested 42 and 82 days after planting. Fibrous roots comprised 22 to 28.1% and 3.9 to 11.1% of the plant dry weight at 42 and 82 days after planting, respectively. There was no difference in the average root length/cm depth of soil among the four sweetpotato cultivars at day 42. While there was no difference in average root length among `Centennial', `Rojo Blanco' and `TI-82-155', these cultivars were significantly different from `Georgia Jet' at day 82. For the four cultivars, there were no significant differences in N, P, K, Mg and Ca Uptake at day 42, but each cultivar absorbed significantly more of each element 82 days after planting. `Georgia Jet' absorbed significantly more of the nutrients measured than the other cultivars, resulting in the highest dry matter yield. The data show that the efficient uptake and utilization of nutrients by sweetpotato are related to the amount of fibrous roots present.
GAS EXCHANGE, CHLOROPHYLL CONTENT AND LEAF AREA INDEX OF OKRA AT SIX IN-ROW PLANT DENSITIES
Authors: Whitehead Wayne F. , Singh Bharat P.
Published: February 2019

The effect of in-row plant densities on gas exchange, chlorophyll content and leaf area index of okra (Abelmoschus esculentus (L.) Moench) was studied. The six in-row plant densities ranged from 8 cm to 48 cm (D1 - D6). On 11 and 27 July 1990, the photosynthetically active radiation (PAR), transpiration (E), net photosynthesis (Pn) and chlorophyll content (Chl) at top- and mid-canopy levels and leaf area index (LAI) were measured. Mid-canopy PAR was 86 ± 6% less than that of the top-canopy and E, Pn and Chl at mid-canopy were respectively 55, 90 and 10% lower than those of the top-canopy. The interaction of plant density with canopy position was significant for E and Pn. The highest E and Pn, (12.28 mmol m-2 s-1 and 22.01 μmol CO2 m-2 s-1, respectively) were recorded at the D5 top-canopy. In-contrast, the lowest E and Pn, (4.17 mmol m-2 s-l and 1.23 μmol CO2 m-2 s-1, respectively) at the D6 mid-canopy were recorded. The LAI also exhibited significant variation among plant densities with a range of 4.65 to 4.97 for D5 and D3, respectively. These results indicate that 40 cm in-row density was the most suited for gas exchange of okra.
EFFECT OF MULCH ON THE GROWTH AND DEVELOPMENT OF LATE FALLTOMATOES
Authors: Patterson Daniel , Hayslett William , Shaw Sabrina
Published: February 2019

The objective of this study was to determine if different mulches would affect days to flowering or prolong the fall growth for tomatoes Lycopersicon esculentum. The mulches used were: black plastic, white plastic and straw. The tomatoes were transplanted to the field on 20 September 1990. Diurnal atmospheric and soil (just under the mulch) temperatures were taken at 12:00 noon. Average daily soil temperatures in September were 24°C, 22.5°C, 22°C and 21.5°C for black plastic, white plastic, the control, and straw respectively. Average soil temperatures ranged from 28.5°C for black plastic to 24.5°C for the straw treatments. Temperatures in October and November were 3 to 4 degrees lower for soils and between 4 to 7 degrees lower for the atmosphere. Average days to flowering were 68, 70, 68.5, and 75 for black plastic, white plastic, control, and straw treatments respectively. The average growth per plant were 20.5, 22.5, 25.9, and 12.5 centimeters for black plastic, white plastic. control. and straw respectively.
INFLUENCE OF BIOCIDES ON NITRIFICATION, DENITRIFICATION, AND TOMATO N UPTAKE
Authors: Somda Zana C. , Mills Harry A. , Phatak Sharad C.
Published: February 2019

As a result of long-term application, some fungicides may accumulate in the soil to levels that can affect soil N transformations and plant growth. Studies were initiated to compare benomyl, captan, and lime-sulfur fungicides with the biological nitrification inhibitors (NI) nitrapyrin and terrazole for their effects on biological nitrification and denitrification, and tomato (Lycopersicon esculentum Mill.) growth and N uptake. In laboratory studies, inhibition of nitrification was less than 5% in a Tifton l.s. soil incubated with 10 μg g -1 a.i. of benomyl but was about 51%, 72%, and more than 85% when amended with lime-sulfur, captan, and NI, respectively. Similarly, increased inhibitory effects on denitrification of NO3 were obtained in a liquid media incubated anaerobically with either NI (37%) than captan or lime-sulfur (25%) while benomyl had no significant effect. In greenhouse studies with tomato plants, weekly drench applications of 0.25 μg a.i. g -1 soil of the appropriate chemical for 4 weeks with three NH4:NO3 ratios showed that the NI and captan produced the greatest plant biomass and N uptake, but benomyl and lime-sulfur had no main effect while all fungicides interacted with the N ratio to affect plant growth and N uptake.
RESPONSE OF `ALASKA' PEA SEEDLINGS TO FREEZING AND CHILLING STRESSES AFTER EXOGENOUS APPLICATION OF ABSCISIC ACID.
Authors: Tignor Milton E. , Weiser Russell L.
Published: February 2019

Alaska peas (Pisum sativum `Alaska') germinated in a dark growth chamber were treated ABA dissolved in a small amount of acetone before diluting in distilled water with 0.1% spreader. A blank solution was identically prepared without ABA. Both solutions were applied via paintbrush to the epicotyls of the peas every twelve hours for seven days following emergence. The blank solution was applied to two controls, chronological and physiological. A methanol bath was used to induce freezing and chilling stresses. ABA significantly improved cold tolerance (electrolyte leakage) in the pea seedlings for both freezing and chilling stress as compared to the physiological and chronological controls. Visual observation of the pea stems suggested a difference in stem flexibility among ABA treated peas and the controls. Pea stem elasticity and plasticity were measured along with plant dry weight, cell wall weight/gram fresh weight, and the quantity of cell wall sugars and amino acids.
USE AND ABUSE OF THE CORE COLLECTION CONCEPT IN MANAGEMENT OF PLANT GENETIC RESOURCES
Authors: McFerson James , Kresovich Stephen
Published: February 2019

Indiscriminate growth can lead to germplasm collections that are too large to maintain, too large to use, or both. Curators' budgets do not often increase with collection size, so conservation and utilization activities are hindered. Maintenance of genetic integrity in large collections is practically impossible. Evaluation is restricted to easily-observed traits, potentially limiting utilization. One strategy to improve management of large collections is the core collection concept, proposed by O.H. Frankel in 1984 and subsequently expounded by A.H.D. Brown. It establishes one subset of accessions, the core, selected to represent “with a minimum of repetitiveness, the genetic diversity of a crop species and its relatives”. The other subset, the reserve, includes all accessions not in the core. Both subsets are conserved according to the highest standards feasible, but the core receives priority for characterization and evaluation to facilitate use and provide subsequent directed access to the entire collection. Use and abuse of the core concept will be discussed, including: definition of terms, genetic and statistical assumptions, and practical implementation.
Ethylene and Polyamine Metabolism in Climacteric and Nonclimacteric Carnation Flowers
Authors: Serrano M. , Romojaro F. , Casas J.L. , Acosta M.
Published: February 2019

We have compared the ethylene and polyamine metabolism of senescing flowers from two cultivars of carnation (Dianthus caryophyllus L.), one showing climacteric (`Arthur') and the other non climacteric behavior (`Killer'). `Arthur' carnations showed the first symptoms of senescence at day 7, coinciding with maximum ethylene and CO2 production, a peak in the ethylene-forming enzyme (EFE) activity, and a 7-fold increase in free ACC content in respect to the initial value. In `Killer' carnations, however, onset of senescence was 15 days after harvest, and no ethylene or CO2 peak was detected. The lack of ethylene production was due to a constantly low level of free ACC and a low EFE activity. Free polyamine distribution was similar in the two cultivars at the preclimacteric stage, with the spermidine content being about three times that of putrescine. But as senescence progressed, this situation was reversed in `Arthur' carnation, with a predominance of putrescine during the senescence, while it was maintained in `Killer', with no significant changes during senescence. No free spermine was found at any stage of senescence in either cultivar. Thus, a correlation exists between ACC level, distribution of polyamides, and longevity of cut carnation flowers. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).
Propagation of Hazelnut Stem Cuttings Using Agrobacterium rhizogenes
Authors: Bassil Nahla V. , Proebsting William M. , Moore Larry W. , Lightfoot David A.
Published: February 2019

Hazelnut (Corylus avellana L.) softwood cuttings of the cultivars Ennis and Casina were propagated under mist during June and July 1987 and 1988. Rooting of stem cuttings was stimulated by both Agrobacterium and IBA treatment; however, IBA caused nearly complete bud abscission. Better rooting and bud retention were observed in `Casina' than in `Ennis' in 1988. Bud retention on Agrobacterium -inoculated cuttings improved as the cuttings approached the semi-hardwood stage. Six months after transplanting, Agrobacterium -inoculated hazelnut cuttings had an extensive root system, characteristic of hairy root. Although the mechanism remains unclear, strains of Agrobacterium rhizogenes are effective rooting agents in hazelnut and may cause less bud abscission than IBA. Chemical name used: 1 H -indole-3-butyric acid (IBA).
Inheritance of Resistance to Alternaria Leaf Blight in Muskmelons
Authors: Boyhan George E. , Norton Joseph D.
Published: February 2019

Muskmelon (Cucumis melo L.) breeding line AC-82-37-2 was identified as having resistance to alternaria leaf blight caused by Alternaria cucumerina (Ell. and Ev.) Elliot. An analysis of this resistance with a three-factor scaling test indicated that both additive and dominance effects were highly significant. The x2 value indicated that there were epistatic effects as well. The six-factor scaling test revealed no significant dominance effect, but the additive and homozygote × heterozygote epistatic interaction effects were highly significant.
APRT SELECTION SYSTEM IN PLANTS
Authors: Agarwal Sunita K. , Schultz David J. , Schaff Dennis A.
Published: February 2019

Most cells have an active turnover of many of their nucleic acids (particularly some types of RNA) which through degradative processes result in the release of adenine, guanine and hypoxanthine. These free purines are converted to their corresponding nucleotides through salvage pathways. Adenine is converted to its nucleotide form AMP by Adenine phosphoribosyltransferase (APRT) which is one of the enzymes associated with the purine salvage pathway. Since all organisms have a de novo pathway for the formation of AMP, APRT is classified as a `salvage enzyme'. The APRT enzyme, in general, does not show a high degree of specificity for the exact structure of adenine and can also act on cytokinins and adenine derivatives like 2,6-diaminopurine, 2-fluoroadenine and 6-methylpurine. The APRT enzyme can utilize adenine analogues as substrate and convert them into their nucleotide forms which are toxic. Plants that lack APRT activity (APRT-plants) survive in the presense of these analogues. The amount of adenine analogue used for selecting APRT-plants is such that it kills all APRT+ (wild type) plants. APRT+ plants survive when grown in the presense of azaserine and alanosine that block de novo synthesis of AMP. APRT-plants transformed with the wild type cloned gene can be selected from a mixture of transformed and non-transformed plants by selecting in the presense of adenine, azaserine and alanosine. The presense of APRT activity can be confirmed by assaying for the APRT enzyme. APRT activity has been detected in many plant species. The presense of a positive forward and backward selection system can thus allow the use of APRT as a selectable marker in plant gene transfer systems.
HOREHOUND (Marrubium vulgaris L.) PRODUCTION IN NORTHERN AMERICA: RESPONSES TO MULCH, SHADING, AND NITROGEN TREATMENT
Authors: Mao Z.Y. , Craker Lyle E.
Published: February 2019

Mulch, light level, and nitrogen fertilization were tested for their effects on productivity of horehound (Marrubium vulgaris L.). Yield of this plant increased under mulched conditions and with the addition of nitrogen fertilizer. Yield decreased with reduced light levels. Productivity of individual plants correlated with the number of branches per plant, leaf size, and leaf chlorophyll content. The number of branches per plant decreased with increased shading, but increased with increased nitrogen fertilization. The influence of mulch and shading on productivity could be due to the changes in soil temperature and in soil water potentials. Full-sun, high nitrogen, and mulch are suggested for optimum field production of horehound.
SPRING FERTILIZATION OF WINTER INJURED STRAWBERRY PLANTS
Authors: Boyce Bertie , Heleba David
Published: February 2019

Winter injury in `Midway' strawberry plants was brought about by not mulching with grain straw in the fall. Minimum crown temperatures in these plants was -7.3C compared to a winter minimum crown temperature of -5.1C when plants were mulched. This 2.2C colder plant temperatures resulted in injury as evidenced by a significant reduction in yield (20%), smaller fruits, reduced vegetative growth and increased browning of the medulla tissues. No significant improvement in yield could be detected from the cold injured plants by the early application of 10-10-10 fertilizer at rates ranging from 0 to 2244 kg/ha. Vegetative growth was increased however.
POLYAMINE ACCUMULATION BY TOMATO PLANTS UNDER NUTRITIONAL STRESS
Authors: Feng Jinan , Barker Allen V.
Published: February 2019

Polyamine accumulation is a response of plants to various environmental stresses. Polyamine accumulation was assessed in relation to ammonium accumulation and ethylene evolution in tomato (Lycopersicon esculentum Mill.) under nutritional stress. Nutritional stresses were imparted on plants grown in quartz sand culture under greenhouse conditions with NH4-based modified Hoagland's solution or with NO3-based solutions without P, K, Ca, or Mg. The plants receiving NH4 nutrition were grown with or without 10-5 M (aminooxy)acetic acid (AOA) or 10-5 M silver thiosulfate (STS). Plants on nutrient deficient solution were grown with or without the AOA. When plants appeared with toxic or deficient symptoms, the new fully expanded leaves were collected and extracted by 5% perchloric acid for polyamine analyzes by HPLC. Plants receiving NH4-based nutrition had high putrescine and low spermidine concentrations. High spermidine and low putrescine concentrations occurred in plants receiving complete NO3-based nutrition. For plants receiving NH4-based nutrition, application of AOA suppressed accumulation of putrescine but had no effect on spermidine, and STS had no effect on polyamine accumulation. For plants receiving NO3-based nutrition without P, K, Ca, or Mg, the application of AOA restricted accumulation of putrescine and spermidine. High putrescine concentration was accompanied by high ammonium accumulation, high ethylene evolution, and stressinduced symptoms, indicating an association between polyamine accumulation and other stress-related phenomena.
SITE EFFECTS ON SUSCEPTIBILITY OF ASIAN PEARS TO FIRE BLIGHT
Authors: Jones T. , Strang J. , Brown G. , Wolfe P.
Published: February 2019

Kentucky is one of seven states in the southeast evaluating 13 Asian pear cultivars for suitability to the region. The cultivars were planted on a (20′ × 10′) spacing in 1989 at three separate locations. Data on time of bloom, tree growth, fire blight susceptibility and fruit quality and yield were collected. This study demonstrates the variability seen in Asian pear cultivars in response to site. There was a significant site by cultivar interaction for fire blight. The Princeton site had significantly more fire blight than either Lexington or Quicksand. Four cultivars, Niitaka, Shin Li, Shinko and Shinseiki had low fire blight ratings which were not significantly different between the three sites. Asian pear growth rates were significantly different between the three sites, but cultivar growth rates were not. Tree growth rate showed a significant negative correlation to fire blight rating. That is infected trees did not grow much. Initial findings show Shinko, Shinseiki and Niitaka to have some tolerance to fire blight spread and to produce good yields of attractive fruit. However, Niitaka had a very tough skin with a tendency towards fruit cracking. The cultivar Shin Li which also had fire blight tolerance did not produce fruit or flowers.
COLD PROTECTION OF KIWIFRUIT PLANTS WITH TRUNK WRAPS AND MICROSPRINKLER IRRIGATION
Authors: Himelrick D.G. , Dozier W.A. , Caylor A.W.
Published: February 2019

Own-rooted four-year-old kiwifruit plants (Actinidia deliciosa) protected by a Reese clip-on styrofoam insulation trunk wrap, or microsprinkler irrigation, sustained less freeze injury than unprotected plants under field conditions at temperatures as low as -17.8C. Trunk splitting occurred on the plants but no injury was detected on canes, buds, or shoots in the canopy of the plants. Unprotected plants had more trunk splitting and at greater heights than protected plants. New canes developed from suckers of cold-injured plants and developed a filled canopy the following season.
SEQUENTIAL CROPPING IN VEGETABLE AND TOBACCO PRODUCTION SYSTEMS UNDER VARIOUS TILLAGES
Authors: Kelley William Terry , Coffey David L.
Published: February 2019

Three cropping sequences and three tillage systems were evaluated under reduced tillage. Sequences were spring `Packman' broccoli followed by `Sunny' tomatoes or 'm.s. Ky 14 × L8 tobacco, spring broccoli/tomatoes or tobacco/fall broccoli, and tomatoes or tobacco/fall broccoli. Each sequence was grown conventionally tilled/no winter cover, conventionally tilled/wheat winter cover and no-till transplanted directly into killed wheat. The study was conducted at Knoxville, (elev. 251m), Greeneville, (elev. 400m) and Crossville, (elev. 549m) during 1989 and 1990. Experiments were arranged in a strip-plot design with sequences stripped across tillages. No. 1 tomato yield was reduced in no-till at Greeneville (1989). Percentage of No. 1 tomatoes was not affected by tillage but the tomato-broccoli system produced a greater percentage at Greeneville (1990). Broccoli head size and subsequent yield was generally greater in conventionally tilled plots. Sequence generally had little affect on broccoli production. Yield and revenue of tobacco were generally lower in no-till treatments. Broccoli/tobacco sequences generally had the highest yield but varied by location. No-till produced lower quality tobacco both years at Knoxville but not at Greeneville.
RESULTS OF A TWO-YEAR STUDY ON POINSETTIA RESPONSE TO IRRIGATION WITH WATER HIGH IN SODIUM
Authors: Griffin John D. , Gallagher Peter W. , Farrish Kenneth W.
Published: February 2019

Three cultivars of Poinsettia (Annette Hegg Lady, V-14 Pink, and Topwhite) were each treated with the same three concentrations of Na and Ca, plus a Tap water and Distilled Water Control. Plants were evaluated for the following parameters: quality (bract diameter, height, foliar blemishes), dry weights (root and shoot), and Na and Ca contents (root and shoot). Postharvest keeping quality was evaluated in a subsequent study with the same cultivars and treatments.

It was found that high levels of Na reduced bract size, height, and overall quality. Root tissue did accumulate Na, but only to a certain level (approx. 300 g/kg). Shoot tissue continued to accumulate Na as concentration of Na increased in the irrigation water. Na accumulation in shoot tissue was approx. doubled in Topwhite when compared to V-14 Pink and Annette Hegg Lady. Postharvest keeping quality was not reduced by increased Na concentrations in irrigation water.
EVALUATION OF METHODS TO PREVENT ROOT GROWTH INTO CAPILLARY MATS
Authors: Hou Guogiang , Buxton Jack W. , Switzer Donna
Published: February 2019

To prevent rooting into an irrigation mat, five water porous materials, perforated black plastic, perforated ground cover, polyester, woven polypropylene and porous plastic, were evaluated as mat covers. Only polyester, woven polypropylene and porous plastic prevented penetration of roots of marigold seedlings into the mat. Under high moisture stress, root tips were killed at the cell drainage hole; however, under low moisture stress the roots formed a mat on top of these mat covers. To prevent root penetration out the drainage hole, polyester and porous plastic were glued over the hole. No difference in shoot growth was observed between the control (only polyester mat cover) and seedlings produced in drainage hole covered cells. Total root growth of plug seedlings with drainage hole covered were greater than the control. Ten days after transplanting, seedlings that had been produced in plugs, with covered drainage holes, were larger.
LANDSCAPE ARCHITECTS AND THE DEMAND FOR PLANT MATERIAL
Authors: Garber Melvin P.
Published: February 2019

Landscape architects occupy a strategic position in the landscape industry; yet, they have not been generally considered an important customer group by nurserymen. They influence selection of plant material for commercial, government, and residential landscapes and are generally the first to know what will be in demand. A recent survey of Georgia landscape architects found they specify $85 M of plants. This compares to the $200 M estimate for the 1989 wholesale value of nursery stock produced in Georgia. In addition, 60% of the landscape architectural firms influence which production nursery supplies plants by determining or recommending the production nursery where the landscape contractor obtains plants. More importantly, 92% of the large firms, which account for 67% of the dollar value, are involved in selection of the production nursery. The results provide the first quantitative estimate of the influence of landscape architects on nurserymen and suggest that nurserymen should view landscape architects as important customers.
Micropropagation of Notholaena `Sun-Tuff Fern
Authors: Rogers Suzanne M. Dethier , Banister Sharon
Published: February 2019

A micropropagation system was developed for micropropagation and rooting of Notholaena spp. Shoot cultures were initiated from mature sori on leaflets of the Notholaena cultivar Sun-Tuff and cultured on gelled Murashige and Skoog (MS) medium without hormones. Rooting and plant growth were evaluated on gelled MS, vermiculite moistened with liquid MS, or vermiculite moistened with water. Vermiculite wetted with MS was superior in promoting frond and root development. High humidity was not needed to acclimatize the plants ex vitro.
LOWBUSH BLUEBERRY PRODUCTION IN THE NINETIES
Authors: DeGomez Tom
Published: February 2019

The wild lowbush blueberry (Vaccinium angustifolium) in Maine and the Maritime Provinces of Canada has been managed for hundreds of years, first by native Americans and more recently by European settlers. Early production practices consisted of periodic free burns over large tracts of land for pruning and weed control. New practices have centered on intensifying production and include flail mow pruning, mechanical harvesting, herbicides for weed control, and monitoring pest populations. Most recently, land smoothing for improved mechanization and leaf sampling for nutrient analysis have been adopted. Land smoothing allows producers with rough land to use labor-saving equipment and apply pesticides more precisely. Leaf analysis predicts nutrient availability much more accurately than soil testing.
AUXIN ACTIVITY OF 3-METHYLENEOXINDOLE
Authors: Tuli V.
Published: February 2019

3-Methyleneoxindole (MO), a metabolite of the plant auxin 1- H-indole-3-acetic acid (IAA), is a potent sulfhydryl reagent that can profoundly affect bacterial growth and metabolism. For investigative purposes, MO is obtained from the degradation of 3-bromooxindole-3-acetic acid (3-Br-lAA) in aqueous media. Alternatively, it can be prepared from the riboflavin-catalyzed photooxidation of IAA. My earlier claims that MO possesses auxin activity were refuted by independent investigators either because the results could not be reproduced when 3-Br-IAA was used, or the results were ascribed to contamination with residual IAA if MO obtained from photooxidation was used. Recent investigations indicate that, contrary to previous assumptions, the quantitative degradation of 3-Br-lAA resulting in the formation of MO is not instantaneous; depending on the purity of 3-Br-lAA, it may take several hours to several days to reach completion. Furthermore, aqueous solutions of MO ≥0.1 mm are rapidly polymerized, thus causing a loss of biological activity. These findings may explain why MO that is derived from 3-Br-lAA often fails to produce auxin action. Ultrapure MO, obtained from either 3-Br-IAA or photooxidation, is 50- to 1000-fold as effective as IAA in the straight growth assay, induction of xylogenesis in parenchymatous tissue, and rooting of explants in tissue culture.
Daylength, Light Quality, and Temperature Influence Growth and Development of Achimenes
Authors: Vlahos J.C. , Martakis G.F.P. , Heuvelink E.
Published: February 2019

The effects of supplementary irradiance (20 μmol·s-1·m-2 for 6 hours) with incandescent light (I) or fluorescent compact gas-discharge lamps (CF) vs. a basic irradiance (96 μmol·s-1·m-2 for 12 h) with fluorescent (F) light at 17 or 25C was studied for Achimenes hybrids `Flamenco', `Hilda', and `Rosenelfe'. The additional I increased leaf area (LA) and plant dry weight (DW) in `Hilda' and `Rosenelfe' and promoted stem elongation in all three cultivars. Additional F had no effect on DW. However, depending on cultivar, responses for LA varied. An increase in the number of flowers was promoted only in `Rosenelfe' by I and CF compared with the control. In all cultivars, the supplementary CF, when compared with the I, reduced LA and DW. LA was significantly larger and DW higher at higher temperature, except for `Rosenelfe', where DW was not influenced and LA was smaller at the higher temperature. All three cultivars produced a longer stem and more flowers at the higher temperature. Calculated growth responses were influenced by an interaction between temperature and cultivar.
Low-temperature Injury to Strawberry Floral Organs at Several Stages of Development
Authors: Ki Woon Kye , Warmund Michele R.
Published: February 2019

Inflorescences of `Earliglow' and `Honeoye' strawberry (Fragaria ×ananassa Duch.) plants were subjected to controlled freezing tests to determine the cold tolerance of styles, anthers, and receptacles of individual flowers at various stages of development. Flowers of both cultivars tended to deacclimate as the stages of development progressed. Styles and receptacles generally exhibited injury at higher temperatures than anthers. The greatest deacclimation of styles and receptacles of primary flowers occurred at earlier developmental stages of `Honeoye' than of `Earliglow'. However, at the sixth stage of development, the critical temperature for receptacle injury in primary and secondary fruit was -3C for both cultivars.
Bolivia's Emerging Cut-flower Industry: A Performance Assessment
Authors: Haydu John J. , Hodges Alan W. , Montenegro Diego
Published: February 2019

Cut-flower production in Bolivia is a growing economic activity with sales increasing > 10-fold in the past 6 years. In spite of this growth, Bolivian producers face considerable financial difficulties. Two distinct patterns emerged from this study. Small and medium growers experienced lower costs than larger producers, but the prices they received were also lower. Large operators received twice the small producer price for their flowers, but this gain was offset by the higher costs they had incurred. In the long term, neither selling too low nor operating at costs too high is a sustainable practice.
Brine Quality of Gibberellic Acid-treated `Napoleon' Sweet Cherries
Authors: Facteau T.J. , Chestnut N.E. , Rowe K.E. , Payne C.
Published: February 2019

Gibberellic acid-treated `Napoleon' sweet cherry (Prunus avium L.) fruit were firmer but lost more weight during brining than nontreated fruit. GA treatment delayed fruit softening, thereby extending the harvest period. Mean fruit weight was increased by GA only in fruit harvested at a more mature state. GA delayed soluble solids accumulation in one of two years. In one orchard district, solution pockets were less frequent in GA -treated fruit in 1988 and in late-harvested GA -treated fruit in 1989. GA treatment did not alter the incidence of fruit with solution pockets in a second district in 1988 and increased levels of solution pockets in fruit harvested later in 1989. Incidence of fruit with solution pockets increased as maturity progressed in nontreated fruit in both years and both districts. Chemical name used: gibberellic acid (G A).
Relationship between Starchy versus Sugary Endosperm and Head Smut Susceptibility of Corn Seedlings
Authors: Baggett James R. , Tibbs Janice
Published: February 2019

Incidence of head smut [Sphacelotheca reiliana (Kuhn) Clinton] in F corn (Zea mays L.) families derived from homozygous starchy (Su) F ears was less than that observed in starchy or sugary (su) families derived from segregating ears or sugary families derived from homozygous sugary ears. This difference was observed at high levels of disease incidence resulting from clipping seedlings and at a lower disease incidence in unclipped plants. Differences in seedling vigor and earliness of starchy and sugary families and differences related to homozygous and heterozygous sources suggest that seedling vigor may be involved in the observed differences in head smut susceptibility.
DORMANCY INDUCTION IN PEPPER SEEDS WITH TETCYCLACIS
Authors: Ilyas Satriyas , Andreoli Claudinei , Khan Anwar A.
Published: February 2019

Seeds of six pepper (Capsicum Anuum L.) cultivars were treated with tetcyclacis (TCY), an inhibitor of the oxidative steps from ent-kaurene to ent -kaurenoic acid in the gibberellin biosynthetic pathway. Seeds were soaked in TCY solutions for 24h in darkness at 25° to 30°C, washed with water and then air-dried. Various concentrations of TCY were needed to induce dormancy in `Yolo Wonder', `Cayenne', `California Wonder', `Sweet Banana', `El Paso' and `Anaheim'. TCY-treated seeds were germinated in water and in various concentrations of GA4+7 in darkness. Dormancy induced by TCY was released with 10 μM GA4+7. The germination inhibitor, abscisic acid (ABA), failed to induce dormancy in pepper seeds even when treated at a concentration of 400 μM for up to 14 d. Similar results were obtained with tomato seeds and will be reported elsewhere. The results indicate that the absence or the unavailability of GA rather than the presence of ABA determines the dormant state in pepper seeds.
PROFESSIONAL EXCHANGE: A NEW EDUCATIONAL PROGRAM OFFERED BY THE CHICAGO BOTANIC GARDEN.
Authors: Baker Cynthia L.
Published: February 2019

In 1989, the Chicago Botanic Garden implemented the Professional Exchange Program for people employed in educational institutions, public gardens, and museums. Other institutional members of the American Association of Botanic Gardens and Arboreta are also beginning to develop similar programs. These “working sabbaticals” at public gardens provide private and commercial sector, as well as academic professionals in horticulture education, management, research, and botany with a unique career opportunity. Experiential education is an inexpensive, short-term, highly effective way to expand and strengthen one's present knowledge and skills and stay on the “cutting edge” of horticulture. Participants work and study with peer-professionals exchanging ideas and expertise in a one-on-one applied setting. Existing programs are reviewed and information provided on how to participate with public gardens and how to develop one in your own area.
CARBON ECONOMY IN SOUR ORANGE IN RELATION TO MYCORRHIZAL COLONIZATION AND PHOSPHORUS STATUS
Authors: Eissenstat David M. , Graham James H. , Syvertsen James P. , Drouillard Diana L.
Published: February 2019

The effects of phosphorus (P) and of the mycorrhizal (M) fungus, Glomus intraradix, on the carbon (C) economy of sour orange (citrus aurantium L.) were determined during and following active M colonization. There were four treatments: mycorrhizal seedlings grown at standard-strength P (M1) and nonmycorrhizal (NM) plants grown at 1, 2 and 5 times standard-strength P (NM1, NM2 and NM5). Mycorrhizal colonization, tissue dry mass, P content, root length, leaf area, 14C partitioning and rate of c assimilation (A) were determined in five whole-plant harvests from 6 to 15 wks of age. In contrast to the effects of P nutrition on C economy in sour orange, M effects were generally subtle. Mycorrhizae increased the root biomass fraction, the root length/leaf area ratio, and the percent of 14C recovered from belowground components. Mycorrhizal plants had a higher percentage of belowground 14C in the respiration and soil fractions than did NM plants of equivalent P status. Mycorrhizal plants tended to have enhanced A at 8 wks but not at 7 or 12 wks. This temporarily enhanced A of M plants did not fully compensate for their greater belowground C expenditure, as suggested by apparently lower relative growth rates of M than NM plants of equivalent P status. Problems of interpreting the dynamic effects of mycorrhizae on C economy that are independent of p nutrition are discussed.
ANALYSIS OF THE NUCLEAR GENOME, AND CONSTRUCTION OF A GENETIC MAP FOR PEACH [Prunus persica (L.) BATSCH.].
Authors: Baird Vance , Belthoff L. , Ballard R. , Scorza R. , Callahan A. , Monet R. , Abbott A.
Published: February 2019

Flow cytometric analysis, of leaf nuclei from three cultivars, was used to estimate the DNA content of peach (∼0.61 pg or ∼0.59 × 109 bp/diploid nucleus; 2x=16), and ndicated that the peach genome is only slightly larger than that of Arabidopsis. This value was indirectly confirmed by measurements of nuclei from haploid, triploid and “tetraploid” (cytochimera) peach accessions. cDNA and genomic clones have been used to determine the level of polymorphism among various peach cultivars and related species. Overall, ∼33% of the clones detected polymorphic loci. As expected, the highest level of polymorphism was found in interspecific hybrids (∼50%); whereas in intraspecific populations, only 1 in 5 genomic clones, and 1 in 3 cDNA clones were able to detect polymorphisms (RFLPs). These clones, as well as RAPD primers, are being used to construct a genetic linkage map by analyzing their segregation in 3 intraspecific peach populations (an Fl from France and two F2s from the U.S.). Taken together, these populations are segregating for 12 Mendelian traits and a number of quantitative traits. Our results have enabled us to identify a number of linkage groups, some composed of both molecular and phenotypic markers. The current structure of the peach map is reported.
STABLE TAXANE PRODUCTION IN TAXUS SHOOT CULTURES.
Authors: Zeldin Eric L. , Ellis David D. , McCown Brent H.
Published: February 2019

Taxol, a promising anticancer drug, is limited by inadequate supply. The production of taxol and related compounds (taxanes) by Taxus tissue cultures has been reported, yet sustained production has not been demonstrated. One theory is that cell differentiation and/or tissue organization is required to sequester taxol and avoid autotoxicity. To investigate this, T. cuspidata shoot cultures were established and the taxane content of various culture stages compared to that of field needles. HPLC analysis identified two peaks which comigrated and had UV spectra identical to taxol and 10-deacetyl taxol. The levels of 10-deacetyl taxol were similar in all samples. Cultured shoots contained much less taxol than field needles, and the level of a third peak which migrates closely to taxol was inversely related to that of taxol. Taxol content was restored in the first flush out of culture. Shoot cultures of T. brevifolia, T. x media, and T. canadensis have also been analyzed. In addition to shoot cultures, nodule cultures, a biological unit that may be suitable for production of taxanes in plant bioreactors, have been initiated and characterized.