bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Tropical Horticultural Commodities To Insect Disinfestation Treatments.
Authors: Paull Robert E.
Published: February 2019

There is a need to develop effective, non-damaging, non-polluting, non-carcinogenic procedures for insect disinfestation and disease control in fresh horticultural products. The loss of ethylene dibromide as a fumigant and the uncertainties of other fumigants, has meant that alternatives are needed. The most likely possibilities include irradiation, heat, cold and controlled atmospheres. Irradiation doses required for sterilization of insects cause only minor physiological changes, while controlled atmospheres appear to require longer periods of exposure than the postharvest life of most tropical fruit. The sensitivity of tropical commodities to temperatures less than 10°C makes cold treatments inappropriate for most tropical commodities. Heat treatments seem to be most promising. For papaya, the requirement is that the fruit core temperature reach 47.2°C, this can occasionally disrupt fruit ripening. The sensitivity to heat is modified by seasonal, variety and rate of heating factors. The sensitivity can be related to the heat shock response and the presence of heat shock proteins.
COMPARISON OF DROUGHT TOLERANCE AMONG PRUNUS SPECIES FROM DIVERGENT HABITATS.
Authors: Rieger Mark
Published: February 2019

Root and shoot characteristics related to drought tolerance were studied for Prunus persica, P. andersonii, P. besseyi, P. maritima, P. subcordata, and P. tomentosa. In general, shoot characteristics were more closely associated with drought adaptation than root characteristics across species. The most xeric species, andersonii, had the most xerophytic leaf morphology, highest rates of leaf gas exchange, high root length/leaf area and root weight/leaf area ratios, but had root length and hydraulic conductivity similar to that of more mesic species. Water use efficiency (WUE) increased as water potentials (ψ) dropped to -3.0 to -4.0 Mpa during a 5-7 day drought for the xeric andersonii and subcordata. However, after an initial increase, WUE decreased with declining ψ in the other 4 species, indicating that carboxylation was affected by stress in the -1.5 to -3.0 range of ψ for besseyi, maritima, persica and tomentosa. CO2 assimilation (A) decreased linearly with ψ during drought in all species, but the ψ at which A reached zero was not well correlated with drought adaptation. Root hydraulic conductivity was similar for all species, indicating a lack of importance of this parameter for drought tolerance. The data suggest that introduction of xerophytic shoot characteristics into commercial cultivars of Prunus would improve drought tolerance to a greater extent than using drought tolerant species as rootstocks.
RANDOM AMPLIFIED POLYMORPHIC DNA VARIATION IN THE CULTIVATED SPECIES OF PRUNUS
Authors: Arulsekar S. , Bliss F. A.
Published: February 2019

Studies of genetic variation at the DNA level in the tree fruit and nut crop species of Prunus have been very limited. Recently molecular markers based on random amplified polymorphic DNA (RAPD) markers have been shown to be highly useful and efficient gene markers in other plant and animal species. We have used a total of 50 primers (10-mers) with arbitrary nucleotide sequence to identify cultivars of cherry, plum, apricot, peach and almond. A total of 120 accessions of different cultivars were assayed. The variation revealed by RAPD markers was highly species specific in the five Prunus species examined. High levels of polymorphism were observed for almond cultivars whereas sweet cherry revealed the lowest levels of polymorphism for the RAPD primers examined. The implications of these results in the germplasm diversity in the cultivated species of Prunus will be discussed.
RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD™) MARKERS FOR ESTIMATING GENETIC RELATIONSHIPS IN MANGIFERA INDICA L.
Authors: Schnell Raymond J. , Knight Robert J.
Published: February 2019

Genetic relationships between commercial mango cultivars are often speculative and only the maternal parent is generally known. RAPD™ primers were used with the polymerase chain reaction (PCR) to provide markers useful in determining individual identity, family relationships, and linkage mapping analysis. In mango, 53 RAPD primers were screened for markers and 27 proved useful. Genomic DNA was isolated from 70 clones of mango maintained in the USDA germplasm collection. DNA from these clones was amplified with each of the 27 primers. Data were scored as the presence or absence of bands. Groupings of the clones using UPGMA based on Nei's genetic distance gave distinct clusters. RAPD clusters vs. clusters based on isozyme analysis are compared.
ABSCISIC ACID LEVELS AND INFLORESCENCE ABORTION IN HELICONIA STRICTA
Authors: Lekawatana Setapong , Criley Richard A.
Published: February 2019

Inflorescence abortion in heliconia contributes to an economic loss to growers. In an effort to determine the cause, we manipulated temperature, daylength and light intensity. Plants of Heliconia stricta cv. Dwarf Jamaican were grown in 4 day/night temperature regimes (15/10, 20/15, 25/20 and 30/25°C) under 14 hr daylength. In a separate experiment, plants were grown in full sun, 60% and 80% shade. Both experiments had been conducted after inflorescences were induced (4 weeks of short days). Apical meristems were dissected weekly to follow inflorescence development. Leaf abscisic acid level was detected by an indirect ELISA. Significantly more inflorescences were aborted in plants grown under high temperature regimes than in plants grown under low temperature regimes and under different light intensity. Abscisic acid concentration increased in heliconia leaves under regimes that induced inflorescence abortion. The results could provide a mean to improve heliconia inflorescence production.
AROMATIC COMPOUNDS AND WATER RELATIONS OF SOUR ORANGE SEEDLINGS.
Authors: Swietlik Dariusz
Published: February 2019

Sour orange seedlings were grown in water culture to which one of seven aromatic compounds, associated with allelopathic effects, was added to produce concentrations ranging from 0.5 to 2.0 mM. Leaf water potential (ψ1), leaf stomatal conductance (gs), and whole plant transpiration (T) were measured during a 7-day treatment period. At the end of that period, the total and average leaf surface area, shoot elongation, and fresh weight gain of seedlings were determined. Solutions of vanillic, coumaric, and ferulic acids of 2mM concentration reduced ψ1, gs, and T. Reductions of gs, and T but not (ψ1) occurred when vanillic acid of 1mM concentration was applied. Solutions of vanillic (0.5; 1.0; 2.0mM), coumaric (1; 2mM), cinnamic (1mM), or chlorogenic (1; 2mM) acids reduced fresh weight gain of seedlings. Only the coumaric and chlorogenic acids treatments of 2mM concentration reduced shoot elongation. No treatment affected total or individual leaf area. Gallic and caffeic acids had no effect on sour orange water relations and growth.
EXTRACTS FROM ASH ROOTS AND VELVETLEAF AFFECT WATER STATUS OF SOUR ORANGE SEEDLINGS
Authors: Fucik John E. , Swietlik Dariusz
Published: February 2019

Water extracts of cocklebur,CBX (Xanthium spinosa L.) and velvetleaf,VLX (Abutilon theophrasti Medic.) shoots and Mexican ash,AshX (Fraxinus Berlandieriana A.DC.) roots were added to 9 month-old sour orange Citrus aurantium L.) seedlings(SOs) in water culture. Final extract concentrations represented either 50 or 12.5 g. of plant material liter-1 of culture solution, i.e. 1/20 or 1/80 dilutions. Leaf water potential(ψ); stomatal conductance(gs);transpiration(T) and growth responses were measured for 13 days. After 1 day, SOs in AshX and CBX had lower ψ than controls. After 11 days SOs in CBX had higher ψ than the others. ψ responded similarly to both extract concs.. Thru day 5, AshX decreased gs vs. the controls and VLX. By day 11, gs of SOs in AshX was less than for VLX but not the others. On days 1 and 5, gs for VLX at 1/20 was lower than controls but at 1/80, gs's were the highest of all treatments. These results supported by the T rates, growth responses and others findings suggest AshX and VLX induce water stress by reducing water absorption and/or transport in addition to possibly disrupting normal root/shoot communications
EFFECT OF WIND SPEED ON CARBON ASSIMILATION, WATER RELATIONS, AND GROWTH OF YOUNG CARAMBOLA AND SUGAR APPLE TREES
Authors: Crane J.H. , Schaffer B.
Published: February 2019

The effect of wind stress on growth, net CO2 assimilation (A), and leaf water potential of eighteen-month-old, containerized carambola (Averrhoa carambola cv. Arkin) and seedling sugar apple (Annona squamosa) trees was investigated. In a glasshouse, trees were exposed to fan-generated wind speeds of 0 (control), 4 (low wind; LW), or 7 (high wind; HW) m sec-1 for 4 hr/day (1000-1400 hr) for 30 days. No differences in A, stomatal conductance, transpiration, and fresh and dry wt of mature carambola or sugar apple leaves or shoots were observed among treatments. In contrast, as wind speed increased, fresh wt of immature carambola leaves and shoots decreased. For carambola and sugar apple, no significant relationship was found between mid-day leaf water potentials and wind speed. However, after 30 days, leaf water potential of carambola subjected to HW (-1.2 MPa) was lower than those of LW (-1.1 MPa) and control (-1.1 MPa) trees. For sugar apple, leaf water potential of control trees was generally higher than those of trees in the LW and HW treatments. The data indicate that exposure to wind speeds of 4 or 7 m sec-1 for as little as 4 hr/day for 30 days reduces new leaf and shoot growth of carambola trees.
NUCLEAR DNA CONTENT IN BLUEBERRY DETERMINED BY FLOW CYTOMETRY
Authors: Ortiz Rodomiro , Costich D.E. , Meagher T.P. , Vorsa N.
Published: February 2019

DNA flow cytometry was used to determine nuclear DNA content in diploid blueberry species, and 3x, 4x, 5x, and 6x ploidy levels. Relative fluorescence intensity of stained nuclei measured by flow cytometry was a function of the number of chromosome sets (X): Y = 3.7X – 2.3 (r2 = 95.1%). DNA flow cytometry should be useful for ploidy level determination in the seedling stage. A significant linear relationship was established between nuclear DNA content and number of chromosomes (x); DNA (pg) = 0.52 x1 (r2 = 99.8%). Based on this equation the haploid genome DNA amount (1C) was calculated as 0.62 ± 0.08 pg, with an approximate haploid genome size of 602 Mbp/1C. The results indicate that conventional polyploid evolution occured in the section Cyanococcus, genus Vaccinium: the increase in DNA was concurrent with increase in chromosome number. DNA content differences among 2x species were correlated with Nei's genetic distance estimates based on 20 isozyme markers. Most of the variation was among species (49%), with 26% between populations within species, and 25% within populations.
POSTHARVEST CaCl2 DIPS INCREASE HIGHBUSH BLUEBERRY FIRMNESS
Authors: Beggs Jane
Published: February 2019

Deformed or damaged berries reduce the grade of frozen highbush blueberries (Vaccinium corymbosum L.). Before berries are frozen, immature fruit are commonly removed by density sorting in water tanks. Three studies were conducted to determine if the firmness or quality of highbush blueberries could be improved by the addition of CaCl2 to sorting tank water. `Bluecrop' and `Jersey' berries were dipped in CaCl2 solutions (0.0-4.0%) for periods of 0.5-8.0 minutes. The effect of rinsing the fruit after treatment was also studied. Berries were held at 2C for several days before evaluation. A 61.5 cm length of PVC pipe (4.0 cm. I.D.) was filled to a depth of 50 cm. with berries and dropped 4 times on to a hard surface from a height of 10 cm. The compression of the column of berries was measured and berries were removed and visually sorted according to the degree of damage. The amount of compression and number of damaged berries were inversely related to the CaCl2 concentration. Rinsing berries immediately after dips negated the effects of CaCl2. Treatment with CaCl2 may result in objectionable flavors.
GENETIC AND PHYSIOLOGICAL ANALYSIS OF SUCROSE ACCUMULATION IN TOMATO FRUIT
Authors: Stommnel John R.
Published: February 2019

Fruit of the cultivated tomato, Lycopersicon esculentum, accumulate the reducing sugars glucose and fructose as the primary storage carbohydrates. In contrast, fruit of several wild green-fruited species store high concentrations of sucrose. Analysis of invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS) enzyme activity throughout fruit development in the sucrose accumulating species L. peruvianum, indicated low levels of invertase and SS during the period of significant sucrose accumulation. Increased SPS activity was noted during the sucrose accumulation phase but was not coincident with maximum rates of sucrose accumulation. The percent soluble solids in ripe L. peruvianum fruit was more than twice that present in L. esculentum and attributed primarily to the high level of sucrose accumulated in L. peruvianum. Analysis of fruit sugar content in F1, F2 and backcross populations derived from an initial cross between plants of sucrose and hexose accumulators suggests that recessive gene(s) are responsible for sucrose accumulation.
PHOTOAUTOTROPHIC MICROPROPAGATION OF CYMBIDIUM PLB
Authors: Kubota Chieri , Kirdmanee Chalermpol , Kozai Toyoki
Published: February 2019

Cymbidium (cv. Lisa rose) PLB (protocorm-like bodies) were cultured in liquid 1/2 MS medium with/without 20 mg g-1 sucrose under continuous lighting conditions. The vessels were shaken at 100 rpm under PPF (photosynthetic photon flux) of 20 and 140 μmol m-2 s-1 and CO2 concentrations outside the vessel (Cout) of 450 and 2000 μmol mol-1 conditions. Photoautotrophic growth was obtained at high PPF and high Cout. The chlorophyll content of the PLB in the medium without sucrose at high PPF and high Cout was almost 3 times that with sucrose at low PPF and low Cout. The number of newly developed PLB with sucrose at low PPF and low Cout was 1.6 times that without sucrose at high PPF and high Cout; the dry weight per unit PLB with sucrose at low PPF and low Cout was almost 3 times that without sucrose at high PPF and high Cout. Photoautotrophic growth of the PLB might be further promoted at higher CO2 concentration (> 1%).
INFLUENCE OF SITE OF PRODUCTION ON LEVELS OF TUBERIZING STIMULUS IN SEED POTATOES
Authors: Waterer Doug , Wahab Jazeem
Published: February 2019

Single nodal cuttings were used to study the degree of tuberizing stimulus found in Norland and Russet Burbank seed tubers produced at latitudes ranging from 40 to 52°N. Seed tubers were planted in the greenhouse under an inductive 8 h or a non-inductive 18 h photoperiod. Single leaf cuttings taken at several intervals after planting were grown under a 12 h photoperiod and the tuberization characteristics of the cuttings were rated 21 days later. Cuttings derived from seed grown at low latitudes produced more tubers under both photoperiods than cuttings from northern seed. The tuberizing stimulus increased with age of the cutting and/or association with the mother tuber. It appears that previously observed differences in yield potential of seed tubers from varying latitudes may be related to differences in an endogenous tuberizing stimulus derived from the mother tuber.
COPPER PHYTOTOXICITY TO YOUNG CITRUS TREES AS INFLUENCED BY SOIL pH
Authors: Alva Ashok K.
Published: February 2019

The aim of this study was to investigate soil pH and copper (Cu) interactions affecting Cu phytotoxicity to young citrus trees on different rootstocks. Hamlin oranges on either Carrizo citrange, sour orange, or rough lemon rootstocks were grown on Candler fine sand at varying soil pH (5.0, 5.5, 6.0, 6.5) without additional Cu or soil applied Cu (liquid form; 240 kg Cu/ha; nine pre- and five post-planting applications over a period of 43 months). Increasing soil pH increased tree height, canopy volume and trunk diameter of trees on all three rootstocks, regardless of Cu treatments. Tree growth response to an increase in soil pH was greater in Cu amended as compared to unamended treatments. Response to pH increase above 6.0 was marginal as compared to that for pH increase from 5.0 to 6.0. Leaf Cu concentrations showed negligible differences in response to Cu treatments; however, Cu concentrations in fibrous roots increased by 126 to 152% in Cu amended as compared to unamended treatments.
EVAPORATIVE COOLING AND CYANAMIDE ON BUDBREAK AND MATURATION OF GRAPEVINE, CV. PERLETTE.
Authors: Osorio Guadalupe , Díaz Daniel H.
Published: February 2019

Chilling accumulation infuence dormancy of grapevines and determines budbreak. Under desert conditions, hydrogen cyanamide (H2CN2) improve bud opening. To increase even further the quantity and uniformity of bud break, the effect of fall evap rative cooling (EC) alone or in combination with H2CN2(2.5%v/v was evaluated. Microsplinklers operated for 40 seconds at 10 min intervals from 10:00 h to 17:00 h, from 20 oct to 18 dec 1990. H2CN2 was applied on 21 dec, one day after pruning.

Cyanamide treated plants or with the chemical + EC, had 19% and 32% budbreak, respectively, by jan 15. Control or EC vines opened until feb 20, and reached 40% and 57% final values by mar 25. Therefore, cyanamide and EC acted sinergisti cally to open buds earlier and uniformily, although not on final budbreak.

Harvest started may 8 with cyanamide + EC, five days earlier than cyanamide alone; by may 13, accumulated harvest was 39% and 13% respectively, and of 92% and 77% by may 28. Control vines with or without EC, were harvested early may to mid june.
THE U.S. CUCUMBER PROCESSING INDUSTRY STUDY: MARKETING POTENTIAL FOR CARIBBEAN EXPORT
Authors: Otis Thomas J.
Published: February 2019

The Caribbean has been considered as a potential region for the winter production of processing cucumbers (Cucumis sativus L.). The industrial framework, transportation considerations, production costs, and marketing strategies are evaluated by utilizing pertinent studies, trade journals, and industry interviews. Three marketing strategies will be discussed; brined, fresh green stock, and attracting the processor to the region. Of these, producing fresh green stock has the greatest short term potential. This can be achieved through securing grower contracts and competitive backhaul rates, market proximity, and reduced production costs. These factors justify the Caribbean as a viable alternative to established areas for the export of cucumber products to the U.S. market during the winter season. The development of this market can be enhanced by improvements in the Caribbean transportation networks and stable governments.
EVALUATION OF FUMIGANTS AND NEMATICIDES FOR THE CONTROL OF ROOT-KNOT NEMATODES ON CARROT
Authors: Johnston S.A. , Probasco P.R. , Phillips J.R.
Published: February 2019

A study was conducted to investigate the effectiveness of soil fumigants and oxamyl nematicide on root-knot nematode, Meloidogyne hapla. A loamy sand carrot field of Danvers 126 carrots with a high population of root-knot nematodes was used for the test. Treatments included: 1, 3-dichloropropene, oxamyl, sodium methyldithiocarbamate, and the combination of 1,3-dichloropropene and oxamyl or sodium methyldithiocarbamate and oxamyl. All treatments were replicated 4 times in a randomized complete block design. Carrots were evaluated for plant stand, vigor, root length, galling, marketable yield, and total yield. Tremendous differences in plant vigor of young plants were observed among treatments. All of the fumigant treatments were significantly better than the other treatments and resulted in high plant stands and increased root length. Only the fumigated treatments, with or without foliar applications of oxamyl, resulted in significant marketable yield increases. Oxamyl foliar applications are beneficial in reducing root-knot nematode populations levels and damage when applied 6 weeks after initial treatment but not when they are initiated 10 weeks after initial treatment.
SEQUENCING OF FORCING SOLUTION PLANT GROWTH REGULATORS ENHANCES MACROPROPAGATION OF LIGUSTRUM VULGARE L. BY SOFTWOOD CUTTINGS
Authors: Yang Guochen , Read Paul E.
Published: February 2019

A forcing solution containing 200 mg 8-hydroxyquinoline citrate per liter and 2% sucrose has been demonstrated to extend the season for obtaining softwood growth suitable for use as explants in micropropagation (Yang & Read 1989). Forcing dormant woody stems in the off-season in this fashion also enhances the macropropagation of woody plant species by providing softwood outgrowth that can be rooted as softwood cuttings. GA3, IBA, IAA and NAA were incorporated into softwood growth which was later used as cuttings for rooting by adding plant growth regulators at various concentrations to the forcing solution. GA3 incorporated into the forcing solution hastened bud break, increased shoot elongation, but inhibited rooting of softwood cuttings taken from stems forced in this manner. IBA, IAA and NAA in the forcing solution exhibited typical auxin effects on rooting of cuttings by increasing root number per cutting and root elongation. In order to expedite macropropagation of woody plants, GA3 and IBA were added SEQUENTIALLY to the forcing solution. Addition of IBA to fresh forcing solution following initial use of GA3 in the forcing solution counteracted the negative effects of GA3 and stimulated rooting. This protocol is proposed as a method to assist propagation in rooting difficult species by softwood cuttings in the off-season.
MOLECULAR ANALYSIS FOR INTROGRESSION OF ALLIUM FISTULOSUM INTO ALLIUM CEPA
Authors: Bark Ockyung H. , Havey Michael J. , Corgan Joe N.
Published: February 2019

The edible Alliums are economically important world-wide. The bulb onion (Allium cepa) is the most widely grown. The Japanese bunching onion (A. fistulosum) has many desirable characters, e.g., resistance to pink root, Thrips, smut, maggot, and Botrytis. Transfer of pink root resistance from A. fistulosum into A. cepa has been attempted for over 60 years. However, sterility of the F1 hybrid is a barrier and there is little evidence of gene introgression during backcrossing to A. cepa. Dr. Corgan has made crosses between A. fistulosum as the seed parent and A. cepa. He backcrossed the F1 hybrids to A. cepa and generated BC2 progenies which showed excellent pink root resistance. RFLPs in the chloroplast genome showed all BC2 progenies had either the normal or sterile cytoplasm of A. cepa. This may be due to not strictly maternal inheritance of the chloroplast DNA or a seed mixture during backcrossing. Other interspecific hybrids and their BC1 progenies had the cytoplasm of A. fistulosum. Nuclear RFLPs show hybrid patterns in the F1 plants. BC1 progenies possess some A. fistulosum markers as evidence of DNA introgression from A. fistulosum into the backcross progenies.
TWO PRUNE-YEAR APPLICATIONS OF PHOSPHORIC ACID INCREASE PHOSPHORUS UPTAKE BY LOWBUSH BLUEBERRIES.
Authors: Smagula John M.
Published: February 2019

Liquid phosphorus (23% phosphoric acid) was applied preemergence at 0, 22.4, 44.8, 67.2, or 89.6 kg·ha-1 to 9 fields: 3 commercial blueberry fields having plants with very low (<.111%), 3 low (.111-.125%), and 3 adequate (>.125%) leaf phosphorus concentrations. Years of application ('89,'89+'91,'89 + '91 + '93) were assigned in a split-block RCB design with 4 replications at each location. A linear increase in leaf phosphorus concentration with increasing rates of P application was found in both 1989 and 1991. Differences in response were found among locations. A second application in 1991 was effective in raising leaf P levels at most locations to higher levels than the application in 1989. Also, there were higher levels of leaf P in treatment plots that only received P fertilizer in 1989 compared to controls, indicating a carry over effect.
BROADER pH RANGE FOR POTATOES WITH MIXED N THAN WITH EITHER NH4 OR NO3
Authors: Cao W. , Tibbitts T.W.
Published: February 2019

Three nutrient culture experiments were conducted to determine the responses of potatoes (Solanum Tuberosum L.) to various solution pH levels with NO3, NH4, and mixed NO3/NH4 (1/1) at the same total N of 4 mM. The pH levels were maintained at 4, 5, 6, and 7 with NO3 or NH4, and at 4, 4.5, 5, 6, 6.5, 7 with mixed N. In each of the experiments, Norland plants were grown for 28 days after transplanting. With mixed N, plant growth as total dry weight, leaf area and tuber number was essentially similar at pH 4.5 to 7, and decreased only at pH 4. However, with either NO3 or NH4 growth peaked at a particular pH level, pH 5 and 6 respectively, and was significantly reduced at other pH levels with severe stunting at pH 7. With mixed N, the concentrations of total N in shoots were similar at pH 4 to 7 whereas, with either N form, the concentrations of total N were higher at particular pH levels, pH 4 and 5 with NO3 and pH 7 with NH4. The concentrations of P, S, Ca, Mg, and Mn in shoots were similar at pH 4 to 7 with mixed N, but varied at certain pH levels with either NO3 or NH4. The results indicate that the useful pH range for nutrient uptake and plant growth is broader with mixed N than with either NO3 or NH4.
STATUS OF TRANSPLANT TECHNOLOGY IN THE USA
Authors: Thomas Berl M.
Published: February 2019

The containerized transplant commercial industry started in the United States in the 1960's. Since then, several different types of growing containers have been developed for the vegetable, tobacco, ornamental and forestry seedling industries. Two basic irrigation methods have developed including overhead and sub-irrigation systems. The irrigation system used depends on the crop needs, value, availability of water, and the need to reduce pesticide use and risk of disease. Sub-irrigation systems have reduced the spread of seed-borne and naturally occurring diseases. Overhead irrigation systems were predominantly used during the early years, but at present, both systems are used and selected for their respective advantages. Future developments in the transplant industry include reduction of production risks and to improve cost per production unit by reducing both nursery and farm labor requirements.
THE POTENTIAL OF CARYA X LECONTEI (LITTLE) AS A ROOTSTOCK FOR PECAN.
Authors: Grauke L. J. , O'Barr R. D.
Published: February 2019

`Oconee' pecan (Carya illinoinensis (Wangenh.) K. Koch) was grafted on seedling rootstocks from nine open-pollinated seedstocks. Rootstocks included three seedstocks each of pecan, water hickory (C. aquatica (F. Michaux.) Nutt.) and their hybrid, Carya X lecontei (Little). Pecan seedlings had the largest basal diameter, water hickory seedlings the smallest, and hybrid seedlings were intermediate. Seedlings of `Elliott' and 'Curtis' seedstocks were larger than seedlings from `Moore' seedstock. Pecan and hybrid seedlings were more successfully grafted than water hickory. Graft success varied between seedstocks of the hybrid, with some as high as pecan. Foliage color of seedlings, indicative of iron nutrient status, was influenced by the species of rootstock: pecan seedlings were darker green than water hickory seedlings, but were inseparable from hybrid seedlings. `Oconee' scions on pecan seedlings were darker green than when grown on hybrid seedlings.
INTRODUCTION OF β-GLUCURONIDASE GENE INTO GINSENG (PANAX CINSENG) BY A TI-PLASMID VECTOR SYSTEM AND ITS EXPRESSION
Authors: Liu Jang R. , Lee Haeng S. , Kim Suk W. , Lee Hyo W.
Published: February 2019

β-Glucuronidase (GUS) gene of Escherichia coli was introduced into ginseng cells by an Agrobacterium binary vector system and expressed in somatic embryos derived from the cells. A binary vector pBI121 carrying CaMV 35S promoter-GUS gene fusion and a neomycin phosphotransferase gene as selection marker was transferred into Agrobacterium tumefaciens LBA4404. Zygotic embryo cotyledonary segments were co-cultivated with A. tumefaciens and transferred to the medium containg 1 mg 2,4-dichlorophenoxyacetic acid/liter, 0.5 mg kinetin/liter, and 100 mg kanamycin/liter. Kanamycin-resistant calli were formed after 3 to 4 weeks of culture. Southern analysis confirmed the resistant calli were transformed with GUS gene. High GUS activities were detected in somatic embryos developed from the calli.
PHYSIOLOGICAL CHANGES DURING MATURATION OF NEW MEXICAN-TYPE PEPPERS
Authors: Wall Marisa M. , Biles Charles L.
Published: February 2019

New Mexican chile peppers were harvested at weekly intervals beginning 105 days after planting (DAP), and evaluated for ethylene (C2H4) production, respiration rates, chlorophyll content, beta-galactosidase activity, polygalacturonase (PG) activity, and fruit firmness. Physiological changes were most apparent in peppers harvested 139-154 DAP. Beta-galactosidase activity increased rapidly beginning 147 DAP, and reached a peak of 24.5 mmol·gfw-1 when peppers were harvested 160 DAP. Polygalacturonase was not detectable at any stage of maturation. Fruit firmness was greatest (35.8 N) at 139 DAP and decreased significantly at 160 DAP. Carbon dioxide production and chlorophyll content were highest in young pods harvested 105 DAP, and decreased steadily thereafter. Ethylene production peaked (0.185-0.202 nl·gfw-1·h-1) in peppers harvested between 146-154 DAP.
ESTIMATES OF POLLEN FERTILITY AND ISOZYME PROFILES OF STAMINATE KIWIFRUIT PLANTS IN SELECTED CALIFORNIA ORCHARDS
Authors: Meyer M. L. , Bliss F. A.
Published: February 2019

Kiwifruit (Actinidia deliciosa) is a functionally dioecious plant where fruit size is dependent on number of seeds set. Pollen fertility was estimated in 1990 and 1991 by percentage stainability and percentage germinability in vitro. Profiles of the isozymes AAT, GPI and PGM were used to assess if any large differences in pollen fertility could be attributed to genotypic variation. Based on these three isozymes, eight different genotypes were discovered. Although significant differences were found among vines within orchards and among orchards, all vines can be considered good pollenizers (stainability > 87%). A positive correlation was found in 1991 between percentage stainability and percentage germination.
MOVEMENT OF OXYFLUORFEN IN CONTAINER NURSERIES
Authors: Gilliam Charles H. , Fare Donna C. , Keever Gary J.
Published: February 2019

Little information is available on herbicide movement in soilless container media and subsequent movement in container leachate and container bed runoff. The objective of this study was to evaluate oxyfluorfen movement in irrigation water following application to container grown nursery crops in a commercial nursery. Oxyfluorfen levels in the container bed runoff were 9 to 27 times higher than those in container leachate during the 3 irrigations following herbicide application. Maximum oxyfluorfen level in the container leachate was 8.3 ppb following the first irrigation but declined to 2.0 ppb by the 12th irrigation. The oxyfluorfen level was still about 2.0 ppb following the 75th irrigation. Oxyfluorfen in the container bed runoff peaked at 99 ppb following the 3rd irrigation before declining to 67 ppb following the 6th irrigation.
DISPERSAL OF TRICHODERMA VIA IRRIGATION WATER
Authors: Jeong GyeSoon , Brown John M.
Published: February 2019

Trichoderma has been known to control soil-borne pathogens and to enhance plant growth and development. The objective of the study was to evaluate dispersal of Trichoderma via irrigation water in container production. 3.81 × 30 cm PVC pipes were filled with Sunshine Mix #5 up to 25 cm. Ten tomato seeds, boiled and coated with T. harzianum, were placed at 0.5 cm depth in each pipe. All treatments were irrigated carefully with 100 ml of DD water from top every 2 days. Before and one hour after irrigation the potting mix was sampled from 5 depths at 5.5 cm intervals every 2 days for 8 days to determine Trichoderma density. Trichoderma density was significantly higher in after irrigation. Trichoderma dispersed up to 25 cm deep in container potting mix after 4 days via irrigation water. This study successfully demonstrates that Trichoderma can be rapidly dispersed via irrigation water.
FLOWERING AND GROWTH REGULATOR RESPONSE IN `FREEDOM' COMPARED TO OTHER POINSETTIA CULTIVARS
Authors: Barrett James E. , Nell Terril A.
Published: February 2019

Euphorbia pulcherrima cvs. Freedom, SUPJIBI, and Celebrate 2 were sprayed with paclobutrazol or a tank mix of daminozide and chlormequat at week 40, 41, 42, 43, or 44. Application time had little effect on plant size. The tank mix had greater efficacy on `Freedom' but not on the other cultivars. Interactions for bract size indicated: 1) time of application had less effect on `Freedom', 2) there was little difference between the chemicals on `SUPJIBI', but the tank mix had greater efficacy on the other cultivars, and 3) the tank mix had greater efficacy than paclobutrazol during weeks 41, 42, and 43.

`Freedom', `Celebrate 2', `SUPJIBI', and `V-14 Glory' were planted on 8 or 15 Aug. and placed under short days on 12, 19, or 26 Sept. `Freedom' reached anthesis between 30 Oct. and 6 Nov., about 5 days before `SUPJIBI' and `Celebrate 2' and 7-10 days ahead of `V-14 Glory'. `Freedom' planted in Aug. and given short days 14 days apart flowered only 7 days apart (40 to 47 days from start of short days), but when planted in Sept. flowering was in 54 days and each long day resulted in 1 day delay in flowering.
EVALUATION OF RESIDENTIAL WATER UTILIZATION UNDER AN EDUCATION AND CONSERVATION PROGRAM
Authors: Wit Richard A. , Horst Garald L. , Steinegger Donald H. , Blad Blaine L.
Published: February 2019

Depletion and contamination of traditional water supplies and population pressures are straining the water resources of the United States. This has placed increased emphasis on the need for water conservation through all phases of the use cycle. Objectives of this research were to: 1) Determine water use in residential, commercial, and institutional landscapes; 2) Evaluate landscape irrigation system performance; and 3) Evaluate feasibility of landscape irrigation scheduling. Beginning in 1991, water meters on 18 test sites in Lincoln, NE were read on a weekly basis. Water meter readings during the winter were used to develop a baseline on non-landscape water use. The “can test” method was used to evaluate landscape irrigation system precipitation rate and distribution efficiency. Four recording weather stations were used to estimate daily potential evapotranspiration (ETp). Lysimeters (20 cm dia. × 31 cm deep) were installed in two Kentucky bluegrass and one tall fescue landscape to estimate water use coefficients for calculating landscape evapotranspiration. Irrigation system Christiansen coefficients of uniformity ranged from .43 to .87 with scheduling coefficients ranging from 1.31 to over 15.14. Poor irrigation system performance characteristics made it difficult to schedule irrigation on estimated water use.
THE USE OF CALCIUM FORMATE FOR THE QUANTITATIVE EXTRACTION OF NITRATE, PHOSPHATE, CHLORIDE, AND SULFATE IN BOTANICAL TISSUES.
Authors: Rivers J. A. , Miller R.O. , Carlson R.M.
Published: February 2019

Ornamentals, fruit and vegetable crops are commonly tested for inorganic anions, NO3-N, PO4-P, Cl and SO4-S, to identify the nutritional status of the plant. Two percent (0.20 M) acetic acid has primarily been used as the extractant for these inorganic anions. The use of acetic acid does not quantitatively extract SO4-S and PO4-P. Research using calcium formate was initiated to assess its effectiveness as an universal extractant for inorganic anions. Results of a series of experiments will be presented identifying the optimum calcium formate concentration, extraction time, and extractant sample ratio for quantitative removal and measurement of NO3-N, PO4-P, Cl and SO4-S. Results of spiking experiments will be presented using a range of horticultural crops important to California agriculture. Additional data will be presented on the use of calcium formate for the determination of K and NH4-N in botanical tissues.
THE DEVELOPMENT OF “FISHMOUTH” SEEDS DURING MUSKMELON FRUIT MATURATION AND DECAY
Authors: Welbaum Gregory E.
Published: February 2019

Muskmelon (Cucumis melo L.) seed crops sometimes contain seeds with split coats that expand to twice their normal water content. These expanded seeds are often referred to as “fishmouth” seeds, because the split seed coat resembles an open fish's mouth when viewed longitudinally. “Fishmouth” seeds are dead seeds. However, little is known about why death occurs inside the fruit before harvest. Hermaphroditic flowers were tagged at anthesis and fruits were harvested at various intervals during the later stages of development and decay. Seeds were removed from the fruits and incubated in water on germination blotter paper for 14 days. The percentage of germinable, dead and “fishmouth” seeds were averaged for each Harvest date. Fruit pericarp samples were analyzed for pH, ethanol, and acetic acid content. At 50 days after anthesis (DAA), just past edible maturity, 100% of the seeds germinated. However, at 60 and 78 DAA germination dropped to 60 and 17%, respectively, while the occurrence of “fishmouth” seeds increased from 2 to 54% over the same period. The ethanol content of the tissue increased from 0.11 to 0.28%, the pH dropped from 6.2 to 5.1, and acetic acid concentration increased from 3.0 to 3.7 mM from 50 to 60 DAA, respectively. However, when dried seeds were incubated in the laboratory under conditions similar to those within the fruit, the formation of “fishmouth” seeds was related to the ageing effects of long term hydration and was not correlated with any chemical product within the fruit.
SCREENING FRESH-MARKET TOMATO CULTIVARS FOR CATFACING SUSCEPTIBILITY WITH GA3 SPRAYS.
Authors: Wien H.C. , Turner A.D.
Published: February 2019

When GA3 foliar sprays are applied to tomatoes at transplanting (7.5 ppm, twice, one week apart) the lowest main stem clusters bear fruits which have large blossom-end scars (catfacing). Later flowering clusters are less affected as long as the plants are being grown under normal temperature conditions. Preliminary trials (Wien and Zhang, Hort Sci. 26:583-585, 1991) indicated that cultivar differences in catfacing susceptibility were reflected in GA3-induced catfacing differences. In 1990 and 1991, field trials were conducted in Freeville, N.Y. to compare the catfacing susceptibility of 14 and 18 fresh tomato cultivars respectively, using GA3 treatment. Catfacing was measured by counting the percentage of fruit on the third main stem, primary branch and two basal clusters that had blossom scars longer than 1 cm. Of the 14 cultivars common to both seasons, Valerie, Sunrise and Basketvee were least affected by catfacing in both control and GA3-treated plots, and Starfire, New Yorker and Olympic were most catfaced. GA3 spray shows promise for selecting catfacing-susceptible tomato cultivars.
AN IMPROVED FIXING AND STAINING PROCEDURE FOR PLOIDY DETERMINATIONS FROM ROOT TIP SQUASHES
Authors: Owen Henry R. , Miller A. Raymond
Published: February 2019

A comparison of pretreatment, fixing, and staining methods for root tips of Fragaria × ananassa (2n=8x=56), a polyploid species with small chromosomes, was made to facilitate chromosome counting. Three pretreatments (8-hydroxyquinoline, α-bromonaphthalene, and p-dichlorobenzene), three fixatives (Farmer's, Carnoy's, and Newcomer's), and five stains (acetocarmine, lacto-propionic orcein, leucobasic fuchsin, altered carbol fuchsin, and alcoholic hydrochloric-acid carmine) were examined in a factorial design to determine which treatment combination produced the best chromosome preparation. Field propagated runners were grown in sand under greenhouse conditions with supplemental lighting to produce root tips for late morning collection. The treatment combinations of α-bromonaphthalene or 8-hydroxyquinoline, Farmer's fixative, and altered carbol fuchsin, or the combination of α-bromonaphthalene, Farmer's fixative, and alcoholic hydrochloric-acid carmine produced the most intensely-stained and well-defined preparations.
ESTIMATES OF OUTCROSSING AND MALE STERILITY FREQUENCY IN LESQUERELLA FENDLERI
Authors: Dierig David A. , Thompson Anson E. , Johnson Earl R.
Published: February 2019

Genetic markers have not yet been described for Lesquerella fendleri (Gray) Wats. a potential new industrial oilseed crop. Seeds of this species are also utilized as a primary component in some desert wildflower seed mixes. Allozyme variation was analyzed for aconitase (ACO), phosphoglucomutase (PGM), and phosphoglucose isomerase (PGI). Four codominant loci, useful as markers, were clearly resolved. In an open-pollinated population, an outcrossing rate and pollen gene frequency was obtained from 20 random families, using these loci. This initial estimate indicated that seed production primarily resulted from outcrossing. Male sterility was discovered in six bulk populations derived from single plant selections. The frequency of this trait, which could affect the outcrossing rate, was found to occur in 15 percent of the plants. Additional populations will be analyzed for validation.
CERTIFIED PROFESSIONALS IN HORTICULTURE
Authors: Angle Tamara , Arnold Jamie M. , Storey J. Benton
Published: February 2019

Evidence of professional competence is needed for those whose activities affect the well-being of the general public. Graduates of BS and MS programs in horticulture are not distinguishable from self styled individuals who assume the title of “Horticulturist” without earning it. Certification of horticultural graduates is the first step in gaining a recognition for the Horticultural Profession. ASHS has established a Certified Professional Horticultural Sub-Board of the American Registry of Certified Professionals in Agronomy, Crops and Soils (ARCPACS). Professional core requirements include courses horticultural crop management, pest management, soil science, plant physiology, botany, chemistry, and genetics. Supporting core courses include math, communication skills, and horticultural specialization courses. Applications from individual horticultural graduates will soon be accepted. Details of the curriculum, continuing education, ethics, and other eligibility requirements will be detailed.
RAPID TESTING OF FILMS FOR MODIFIED ATMOSPHERE PACKAGES USING ACTIVE MODIFICATION
Authors: Gong Sannai , Corey Kenneth A.
Published: February 2019

It frequently takes days to weeks for testing films to determine if desired steady state concn of gases are reached when atmospheres are passively modified through commodity respiration. Our objective was to develop a rapid method to test the appropriateness of packaging films and designs using active modification of the atmosphere. Repeated exposures of commodities to partial vacuum were followed by infusion of N2 to 1 atm. Three to five minutes were allowed following each N2 infusion. Initial O2 concn achieved in packages (polyethyl vinyl acetate) depended upon the extent of the vacuum and the number of exposures. Within packages of tomatoes, O2 concn of 8.3 ± 0.5% and 5.0 ± 1.0% were measured following exposure to 460 and 360 mm Hg vacuum, respectively. Three exposures of cabbage and muskmelon packages to 460 mm Hg resulted in O2 concn of 5.1 ± 1.4% and 5.0 ± 1.4%, respectively. Maintenance or deviation from actively established atmospheres was determined within hours.
SENSITIVITY OF FRENCH PRUNE PRODUCTION TO WATER DEPRIVATION AT DIFFERENT STAGES OF FRUIT GROWTH
Authors: Lampinen Bruce , Shackel K. A. , Southwick S. , Goldhamer D. , Olson B.
Published: February 2019

During this three year study, irrigation water was withheld from trees in a commercial drip irrigated french prune orchard (Butte County, CA), during different periods within the double sigmoid fruit growth pattern (stage I - III), and postharvest. Tree water stress associated with early season water deprivation was minimal, due to the presence of stored soil moisture and low evaporative demands. For mid and late season water deprivation there was no fruit growth stage that was particularly sensitive to water stress, although severe and prolonged stress caused smaller fruit with lower quality. For the three year average, irrigation treatments caused no statistically significant effects on fruit set or drop relative to the control, however most of the stress treatments increased return bloom relative to the control, resulting in higher fruit loads and higher yields. These results suggest that moderate water stress may enhance economic prune productivity.
PHENOLOGICAL RESPONSES OF PLANTS TO THERMAL GRADIENTS
Authors: McWilliams Edward L.
Published: February 2019

Controversy over regional climatic change (RCC) and the direction of RCC continues. Models that predict how local plants would respond to defined regional climatic warming (RCW) would be useful.

The urban heat island intensity (UHII) has been documented in a number of cities including Houston, Texas, Phoenix, Arizona, St. Louis, Missouri, and Gainesville, Florida. We studies the phenological response of selected horticultural plants growing along urban/rural thermal gradients in several cities where the UHII had previously been defined. Deciduous plants flowered earlier in the spring and retained their leaves longer in the fall in warmer urban areas than they did in adjacent rural areas.

The phenological response of local plants to known thermal gradients appears to be a useful model of the phenological effects of potential RCW.
MOLECULAR MARKERS FOR CHARACTERIZATION OF GRAPE CULTIVARS II
Authors: Gogorcena Y. , Arulsekar S. , Parfitt D.E.
Published: February 2019

The work reported here is an extension of studies reported in 1990. The general objective was to develop molecular markers for genotype `fingerprinting', with specific reference to possible clonal differences among `Pinot noir' clones. Leaf DNA from 8 cultivars and 9 `Pinot noir' clones were isolated. RFLP and RAPD markers were identified and used to characterize the genotypes. 65 32-P labelled cloned probes were constructed with the pUC18 plasmid and Hind-III digested `Pinot noir' DNA. The probes were tested for their ability to discriminate among the 8 cultivars. 3 probes pGAD10, pGAD15, and pGAD44 showed polymorphisms among the cultivars. pGAD15 was most useful, with 5 polymorphisms for the 8 cultivars. RAPD makers were also tested for `fingerprinting'. Several primers were tested and polymorphisms were identified among cultivars. However, significant problems with repeatability for some bands were observed. Therefore, a series of experiments were conducted to test the effect of season and extraction method. These factors did not account for the inconsistancy which seemed to be more a function of the primer used. None of these studies showed clear evidence that the `Pinot noir' clones tested were geetically different.
ROLE OF SEED STORAGE RESERVES IN OSMOCONDITIONING OF SWEET CORN
Authors: McClure G.B. , Lang N.S.
Published: February 2019

Interconversions of seed storage reserves during osmoconditioning (controlled imbibition of water) may influence seed performance under suboptimal conditions. Sweet corn (Zen mays L. cv. Florida Staysweet) storage reserve changes were examined during osmoconditioning in relation to seed germination performance. Seeds were osmoconditioned in two experiments using distilled water (duration 3, 6, 9, 12, and 24 h) and polyethylene glycol 8000 solutions (0, .5, and 1.0 MPa for 12, 24, 48, 72 and 96 h). Germination performance was evaluated at 10 and 25C, and seed moisture, carbohydrate, and protein concentrations were quantified at each water potential x duration combination. Germination performance was not significantly improved by any treatment at 25C. Germination percentage at 10C was increased 10% for seeds osmoconditioned for 24 h in distilled water, and time to germination was decreased 50%. For seeds osmoconditioned 12 and 48 h at .5 and 1.0 MPa, respectively, germination percentage at 10C was increased 15%. Time to germination was reduced 50% for seeds osmoconditioned at .5 and 1.0 MPa after 48 and 96 h, respectively. Starch levels increased for seeds osmoconditioned at higher water potentials, but remained the same or decreased at lower water potentials.