bluuebunny/crossref_metadata_2025 huggingface dataset:
470 PB 339 DNA AMPLIFICATION USING TAQ POLYMERASE AND STOFFEL FRAGMENT IN POLYPLOID SWEETPOTATO
Authors: Buteler Mario I. , LaBonte Don R. , Oard James H.
Published: February 2019

RAPD and the single dose polymorphic band (SDPB) are powerful tools for genome map construction of higher polyploids, such as hexaploid sweetpotato. Duplication in the genome of higher polyploids results in fewer polymorphisms per primer screened than one would expect in diploids. The Stoffel fragment (Sf) is suggested as an alternative to the most commonly used Taq DNA polymerase to maximize the number of polymorphisms. Genomic DNA from two sweetpotato varieties, `Excel' and `Beauregard', and F1 progeny was isolated using a modified CTAB procedure. The DNA was assayed with twelve primers from Operon Technologies groups A and F. Each enzyme was tested with and without a ramp temperature treatment between the annealing and the extension temperatures. Results are based on three separate amplifications and electrophoretic runs. Band reproducibility was better using Sf than Taq; unfortunately, resolution was lower making bands difficult to score. 8.4% more scorable bands and 20.3% more storable polymorphisms were obtained with Taq. The ramp treatment did not alter results using Sf, but did improve the reproducibility of Taq and ease scoring. The number of bands and their location were the same.
480 PB 408 HORTICULTURAL GERMPLASM MAINTAINED AT THE WESTERN REGIONAL PLANT INTRODUCTION STATION
Authors: Hannan Richard M. , Simon Charles J. , Clark Raymond L.
Published: February 2019

The Horticulture Program at the Western Regional Plant Introduction Station is responsible for the maintenance and distribution of germplasm collections of ten crop genera. These ten genera include over 28,000 accessions of 267 species of germplasm with either food or ornamental potential. The largest collection is beans (Phaseolus, > 11,500 accessions) which includes 32 species. Large collections of the cool season food legumes include Cicer, Pisum and Lens. Smaller legume collections include Lupinus, Lathyrus, Trigonella and Vicia. Although there are fewer than 3300 accessions within these four genera, there are 134 species represented. Although smaller in number of accessions, the Allium and Lactuca collections are extensively utilized for food and ornamental development programs. Associated with the curation and seed maintenance of these crops is a seed-borne virus eradication program, the development of core collections, and expansion of the evaluation data and other documentation into the Germplasm Resources Information Network.
483 PB 417 BREEDING SPINACH WITH MULTIPLE DISEASE RESISTANCE
Authors: Morelock T.E. , Correll J.C. , Brandenberger L.P.
Published: February 2019

Downy mildew (Blue mold) is probably the most common spinach disease in most parts of the world, and it can be a problem in the mid-South. Frequently, other diseases such as white rust and fusarium cause major crop loss. The Arkansas breeding program was initiated 25 years ago to address white rust and fusarium, as well as other diseases that destroy spinach crops. Since single gene resistance is not available for most spinach diseases, it was necessary to utilize polygenic resistance to develop varieties that are resistant to most of the common spinach diseases that occur in the Arkansas River Valley of Arkansas and Oklahoma. Highly resistant genotypes have been developed by using disease nurseries and field screening, so frequent selections are made based on the reaction to 3-4 diseases.
493 PB 169 VARIATION ASSOCIATED WITH TESTING PROCEDURES FOR PH AND ELECTRICAL CONDUCTIVITY OF SOILLESS POTTING MEDIA
Authors: Lang Harvey J.
Published: February 2019

Analysts of potting media for pH and electrical conductivity (EC) can be a useful tool for monitoring the nutritional status of greenhouse grown plants. This research examined the variability associated with procedures involved in the determination of pH and EC in greenhouse potting media. Three commonly used methods, the 1:5 dilution, the 1:2 dilution and the saturated media extract, were examined on several different commercial potting media. Because of the different dilution volumes used, there were significant differences in pH and EC between the three methods for all media tested. Within each method, results varied baaed on whether readings were taken in the slurry, solution phase, or extract, with extracts resulting in consistently higher pH, but lower EC values. There was a significant effect of medium-solution equilibration time on both pH and EC, with variability decreasing after 30 minutes of equilibration. Samples taken from the upper half of pots had higher EC readings than those collected from the bottom half of pots only on plants fertilized with N concentrations greater than 200 ppm. There was also slight variability between the different calibrated instruments used in determining pH and EC. Details of each study along with grower recommendations will be discussed.
502 PB 216 GROWTH OF NEW GUINEA IMPATIENS AT THREE FERTILIZER CONCENTRATIONS AND TWO IRRIGATION REGIMES USING SOLID-STATE MICROTENSIOMETERS
Authors: Pannkuk Timothy R. , Lang Harvey J.
Published: February 2019

`Barbados' New Guinea impatiens were grown in 500 cm3 pots under drip irrigation and fertilized with solutions containing either 6, 12 or 18 mM N at two leaching fractions (0 and 30-50%). Soil moisture within the pots was characterized and controlled using electronic microtensiometers. The 0% leachate plants were automatically irrigated to container capacity when the soil tension in the pot reached 4.5 kPa, while the 30-50% leachate plants were irrigated for five minutes at a time whenever the soil tension was at or slightly greater than 4.5 kPa. After 6 weeks, there was only a slight effect of fertilizer concentration on height, width, or leaf number of the plants. Plants grown under 0% leachate did not differ significantly in overall growth and performance than those that were leached at every irrigation. Electrical conductivity of the potting media was highest in the 0% leachate treatments (highest readings in upper one-third of the pot) and increased as fertilizer concentration increased. After 6 weeks of production, total volume of irrigation solution leached per pot range6 from 2.2 to 3.6 liters for plants grown under the 30-50% leachate treatment.
506 PB 248 DETERMINING THE EFFECT OF CLOUD CONDITIONS ON THE VARIATION IN DAYLENGTH PERCEIVED BY PLANTS
Authors: Faust James E. , Heins Royal D.
Published: February 2019

Quantum sensors were placed at plant canopy height inside and outside a glass greenhouse. Photosynthetic photon flux (PPF) was measured during September for a 3-hour period near sunrise and sunset, which were determined from US Naval Observatory Circular #171. Under clear skies, the PPF at the canopy exceeded 0.25 μmol·m-2·s-1 for nearly 20 minutes before sunrise through 20 minutes after sunset. Under heavy overcast, the duration was only 5 minutes before sunrise through 5 minutes after sunset. The PPF at the canopy reached 0.25 μmol·m-2·s-1 approximately 12 minutes later in the morning and 12 minutes earlier in the evening than it did outside the greenhouse. The length of the dark period perceived by plants in a greenhouse on September 21st (assuming plants perceive light at 0.25 μmol·m-2·s-1) can range from 11:37 (hr:min) during cloudy conditions to 11:15 during clear ones, a difference of 22 minutes. At 43°N latitude, the maximum difference in date of flower initiation because of an extended period of heavily overcast versus clear weather on a crop such as poinsettias would be one week since the night length during September increases by 3 minutes per day. The actual difference from year to year is probably less because a seven-day duration of heavily overcast weather is unlikely.
512 PB 286 EFFECTS OF INTERIOR PLANTS ON RELATIVE HUMIDITY AND AIR-BORNE PARTICULATE MATTER IN INDOOR ENVIRONMENTS
Authors: Lohr Virginia I. , Goodwin Georgia K. , Pearson-Mims Caroline H.
Published: February 2019

Foliage plants were added to different environments, including an office and a computer lab. Relative humidity and air-borne particulate matter were monitored in the presence and absence of the plants. When the relative humidity was low, the addition of plants increased the relative humidity slightly, but significantly, over that when no plants were present. Particulate matter accumulation was not increased in the presence of plants. Some have hypothesized that the growing medium could be a source of increased particulates when plants are used indoors. Some of our experiments used self-watering containers, irrigated from below, resulting in very dusty conditions in the top of the container. If the growing medium could contribute to increases in particulate matter, we should have detected it in this study.
519 PB 477 INHERITANCE OF CONTORTED GROWTH HABIT IN HAZELNUT
Authors: Mehlenbacher Shawn A. , Smith David C
Published: February 2019

The contorted hazel, Corylus avellana `Contorta', is an ornamental tree prized for its grotesquely twisted trunk and branches. `Contorta' was discovered in a hedgerow in England about 1863 and has been commercially propagated by layerage or graftage because it was thought to not breed true from seed. We investigated the inheritance of contorted growth habit in the course of our work breeding hazelnuts. Crosses between normal growth habit cultivars and `Contorta' produce all normal seedlings. Sib matings of compatible normal seedlings of `Contorta' produce offspring in the proportion of 3 normal: 1 contorted. The backcross of a normal `Contorta' seedling to `Contorta' gives progeny in the ratio of 1 normal: 1 contorted, indicating control of the trait by a single recessive gene.
525 PB513 SEED SIZE OF SELECTED RUBUS SPECIES
Authors: Hummer Kim E. , Peacock Derek N.
Published: February 2019

Recent USDA plant collecting expeditions to Ecuador; the People's Republic of China, and within North America, have obtained a number of lesser known wild Rubus species. These, and additional species, are preserved as seedlots with some plant representatives, at the USDA-ARS National Clonal Germplasm Repository-Corvallis. In this study, the seed size of 40 Rubus species was measured and contrasted. The average weight of the largest-seeded species of the study group, R. megalococcus Focke, an Ecuadorean blackberry, was 24.2 mg; European blackberry, R. procerus Muller, was 3.0 mg. The average weight of other European and North American blackberry and raspberry seed ranged from 2.7 to 1.3 mg. Asian raspberry species tended to be the smallest, ranging from R. coreanus Miq. at 1.2 mg to R. eustephanus Focke ex Diels at 0.3 mg. Several of the smaller seeded Asian species such as R. formosensis Kuntze, R. minusculus A. Leveille & Vaniot, R. hirsutus Thunb., and R. eustephanus had many drupelets, which may be a heritable trait to benefit yield through breeding for increased fruit size.
530 PB 002 SIZE DISTRIBUTION OF PICKLING CUCUMBER FRUIT DURING THE HARVEST PERIOD
Authors: Craig R.
Published: February 2019

Three different types of pickling cucumber (Cucumis sativus) were planted in the field with 4 replications in a randomized complete block design. The cultivars selected were standard leaf, “little leaf”, and standard X “little leaf” crosses. The growth of populations of cucumber fruit from each of the three types was measured over a 14 day period which included the optimum harvest date for mechanically harvesting the fruit. A plant sample one m2was randomly selected, the population of fruit diameter and length in each sample was measured daily. The standard leaf types were the first to reach a harvest date. The standard X “little leaf” crosses were next, followed by the “little leaf” cultivar. The differences in days to harvest could be 14 days or more between the standard and “little leaf types. The distribution of fruit by number and volume will be presented. Using this information a harvest date for maximum economic return can be predicted for each of the cultivars.
539 PB 049 SINGLE-UNIT BROCCOLI AS AN ALTERNATIVE CASH CROP
Authors: Jett Lewis W. , Morse Ronald D. , O'Dell Charles R.
Published: February 2019

Consumer attitudes and preferences towards fresh market broccoli (Brassica oleracea L. Group Italica) are changing. Consumers desire large-head broccoli with more florets per unit weight, which we term single unit broccoli. Single unit broccoli could be field established by transplanting, alleviating the problems of poor stand establishment encountered with direct-seeded broccoli in the Southeast. The objectives of this research were to determine the feasibility of producing single unit broccoli and the optimal plant arrangement and spacing to maximize the yield of single unit broccoli. Two spatial arrangements (single vs. twin row) and five plant densities (10.8, 7.2, 5.4, 4.3 and 3.6 plants/m2) were examined in 1990 and 1991 for production of single unit broccoli. Spatial arrangement had no significant effect on any measured variable, although the twin row arrangement resulted in less plant damage with each multiple harvest. For exclusive production of high quality, single unit broccoli with high yields of marketable florets, a planting density of 3.6 plants/m2 (46 cm within row spacing) should be used in a twin row arrangement.
549 PB 099 VEGETABLE PRODUCTION IN NORTH DAKOTA
Authors: Jackson Marcus B. , Ke Shanqianq , Laschkewitsch Barbara A. , Lee Chiwon W.
Published: February 2019

The growing conditions of North Dakota are characterized by short frost-free seasons (< 120 days), long photoperiods, a large fluctuation in summer temperatures, and fertile soils especially in the Red River Valley region. Commercial production of vegetables in the state has been increasing with renewed interests in fresh and processed products. Currently, about 1,200 acres are devoted to vegetable production in the state with most of it conentrated in the eastern part of the state. This excludes 158,000 acres used for potato production. The top ten vegetables, excluding potato, are onion, carrot, sweet corn, squash, cabbage, red beet, muskmelon, asparagus, pumpkin, and garlic in the descending order of acreages devoted. While onions are grown mainly for fresh markets, carrots are produced for both fresh and dehydrated products. Acreages for these two crops are expected to expand, especially for supplying onions for ringing operations and carrots for dehydration and p-carotene extraction. Each year, selected cultivars of onions, carrots and other vegetables are evaluated for their performance in this northern growing environment.
551 STUDIES ON SEEDLING PRODUCTION OF ASPARAGUS UNDER DIFFERENT GROWTH CONDITIONS
Authors: Okasha Kh. A. , Gomma H.
Published: February 2019

This study was carded out on Asparagus (Asparagus officinalis L.) during the two successive seasons of 1987/1988 and 1988/1989 at the Agricultural Experimental Station of National Research Center at Shalakan Kaloubia Governorate The investigation was aimed to study the effect of cultivar, propagation methods and polyethylene mulching on plant growth and performance

The application of plastic mulching caused signficant increases in plant height. number of shoots. number of branches, fern fresh and dry weight and roots an rhizome fresh and dry weight

Covering the soil surface with black and transparent polyethylene enhanced the vegetable growth of asparagus plant significantly as compared with unmulched treatments. Mulching with transparent polyethylene increased soil temperature over black polyethylene mulch and both treatments were higher in soil temperature than the control. Concerning the variation existed among cultivars, UC 157 F1 showed a significant increment in vegetable growth compared with UC 157 F2.
559 PB 380 A COFFEE YIELD MODEL FOR KONA, HAWAII
Authors: Loero D. Richard , Kobayashi Kent D. , Bittenbender H. C.
Published: February 2019

Coffee (Coffea arabica L.) is grown mainly as an uninigated crop in the Kona district of Hawaii (Big Island). Previous research has shown that water status and crop load are major components of annual yield fluctuations exhibited by coffee in Kona. The need for a quantitative method to estimate yield has led to the development of a yield model. Seven years of historical yield, meteorological, and soil data were utilized. Meteorological and soil data were used in a soil water balance model developed with the simulation language Stella® (High Performance Systems Inc.) to generate a daily soil water status value. Then, values for the number of days and mm of deficit (duration and magnitude) were grouped in trimesters and used to estimate yield: Yn = 17425 - 6.3(T2)n-1 - 181(T3)n-1 + 0.26(Y)n-1 where Yn, is the current year's yield (kg/ha); T2 is the water deficit during April-June of the previous year (days-mm); T3 is the water deficit during July-September of the previous year (days-mm); Yn-1 is the previous year's yield (kg/ha); and n is the current year. The use of this model permitted yield estimation three months before anthesis and nine months before the start of harvest with a mean prediction error of 17% or 3,154 kg/ha of coffee cherry.
EFFECTS OF HYDROGEN CYANAMIDE AND CYSTEINE ON BREAKING DORMANCY AND PHYTOTOXICITY
Authors: Zhen Liping , Fuchigami Leslie H.
Published: February 2019

Hydrogen cyanamide (CY) induced earlier, more uniform, and a higher percentage of budbreak in poplar (Populus alba × P. gradidentata, N C 5339). c y was phytotoxic at 0.5 M or higher concentration. Percent budbreak increased and percent dieback decreased when plants were treated with a mixture of CY and Cys. No difference was found in percent budbreak or dieback between plants treated with CY alone and a mixture of CY and Ser. Mixing CY with Cys concentrations in vitro reduced the percentage of the cyano group, and mixing of Cys with CY concentrations decreased the percentage of the SH group remaining in the mixture. Mixing CY with Ser concentrations in vitro had no effect on CY level. These studies suggest that the SH group reacts with CY directly and the improvement of budbreak and toxicity caused by mixing CY and Cys may be due to the reduction of CY concentration.
567 PB 006 AUXIN SENSITIVITY OF DOUGLAS-FIR STEM CUTTINGS
Authors: Proebsting William M.
Published: February 2019

Douglas-fir clones have a wide range of rooting potential, but the species is generally considered difficult to root. We have reported previously that NAA is approximately 14-times more active than IBA in the clones tested, with an optimum of about 5 to 10 mM NAA. In contrast, other programs routinely use about 25 mM IBA to propagate Douglas-fir cuttings, a concentration that is relatively inactive in our clones. To address questions raised by these observations, we have incorporated auxin treatments into our long term program to select Douglas-fir clones with high rooting potential. We collect 20 cuttings of each clone identified in Christmas tree plantations, and retain clones rooting ≥ 80%. Beginning in 1991, we treated 10 cuttings of each clone with 5 mM NAA, the other 10 cuttings with 25 mM IBA. Over three years, 1158 clones received the split treatments. Of 222 clones rooting ≥ 80%) approximately half rooted ≥ 80% in response to NAA only. The remainder either responded to IBA or to both NAA and IBA. These results support our previous observations that NAA stimulates rooting of Douglas-fir better than IBA. However, they also suggest that there may be clones sensitive to IBA or to both NAA and IBA.
568 PB 009 IMPROVING PROPAGATION AND PRODUCTION TECHNIQUES FOR NATIVE PLANTS
Authors: Englert John M. , Meyer Gwen C.
Published: February 2019

In recent years the use of native plant materials for conservation and revegetation projects has received increased awareness and interest. The National Plant Materials Center (NPMC), in cooperation with the USDI-National Park Service, is involved in the revegetation of disturbed areas within our National Parks using native herbaceous and woody plants. This involves the collection of germplasm from selected niches within the Parks, an increase in seed and production of transplants, and reestablishment of native communities in natural areas.

One major focus of the program is to develop technology for improving native plant propagation and production, which should make the use of native plants more viable in the commercial sector. Germination of species of Tridens, Dichanthelium, Danthonia, Helianthus, Schizachyrium, and Andropogon has been improved to 80-95% by altering the germination environment. Production of these species in plugs has also been streamlined to maximize space efficiency and provide cost-effective methods for planting native grasses and wildflowers.
574 PB 047 STABILITY OF A VARIANT LEAF TYPE OF `THORNLESS EVERGREEN' BLACKBERRY FOLLOWING A REGENERATION CYCLE IN VITRO
Authors: Norton Margaret A. , Skirvin Robert M.
Published: February 2019

Rubus laciniatus Willd. `Thornless Evergreen' (TE) is a chimeral blackberry with a thornless epidermis that overlies a genetically thorny interior. Most canes of TE produce leaves with 5 finely cut (lacinate) leaflets. Occasionally, canes appear which produce leaves with entire leaflets. Genetically pure thornless plants were regenerated from epidermal cells of chimeral TE with lacinate leaves. These regenerants exhibited somaclonal variation for growth habit, degree of thornlessness, and fruitfulness. All had lacinate leaves. When moved to the field, some of these regenerants produced canes with entire leaflets.

To examine the stability of the entire leaflet characteristic, plants were regenerated from lacinate leaves and entire leaves of both dwarf and normal pure thornless TE regenerants. Regenerants were rooted, moved to soil, and grown in the greenhouse for observation. Stability of this characteristic will be discussed.
576 PB 053 METHODS TO MAXIMIZE AND MINIMIZE SEGREGATION OF CHIMERAL PEAR (PYRUS SPP) IN VITRO
Authors: Al-Wasel Abdelrahman S. , Skirvis Robert M.
Published: February 2019

Variegated `Louise Bonne' (LB) pear is a periclinal chimera in which the LIII layer is albino. Chimeral shoots propagated in vitro segregate spontaneously into green, albino, pale, or rearranged chimeral types, making them difficult to maintain in culture. We investigated the role of growth regulators on chimeral stability and destability to find a combination that would maintain the chimera through repeated subcultures. 70 to 90% of shoots remained chimeral on Lepoivre (LP) medium supplemented with 8 μM BA or less. Only 36 to 58% of shoots grown at concentrations greater than 8 μM were stable. Shoots grown on LP with thidiazuron (TDZ) were very unstable (4 to 44%). NAA had no significant effect on chimeral stability. While shoots multiplied better on LP, the chimeral pattern was more obvious on MS, making it a good screening medium. Selection and subculturing chimeral shoots on a good medium (LP with 2 to 4 μM BA) increased the percentage of chimeral shoots from 26% at the 4th subculture to 84% at the 27th subculture.
583 PB 094 CALLUS INDUCTION AND SHOOT ORGANOGENESIS IN RHODODENDRON `BESSE HOWELLS' AND `CATAWBIENSE ALBUM'
Authors: Ruan Yiqin , Brand Mark
Published: February 2019

Combinations of me auxins 2.4-dichlorophenoxyacetic acid (2.4-D). indolebutyric acid (IBA). and naphthaleneacetic acid (NAA), with isopentenylademne (2-iP) were studied in Woody Plant (WP) medium for callus induction and shoot organogenesis from leaves of Rhododendron `Besse Howells' (BH) and `Catawbiense Album' (CA). IBA was more effective than NAA and 2,4-D at inducing shoot organogenesis when combined with 2-iP. Addition of 1 uM IBA and 15 or 30 uM 2-iP to WP medium resulted in the highest percentage of explants producing shoots (90% in BH, 100% in CA), and the greatest number of shoots per explant (18.4 in CA, 10.1 in BH) after 12 weeks of culture. Shoot organogenesis also occurred using 1 uM NAA and 2-iP combinations, but me number of shoots produced was much less than for IBA treatments. 2,4-D and NAA were more productive than IBA for callus induction. Media containing l-10 uM 2,4-D plus 5 uM 2-iP. or 10 uM NAA plus 15 uM 2-iP. were me best for callus production. In studies using thidiazuron instead of 2-iP as the cytokinin, leafy buds and very short shoots developed.
591 PB 161 CITRUS MANAGEMENT SURVEYS
Authors: Ferguson J. J. , Taylor C.L.
Published: February 2019

Management problems and information needs of Florida's approximately 12,000 citrus growers on 791,290 acres were identified by a statewide citrus management survey. During the summer of 1992, citrus county agents' mailing lists were compiled to create a master list of 2,964 addresses, from which a sample of 833 growers was selected by a stratified proportional sampling procedure. Three hundred ninety-eight useable questionnaires were returned from commercial citrus grove owners and managers in 23 citrus producing counties, representing 307,022 acres, 39% of the current acreage. Survey data on general management, young tree care, pest management, water management and cold protection was further analyzed by whether respondents' groves were bedded or unbedded. Information from this citrus survey and previous ones has been used to develop and evaluate comprehensive statewide citrus extension programs.
592 PB 164 POST-TRANSPLANT ROOT GROWTH OF CITRUS PLANTS AS INFLUENCED BY PRODUCTION TIME IN NURSERY CONTAINERS
Authors: Marler Thomas E.
Published: February 2019

An aeroponics system was used to determine root growth of Citrus aurantifolia Swingle following removal from containers. Rooted cuttings were planted in 0.46-liter containers in a 1 sand: 1 perlite medium, and watered daily and fertilized with a complete nutrient solution weekly. The plants were grown in the containers until root growth had filled the container volume. A sample of plants was removed from the bench after 86, 146, or 210 days in container production. Plants were bare-rooted and the existing root system dyed with methylene blue, and placed in the aeroponics system. The plants were maintained in the aeroponics system for 50 days, then were harvested and the roots separated into pre-existing roots and new roots. Two dimensional area and dry weight of roots were measured. Relative new root growth of plants that were maintained 210 days in the containers was less than that of plants that were removed from containers earlier. The data indicate that maintaining plants in containers for extended periods of time may reduce root regeneration following removal from containers.
594 PB 170 MANGIFERA PAJANG - PROSPECT FOR COMMERCIAL PRODUCTION AND MANGO IMPROVEMENT
Authors: Tinggal Serudin , Tee Thean S.
Published: February 2019

Magifera panjang Kostermans, indigenous to Brunei is widely adapted to lowland and hilly areas. The vigorous tree grows tall (30 - 40 metres high). Grafting on M. indica stock or own stock has dwarfing effect and shortens juvenile stage to stimulate fruit production within 5-6 years. The obicular fruits are large with tough brown skin. The thick golden yellow flesh is juicy, pleasant to eat, having aromatic fragrance. Some cultivars are less fibrous. The fruit has wide traditional usage and demand is seemingly unsatisfiable.

Mangifera pajang is quite tolerant to various diseases affecting mangoes. Insect pests do not appear to damage the trunk or the fruits.. The blossoms on stout and erect flowering spikes attract a host of pollinators. Anthracnose problem is unknown even in the wet season. These features are useful for possible transfer to the more susceptible M. indica cultivars.
603 PB 217 IMPROVEMENT OF APRICOT BUDBREAK BY APPLICATION HIDROGEN CYANAMIDE
Authors: Contreras Raúl Leonel Grijalva , Contreras Fabian Rubles
Published: February 2019

A major obstacle to economic production of deciduous fruit tree under desert conditions is an insufficient period of chilling temperatures. Inadequate chilling on apricot may result in poor and uneven budbreak, reduced and delayed foliage development, sparse bloom, poor fruit set, and/or early grown cesation, with the objective of improve budbreak, applications of Hidrogen Cyanamide (H2 C N2) were made to mature apricot `Canino' trees on January 30. Two rates of H2 C N2 and a control were evalluated for that proposal. Amount of chilling accumulated was 360 chill hours according Da Motta model. Hidrogen Cyanamide advanced budbreak 7 days at the highest rate as compared to control. Cumulative percent budbreak on March 15 were 40, 64 and 72% for o, 0.75 and 1.5% respectively. In this year, bud abscission was similar for all the treatments.
605 PB 243 NEW BLOSSOM THINNERS FOR STONE FRUITS
Authors: Williams Max W.
Published: February 2019

Two chemicals being tested as blossom thinners for apple are effective for bloom thinning of peaches and nectarines. Monocarbamide dihydrogen sulfate (Wilthin) and Endothall applied at 90% of bloom open reduced fruit set by 50%. Fruit size and quality of the crop were improved. Both of the above chemicals gave adequate fruit removal without serious phytotoxic effects on leaves, buds or shoots. With chemical rates which over thinned, no fruit marking occurred on either nectarines or peaches.
613 P3 287 LIGHT PENETRATION AFFECTS COLOR AND FLAVOR OF'RED DELICIOUS' APPLES
Authors: Miller T.W. , Mattinson D.S. , Bostick B.C. , Fallahi E. , Fellman J.K.
Published: February 2019

Light has long been known to stimulate anthocyanin accumulation in apple peel, but changes in apple flavor as a result of fruit shading is poorly understood. Some growers maintain that the redder the strain, the less flavorful the fruit. An experiment was conducted to help characterize the role of light in biosynthesis of color versus flavor molecules in apple peel. Bags fashioned from 3 meshes of shade cloth were fastened around fruitlets of red delicious strains `Starkrimson' and `Topred' on M26, MM106, and MM111 by 21 DAFB to produce average light ranges of 100%. 41-68%, 12-30%, and < 1% of full sun incident upon the fruit. Observations from the 1993 harvest indicate that anthocyanin content of peel increased with fruit maturity and level of sunlight. Concentrations of flavor molecules were higher with low and moderate shade than with full sun, and also increased with fruit maturity. From this harvest data, it appears that apple flavor can be enhanced by lightly shading fruit without substantially reducing fruit color.
623 PB 445 ALTERNATIVES TO METHYL BROMIDE FUMIGATION IN TOMATO PRODUCTION
Authors: Barbour Sandra L. , Brock Kathy H. , Fortnum B.A. , Decoreau Dennis R.
Published: February 2019

Pest control-related problems jeopardize the advancement of our nation's vegetable industry. Because of the adverse effects of many fumigants. the grower is increasingly pressured to utilize sustainable. environmentally sound agricultural practices yet still maintain a marketable, blemish-free product.

The effects of wavelength selective mulches and three different fumigants on overall plant development and nematode control were studied in field grown, staked tomatoes. Plots were fumigated with methyl bromide. Telone II, or Telone C17. Within rows, mulch color was established by application of either white or red exterior enamel paint to the black plastic surface of polyethylene mulch. Reflective light from each mulch color was measured using a LiCor 1800 Spectroradiometer. Temperature below the mulch surface was monitored with a datalogger.

Prior to the first marketable harvest, plants grown on white mulch produced greater fruit weight and total dry weight than plants grown on black or red mulch. Total marketable yields, however. were not significantly different between the three mulches. Early and marketable yields from fumigated plots did not differ from control treatments. The lack of response due to fumigation may have been due to low initial nematode populations in the field.
630 PB 484 AN ORGANIC VS. CONVENTIONAL FARMING SYSTEM IN KIWIFRUIT
Authors: Hasey Janine K. , Johnson R. Scott , Meyer Roland D. , Klonsky Karen
Published: February 2019

A kiwifruit vineyard converted to an organic farm was compared to a conventionally farmed vineyard from 1990 through 1992. February or March applications of composted chicken manure (organic plot) or NH4N O3 plus CaNH4 (NO3)3 through microsprinklers during the growing season (conventional plot) were applied to give equal rates of N. Soil analyses indicated no differences in nutrient or salt levels. Nitrogen leaf levels from the organic plot were consistently lower than those from the conventional system but were not deficient. Leaf concentrations of sodium and chloride increased over the three-year period in the organic plot, but not to phytotoxic levels. Organically grown fruit was as firm or firmer than conventionally grown fruit at harvest and four months after harvest. Damage from latania scale or omnivorous leaf roller was minimal in both plots until 1992, when the organic plot had 3.9% scale compared to 0% in the conventional plot. An economic analysis comparing the short-term profitability of the two systems will be presented.
635 PB 334 HISTOCHEMICAL LOCALIZATION OF LIPOXYGENASE, PEROXIDASE AND POLYPHENOL OXIDASE IN POTATO TUBER TISSUE
Authors: Vaughn Steven F.
Published: February 2019

Localization of enzymes in specific plant tissues is crucial to understanding their role in processes such as differentiation and disease resistance. The oxidative enzymes lipoxygenase (LOX; EC 1.13.11.12), peroxidase (PER, EC 1.11.1.7) and polyphenol oxidase (PPO; EC 1.10.3.1) have all been implicated as playing critical roles in plant disease resistance. The histochemical localization of all three enzymes in potato tuber slices was accomplished either directly on the tissue slices (for LOX) or by blotting of the tissue onto nitrocellulose membranes (for PER and PPO). LOX was visualized in specific tissues by the oxidation of KI to I2 via lipid peroxides and the subsequent reaction of I2 and endogenous starch to form a colored, insoluble complex. PER and PPO activities were visualized with 4-methoxy-α-naphthol and 3,4-dihydroxy-phenylalanine, respectively. Fractionation of the slices and determination of enzyme activities in the fractions confirmed the reliability of these techniques.
636 PB337 POLYGALACTURONASE INHIBITOR IN BEAN PODS
Authors: Pressey Russell , Russell Richard B.
Published: February 2019

Polygalacturonase inhibitors have been reported in a number of dicotyledonous plant tissues including pear and raspberry fruits and bean seedlings. These proteins inhibit fungal polygalacturonases and thus have been implicated in disease resistance in plants. The earlier work on the inhibitor from bean plants was conducted with hypocotyls as the source. We have found that immature bean pods contain much more inhibitor than other parts of the plant and developed a procedure for purification of this inhibitor. Fresh bean pods were extracted with 1.0 M NaCl at pH 7 and the proteins were precipitated with ammonium sulfate. The proteins were dissolved, dialyzed and chromatographed on a column of S-Sepharose. The inhibitor from this step was then chromatographed on a Mono Q column at high pH. Yields of the inhibitor varied somewhat with bean cultivar and pod maturity but were about ten times higher than from hypocotyls. The purified inhibitor reacted optimally with Aspergillus niger endopolygalacturonase at pH 4.3 and appeared to be similar to the inhibitor from hypocotyls. Bean pods thus are a convenient source of polygalacturonase inhibitor for studies on fruit maturation and disease resistance in plants.
638 PB 366 EFFECTS OF PHENOLIC METABOLISM ON SUSCEPTIBILITY OF PEACH ROOTSTOCKS TO NEMATODES
Authors: Yongbing Yuan , Simeone A. M. , Cappelini P.
Published: February 2019

Peach rootstocks Rancho Resistant (RR) and GF 677 are resistant and susceptible to nematodes, respectively. One-year-old seedlings of RR, GF677 and their reciprocal grafts were inoculated with 10,000 larvae. Both inoculated and control plants were harvested at intervals for assay. Phenylalanine ammonia lyase (PAL) activity and soluble phenol content were enhanced in both RR and GF677 after inoculation, but RR always had a 2-fold higher peroxidase (PO) activity than GF677. When GF677 was grafted on RR, the resistance of RR was not altered. When RR was grafted onto GF677, the number of galls on the plant were 66% and 77% less than on GF677 2 weeks and 2 months after inoculation, respectively. However, no interaction was found in the reciprocal graft. The results showed that higher soluble phenol content and PAL activity induced by nematode attack were common features of RR and GF677, and a positive relation between PO activity and resistance to nematode existed in the two rootstocks.
643 PB 401 TRAP CROP AND GENOTYPE EFFECT ON DIAMONDBACK MOTH POPULATION DYNAMICS IN HEAD CABBAGE
Authors: Valenzuela Hector R. , DeFrank Joseph , Luther Greg
Published: February 2019

The diamondback moth (DBM). Plutella xylostella, is the number one pest of cabbage in the the world. The pest is resistant to most pesticides registered for its use, and resistance has also been detected in several areas for registered biopesticides. Four experiments were conducted to: 1) Determine the tolerance to DBM feeding among 20 commercial head cabbage cultivars, 2) Evaluate the effect of three nitrogen fertility levels on DBM numbers. and 3) Evaluate the effect of Indian mustard. Brassica juncea trap crops as a tool to manage DBM populations in head cabbage agroecosystems. Experiments were conducted at University of Hawaii experiment stations located in Kamuela. Hawaii, and in Kula, Maui. The trap crop treatments consisted of planting two border rows of Indian mustard in cabbage field borders. Three or 4 biweekly insect counts were conducted for each trial. Insect counts consumed of destructive sampling of 3-6 plants per plot and determination of larvae and pupae number and parasitation levels. The nitrogen studies found more DBM in monoculture cabbage receiving 300 kg Ha-1 N than in controls even though cabbage yields did not vary among treatments. A range of tolerance to DBM feeding was found among the cultivars tested. The trap crop system was shown to be more effective during the summer than in the winter months. Data indicates that the trap crop also acted as attractant for beneficial insects, which may aid in the biological control of DBM in cabbage
663 PB 101 IDENTIFICATION OF POINSETTIA CULTIVARS USING RAPD MARKERS
Authors: Ling Jing-Tian , Sauve Roger , Gawel Nick
Published: February 2019

The development of scoreable genetic markers in poinsettia will be valuable for cultivar identification and for use in patent protection. In this study, polymerase chain reaction (PCR) and randomly amplified polymorphic DNA (RAPD) techniques were investigated for their feasibility in the identification of poinsettia cultivars. DNA was extracted from leaf tissues using the CTAB method. Thirty-six out of 39 (92.4%) primers amplified poinsettia DNA. The size of the amplified DNA fragments ranged from 140 to 2,000 base pairs. On average, 5.4 bands (range 1 - 13) were obtained per primer. A total of 195 bands were obtained; 49 (25.1%) bands were polymorphic in the 9 tested poinsettia cultivars. All tested cultivars could be discriminated with the banding profiles generated from 2 primers. RADP markers provide a consistently reliable and efficient technique for the identification of poinsettia cultivar.
665 PB 107 DNA POLYMORPHISM IN SILVER MAPLE (ACER SACCHARINUM L.)
Authors: Freire A. Virginia , Preece John E. , Lightfoot David A.
Published: February 2019

Silver maple has great potential as a biomass feedstock. We selected 21 elite silver maple clones representing 7 provenances located on east to west and north to south transects across the natural area of distribution. In addition five different red maples including one commercial cultivar as well as four interspecific hybrids between red and silver maple were compared to the silver maples. DNA was extracted using a modification of the CTAB technique (Murray and Thompson, 1980). Polymerase chain reaction was used with random primers from the OPF series (1-20) and primers used by Krahl et al. (1993). Polymorphism was detected at high frequency. Greater polymorphism was observed between species than within species. However, we have observed DNA concentration dependent polymorphism. RAPD technology has potential for determination of genetic relationship among silver maple clones.
669 PB 119 VARIABILITY AND INHERITANCE OF RAPD MARKERS IN JAPANESE-TYPE PLUMS
Authors: Boonprakob Unaroj , Byrne David H.
Published: February 2019

Six controlled crosses of cultivated and advanced selection Japanese-type plums adapted to southeast and southwest regions of the United States were made in 1990 and 1991. Over 800 seedlings from these crosses along with open pollinated seedlings of the parents were established in Suiting nurseries. The long range objective of this study is to determine linkage relationships between RAPD markers and commercially important traits (soluble solid, resistance to bacterial leaf spot, chilling requirement, fruit development period). The first step in the projects to characterize RAPD genotypes in the progenies. Eighty oligodecamers have been screened and 57 yielded successful reactions with an average of two to three bands per primer. The variability and inheritance of the RAPD markers in these plum populations will be described.
686 PB 230 RESEARCH AND DEVELOPMENT OF A MINIATURE PAN EVAPORIMETER FOR GAUGING THE DIFFERENCE BETWEEN EVAPOTRANSPIRATION AND EFFECTIVE RAINFALL
Authors: Browne Christopher L. , Cook Thomas W.
Published: February 2019

Knowledge of the current irrigation requirement of well-watered grass provides the basis for efficient scheduling of turf and landscape irrigation. A portable, miniature pan evaporimeter has been developed to conveniently provide this information for localized micro-climates. The underlying equation for the instrument is: IRnet = (Kpan • Epan - Kpan • R) where IRnet is the net irrigation requirement of healthy, non-stressed grass; Kpan is the pan coefficient for the instrument; Epan is accumulative pan evaporation; Kpan • Epan is “reference evapotranspiration”; and Kpan • R is a measure of effective rainfall received. This equation was established using turfgrass sites located throughout the Pacific Northwest over a 3-year period. The sites were in proximity to U.S. Class “A” pan evaporimeters, and were automatically irrigated using moisture sensors. Tests of the miniature evaporimeter against automated meteorological stations have determined the factors that influence its pan coefficient, and therefore its ultimate design.
700 PB 312 EFFECT OF PRE-HARVEST CALCIUM APPLICATIONS ON FIRMNESS, DECAY, AND MINERAL DISTRIBUTION IN STRAWBERRY FRUIT
Authors: Makus D. J. , Morris J. R.
Published: February 2019

Supplemental calcium supplied foliariy as Ca glutarate, soil incorporated as gypsum, fertigated as CaNO3, in 3-way combination, or none at all, had no effect on fruit firmness, as measured by shear, reduced fruit decay by as much as 23%. over controls (1986-1988), and generally improved fruit Ca levels only in the combination treatment of 904 kg/ha. Fruit raw product quality (pulp pH, acidity, soluble solids concentration, and Hunter color values) were not consistently affected, although there were significant interactions between cvs Fern and Cardinal, harvest dates, holding time, and years. Supplemental Ca reduced fruit size, but tended to increase yield. In 1988, individual fruits were partitioned into upper/lower, dermal/interior, and upper/lower seeds (6 parts), Ca was the third most abundant mineral nutrient in receptacle tissue, but most abundant in seeds. Highest Ca levels were found (descendingly) in the seed, dermal, and interior pulp tissue, Ca was higher in the upper (stem) end. Differences in fruit Ca levels between cvs were found in the seeds and not the receptacle. No clear relationship was observed between fruit firmness, decay, and Ca level.
701 PB 315 SOUTHERN HIGHBUSH BLUEBERRIES DIFFER IN POSTHARVEST QUALITY
Authors: Perkins-Veazie P. , Collins J. K. , Clark J. R. , Magee J.
Published: February 2019

Although several new southern highbush blueberry cultivars have been introduced, little is known about their shelflife quality. Five southern highbush cultivars and three advanced selections were harvested from plantings at Clarksville, Ark. and held at 5C, 95% RH for 21 days followed by 1 day at 20C. `Gulf Coast' fruit had the most and `A109' the least weight loss after storage (12% and 6%). `Gulf Coast' fruit were rated softest after storage, Anthocyanin content was highest in `Cape Fear' and lowest in `MS108' (142 and 57 abs. units/g FW, respectively). After storage, total anthocyanin content increased 60% in `Cape Fear' and `O'Neal' fruit. Fruit pH was higher in stored fruit but titratable acidity decreased only in `ONeal', `Sierra', and `G616' fruit. Results indicate that southern highbush blueberries cultivars show great variability in shelflife quality.
708 PB 356 PREDICTING SUPERFICIAL SCALD ON `DELICIOUS' APPLE
Authors: Weis Sarah A. , Bramlage William J.
Published: February 2019

Fruit from five regions worldwide were rated for scald development after four months in 0°C air plus one week at 20°C. Scald incidence was quantitatively related to preharvest temperature conditions and fruit maturity, as measured by starch index. Various low temperature cutoffs were used, and high temperatures over 30°C were also used in the equations. Where data were available light conditions and rainfall were included in the equations. Several models were developed and tested to determine if prediction equations could be of commercial value. The most successful equations explained over 50% of the variation in scald. While they could not predict exact percentages of fruit which would develop scald, equations could predict cases of very high and very low scald, thus identifying fruit requiring the greatest scald control measures and those needing minimal scald control action.
718 PB 426 PHYTOTOXICITY OF METHYL BROMIDE FUMIGATION TO CITRUS FRUIT PACKED IN SHIPPING BOXES
Authors: Houck Laurie G. , Jenner Joel F. , Mackey Bruce E.
Published: February 2019

Commercially packed lemons (Citrus limon (L.) Burm.), grapefruit (C. paradisi Macfayden) and oranges (C. sinensis (L.) Osbeck) from CA and AZ were fumigated in corrugated fiberboard shipping boxes with methyl bromide (MB) at doses efficacious for controlling various postharvest insect pests. Fruit developed no rind injury when fumigated at 24 or 32 g MB/m3 for 2 hr at 21C. At 40 g MB fruit developed slight to moderate peel injury, and sometimes there were more decayed fruit. More rind injury developed at 48 gm MB, the injury was more severe, and there were more decays. Curing fruit for 3-4 days at 15-20C before fumigation, and extending the aeration period after fumigation from a few hours to 1 or 3 days reduced fruit injury. Early-season fruit were not injured as severely as late-season fruit. Lemons picked with green-colored peel but fumigated after they turned yellow (by holding at 13C for 4-10 weeks to degreen) were not injured as much as silver or yellow lemons.
720 PB 432 THE EFFECT OF APPLYING CALCIUM ON THE RIPENING OF MANGO FRUITS (Mangifera indica L)
Authors: Zambrano Judith , Manzano Juan
Published: February 2019

The effect of applying Ca++ in two forms: infiltration and dipping on mango fruit cv `Haden' was investigated. This effect was evaluated by measuring some quality parameters in the flesh and in the skin of the fruit. It was found that postharvest application of Ca++ extent the storage life of the fruit by a week. This fact, together with the results obtained from the quantification of sugars, ascorbic acid, total soluble solids alcohol. insoluble solids, starch and titrable acidity seem to indicate that the application of Ca++ delays slightly the process associated with ripeness. Furthermore, no significant difference between the two forms of Ca++ applied was found, except for the amount of ascorbic acid and total sugar. Finally, dipping application of Ca++ is easier than infiltration and it is therefore suggested.