bluuebunny/crossref_metadata_2025 huggingface dataset:
142 ESTER FORMATION IN RELATION TO HARVEST MATURITY AND CONTROLLED-ATMOSPHERE STORAGE OF `GALA' APPLES
Authors: Fellman J. K. , Mattinson D. S. , Mattheis James P. , Buchanan D.A.
Published: February 2019

Volatile esters from acids and alcohols are important components of flavor and odor perception in apples (Malus domestica Borkh.). We are interested in understanding the biochemical basis for ester synthesis/flavor retention in `Gala' apples held in controlled atmosphere storage. The relationship between acetyl CoA alcohol transferase (AAT) acetate ester-formin activity, non-ethylene volatile emission, and flesh volatile content of `Gala' apples during the maturation period and after removal from CA storage was investigated. At the appropriate times, apples were sampled for volatile compounds in the headspace and flesh using solid sorbent along with purge-and-trap capillary gas chromatography. Subsequently, acetate ester forming activity was assayed on partially-purified extracts of cortical tissue. During storage, the accumulation of the major flavor notes butyl acetate and 2-methyl butyl acetate in the flesh was decreased as oxygen levels in storage atmospheres were lowered. AAT activity is closely linked to the onset of climacteric ripening and is sensitive to atmospheres having low oxygen contents.
147 GENETIC DIVERSITY, AND INHERITANCE AND LINKAGE OF ISOZYME LOCI IN MELON (Cucumis melo L.)
Authors: Meglic V. V. , Horejsi T. F. , Staub J. E. , McCreight J. D.
Published: February 2019

The genetic diversity of 400 U.S. melon germplasm plant introductions was assessed using 35 enzyme systems. Polymorphisms were observed at 24 putative loci (Ac, Acp1, Acp4, Ak2, Ak3. Ak4, Fdp1, Fdp2, Fdp4, Gpi, Idh, Mdh2, Mdh4, Mdh5, Mdhb, Mpi1, Mpi2, Pgd1, Pgd2, Pgm, Pep-g1, Pep-1a, Pep-pap, Skdh) representing 17 different enzymes. Sixteen loci demonstrated simple Mendelian inheritance. Multivariate analyses aided in reduction of data using 16 loci and linkage relationships were observed among the plant introductions. Two of 16 loci (Pgd1 and Acp1) segregated independently. Fourteen loci were assigned into three linkage groups (A-C): A Fdp1, Fdp2, Acp4, Skdh; B Mdh2, Mdh4, Mdh5, Mdh6, Pep-g1, Pgm; C Mpi2, Ac, Idh.
148 GENOTYPE X ENVIRONMENT INTERACTIONS OF MUSKMELON HYBRIDS FOR YIELD AND FRUIT SIZE
Authors: Wolff David W. , Miller Marvin E. , Lander Carmen
Published: February 2019

The nature and magnitude of genotype × environment interactions will determine the extent of testing required (locations, years) to accurately evaluate a genotype's performance. Data from yearly T-AES muskmelon variety trials were analyzed to determine the level of variety (V) × year (Y), V × location (L), and V × Y × L interactions for yield and fruit size. Data analyzed were of nine hybrids grown at three commercial farms over two years. Fruits were harvested similar to grower practices, and were sorted into size classes (9 - 30) or culls. V × Y and V × L interactions for marketable yield and total yield were not significant. V × Y × L interaction was significant for marketable yield, but not for total yield. V × Y × L interactions were highly significant for percentage culls and percentage of fruit in each size class. V × L interactions were also significant for percentage of fruit in most size classes. Data indicate that specific location-year combinations differentially affect a genotype's fruit size, most likely due to weather, planting time, and stress factors. Multiple year and location testing of genotypes is therefore critical, particularly for evaluation of fruit size.
149 DIFFERENTIAL REACTIONS OF MELONS TO ISOLATES OF PAPAYA RINGSPOT VIRUS WATERMELON STRAIN
Authors: Fashing-Burdette Patti , McCreight James D.
Published: February 2019

In 1963, melon (Cucumis melo L.) plant introductions (PI) 124112 and PI 180280 were reported variable in response to inoculation with the T-1 or Freitag's isolates of watermelon mosaic virus. Most plants were symptomless, but some had small pinpoint necrotic lesions on cotyledons and leaves. The T-1 and Freitag's isolates of watermelon mosaic were later designated watermelon mosaic virus 1, and more recently renamed papaya ringspot virus watermelon strain (PRSV-W). When inoculated with California or Florida isolates of PRSV-W in 1993, WMR 29 a western U.S. shipping type melon derived from PI 180280 was symptomless (incompatible reaction) and SDS-immunodiffusion assays were negative. In contrast when inoculated with the same PRSV-W isolates, PI 124112 had incompatible reactions characterized by wilting, local lesions, systemic necrotic spots and necrosis and negative SDS-immunodiffusion assays.
150 THE IDENTIFICATION OF TETRAPLOID REGENERANTS FROM COTYLEDONS OF DIPLOID WATERMELON AND THEIR USE IN BREEDING TRIPLOID HYBRIDS
Authors: Compton Michael E. , Gray D.J. , Elmstrom G.W.
Published: February 2019

Tetraploid individuals were identified among plants regenerated from cotyledons of diploid watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] cultured in vitro. Tetraploid and diploid plants were distinguished by counting the number of chloroplast per guard cell pair. The mean number of chloroplasts was 19 and 11 for tetraploid and diploid plants, respectively. Self-fertile tetraploids were obtained from the diploid cultivars Mickylee, Jubilee II and Royal Sweet. `Dixielee' and `Minilee' tetraploids failed to set fruit. Progeny obtained from self-fertile tetraploids were crossed with diploid pollinators to produce triploid hybrid seed. All triploid plants produced seedless fruit that was superior or equal to fruit produced by currently available triploid hybrids. This demonstrates that tissue culture can be used to produce high quality tetraploid plants for use in triploid hybrid seed production.
153 GENES FOR INTENSE COLORATION OF ACORN SQUASH
Authors: Paris Harry S.
Published: February 2019

The fruits of Cucurbita pepo cv. Table Queen are light green when young, turn dark green by intermediate age (15-18 days past anthesis) and remain dark green through maturity. Three major genes are known to affect developmental fruit color intensity in C. pepo: D, 1-1, and 1-2. Table Queen was crossed with cv. Vegetable Spaghetti and with tester stocks of known genotype in order to determine the genetic basis of its developmental fruit coloration. The results from filial, backcross. and testcross generations suggest that Table Queen carries gene D, which confers dark stem and fruit color from intermediate fruit age through maturity. Table Queen also carries L-2. which confers Light Type 2 (a pattern of grayish green hue) fruit color from intermediate age, but D is epistatic to L-2. The genotype of Table Queen is D/D 1-1/1-1 L-2/L-2. Clear-cut results were not obtained -- regarding the genetic basis of the retention of green color through maturity of Table Queen fruits.
155 INFLUENCE OF CONSERVATION TILLAGE ON SOIL TEMPERATURE AND TOMATO YIELD
Authors: Garton Ronald W.
Published: February 2019

Processing tomatoes were planted on a sandy loam soil on raised beds which were prepared in a conventional method with a power bedder (PB), or with conservation tillage (CT). The CT treatments were prepared by using Glyphosate herbicide to burn-off a fall-seeded rye cover crop at either 10cm, 15cm or 30cm height. The center of the bed was tilled with a modified conservation tillage coulter caddy, prior to planting the tomatoes, to loosen the soil but leave the rye residue on the surface. Crop residue cover on the soil surface after planting the tomatoes increased from 9% in the PB treatment, to 63% with CT at 30cm. Increasing crop residue cover resulted in cooler soil temperatures during the day and warmer soil temperatures at night. Transplant survival and early growth was comparable between the tillage systems. Tomato yield was approximately 10% higher in the PB treatment than in the CT treatments. In the conservation tillage treatments, the tomato plants had lower total nitrogen concentrations in the petioles. Nitrogen immobilization by microbes in the decaying cover crop residue may have contributed to the lower petiole N concentrations, and the yield reduction.
159 EVALUATION OF A NUTRIENT/MOISTURE GRADIENT FOR PRODUCTION OF CONTAINERIZED TOMATOES
Authors: Geraldson C. M.
Published: February 2019

The gradient concept, which has been used to provide nutritional stability in a field orientated full-bed mulch production system, is being evaluated as a component in a containerized concept. Conceptionally, the nutrient/water Input must be synchronized with removal. A built-in water table and a time-clock regulated microirrigation procedure were evaluated as water sources. A reservoir of soluble N-K banded at the media surface was used to maintain and evaluate the nutritional gradient. Container design, choice of media, plant populations and even dual containers are being evaluated and selected to enhance the functional efficiency of the concept. Yields of 6.8 to 13.6 kgs of marketable, above average quality tomatoes per plant have verified the feasibility of the concept. The containerized gradient concept using minimal water with minimal pollution and using the gradient approach to allow a maximum productivity with minimal management, has the potential to become a globally sustainable production system.
178 RESISTANCE TO CODLING MOTH: EXPRESSION OF SYNTHETIC CRYIA(C) GENES IN TRANSGENIC WALNUT EMBRYOS
Authors: Dandekar Abhava M. , McGranahan Gale H , Uratsu Sandra L. , Leslie Charles , Tebbets J. Steven , Vail Patrick V.
Published: February 2019

Insecticidal crystal protein fragments (ICPFs) of Bacillus thuringiensis (Bt) encoded by cryIA(c) gene were shown in diet incorporation studies to be lethal to codling moth (CM; Cydia pomonella) the key insect pest for walnut. However transformed walnut tissues expressing cryIA(c) with Bt codon usage patterns and native DNA sequence revealed very low levels of expression in planta. To correct this problem synthetic versions of one of these genes, cryIA(c) was used to transform walnut tissue. A total of 61 individual transgenic embryo lines were obtained. 34% of these lines (21/61) were high expressors (“class A”) demonstrating 80 to 100% mortality of first in star CM larvae and displaying no further larval development. Twelve clones (20%) were designated “class B” and these showed a marked retardation of larval development and a mortality between 40 to 79%. Embryos from the remaining 28 lines designated “class C” (46%). although transformed, were indistinguishable from the control (untransformed embryos) and showed a mortality of 0 to 39%.
180 GENETIC TRANSFORMATION OF RED RASPBERRY (RUBUS IDAEUS L.) WITH A GENE TO CONTROL ETHYLENE BIOSYNTHESIS
Authors: Mathews Helena , Cohen C. , Wagoner W. , Kellogg J. , Dewey V. , Bestwick R.
Published: February 2019

We have developed efficient plant rageneration and transformation systems for red raspberry (Rubus idaeus L.). We have successfully introduced a gene for controlling biosynthesis of ethylene into raspberry for the first time. Leaf and petiole segments were co-cultivated with disarmed Agrobacterium strains EHA 101 or 105 containing plasmids pAG5420, pAG 1452 or pAG1552. The plasmids encoded gene sequences for S-adenosylmethionine hydrolase (SAM ase) driven by the fruit specific or wound and fruit specific tomato SE8 or E4 promoters. SAM ase catalyses the conversion of S-adenosylmethionine (SAM) to methylthioadenosine (MTA) and homoserine which can reenter the methionine recycling pathway. SAM is therefore not available for the synthesis of 1-am inocyclopropane carboxylic acid (ACC), the metabolic precursor for ethylene biosynthesis. Initial shoot regenerants were mostly chimeras containing transformed and non-transformed cells. Solid clones of pure transgenics were developed by repeated culture of leaf, petiole and nodal explants of primary regenerants on higher stringency selection medium. Transformants were screened on medium with kanamycin, geneticin or hygromycin depending on the selection marker gene NPTII or hpt. Genomic integration of transgenes were confirmed by Southern hybridization. Transgenic plants of cultivars Canby, Meeker and Chilliwack have been transplanted to the greenhouse for fruit set and further evaluation of transgenic traits.
184 Timing of Benzyladenine Application as a Chemical Thinner of `Empire' Apple
Authors: Emongor V. E. , Murr D. P.
Published: February 2019

Benzyladenine (100 or 200 mg.litre-1) was applied to mature Empire/M.26 apple trees as dilute sprays 2, 4, 9, 11, 13, 15, 17, 20, 25, 27, 29 or 31 days after full bloom (DAFB). The most effective time of thinning was 25-29 DAFB (king fruit diameter 8.94-13.91 mm), and the thinning response to BA concentration was linear. Benzyladenine (BA) did not reduce fruit set when king fruit diameter was less than 5.35 mm, but BA significantly increased fruit weight, diameter (D), length (L) and L:D ratio compared to unsprayed controls and later BA treatments. BA - treated fruitlets had higher ethylene production, 24 hours and 7 days after spraying compared to untreated controls. We suggest that the response of apple fruitlets to BA applied as a thinner is mediated by ethylene. High fruit quality was obtained when BA was applied at 17-31 DAFB. Timing of BA sprays had no effect on seed number, though BA significantly increased seed number, fruit size, weight and L:D ratio. These results suggest that BA has the potential to substitute for the use of carbaryl as a thinner of apples in Ontario orchards.
189 BLOOM THINNING WITH ARMOTHIN®, AN AKZO SURFACTANT
Authors: Evert Dean R.
Published: February 2019

Armothin® thinned `Sentinel' fruit on peach trees (Prunus persica L.) in 1993. Thinning increased as Armothin® rate in the single spray increased from 1.5X, to 3.0% to 6.0% (v:v) and as the percentage of open blossoms increased from 30% to 61%. The 1.5 % rate of Armothin® thinned significantly only on the third date, and the 6.0% rate overthinned slightly on the third date. Minor discoloration developed on the expanding leaves of a few of trees but disappeared in a few days. No leaf abscission occurred on treated trees and tree growth was normal. Variability between trees treated alike probably reflects the variability in bloom when sprayed. According to Akzo, Armothin® prevents pollination by reacting with the surface of the receptive stigma. Spraying after full bloom should selectively prevent fertilization of the last blossoms to open without destroying the fertilized fruit. This possibility will be tested in 1994. Armothin®, which is a contact thinner, seems to avoid the problems associated with thinners that act as growth regulators and with nonselective caustic thinners. Because of its low phytotoxicity and wide range of effective rates, Armothin® has great potential as a chemical thinner.
192 EXPOSURE TO ULTRAVIOLET-B RADIATION INCREASES COLD HARDINESS IN RHODODENDRON
Authors: Dunning Chris A. , Chalker-Scott Linda , Scott James D.
Published: February 2019

The change in the cold hardiness of Rhododendron (cv. `English Roseum' following chronic exposure to ultraviolet-B radiation (280-320 nm) was studied. Leaf disks removed from ultraviolet-B exposed plants exhibited a greater tolerance to freezing temperatures than plants which received no ultraviolet-B exposure. Visual browning and percent phenolic leakage indicated that UVB-exposed leaf disks were killed at -11 °C, while control disks were killed at -8°C. The increase in phenolics seen in UV-B exposed plants most likely contributed to their increased resistance to cold temperature through the synthesis of cell-wall associated components such as lignin and suberin.
195 PHYSIOLOGICAL STUDY OF HEAT TOLERANCE IN RHODODENDRON SPP.
Authors: Ranney Thomas G. , Blazich Frank A. , Warren Stewart L.
Published: February 2019

Temperature sensitivity of net photosynthesis (Pn) was evaluated among 4 taxa of rhododendron including Rhododendron hyperythrum, R. russatum, and plants from two populations (northern and southern provenances) of R. catawbiense. Measurements were conducted on individual leaves at temperatures ranging from 15 to 40C. Temperature optima for Pn ranged from a low of ∼21 C for R. russatum to a high of ∼27C for R. hyperythrum. At 40C, Pn rates for R. hyperythrum, R. catawbiense (northern provenance), R. catawbiense (southern provenance), and R. russatum were 7.8, 5.7, 3.5, and 0.2 μmol·m-2·s-1, respectively. R. catawbiense from the southern provenance did not appear to have greater heat tolerance than plants from the northern provenance. There was no difference in temperature sensitivity of dark respiration among the taxa. Variations in heat tolerance among species appeared to result from a combination of stomatal and nonstomatal limitations on Pn at high temperatures.
203 ETIOLOGY OF STRAWBERRY BLACK ROOT ROT
Authors: Wine Katherine , Pritts Marvin
Published: February 2019

Black root rot is a devastating, poorly understood disease complex affecting strawberries throughout the world, especially in perennial plantings. Field measurements at 54 sites in New York were made for 113 cultural and environmental variables, and root health was quantified. Root health was negatively associated with wet, compacted soils where plants were grown for several years on flat beds with terbacil herbicide. Pratylenchus penetrans numbers were associated with rotting rots, but not in all sites. Rhizoctonia fragariae and Pythium spp. were usually isolated where black root rot was present, but not always. When strawberry plants were grown in infested soil at warm temperatures (23C), R. fragariae was most commonly isolated, and when grown in the same soil at cool temperatures (5C), Pythium was found. Inoculation of sterile soil with Pythium and/or Rhizoctonia reduced root dry weights, but symptoms were not identical to those observed in the field. Various combinations of pathogenic fungi, nematodes, soil compaction, flooding, low light and terbacil failed to recreate field symptoms in the laboratory. Tolerance rankings of 20 cultivars were different at four field sites. These observations suggest that black root rot can have many causes, and that susceptibility may be stress induced under field conditions.
207 TASK ANALYSIS IN STONE FRUIT FREEZE PROTECTION DECISION SUPPORT SYSTEM DEVELOPMENT
Authors: Willett Michael J. , Andrews Preston K. , Proebsting Edward L.
Published: February 2019

There has been an explosion of interest in the development of computer-based Decision Support Systems (DSS) in agriculture. Humans factor, which is the design and evaluation of a system to optimize human and total system performance, offer tools to improve the usefulness of DSS. Task analysis, a formal human factors approach to study human-machine interaction, identifies all of the physical and psychological tasks which must be completed by either the human or the machine in order to meet the various system performance requirements and constraints. Our study focuses on the tasks associated with mid-winter stone fruit freeze protection. Using this technique we have identified work load and output requirements of current critical temperature estimation procedures, additional information needed to improve critical temperature estimates and training needs of fruit industry personnel making critical temperature determinations. This information will be used to produce a requirements specification for a freeze protection DSS.
209 THE WASHINGTON TREE FRUIT MANAGEMENT PROGRAM
Authors: Tvergyak Paul , Mullinix Mark K.
Published: February 2019

To address the acute need of Washington's tree fruit industry for professional horticulturists, the Agriculture Sciences Department at Wenatchee Valley College and the Department of Horticulture and Landscape Architecture at Washington State University have developed and implemented a unique undergraduate degree program. This program represents a new way of addressing the need for professional horticultural positions in Washington's tree fruit industry amidst tradition, reductions in state higher education budgets, and eroding confidence in the public education system. This program is not a credit transfer program but a fully articulated agreement. We established a small working team that represented the partners. Their goal was to discuss and develop a concept framework that has three parts: administrative, curriculum and industry support. The objectives of the program are to address the need of Washington's tree fruit industry for entry level horticulturists who could assume more responsibility earlier in their career, to make the fruit industry and integral partner, to prepare students for graduate study as well as industry professionals and to capitalize on the respective strengths of the partners.
210 CUSTOM-PRINTED ELECTRONIC FACT SHEETS AT HORTICULTURAL EVENTS
Authors: Marr Charles
Published: February 2019

A series of 62 fact sheets on a variety of topics related to vegetable gardening were constructed in WordPerfect and, using a series of macros and styles, were modified to a standard format and printed to a file for storage. Sheets were organized into a heirarchal menu so they could be copied to the printer upon request using only DOS commands. A portable laptop computer and a Hewlett Packard Portable DeskJet printer was used to print files at such remote locations as nurseries/garden centers, shopping malls, fairs, and public events where Master Gardener volunteers set up and operated the equipment. Single sheets could be printed in about 20 seconds. At garden shows with larger attendance, a HP Laser 4 printer and a standard computer were used to print fact sheets at about 5 seconds each. Fact sheets consisted of text and tables but no graphics were included. Most sheets were single pages although several were 2 pages in length. Additional information was available from a comprehensive for-sale publication sold or available for ordering on-site. Costs of custom printed fact sheets compared to standard printing will be discussed.
214 LIVING-MULCH AND GENOTYPE EFFECT ON THE PRODUCTIVITY AND GROWTH OF EGGPLANT
Authors: Valenzuela Hector R. , DeFrank Joseph
Published: February 2019

Living mulches offer a low-input alternative to achieve weed control while minimizing herbicide applications, decreased fertilizer leaching, insect and nematode management. and improved soil texture. A study was conducted to evaluate the effect of a Rhodes Grass (Chloris gayana cv. Katambora) living mulch on the growth and productivity of ten eggplant. Solanum melongena, cultivars grown under fertigation. The living sod was established at the Univ. Hawaii Waimanalo Experiment Station in June 1992. Soil analysis was taken before experiment initiation. Ten eggplant cultivars were transplanted on both living-mulch and control (woven-polyethelene mulch) plots on 4 March 1993. Weekly or bi-weekly harvests were conducted for six months. beginning on 19 May 1993. In addition plant height and canopy dimensions were determined on 16 April. and 10 Nov. Plant growth was monitored throughout the experiment. Soil samples were taken from the eggplant rhizosphere, hare-ground and in Rhodes grass monoculture, for nematode count determinations. Soil samples were also taken for nutrient determination after completion of the experiment. Overall yields were greater in the polyethelene mulch than in the living mulch plots. A differential response was observed on the response of cultivars to cropping system. However the most vigorous cultivars performed well in both systems. The living mulch system showed potential for nematode management in eggplant agroecosystems.
215 THE INFLUENCE OF SWEETPOTATO WHITEFLY MANAGEMENT AND POTASSIUM FERTILIZATION ON YIELD AND IRREGULAR RIPENING OF TOMATO
Authors: Csizinszky A. A. , Schuster D. J.
Published: February 2019

Two insecticidal spray frequencies, 0 and 3x per week, against the sweetpotato whitefly, Bemisia tabaci Gennadius, were evaluated at three K rates, 190, 380 and 760 kg.ha-1, for their effect on whitefly population, fruit yield and incidence of irregular ripening on tomato, Lycopersicon esculentum Mill., cv. Sunny. Whitefly populations were reduced with three weekly sprays, but not by K rates. Early yields were best with three weekly sprays and with the highest K rate. For the season, yield of extra large (≥ 70 mm diameter) fruit was reduced with three weekly sprays and with increasing K rates. Proportions of irregularly ripened fruits were similar with either spray frequency, but were reduced at the highest K rate.
216 COMPARISON OF CELERY TRANSPLANTS NUTRIENT DEFICIENCY DIAGNOSIS BY MEANS OF DRIS OR CND METHODS
Authors: Tremblay Nicolas , Parent Léon-Étienne
Published: February 2019

Celery (Apium graveolens var. Dulce) is a species particularly sensitive to nutritional balance. Seedlings in multicellular trays sometimes present problems that can be traced to nutritional causes. DRIS (Diagnosis and Recommendation Integrated System) and CND (Compositional Nutrient Diagnosis) are two recent concepts that can be implemented to diagnose nutritional imbalances from tissue analyses of any plant species. A data bank of 215 observations was used to elaborate DRIS and CND norms for celery transplants. The threshold yield for high yielders was set at 1600 g/plant (27% of the population). Both DRIS and CND systems were implemented and a validation process was undertaken. Nutrient deficiencies (N, P, K, Ca, Mg, Fe, B and Zn) were induced on celery seedlings in growing chambers. Tissues samples were given a balanced fertilization. The diagnosing methods (DRIS and CND) were compared on the basis of their ability to identify correctly the induced nutrient deficiencies.
219 CONSUMER HORTICULTURE: CHARACTERISTICS, TRENDS, AND IMPLICATIONS FOR EXTENSION
Authors: Schrock Denny
Published: February 2019

Consumer horticulture surveys conducted 7 years apart examined the scope and trends in home horticulture in Olmsted County, MN. Master Gardener volunteers were trained to conduct the telephone surveys. Landscape horticulture was important in terms of numbers of people involved and reasons for gardening. Fewer people viewed vegetable gardening as important. Young people were less likely to garden than older ones. Lack of space was the biggest barrier to gardening.

It was concluded extension should expand newspaper and newsletter media efforts. Development of cooperative programs with garden centers and other agencies was suggested. Opportunities exist for training consumers in pesticide safety and best management practices for horticulture.
225 SURVEY OF PLANT MATERIALS INSTRUCTORS
Authors: Niemiera Alex X. , Leda Carol E.
Published: February 2019

A survey to determine teaching methodologies for plant material courses was conducted. A total of 120 surveys was sent to horticulture programs at U.S. universities and colleges. Thirty-nine, 22, and 8 respondents taught a woody plant (W), a herbaceous perennial (HP)/annual (A) course, and a foliage plant course, respectively; 21 respondents taught a combination of theses courses. The following similarities were noted for W and HP/A: 1) about 190 species per Semester were presented usually in a taxonomic order using slides as the primary teaching medium for lecture, 2) the most common student complaint was too much work and memorization, 3) the most common student compliment was the practical and useful nature of the subject matter, 4) in order of importance, plant identification, landscape value, and plant cultural aspects were emphasized. For W and HP/A, 93% and 65% of plants, respectively, were presented as landscape and arboreta specimens. Seventy percent of W courses used Dirr's Manual of Woody Landscape Plants; 58% and 10% of HP/A courses used Still's Manual of Herbaceous Ornamental Plants and Taylor's Guides, respectively.
231 A COMPARISON OF GENOMIC AND MORPHOLOGICAL EVALUATION FOR SELECTION IN INTERSPECIFIC BACKCROSS POPULATIONS OF WALNUT
Authors: Woeste Keith , Shaw Douglas , McGranahan Gale , Bernatzky Robert
Published: February 2019

We characterized a population of hybrids between English walnut and Northern California black walnut (Juglans regia X J. hindsii) and their backcrosses (BC) using both genomic markers and morphological traits. ANOVA and regression methods were used on three years' data to identify a subset of five variables that describe the morphological variability among backcross populations and their parents (R2 = 0.89). Genomic markers were identified using randomly amplified polymorphic DNA (RAPD). A subset of 60 markers specific to the donor species (J. hindsii) were scored in 50 backcrosses to estimate the percent recipient genome in each evaluated BC. The backcrosses were ranked using each method of evaluation; correlation between the ranks was 0.423 and highly significant. Each evaluation method has advantages but neither was able to reliably identify elite progeny.
241 NUTRIENT MASS BALANCES AND RECOVERY STRATEGIES FOR GROWING PLANTS IN A CELSS
Authors: Mackowiak C.L. , Wheeler R.M. , Berry W.L. , Garland J.L.
Published: February 2019

Wheat, soybean, potato, and lettuce crops were grown in a large (20 m2), closed chamber to test plant production for life support in a Controlled Ecological Life Support System (CELSS). Plant crude protein levels were about 15% in wheat and potato biomass, 20% in soybean biomass, and 27% in lettuce biomass at harvest. Nitrate levels were not assayed, but likely contributed to the protein estimates. Nitric acid (used in hydroponic system pH control) contributed 43% for wheat nitrogen needs, 33% for soybean, 30% for potato, and 27% for lettuce. Lettuce contained the highest percent ash (22%) and wheat the lowest (10%). It was likely that the continuous nutrient supply in the hydroponic systems resulted in high ash values. The percentage of plant macronutrients in the inedible biomass was 7% in lettuce, 50% in soybean and potato, and 80% in wheat. Based on these values, perhaps 50% of the macronutrients needed in a multi-crop system could be removed from the inedible biomass and recycled back into the hydroponic system. Applicable technologies for nutrient recovery would include wet or dry oxidation (ashing), water soaking (leaching), or bioreactor degredation. The mass of reagent-grade salts needed in place of nutrient recycling could equal about 30% of the dry food mass required per person day-1.
246 DEVELOPMENT OF A NEGATIVE WATER PRESSURE SYSTEM AND USE FOR CONTROLLING ASSIMILATE PARTITIONING IN POTATOES
Authors: Tibbitts T.W. , Cao W.
Published: February 2019

A nutrient delivery system developed for plant growth in space provides a unique system for maintaining a constant, slightly-negative water tension for plant research. The system involves the use of multiple porous stainless steel tubes positioned 4 cm apart in shallow trays (44 cm long, 32 cm wide and 8 cm deep), and then covered with a 4 cm layer of fine medium. Nutrient solution is recirculated through the porous tubes under -5 cm (water head) of negative pressure maintained with a siphoning procedure. Potatoes grown with negative pressures were compared to growth in similarly constructed trays that were maintained on a slant and solution added to the upper end of the trays and drained from the lower end. The same nutrient solution was recirculated through the trays of each treatment and maintained at a pH of 5.6. A microcultured plantlet of Norland cv. was transplanted into each tray. The negative pressure produced plants with less total plant dry weight, leaf area, branches, and stolons but increased biomass partitioning into tubers. The data suggest that this small constant negative water pressure regulates assimilate partitioning to encourage production of tubers.
251 CARBON DIOXIDE ENRICHMENT AND CARBOHYDRATES IN ANDROGENESIS OF CAPSICUM ANNUUM L.
Authors: Dolcet-Sanjuan Ramon , Claveria Elisabet
Published: February 2019

Anthers from more than 17000 flowers of 19 bell pepper Capsicum annuum L. hybrids (provided by `Semillas Fitó S.A.') were cultured in a double layer modified H medium (Nitsch and Nitsch, 1969) supplemented with 0.5 % activated charcoal and 0.26 % Gelrite in the solid phase. Significant differences between genotypes were observed on embryogenesis (472.3 to 9.7 embryos / 100 flowers) and number of plants rescued (4.0 to 0.3 plants / 100 flowers). Trying out maltose, malt extract, and sucrose. as carbohydrates, at 20, 40, 60 or 80 g/l, gave significantly better results for maltose (20 or 40 g/l). In addition, maintaining the anther cultures in an atmosphere enriched with 600 ppm CO2 was beneficial for embryo number, embryo development and number of rescued plants. Isocitrate dehydrogenase zymograms from leaf extracts indicate the microspore origin of the acclimated plants. Flow citometry of nuclei was used to determined an early diploidization of 70 % of the acclimated plants.
255 LEACHING FRACTION, FERTIGATION RATE AND PHOSPHORUS LEACHING FROM POTTED GERANIUM
Authors: Ku Catherine S. M. , Hershey David R.
Published: February 2019

Single-pinched `Yours Truly' geranium (Pelargonium × hortorum) were greenhouse grown in 15-cm diameter pots. They received constant liquid fertigation with a modified Hoagland solution #1 at 0.25, 0.5, 1.0, and 1.5 strength. The 1.0 strength Hoagland solution contained 210 mg/L NO3-N and 31 mg/L P. Leaching fractions (LFs) were 0, 0.2 and 0.4. The total P applied via fertigation ranged from 33 mg at 0 LF and 0.25x Hoagland to 407 mg at 0.4 LF and 1.5x Hoagland. The leachate P concentration ranged from <5 mg/L to -60 mg/L. The P concentration in the recently matured leaves was in the acceptable range for all treatments. We were able to recover 90 to 99% of the applied P by analyzing the shoots, soilless medium, and leachate. Only 4% of the recovered P was in the leachate for plants receiving 0.5x Hoagland and a 0.2 LF. However, these plants were equal in yield to plants receiving higher fertigation rates and higher LFs.
258 AVAILABILITY AND PERSISTENCE OF MACRONUTRIENTS FROM PREPLANT NUTRIENT CHARGE MATERIALS AND LIME IN PEAT-BASED ROOT MEDIA
Authors: Argo William R. , Biernbaum John A.
Published: February 2019

Four experiments were conducted with six liming materials of different particle sizes and six commercially available blended preplant nutrient charge (PNC) materials in the laboratory and in container culture with subirrigation for durations up to twenty-eight days. Liming material, particle size, and incorporation rate affected both the initial and final stable pH of one type of peat without an incorporated PNC. Saturated media extract (SME) Ca2+ and Mg2+ concentrations were below the acceptable recommended concentrations for both pulverized and superfine dolomitic lime at incorporation rates up to 7.2 kg·m-3. For the blended PNC materials, initial N, P, K+, Ca2+, and Mg2+ concentrations for five of the six PNC materials were at or above the optimal concentrations recommended for an SME, but did not remain persistent in the root zone. A large percentage of all nutrients tested moved from the root zone into the top 3 cm (top layer) of the pot within two days after planting. Nutrient concentrations in the top layer continued to increase even when nutrient concentrations in the root zone fell below acceptable levels for an SME. The importance of this fertilizer salt stratification within the pot lies in the reduced availability of nutrients to the plant.
259 NITROGEN RATE/SOURCE/TIMING EFFECT ON CHRYSANTHEMUM ROOT CHEMISTRY AND FUNCTION IN POSTHARVEST
Authors: Carver Stephen A. , Knee Michael , Tayama Harry K.
Published: February 2019

Dendranthema grandiflora `Spirit' and `Iridon' were grown in a 2-factor experimental design consisting of 3 nitrogen rate/source treatments (100 mg/liter N (25% NH4+}, 400 mg/liter N (25% NH4+}, and 400 mg/liter N {5% NH4+}), and 2 fertilizer termination treatments (bud-color and harvest) Evaluation of various production characteristics including plant and flower size, days to flower, leaf number and size, and leaf, shoot, flower and root fresh/dry weight, revealed few significant differences among treatments. High foliar N content in all treatments (ranging from 6.1 to 8.5%) may provide an explanation for the apparent lack of differential treatment production response. However, there were significant treatment differences in floral and foliar postharvest keeping quality. High NH4+ grown plants declined 1-2 weeks sooner than other treatments, and plants fertilized to harvest declined 0.5-1 week sooner than those fertilized to bud color. Root fresh and dry weights measured 2 weeks into postproduction disclosed significant differences between treatments that mirrored foliar and floral longevity. Results of a satellite study in which root and stem hydraulic conductivity, root total soluble carbohydrates, starch, and protein content, and water loss rate during postharvest will be presented.
269 CELL WALL CHANGES IN RIPENING NASH1 (HOSUI) FRUIT
Authors: Melton L.D. , Davies L.M.
Published: February 2019

Cell wall changes during ripening have a major effect on fruit texture. The cell walls isolated using phenol-Tris buffer were sequentially extracted to give polysaccharide fractions that contained mainly water-soluble pectin, chelator-soluble (CDTA) pectin, hemicelluloses (0.05 M Na2CO3 followed by 1M and 4M KOH) and cellulose. The fractions were analyzed colorimetrically for uronic acid, total neutral sugar and cellulose contents. The component sugars of each fraction were determined as their alditol acetates by GC. Then was a decrease in the two pectin fractions during ripening. The pectins appear to have arabinan and galactan side chains. Pectic galactose decreases during ripening. The weight of the combined hemicellulose fractions did not change during ripening, nor did the cellulose level. At least two types of arabinan are present. Pectins were found in all cell wall fractions. Nashi cell walls contain a relatively large amount of xylan compared to other fruit.
270 EFFECTS OF INTERMITTENT WARMING ON CELL WALLS OF NECTARINES
Authors: Dawson D.M. , Melton L.D. , Dawson D.M. , Watkins C.B.
Published: February 2019

Nectarine fruit (Prunus persica (L) Batsch) cv. Fantasia, were ripened immediately after harvest (normal ripening), or stored for 6 weeks either continuously at 0°C or were intermittently warmed (IW) for 48 h at 20C after 2 and 4 weeks, and then ripened. Fruit subjected to IW ripened normally, whereas the continuously stored fruit developed mealiness during ripening. Normal ripening was associated with solubilization and depolymerization of pectic polymers and a net loss of galactose. Only limited pectic solubilization and removal of side chains occurred during ripening of mealy fruit. Pectic polymer polymerization occurred at each IW occasion continued during ripening after storage, but was not as extensive as in normally ripened fruit. Mealy fruit had high autolytic capacity, probably as a result of insoluble pectic polymers in the cell wall that were not solubilized during ripening. The release of uronic acid suggests that cool storage temperatures do not irreversibly inhibit polygalacturonase activity.
272 CONTROL OF BROWN ROT OF PEACHES AND APRICOTS WITH HOT WATER AND CONTROLLED-ATMOSPHERE STORAGE
Authors: Youssef Salah E. , Mitcham Elizabeth J.
Published: February 2019

Peaches and apricots were obtained at harvest. One-half were inoculated with the brown rot organism (Monilinia fructicola) and incubated overnight before immersion in 52C water for 2.5 and 2 minutes, respectively. Fruit were placed in storage at SC in air, 2% O2 and 15% CO2, or 17% O2 and 15% CO2 for 5 or 15 days before ripening at 20C. For peach, controlled atmosphere (CA) had no influence on decay while hot water significantly reduced decay incidence and severity. For apricot, after 15 days cold storage, both hot water and controlled atmosphere storage reduced decay incidence and severity. CA with 2% O2 and 15% CO2 controlled decay better than 17% O2 and 15% CO2. Growth and sporulation of Monilinia fructicola in air and CA was also evaluated in vitro. The combination of heat and CA controlled decay better than either treatment alone. The hot water treatment resulted in minor surface injury on peaches while apricots were not injured. Fruit were evaluated after storage for firmness, soluble solids, and titratable acidity. Accumulation of ethanol and acetaldehyde as a result of CA storage was monitored.
274 EFFECTS OF STORAGE TEMPERATURE, KERNEL INTACTNESS, AND ROASTING TEMPERATURE ON VITAMIN E, FATTY ACIDS AND PEROXIDE VALUE OF HAZELNUTS
Authors: Ebrahem Kais S. , Richardson Daryl G. , Tetley Richard M.
Published: February 2019

Kernels in the shell were compared to bare kernels with pellicles, half nuts, blanched nuts, finely chopped nuts, and roasted nuts. Whole nuts and whole kernels were stable for up to two years of storage provided they had not been exposed to high temperatures. Nuts stored at low temperatures (0 and 5°C) did not lose significant amounts of vitamin E. Increasing surface area by dividing nuts or finely chopping them, increased the loss of vitamin E. Samples that had lower surface areas did not lose much vitamin E and peroxide value was low. Higher roasting temperatures caused losses in vitamin E and increased peroxide values at the beginning and during storage, even when stored at 0°C. Intact nuts and low storage temperatures did not show changes in fatty acid composition. High temperature treatments changed fatty acid composition, mainly decreasing linoleic initially and finally oleic acids.
275 VAPOR PHASE HYDROGEN PEROXIDE TREATMENT OF WALNUT NUTMEATS (Juglans regia L.) FOR CONTROL OF MICROORGANISMS
Authors: Simmons Gilbert F. , Smilanick Joseph L. , Denis-Arrue Nuria , Margosan Dennis A , John Shama
Published: February 2019

A new vapor phase hydrogen peroxide (VPHP) technology that uses relatively dry hydrogen peroxide pulses is a promising method for the disinfection of surface-borne bacteria, yeasts, and molds on walnut nutmeats. The number of colony forming units per gram (cfu/g) on untreated nutmeats was compared to those VPHP treated. Three culture media; dichloran rose bengal chloramphenicol agar base (DRBC, Oxoid), aerobic plate count agar (APC, Oxoid), and potato dextrose agar (PDA, Sigma), were utilized to evaluate cfu/g. Similar numbers of cfu/g of product were observed on APC and PDA. The more selective DRBC had lower cfu/g. Microorganisms washed from untreated walnut nutmeats purchased at retail outlets ranged between 17,000-29,000 cfu/g depending upon the culture medium used. The number of cfu/lg on nutmeats after VPHP treatments was reduced to 500-1400, a 95% reduction. VPHP may offer an alternative to propylene oxide fumigation. The moisture content of nutmeats was not significantly altered by VPHP. The Food and Drug Administration lists hydrogen peroxide as a “generally recognized as safe substance” (GRAS). Hydrogen peroxide is already produced in a food grade for aseptic packaging.
279 COMPARISON OF OPEN-POLLINATED AND HYBRID CALABAZA
Authors: Maynard D.N. , Elmstrom G.W. , Brecht J.K. , Wessel-Beaver L.
Published: February 2019

Bush and short-vined calabazas [Cucurbita moschata (Duchesne) Poir.] derived from crosses of `Bush Butternut' with `La Primera' and `La Segunda' followed by several generations of selection and self pollination, are quite uniform in plant and fruit characteristics. Likewise, selfing and selection of vining cultigens has resulted in uniform vine and fruit characteristics. Hybrids between bush/short-vined and vining lines usually retain the plant habit of the bush/short-vined parent, and produce higher yields of fruit with thicker and better-colored flesh than open-pollinated cultigens. Hybrid bush/short-vined calabazas are earlier, have more concentrated fruit set, and utilize space better than open-pollinated cultigens. Commercial seed of hybrids is likely to be more readily available than seed of open pollinated cultigens.
282 INHERITANCE OF SPECIFIC AND ADULT PLANT RUST (UROMYCES APPENDICULATUS) RESISTANCE AND LEAF PUBESCENCE IN DRY BEAN (PHASEOLUS VULGARIS L.)
Authors: Bokosi J.M. , Coyne D.P. , Arnaud-Santana E. , Steadman J.R. , O'Keefe D.
Published: February 2019

An association between abaxial leaf pubescence (ALP) and adult plant resistance (APR) on trifoliolate leaves was reported previously. Recombinant inbred (RI) lines from crosses PC-50 (P1) with XAN-159 (P2) and BAC-6 (P3), and P3 with HT7719 (P4) were used to study the inheritance of specific resistance (SR), APR and ALP. P1 is resistant to A88TI-4b and has abaxial hairs on the trifoliolate leaves while P2, P3, and P4 are all susceptible (S) and have glabrous (G) leaves. P3 is resistant to D85C1-1. SR to A88TI-4b on primary leaves (PL) was determined by a single dominant gene with an additional dominant gene for APR on the 4th trifoliolate leaves in P1 × P2. ALP was governed by a single dominant gene with no association with APR. SR to A88TI-4b on PL in P1 × P3 was controlled by a single dominant gene. SR to DC85C1-1 on the PL was determined by a single dominant gene in P3 × P4.
283 BREAKUP OF LINKAGES FOR DIAGNOSTIC TRAITS IN THREE-SPECIES CONGRUITY BACKCROSS (CBC) PHASEOLUS HYBRIDS
Authors: Anderson Neil O. , Ascher Peter D.
Published: February 2019

Advanced, two-species CBC individuals were used to create the first-ever, three-species hybrids between P. acutifolius, P. coccineus and P. vulgaris. M6 (2 species) × H15 (3 species) is the only three-species hybrid to date that segregates for diagnostic traits. Three generations of M6 (F2, F3, F4,) were used to create the series. Hybrid breakdown was most severe with M6 F2 × H15, producing 100% cripples that died before anthesis. In M6 F3 × H15 hybrids, segregation for stigma position, flower color, germination type, growth habit, leaf length/width ratios, and seed morphology commenced in the F1 hybrid generation. F, phenotypes, with P. coccineus flowers & seeds and P. acutifolius leaves & growth habit, had severe hybrid breakdown with weak self compatibility; purple seed coats, with or without black circundatus markings, and new flower colors were also produced. F1's with P. vulgaris growth habits were self-fertile and ceased segregating after the F2.
296 INTERACTION BETWEEN NAA AND BA ON CROPPING AND FRUIT SIZE IN `DELICIOUS' AND `EMPIRE' APPLES
Authors: Bukovac Martin J. , Black Brent L. , Hull Jerome , Stopar Matej
Published: February 2019

Benzyladenine (BA), reported to increase fruit growth in apples, was evaluated with NAA to overcome NAA-induced inhibition of fruit growth. High volume sprays of NAA (15 mg·liter-1), BA (25 to 100 mg·liter-1) and combinations were applied to Redchief `Delicious' (king fruit = 10 mm). Yield was not significantly reduced. The combinations (NAA + BA 25, 50 or 100 mg·liter-1) resulted in the highest percentage of small fruit (39% < 70 mm) and the lowest percentage of large fruit (35% > 77 mm) compared to NAA, BA and hand thinned control. There was no significant effect of NAA or BA on size of king fruit in absence of lateral fruit competition on a given spur, while the combinations decreased (P = 0.01) king fruit size. NAA, but not BA, reduced growth of lateral fruit, with or without competition. However, the combinations caused marked suppression of lateral fruit growth and reduced seed content. With `Empire', both NAA (10 mg·liter-1) and BA (25 to 150 mg·liter-1) effectively thinned. Fruit size was greater with BA than NAA. The combinations (NAA, 10 mg·liter-1 + BA, 25 or 50 mg·liter-1) over-thinned and did not increase the amount of small fruit as in `Delicious'.
304 COMPARISON OF HORTICULTURAL CROPS GROWN AT TWO ROOT-ZONE TEMPERATURES
Authors: Klock Kimberly A. , Taber Henry G. , Graves William R.
Published: February 2019

Two root-zone temperatures (RZT) treatments, 21C and 34C were compared to evaluate their effects on growth and nutrient uptake for tomato (Lycopersicon esculatum Mill.), muskmelon (Cucumis melo L.), honey locust (Gleditsia triacanthos var. inermis Willd.), and geranium (Pelargonium hortorum L.H. Bailey). Plants were grown in a specialized hydroponic system with full strength Hoagland's No. 1 solution. RZT were initiated after a 7 day acclimation period and were held at the respective RZT continuously. Significant differences among the species were expected and noted for growth parameters of fresh wt., dry wt. of shoot and root, and elemental uptake. The 34C RZT, compared with 21C, reduced root length by 22, 51, and 57% for honey locust, tomato, and melon, respectively. P uptake rate dropped to 0 at 34C, as compared to 1.86 mg P/g root/day at 21C for melon. P uptake rate of the other crops was not affected by RZT.