bluuebunny/crossref_metadata_2025 huggingface dataset:
ATMOSPHERIC CO2 ENRICHMENT OF TOMATO AND STRAWBERRY PLANTS UNDER FIELD PRODUCTION CONDITIONS
Authors: Houtz Robert L. , Archbold Douglas D. , Royer Malcolm
Published: February 2019

A technique was developed for controlled micro-release of CO2 into the leaf canopy of strawberry and tomato plants under field production conditions; The leaf canopy atmosphere of tomato plants was enriched to 500 and 1200 ppm CO2 with release rates of 60 and 300 l/h·30 m of row respectively. After 60 days of enrichment for 6 h each day beginning at fruit set, the total shoot biomass and yield was increased 41% and 25 % respectively for the high CO2 release rate. Strawberry leaf canopies did not show increased CO levels with CO2 enrichment except under ventilated2 row-covers where the atmospheric CO2 level was increased to 1500 ppm CO2. Although the total biomass was increased 39% this did not translate into increased yields perhaps due to excessive temperatures under the row covers.
CHARACTERIZATION OF CUCURBITA ARGYROSPERMA, A POTENTIAL NEW CROP FOR SEED AND FRUIT PRODUCTION
Authors: Merrick Laura C.
Published: February 2019

Cucurbita argyrosperma, formerly known as C. mixta, is a squash species native to Mexico and Central America. Cultivars of the species which have been grown in the United States include many of the cushaws and the `Silverseed Gourd. A recent biosystematic analysis-which included studies of experimental and natural hybridization, isozymatic and morphological variation, ethnobotany, and ecological and geographical distribution-has shown that the closest relative of C. argyrosperma is C. moschata. The data reveal intriguing implications for evolution of the genus as a whole, since the previous hypothesis that C. lundelliana is the progenitor of C. moschata is refuted. A wild ancestor, three cultivated varieties and a feral derivative are recognized within C. argyrosperma. Two of the three cultivated botanical varieties-vars. argyrosperma and stenosperma -have been selected in many regions almost exclusively for seed production. The relatively large seeds are marketed either with or without hulls. The other botanical variety, var. callicarpa, has been selected for both fruit and seed production. Northern cultivars of var. callicarpa arc notable for their adaptation to marginal environments, including hot climates and poor soil conditions.
EX SITU PRESERVATION, MAINTENANCE, AND EVALUATION OF VIRUS-FREE CLONAL CITRUS GERMPLASM
Authors: Williams Timothy
Published: February 2019

The USDA-ARS National Clonal Germplasm Repository for Citrus is establishing a virus-free clonal collection of 830 citrus germplasm accessions at its Riverside, California facility with the objective of reducing genetic vulnerability of citrus and providing virus-free clonal germplasm to researchers worldwide. Accessions in the collection are evaluated for trueness-to-type using leaf isozymes and are characterized for 58 descriptors. Research is expanding into RFLPs for development of a usable genomic map and cultivar-specific probes. Citrus seed, pollen and buds are being investigated for extended preservation under low temperatures and cryostorage. Preliminary data is promising but indicates considerable variability between cultivars. In-vitro culture of excised embryo tissue is being investigated. A comprehensive pathogen detection program is underway. Infected accessions receive shoot-tip micrografting and thermotherapy treatments to eliminate pathogens. Accessions are maintained as potted trees in greenhouse or aphid-proof screenhouses. A complete computer based record is maintained for each accession on site and in the USDA-ARS GRIN database.
THE USE OF DORMANT-BUD CRYOPRESERVATION FOR LONG-TERM STORAGE OF PECAN AND WALNUT GERMPLASM
Authors: Morrissey Todd M. , Gustafson William A.
Published: February 2019

A study was designed to determine if current dormant-bud cryopreservation techniques investigated on woody plants, such as apple (Malus domestica), gooseberry (Ribes), blueberry (Vaccinium corymbosum) and pear (Pryus communis) etc., could be applied to certain nut tree species for long-term preservation. Pecan (Carya illinoinensis) and black walnut (Juglans nigra) were exposed to prefreezing temperatures ranging from -10° C to -40° C and then directly immersed in liquid nitrogen for 2 hrs. Dehydration by prefreezing was not sufficient for bud survival in pecan. Bud survival was increased by dehydrating stem sections prior to prefreezing. Prefreezing at -30° or -40° C was suitable for survival of black walnut.
INTERSPECIFIC HYBRIDIZATION OF ORNITHOGALUM
Authors: Griesbach R.J. , Meyer F. , Koopowitz H.
Published: February 2019

Three species of Ornithogalum are extensively grown. They are O. umbellatum, arabicum and thyrsoides. All three have white flowers. Another species, O. dubium, has deep orange flowers, but produces a weak inflorescence. Hybrids have been produced within a species but no wide crosses have been reported. Embryo rescue was successfully applied to develop new hybrids between O. dubium with strong color and O. thyrsoides with a strong inflorescence. The F1 hybrids produced buff-colored flowers on strong inflorescences with short internodes and long strong pedicels. The meiosis of these hybrids was not normal with univalent, laggards and bridges present. The F1 hybrids were slightly fertile and F2 and backcross progeny were produced. The progeny showed considerable segregation for both flower color and inflorescence traits. Clones were obtained which combined the orange flower colors of dubium with the strong inflorescence of thyrsoides.
BREEDING OF NEW HIPPEASTRUM CULTIVARS USING DIPLOID SPECIES: THE F-1 EVALUATION.
Authors: Meerow Alan W. , Broschat Timothy K. , Kane Michael E.
Published: February 2019

An amaryllis breeding program using diploid species not represented in commercial tetraploid cultivars has been underway since 1988. Objectives are to develop evergreen cultivars with attractive foliage and fragrant flowers of novel form and coloration. Five crosses with Hippeastrum papilio as a parent were evaluated at first flowering in the spring of 1990. The F-1's showed significant variation, suggestive of high heterozygosity within the parental genomes. Several natural tetraploids were identified among the progeny. Superior selections were made, and sib- or intercrosses accomplished. We estimate that a minimum of 50% genes from H. papilio will need to be maintained to guarantee evergreen foliage in the progeny. Superior F-1's have also been crossed with fragrant, trumpet-flowered primary hybrids, and new primary F-1's are being generated with H. papilio and these species or their hybrids, as well as with H. reticulatum var. striatifolium. A percentage of these germinated seedlings have been treated with colchicine to induce polyploidy. The best F-1 selections are also being micropropagated, and induction of polyploidy will be attempted in a percentage of the subcultures.
PRUNING EFFECTS ON COLD HARDINESS OF TWO WOODY ORNAMENTAL PLANT TAXA
Authors: Haynes C.L. , Lindstrom O. M. , Dirr M. A.
Published: February 2019

The effects of timing of pruning in relation to cold hardiness of X Cupressocyparis leylandii (A. B. Jacks. and Dallim.) Dallim. and A. B. Jacks. `Haggerston Grey' and Lagerstroemia L. `Natchez' were evaluated on 6 test dates from August 1989 to March 1990. Pruning treatments decreased the cold hardiness of both taxa compared to unpruned controls on 5 test dates. Cold tolerance of `Haggerston Grey' decreased for 4 to 5 months following the August and October pruning compared to the unpruned controls. `Haggerston Grey's cold tolerance were reduced by 6C in February. October and December pruning of `Natchez' reduced cold hardiness by 4C in January. However, cold hardiness of January and February pruning treatments was similar to unpruned controls. In general, the data indicated that plants of `Haggerston Grey' pruned in October through February were less cold hardy than plants pruned in August. Ideally, `Natchez' crape myrtle should be pruned in late winter.
EFFECT OF SUPRAOPTIMAL TEMPERATURES ON ROOT RESPIRATORY CHARACTERISTICS OF `ROTUNDIFOLIA' HOLLY
Authors: Ruter John M. , Ingram Dewayne L.
Published: February 2019

Respiration of excised Ilex crenata `Rotundifolia' roots as influenced by root-zone growth temperature and buffer solution temperature was measured in the presence and absence of SHAM and KCN. Respiration rates of roots excised from plants grown for three weeks at root-zone temperatures of 30, 34, 38, and 42 C decreased linearly as root-zone temperature increased when the buffer solution was maintained at 25 C. When the buffer solution temperature was the same as the root growth temperature, no differences in respiration rate were found. When plants were grown at a root-zone temperature of 30 C, respiration was maximal at 34 C and decreased to a minimum at 46 C. Above 46 C, stimulation of O2 consumption occurred which was presumed to be extra-mitochondrial. CN-resistant pathway activity decreased at a buffer solution temperature of 46 C which was similar to the critical threshold temperature (48±1.5 C) for `Rotundifolia' holly roots.
HONEY LOCUST SEEDLING DEVELOPMENT DURING OSMOTIC AND HIGH ROOT TEMPERATURE STRESS
Authors: Wilkins Lorna C. , Graves William R.
Published: February 2019

Development of half-sib Gleditsia triacanthos inermis Willd. (honey locust) seedlings was studied during exposure to osmotic and high root temperature stress. Seven days after seed scarification, seedlings of uniform fresh weight were transferred to static hydroponic culture vessels in a growth chamber. Three days later, vessel solutions were replaced with polyethylene glycol 8000-amended solutions with osmotic potentials (ψπ) of -0.05, -0.10, or -0.20 MPa at 23C. Within each ψπ treatment, root temperature was increased from ambient (23C) to 35C for 0, 6, 12, or 24 hr day-1 for 20 days. Root and shoot dry weights decreased with increasing exposure to 35C among seedlings in the -0.05 MPa solution and decreased for seedlings in -0.10 and -0.20 MPa solutions in all temperature regimes. Epicotyl expansion tended to decrease with decreasing ψπ and increasing exposure to 35C. However, for plants in the -0.20 MPa solution, epicotyl length was greatest when roots were exposed to 35C for 6 hr day-1.
HEAT TOLERANCE AND ETHYLENE PRODUCTION IN RED-OSIER DOGWOOD STEM TISSUES AT DIFFERENT GROWTH STAGES
Authors: Shirazi Abbas M. , Fuchigami Leslie H. , Chen Tony H.H.
Published: February 2019

Red-osier dogwood sterns, Cornus sericea L., at ten different growth stages were subjected to a series of temperatures ranging from 25C to 60C by immersing them in a water bath for one hour. After heat treatments, the viability of internode tissues were determined by electrical conductivity and ethylene production. Heat tolerance was expressed as LT50, the temperature at which 50% of the tissues were injured. The results suggest that the LT50 of dormant plants remained relatively constant, approximately 53C. During dormancy, heat stress did not stimulate ethylene production from internode tissues. In contrast, tissues from non-dormant plants exposed to heat stress produced increasing levels of ethylene reaching a peak at 40C followed by a steady decrease at higher temperatures. Application of 1-aminocyclopropane-1-carboxylic acid (ACC) to stem segments from dormant plants, following heat treatment, enhanced production of ethylene.
THE EFFECTS OF WEED INTERFERENCE: IN NEWLY PLANTED VINEYARDS
Authors: Agamalian Harry S.
Published: February 2019

Initial weed competition in newly planted grapevines can delay vine development, resulting in reduced first harvest. The experiments were conducted over a three year period on three wine grape varieties: Chardonnay, Semillon, and Napa Gamay.

Dormant rooted plants were winter planted and subjected to soil applied preemergence herbicides. The experiment was conducted on a Greenfield sandy loam under sprinkler irrigation. Major weeds were little mallow (Malva pariflora), hairy nightshade (Solanum sarachoides), lambsquarters (Chenopodium album), and Russian thistle (Sasola iberica).

Vine growth was evaluated on cane weights, cane diameter, and cane length. Weed interference over the three year period resulted in 50% reduction in vine growth the first year. Yield data obtained from the third year resulted in significant differences between the weed free vines compared to the non-weeded treatments.
PESTICIDE INFLUENCE ON NITROGEN FIXATION AND MODULATION BY SOYBEAN AND LIMA BEAN
Authors: Yueh Lih-Yuh , Hensley David L.
Published: February 2019

The influence of 12 pesticides on C2H4 reduction and modulation of soybean (Glycine max L. Merr.) and lima bean (Phaseolus lunatus L.) was evaluated. All except diazinon were innocuous at 3× the label rate. Diazinon decreased C2H4 reduction of soybean 2 days after application, but not after 7 days or at normal label rates. Nitrogen fixation of excised nodules imbibed with diazinon indicated that it may have directly affected nitrogenase function. Soybean nodule numbers were decreased by application of 3× rates of methomyl and trifluralin, but lima bean nodule numbers were decreased only by trifluralin. Trifluralin also depressed soybean but not lima bean modulation at label rates. Methomyl did not affect soybean modulation at label rate. Both chemicals were non-toxic to Rhizobium sp. in a disc inhibition study.
HIGH CO2 SLOW COOLING CA STORAGE FOR `MCINTOSH' APPLES
Authors: Liu F. W.
Published: February 2019

A high CO2 slow cooling CA storage procedure was developed for `McIntosh' apples (Malus domestica Borkh.). The apples were cooled from 18° to 3°C in 15 days in atmospheres containing a constant O2 at 2.5% and decreasing CO2 starting with 12% and ending at 3%. The results of several tests in a flow-through simulated CA storage system revealed that the new procedure was nearly as effective as rapid CA and was much more effective than traditional slow CA in preserving the firmness of `McIntosh' apples for up to 4 months of storage. Maintaining a constant CO2 either at 12% or 3% instead of gradually decreasing it from 12% to 3% during the slow cooling period resulted in more storage disorders or/and softer apples.
CHILLING INITIATES ETHYLENE PRODUCTION IN GRANNY SMITH APPLES
Authors: Jobling Jenny , Dilley David , McGlasson Barry
Published: February 2019

The onset of the respiratory and ethylene climacterics in Granny Smith apples is usually protracted when the fruit are held continuously at 20°C. We have found that a period of at least 4 days at 0°C stimulates ethylene production when the fruit are returned to 20°C. Once initiated ethylene production proceeds at a high rate. Data will be presented showing the pattern of ethylene production following chilling by Granny Smith apples from two commercial districts in Australia. Our data suggests that a period of chilling stimulates ACC Synthase as in Winter Pears.
EFFECTS OF ROOTSTOCK ON `DELICIOUS' APPLE FRUIT PROPERTIES
Authors: Autio Wesley R.
Published: February 2019

The effects of rootstock on `Delicious' apple maturity, quality, size, mineral composition, and storability were studied over a 4-year period. Removing the effects of crop load and crop load within year by analysis of covariance produced results suggesting that M.27 EMLA and Ott.3 advanced fruit maturity and that M.7 EMLA delayed fruit maturity. M.9, MAC 9, OAR 1, M.9 EMLA, and M.26 EMLA either were inconsistent in their effect on maturity or consistently resulted in an intermediate maturity. Size, after adjusting for the effects of crop load and crop load within year, was consistently high for fruit from trees on M.9 EMLA, and lowest for fruit from trees on OAR 1. After adjusting for fruit size, fruit from trees on MAC 9 generally had high Ca contents, and fruit from trees on OAR 1 had low Ca contents. The effect of rootstock on storability appeared to be secondary and related to maturity and Ca level.
SENSORY ATTRIBUTES OF APPLESAUCE PROCESSED FROM APPLES PREsSURE INFILTRATED WITH CALCIUM CHLORIDE PRIOR TO STORAGE
Authors: Portillo Robert J. , Sams Carl E. , Conway William S. , Collins Jimmie L. , Penfield Marjorie P.
Published: February 2019

`Golden Delicious' (`GD') and `Red Rome' (`RR') apples were pressure infiltrated at harvest with 0, 1, 2, 3 or 4% and 0, 2, 4, 6 or 8% CaCl2 solutions (w/v), respectively. Sauce was prepared after 0, 2, 4 and 6 months in 0°C storage. Sensory evaluation was conducted to determine the effects of CaCl2 concentration on color, off-flavors, consistency, uniformity of particles, and overall acceptability of the sauce. Sauce from `RR' was lighter while sauce from `GD' was darker with increased CaCl2. Calcium chloride increased the consistency of `RR' and `GD' sauce but the highest concentrations decreased the consistency of `GD' sauce. The uniformity of sauce particles from both cultivars decreased with increased CaCl2. The presence of off-flavors increased in `GD' sauce with the highest concentrations but decreased in `RR' sauce as CaCl2 was increased. Overall acceptability of sauce made from `RR' and `GD' increased as CaCl2 increased, however, acceptability of sauce made from `GD' decreased at the highest concentrations of CaCl2.
FOLIAR NUTRIENT UPTAKE IN CRANBERRY
Authors: Davenport J. R.
Published: February 2019

Foliar feeding of crop plants is an increasingly popular practice. The use of foliar nutrients relies on the ability of the plant to sorb nutrients through the leaves. Cranberries (Vaccinium macrocarpon Ait.) are known to have a waxy cuticle on the leaf surface which may impede nutrient uptake, leaving only the lower leaf surface for effective uptake. This study was undertaken to determine the extent of foliar nutrient uptake by cranberries using rubidium as a tracer. Rubidium was chosen for its similarity to potassium in plant uptake. In replicated plots, cranberries were sprayed with rubidium at the rate recommended for foliar potassium at three different growth stages and three different times of day. Washed and unwashed leaves were analyzed one day, one week, and one month after rubidium applications. Stem, soil, and root material was analyzed for rubidium at the one week and one month sample times. Results will be discussed with reference to uptake and movement of foliar applied nutrients in cranberries.
N RATE AND TIMING AFFECT ON CRANBERRY YIELD AND YIELD COMPONENTS
Authors: Hart J. M. , Poole Arthur , Wilder Kris L. , Strik B. C.
Published: February 2019

Cranberries (Vaccinium macrocarpon Ait.) require low rates of N fertilizer compared to many horticultural and agronomic crops. Excess N promotes vegetative growth at the expense of yield. Growers desire information about N fertilization to achieve optimum yields without overgrowth, Little information has been published about N rate and timing influence on cranberries in south coastal Oregon. An N rate and timing field experiment with Crowley and Stevens cultivars was established to answer grower questions. N was applied at 0, 18, 36 and 54 kg/ha in various combinations at popcorn (white bud), hook, fruitset, early bud, and late bud. Yield, yield components, (fruit set, number of flowering and total uprights, berry size, flowers per upright and the proportion of uprights that flower), vegetative growth and anthocyanin content were measured. After 2 years of treatments, N rate or timing had little influence on yield or yield components in the previously heavily fertilized Crowley bed. In the previously lightly fertilized Stevens bed, N rate increased yield, vine growth, and the number of flowering uprights, N timing also influenced the number of flowering uprights. The total number of uprights was influenced by the interaction of N rate and timing.
INFLUENCE OF SUPPLEMENTAL CA2+ ON UPTAKE AND TRANSLOCATION OF 22NA+ IN RABBITEYE BLUEBERRY
Authors: Wright G.C. , Drew M.C. , Patten K.D.
Published: February 2019

Blueberry reducers in Texas must often irrigate with sodic water. Excess Na+ leads to reduced growth, necrosis, and plant mortality. Ca2+ is known to ameliorate such detrimental effects in many crops, but little is known about the response of rabbiteye blueberry. To elucidate the influence of Ca2+ on the uptake and translocation of Na+, plants were subjected to NaCl in hydroponics solutions (10, 25, 50 and 100 mM NaCl) and the uptake of Na+ was traced over a 24h period using 22Na+ Additionally, for each treatment, half the plants were supplied with 10 mM Ca2+. Plants were then transferred to identical, but unlabeled, solution, then harvested at intervals up to 28 days following cessation of labelling.

Preliminary results indicate that plants subjected to 25 mM Na+ and 0 mM Ca2+ showed less ability to exclude Na+ from the roots, and accumulated more Na+ in roots, stems, an leaves than did plants supplied with 25 mM Na+ and 10 mM Ca2+. Leaf tissue accumulated more Na per gram fresh weight than did any other part of the plant, regardless of Ca2+ treatment.

Results from the remaining treatments, root 22Na+ efflux data, and total tissue Na+ and Ca2+ concentrations will also be reported.
EFFECT OF MECHANICAL STRESS ON CONDITIONING AND YIELD OF FOUR JAPANESE CULTIVARS OF CUCUMBER
Authors: Latimer J.G. , Johjima T. , Harada K.
Published: February 2019

Cucumber (Cucumis sativus L.) seedlings were brushed with a suspended bar for 1.5 min twice daily for 12 days (ST) prior to planting. One group of plants was brushed for an additional 10 days (LT) after planting. ST reduced stem length 12 to 28% and shoot dry weight 6 to 24% with `Kurume-ochiai-H' least responsive. ST reduced the numbers of female flowers on lateral shoots of `Ritsurin' and `Chikanari-suhyoh' while LT affected `Nanshin' and `Chikanari-suhyoh'. Brushing did not affect the total number of fruits or mean fruit size or weight of any cultivar, but both ST and LT decreased the total yield of `Ritsurin' grown in a plastic house. Brushing provides good growth control of containerized cucumber transplants with some responses differing among the cultivars. [Project funded by JSPS and Monbusho.]
SEASON OF SEED DEVELOPMENT AFFECTS GERMINATION OF LETTUCE SEED WITH HIGH TEMPERATURE
Authors: Mnichowicz Margaret , Coons Janice , McGrady John
Published: February 2019

Lettuce (Lactuca sativa L.) seed germination is inhibited at temperature higher than 25-30C. The extent of this inhibition varies between seed lots. Our objective was to determine how the season during which seed develops affects the ability of seeds to germinate and establish a stand at high temperatures. Lettuce seed, `Empire', was produced during 2 summers and 2 winters (1988 and 1989) in Yuma, AZ. These seeds were germinated at 20, 25, 30 or 35C in petri dishes or in growth pouches to determine percent germination or root lengths, respectively. Electrical conductivity of seed leachates was measured. Field emergence of seeds was tested with early fall plantings in Yuma, AZ. Percent seed germination was greater and root lengths were longer for the seeds produced in summer than in winter. Conductivity will be correlated with relative tolerance to high temperatures of the different seed lots. In the field, percent emergence of seed lots from summer and winter averaged 60% and 38%, respectively.
HEAT TOLERANCE OF SELECTED TOMATO CULTIVARS AND GERMPLASM LINES
Authors: Abdul-Baki Aref A.
Published: February 2019

Selected breeding lines and cultivars of tomatoes (Lycopersicon esculentrum Mill.) were evaluated for heat tolerance in the greenhouse (39°C day and 28°C night) and field using flowering, fruit-set, yield, fruit quality, and seed production as criteria. Under high temperature, heat tolerant lines performed better than the other two groups in all evaluation criteria except for seed production. The opposite was found under normal field conditions where heat sensitive commercial cultivars outyielded the heat tolerant lines and cultivars. Production of viable seeds under high temperature was severely reduced regardless of the heat tolerance level exhibited by the line or cultivar. Some of the heat tolerant lines could provide valuable sources of plant material for physiological studies to establish the molecular basis of heat tolerance and also could provide excellent germplasm sources for breeding heat tolerant tomato cultivars.
TOMATO FRUIT QUALITY AND ION STATUS: THE EFFECTS OF SALINITY, PHYTOPHTHORA ROOT ROT AND GENOTYPE
Authors: Snapp Sieglinde , Shennan Carol
Published: February 2019

Tomato Fruit quality can be improved by the use of moderately saline irrigation water. However, decreased fruit yields may occur if the saline treatment is initiated early in plant development or the salt concentration is high. Another concern with the use of saline irrigation water is increased plant susceptibility to disease. Two processing tomato cultivars were grown under low salt (ECa=1.1 ds/m), medium salt (ECa=2.8 ds/m) and high salt (ECa=4.6 ds/m) regimes, and in the presence and absence of Phytophthora parasitica, the casual agent of Phytophthora root rot. Salinity increased Phytophthora root rot severity in UC82B, the susceptible cultivar, but had a limited effect on CX8303, a cultivar known to have a measure of resistance to Phytophthora root rot. Fruit acidity and percent total soluble solids were enhanced in both cultivars by increasing salinity. Infection by P. parasitica increased acidity and soluble solids in UC82B fruit grown under high salt. Sodium and chloride concentrations in tomato fruit increased in a manner proportionate to the salt treatment applied; however, in the absence of disease, fruit Na+ and Cllevels were markedly lower compared to other tissues in the plant, The presence of salt-enhanced Phytophthora root rot in UC82B increased fruit Na+ concentration by almost 100%. Fruit Ca2+ and K+ levels, in contrast, declined moderately with increasing salinity and were not affected by disease.
SALINITY STRESS RESPONSES OF MINIATURE DWARF TOMATO IN A WHOLE PLANT MICROCULTURE EVALUATION SYSTEM
Authors: Smith M. A. L. , Knight S. L. , Bass M. J.
Published: February 2019

A whole plant microculture (WPMC) screening system facilitated rapid, quantitative appraisal of salt stress effects on `Micro-Tom' miniature dwarf tomato. Axillary bud explants were micropropagated on a hormone-free control medium (conductivity = 3.3 dS m-1), gradually introduced to treatments with increasing NaCl or Na2SO4 concentrations via biweekly subculture to fresh media (7,6, 12.8, or 18 dS m-1), and monitored over a subsequent 5 week culture period. Non-intrusive video image analysis techniques were adapted to quantify morphometric (shoot growth rate, area, and length; root length and area) and photometric (ruler and tissue quality) plant responses. Shoot growth was only slightly inhibited at 7.6 and 12.8 dS m-1, but was severely stunted and distorted on high salt (18 dS m-1) media. Root growth inhibition (significantly shorter and thinner primary rants) was first evident at 12.8 dS m-1 after 3 weeks of treatment. At 18 dS m-1, conspicuous retardation of root growth relative to controls could be gauged after only one week. Shoot tip chlorosis was observed in the lowest salt-supplemented treatment after three to four weeks of culture, but overall shoot yellowing at the two highest conductivities was marked after only a few days. Chlorosis symptoms were not uniform within treatments. Cell osmotic concentration showed a linear increase with increasing medium salinity. The WPMC system expedited time course observations of stress symptom development, paralleled stress response trends observed in solution culture tests, and provided an excellent vehicle to investigate plant adaptation to saline conditions.
MICROPROPAGATION OF THEOBROMA CACAO, A RECALCITRANT SPECIES, WITH HIGH CO2
Authors: Figueira Antonio , Whipkey Anna , Janick Jules
Published: February 2019

Cacao (Theobroma cacao) has long been considered a recalcitrant species in regard to microproagation. Although axillary shoots from cotyledonary nodes will proliferate and grow in vitro provided either cotyledons or roots are attached, excised shoots fail to grow in spite of conventional medium and hormonal modifications. Charcoal supplemented medium and rapid medium change are only marginally effective in inducing shoot elongation. The recalcitrance of cacao appear to be due to the presence of gums which are produced from stem tissues in response to wounding. However, growth of axillary cotyledonary shoots as well as mature shoots was obtained under conditions of high CO2 (20,000 ppm) and high light (quantum flux of 200 μmol m-2s-1) with or without sugar. Under these conditions leaves develop and shoots elongate which can be subdivided and subcultured. Shoots root under these conditions in vitro. We hypothesize that growth of cacao shoots in response to high CO2 is due to translocation of metabolizes from photosynthesizing leaves and stems.
A TWO-STAGE MICROPROPAGATION SYSTEM FOR CRANBERRIES
Authors: Marcotrigiano Michael , McGlew Susan P.
Published: February 2019

In an effort to accelerate breeding programs and to study somaclonal variation, a micropropagation system was devised for cranberries (Vaccinium macrocarpon). Using a factorial design, explants taken from greenhouse grown plants were placed on Anderson's medium containing different concentrations of 2ip' GA3, and IBA, with 4 cultivars tested over 3 subcultures. In other experiments, explant source, macro and micro salt formulations, and rooting treatments, were studied. Optimal multiplication and shoot quality occurred when single node explants taken from greenhouse grown plants were placed on Anderson's media containing 150 uM 2iP, 1.0 uM IBA and no GA3. Histological examinations indicate that initial response is axillary bud proliferation but upon subculture adventitious shoot formation may be possible. Proliferated shoots could be rooted ex vitro in plug trays under plastic tents and without hormone treatments. Optimal rooting occurred under high light conditions in a 1:1 (v:v) peat:sand mix. Plants were easily transplanted into the field in spring and will be evaluated by comparison to conventionally propagated material.
SHOOT POSITION, IBA AND AGROBACTERIUM RHIZOGENES INFLUENCE PROPAGATION OF HAZELNUT, CORYLUS AVELLANA
Authors: Proebsting William M. , Bassil Nahla V. , Lightfoot David A.
Published: February 2019

Propagation of Corylus avellana stem cuttings may be limited by either root initiation or bud abscission. We divided juvenile shoots of 3 varieties growing in layering beds in mid-July into 4 or 5 3-node cuttings with leaves at the upper two nodes, except that terminal cuttings had one expanded leaf. Cuttings were treated with 5 mM IBA in 50% EtOH, a mixture of A. rhizogenes strains A7 + 22 or left untreated. IBA and bacteria stimulated rooting of cuttings from all shoot positions. Rooting of the terminal cuttings (<50%) was less than that of the sub-terminal cuttings (>80%). Bud retention was <50% on terminal cuttings, nearly 100% on sub-terminal cuttings. Using juvenile stock plants of various varieties, sub-terminal cuttings treated with Agrobacterium or 5 mM IBA may yield 70-90% cuttings with both roots and buds, Agravitropic roots, characteristic of genetic transformation, were observed on Agrobacterium-treated cuttings. Dot blots probed for TL-DNA were negative, however.
NUTRIENT ACCUMULATION IN POTATO PLANTS GROWN IN NFT AT VARIED FLOW RATES AND SOLUTION CONCENTRATIONS
Authors: Cao W. , Tibbitts T.W.
Published: February 2019

A modified nutrient film technique (NFT) with a shallow granite medium was developed to control the flow rate and concentration of nutrients to which potato plants were subjected. Flow rates were 2, 4, and 8 ml per minute with balanced nutrient concentrations at 25, 50, and 100% (0.6 to 2.4 dS m-1 conductivity) of modified Hoagland's solution that was not recycled. Potato growth was greatest and about equal at 4 ml of 50% solution and at 8 ml of 25% solution. In shoots, accumulation of P, Fe, and Mn increased with both increasing concentrations and increasing flow rates. Zn accumulation decreased with increasing concentrations, and Ca, Mg, and Cu accumulation decreased with increasing flow rates. Accumulation of K, S, and B differed little with either concentrations or flow rates. In tubers, the differences resulting from variations in concentrations and flow rates were less than in shoots but accumulation patterns were similar except Ca and Mg accumulation did not decrease with increasing flow rates and K accumulation increased with both increases in concentration and increases in flow rate.
CARBON DIOXIDE EXCHANGE OF A WHEAT STAND GROWN IN NASA'S BIOMASS PRODUCTION CHAMBER
Authors: Corey K.A. , Wheeler R.M. , Sager J.C. , Prince R.P.
Published: February 2019

A wheat (Triticum aestivum cv. Yecora Rojo) stand was grown using nutrient film culture in the closed conditions of NASA's Biomass Production Chamber. Rates of photosynthesis and respiration of the entire stand (about 20 m2) were determined daily using a regime of 20 hr light/4 hr dark, 20 C light/16 C dark an average PPF of 600 μmol/m2/s from HPS lamps, and a CO2 cone of 1000 ppm. Fractional interception of PPF by the stand reached a maximum of 0.96 at 24 days from planting. Rates of photosynthesis were constant throughout the photoperiod as determined by short term drawdowns of CO2 throughout the photoperiod. Drawdown rates of CO2 were correlated with rates determined by logging of mass flow of CO2 injected during chamber closure. Photosynthetic drawdowns of CO2 indicated that photosynthesis was not saturated at 1000 ppm CO2 and that the CO2 compensation point was about 50 ppm. Whole stand light compensation points were 200 to 250 μmol/m2/s between days 13 and 70 and then increased rapidly during senescence.
CITRUS ROOTSTOCK SHOOTS ENHANCE SCION GROWTH AFTER BUD FORCING
Authors: Williamson Jeffrey G. , Koch Karen E. , Castle William S.
Published: February 2019

Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] seedlings were budded with `Hamlin' orange [Citrus sinensis (L.) Osb.] and subjected to 3 bud forcing treatments: (1) topping [T] by removing the seedling above the bud union; (2) lopping [L] by cutting half way through the seedling above the bud union and breaking the rootstock over; or, (3) bending [B] the seedling top over and tying it to the base of the plant. As scion buds emerged and grew, plants were sacrificed for dry weight measurements; also, the portion of the rootstock seedling above the bud union was exposed to 14CO2 at 3 stages of scion development. Plants with seedling tops attached (B,L) gained more dry weight and fibrous roots than T seedlings. Scion elongation was greater for B plants than for T plants. Plants usually flushed twice regardless of bud forcing treatment. No treatment differences were noted for time of flushing or scion bud emergence. Labeled photosynthate from attached rootstock leaves was translocated to scions during both flushes suggesting that recently fixed C enhanced scion growth for B and L plants.
MICROSPRAYER VS. EMITTERS FOR IRRIGATING PEACH TREES WHEN USING A COMPUTER MODEL TO PREDICT APPLICATION RATES
Authors: Worthington Josiah W. , Lasswell James L. , McFarland M.J.
Published: February 2019

A computer model was used to predict irrigation rates and numbers of emitters or microsprayers required to trickle irrigate Redskin/Nemaguard peach trees. Irrigation rates were 0, 50%, and 100% of the predicted requirement based on a crop coefficient of 50, 80, 100, 80, and 50 percent of pan evaporation for the tree's canopy area for May, June, July, August and Sept. respectively. Full irrigation (100% of predicted) was applied through 6, 8L/hr emitters or one 48L/hr microsprayer. Half the predicted rate was applied through 6, 4L/hr emitters or 1 24L/hr microsprayer. Control trees received no supplemental irrigation. Microsprayers height was adjusted to wet a surface area comparable to the 6 emitters. There was no significant difference in fruit size or yield based on emitter vs microsprayers, but fruit size and total yield was increased in direct proportion to irrigation rate. There was no treatment effect on tree pruning weights. Moisture measurements indicated that trees de-watered the soil efficiently enough that water never moved below the 30 cm level in spite of the fact that up to 260 liters per tree per day were applied in mid-summer.
RELATIONSHIP OF ROOTSTOCK SEEDLING CHARACTERISTICS TO FIELD VIGOR OF `REDGLOBE' PEACH
Authors: Reighard Gregory L.
Published: February 2019

Eight rootstock cultivars of peach (Prunus persica) were grown for 3 months in a greenhouse and evaluated for vigor by measuring root hydraulic conductivity and recording stem caliper, shoot and root dry weights, and root lengths. These data were compared with tree diameter data from 3rd leaf `Redglobe' orchard trees budded on the same rootstock cultivars. The objective was to determine if rootstock seedling growth could be used as a predictor of scion vigor in the field. Correlations between orchard tree diameters and the stem calipers (r = 0.87), whole plant dry weights (r = 0.91), and root dry weights (r = 0.89) of greenhouse rootstock were statistically significant (P < 0.05), but not significant was the correlation between root length (r = 0.76) and tree diameter. Root hydraulic conductivity as measured with a pressure-induced water flux system at 0.4 MPa of pressure and calculated on both a root length and a root dry weight basis was inversely correlated with both the greenhouse and field data. This suggested that root hydraulic conductivity was a function of a pressure-mediated mechanism that was independent of root membrane permeability and xylem conductance.
INFLUENCE OF ORCHARD-FLOOR VEGETATION MANAGEMENT ON APPLE TREE GROWTH, NUTRIENT UPTAKE AND LEAF TRANSPIRATION RATES
Authors: Merwin Ian , Stiles Warren C.
Published: February 2019

Eight vegetation management systems (VMS) were evaluated over four years in a newly planted apple site. VMS treatments included pre- and post-emergence herbicide strips, a close-mowed sodgrass, a growth-suppressed (maleic-hydrazide) sodgrass, a crownvetch “living mulch,” clean cultivation, and straw mulch. Soil moisture supply was highest under the straw mulch and lowest under crownvetch, and varied inversely with groundcover biomass. Leaf N was deficient in tress in both sodgrass VMS, and increased by the lequme “living mulch” only after four years. Leaf Cu was lowest, and appeared to limit tree growth in VMS with prolonged soil moisture deficits. No significant differences were observed in leaf transpiration over a broad range (10 to 700 kPa) of soil matric tension. Cumulative trunk crosssectional area was greatest in straw-mulched trees and least in sodgrass and crownvetch VMS. The optimal soil matric tension for nutrient uptake and tree growth appeared to be 175 to 200 kPa in this orchard. Increasing the width of glyphosate herbicide strips from 1.5 to 2.5 m in tree rows did not improve tree growth, nutritional status or fruit yield.
ISOZYME VARIATION IN SEXUALLY AND ASEXUALLY REPRODUCED GARLIC
Authors: Pooler M. , Simon P.W.
Published: February 2019

Despite its long history of obligate vegetative propagation, garlic (Allium sativum L.) exhibits a surprisingly large amount of variation between clones, as evidenced by both morphological and isozyme markers. As reported previously, several garlic clones which produce viable seed have been identified in the Wisconsin collection, and a possible correlation between clone fertility, morphology, and isozyme banding patterns was examined. The potential use of isozymes to analyze sexually-derived hybrid garlic lines, haploids, and interspecific hybridizations was also investigated.
LINKAGE OF RESTRICTION FRAGMENT LENGTH POLYMORPHISMS AND ISOZYMES IN A BACKCROSS OF CITRUS AND PONCIRUS
Authors: Durham Richard , Moore Gloria , Guy Charles
Published: February 2019

Genetic linkage analysis was performed on an interspecific backcross of citrus [Citrus grandis (L.) Osbeck cv. Thong Dee X (Thong Dee X Poncirus trifoliata (L.) Raf. cv. Pomeroy)], using restriction fragment length polymorphism (RFLP) and isozyme analysis. Sixty-five progeny were analyzed for a total of 57 segregating markers including 9 isozymes and 48 RFLPs. Significant (p = 0.05) deviation from an expected 1:1 segregation ratio was observed for 21 (37%) of the 57 loci, but this did not exclude their use in the mapping study. Linkage analysis revealed that 50 loci mapped to 12 linkage groups while 7 loci segregated independently from all other markers. The total map distance included in the 12 linkage groups was 472 cM with the mean distance between markers being 12.8 cM. This does not represent a saturation of the genome with markers; however, this work demonstrates the potential for mapping traits of economic importance in citrus.
CELL GROWTH OF EUCALYPTUS SUSPENSION CULTURE
Authors: Rogers Suzanne M.D. , Rudolph Victoria E. , Dias Kalyani
Published: February 2019

A suspension culture of Eucalyptus tereticornis was initiated from callus and grown for 7 months under indirect light in a Murashige and Skoog (1962) basal medium containing 3% glucose and 1 mg/l 2,4-D. Glucose was used, instead of sucrose, as it reduced production of phenolic-like compounds. The inoculum size for maximum cell yield was determined. Cells (0.1, 0.2, 0.5, 1.0, 2.5 and 5.0 g fresh weight) were cultured in basal medium for 14 days. Maximum fresh weight (mean 11.8 g) was attained from samples inoculated with at least 1.0 g of cells. Largest dry weight (mean 608 mg) occurred following, inoculation with at least 0.5 g fresh weight of cells. Inoculation with 0.5 g of cells resulted in the most rapid fresh weight doubling time (3.4 days).

After 17 months of culture, cells were grown in basal medium or m basal medium supplemented with 1 mg/l kinetin, under continuous, direct light. Growth, based on fresh and dry weight increases, was measured over the 2-week subculture period. Growth of cells was similar in both media. The cells' chlorophyll content remained low. Fresh weight doubling time averaged 3.8 days.
ANATOMICAL DEVELOPMENT OF ROOTS INDUCED BY AGROBACTERIUM RHIZOGENES ON APPLE SHOOTS GROWN IN VITRO
Authors: Luza Juvenal , Sutter Ellen G.
Published: February 2019

Development of roots on M.26 apple shoots grown in vitro induced by A. rhizogenes was compared with that of roots induced by NAA. Shoots were inoculated with 4-day colonies of A. rhizogenes strain A4 and were sampled at 1, 2, 4, 8 weeks after inoculation. Roots formed on approximately 30% of inoculated shoots. Roots induced by A. rhizogenes typically were agravitropic and branching. The outer layer of cells on these roots, especially on older roots, often resembled callus and sloughed off easily when the plants were transferred. The internal structure of the roots did not differ between the two treatments. Roots induced by NAA always arose endogenously and clear connections to the vascular system of the shoots were apparent. Many roots induced by A. rhizogenes appeared to develop exogenously, arising from anomalous cellular proliferation in the cortex of the apple stems or in callus at the base of the stem. These roots also showed vascular connections to the shoot.
APPLICATION OF CALLUS CULTURE FOR THE STUDY OF BLACKSPOT DISEASE RESISTANCE IN ROSES
Authors: Sherman J.M. , Reddy K.S. , Newman S.E. , Spencer J.A.
Published: February 2019

The objective of this study was to determine whether tissue culture can be used for studying the blackspot resistance found in some roses. Callus was initiated from leaves, petioles, and stems of resistant and susceptible genotypes. Good callus formation for susceptible roses (hybrid teas) was obtained on a medium containing MS basal salts, vitamins, sucrose, and 8 g/L agar supplemented with 2 mg/L 2,4-D, 1 mg/L NAA, and 0.2 mg/L BA. Callus formation for resistant roses (species roses) was best when the concentrate ions of growth regulators in the medium were halved. Browning in species rose cultures, was decreased with the addition of 0.05 g/L ascorbic acid to the medium followed by incubation in the dark. The subculture calli were inoculated with the fungal conidia and were analyzed for proteins by SDS-PAGE. These protein profiles were compared to those of whole leaf samples. The results are discussed in terms of similarities and differences in the biochemical responses of callus cultures versus whole leaves to the blackspot infection.
PRIMING PETUNIA
Authors: Khademi M. , Koranski D. S. , Karlovich P. T.
Published: February 2019

NaCl, KNO3 (0.3, 0.4, 0.5M), KH2P O4 (0.4, 0.5, 0.6M), and PEG 8000 (320 to 370 g/L with the increment of 10g/L) were used for priming Petunia `Ultra White' seeds for three to six days. Seeds were germinated in a growth chamber at 25C. Germination was recorded for seven days and the number of acceptable seedlings (seedlings with open cotyledon and normal root) was counted on the day seven. KH2P O4 at 0.6M was the best salt treatment. Rate of germination was improved by salt priming but the number of acceptable seedlings was lower than the control. Addition of GA (5 ppm) to the salt treatment was not effective. More abnormal seedlings were observed when seeds were primed in aerated salt solutions than when primed in petri dishes. Aerated PEG at 325 g/L for three days and 365 g/L for six days gave the best results. Priming in PEG improved percent of germination, rate of germination, and number of acceptable seedling as compared to control. Primed seeds lost some of the advantages of priming during 24hr air drying (22C), however quality was maintained when dried at 10C. Drying primed seed in 80% R.H. was not effective.
DRISCALC: A COMPUTER PROGRAM TO CALCULATE DRIS INDICES ON NUTRITIONAL ANALYSES.
Authors: Sistrunk Laurence A. , Storey J. Benton
Published: February 2019

Since DRIS calculations prove to be tedious for most researchers, a computer pro am was written to use test data from foliar analyses to compile DRIS norms for a population and using these norms, calculate the indices for each of 14 elements.

The data to be tested is first put into a record base format and stored as an ASCII file. When DRISCALC is run on IBM compatible microcomputers, this data is separated into two subpopulations based on the mean yield for the main population. The next procedure calculates the mean, the standard deviation (from the mean), and the variance for each subpopulation as well as the variance ratio (low yield/high yield) and the CV.

The F test for variance and the student's t test selects the norms (high population mean and CV'S). After construction of this temporary database, and unknown sample is entered into the program for testing. DRIS indices are calculated and several statistical options can be selected b the user. Hidden deficiencies can be found by the researcher or DRIS principles can be taught to students.
EFFECT OF A CRIMSON CLOVER GREEN MANURE ON YIELD AND QUALITY OF SWEET POTATO
Authors: Funderburk Sharon R. , Collins Wanda W.
Published: February 2019

Crimson clover Trifolium incarnatum L.) was used as a N source for sweet potato [Ipomoea batatas (L.) Lam.]. Treatments were designed to compare estimated N delivery by clover incorporation amounts of N delivered by inorganic fertilizer. Plants were sampled every 14 days and sectioned into four parts: shoots, stem tips, fibrous and storage roots. Dry matter content was significantly influenced by time. Total plant dry matter was lowest in the highest inorganic N treatment. Nitrogen concentration (DWB) decreased over time and was highest in the highest inorganic N treatment. Similar vine weights were noted in N and clover treatments while number of storage roots per plant was unaffected by treatment as was weight per storage root, which increased linearly over time. No significant difference existed between the high and low N application treatment or late clover incorporation treatment in any grade of storage roots except culls, which were 90% lower in clover treatments than in N fertilizer treatments.