bluuebunny/crossref_metadata_2025 huggingface dataset:
309 GENOMIC ANALYSIS OF TWO FUNGI CAUSING ANTHRACNOSE OF DOGWOOD (CORNUS SPECIES) IN THE EASTERN UNITED STATES
Authors: Trigiano R. N. , Caetano-Anollés G. , Bassam B. J. , Windham M. T.
Published: February 2019

DNA Amplification Fingerprinting (DAF) was used to characterize ten isolates of Discula destructiva Redlin and three isolates of an undescribed species of Discula, the causal organisms of dogwood (Cornus species) anthracnose. Isolates were obtained throughout the disease range in the eastern United States and DAF profiles generated with ten arbitrary oligonucleotide primers. Very few polymorphic loci (27/298) were detected between isolates of D. destructiva; whereas, a greater number were observed between and among the isolates of Discula species. Relationships among and between the two fungal groups were analyzed using PAUP and UPGMA and indicate that the genome of D. destructiva is highly conserved throughout the distribution. In contrast, isolates of Discula species exhibited greater variability. This suggests that D. destructive was recently introduced to the eastern United States.
310 IN SITU GENETIC COMPLEMENTATION OF FLOWER COLOR MUTATIONS VIA PARTICLE BOMBARDMENT
Authors: Griesbach R. J.
Published: February 2019

Genetic complementation was used to correct the albescent flower color mutation of the orchid Doritis pulcherrima. The Zea mays anthocyanin regulatory genes C 1 and B were introduced into the petal cells via particle bombardment. Anthocyanin pigmentation developed within the bombarded cells after 48 hours. This suggests that the albescent phenotype was the result of a defective regulatory gene(s) and not the result of a defective structural gene(s). Genetic complementation via particle bombardment requires considerably less time than via classical breeding and could be used on other species or with other genes.
312 FLUID STRESS RESPONSES OF YOUNG APPLE TREES ON 3 ROOTSTOCKS
Authors: Fernandez R.T. , McLean R.M. , Perry R.L. , Flore J.A.
Published: February 2019

`Jonnee' on M.9 EMLA, M.26 EMLA and Mark rootstocks were subjected to flooding for 2, 4, 8, 16 and 32 days duration. Recovery was monitored after each stress period until 28 days after the 32 day flood stress. The objectives were to determine growth and physiological adaptation of the three rootstocks to flooding. Gas exchange, root dynamics, leaf area and emergence, and shoot length were measured for each stress and recovery period. CO2 assimilation initially was increased for flooded treatments of Mark and M.9 EMLA up to 300% and 200% of controls until three days after flooding. After 4 days of flooding, CO2 assimilation decreased to 30% or less of controls for both rootstocks. No initial increase was seen for flooded M.26 EMLA, rather a steady decline until net respiration occurred. Root number was not affected until 32 days of flooding where all flooded treatments had fewer roots counted compared to controls. After release from flooding trees on Mark recovered root growth while M.9 EMLA and M.26 EMLA continued to decline in root numbers. Shoot system growth of flooded trees on M.26 EMLA was reduced first and to the greatest extent followed by Mark and then M.9 EMLA.
313 PERFORMANCE OF `STARKSPUR SUPREME' ON 15 APPLE ROOTSTOCKS OVER 10 YEARS AT 28 LOCATIONS IN THE NC-140 TRIAL
Authors: Ferree D.C.
Published: February 2019

In 1984 trees of `Starkspur Supreme Delicious' apple on 15 rootstocks were planted at 28 locations in North America according to guidelines established by The North Central Regional Cooperative Project (NC-140). The largest trees were on P.18, ANT.313, B.490 and seedling. Producing trees approximately 70% the size of seedling were rootstocks P.1 and M.7 EMLA while M.26 EMLA and C.6 were 50% the size of seedling. A group of rootstocks 30% the size of seedling or smaller were B.9, MAC.39, P.22, P.2, P.16. Rootstocks with high production efficiency were P.16, 8.9, P.22, P.2 and C.6. Rootstocks with low production efficiency similar to apple seedling were MAC.1, M.4., B.490, P.18 and ANT.313.
322 WHY DOES SOUR CHERRY (Prunus cerasus) PRODUCE SO MANY MORE FLOWERS THAN FRUITS?
Authors: Kahn A. , Iezzoni A.F. , Kalisz S. , Mulinix CA. , Delasalle V.
Published: February 2019

The number of flowers produced by sour cherry greatly exceeds the number of fruits developed. Two hypotheses to explain this disparity were investigated: (1) pollen may be limiting, and (2) a large flower display is important for pollinator attraction. Self-incompatibility, which is common in sour cherry, was considered. Fruit set, floral morphology, and flower density were measured on 18 sour cherry selections, both self-compatible and self-incompatible (SI), in the MSU sour cherry germplasm collection following open- and bulk-pollination. Although supplemental hand pollination resulted in a significant increase in fruit set, the final fruit set was still low (18% vs 14%) indicating that lack of pollination alone was insufficient to account for the low fruit set. The SI selections had significantly larger flower cups, pistil/petal size ratio, and more flowers/branch cross-sectional area suggesting that flower display may have an increased role in pollinator attraction in the SI selections. These results will be discussed in relation to 2 additional hypotheses: insufficient maternal resources and genetic factors resulting in pre- or post-zygotic selection.
325 FREEZE RESISTANCE OF STRAWBERRY FLOWERS IN THE PACIFIC NORTHWEST
Authors: Hummel Rita L. , Moore Patrick P.
Published: February 2019

Freezing resistance of strawberry flowers from `Benton', `Honeoye', `Hood', `Puget Beauty', `Rainier', `Redcrest', `Shuksan', `Sumas', `Totem', and WSU 1988 was measured in laboratory tests. Flowers with approximately 13 mm of pedicel attached were placed in test tubes containing 2 ml DI water. Tubes were immersed in an ethylene glycol bath, the temperature lowered to -1°C, and the flowers inoculated with crushed ice. The temperature was lowered to -1.5°C, held overnight then lowered 0.5°C every 2 hours. Samples were removed at 0.5°C intervals, thawed overnight at approximately 3°C and incubated 24 hours at room temperature and 100% RH. Freeze damage of styles and receptacle was determined by visual browning. Flower survival with no visible damage averaged 27% at -1.5, 13% at -2.0, 7% at -2.5, and 4% at -3.0°C. There was clonal variation in flower survival: 56% of `Hood' flowers survived -1.5 and 45% survived -2.0 while 5% of `Redcrest' and `Sumas' flowers survived these temperatures. Results seem to indicate that strawberry flower freeze resistance was due to freezing avoidance via supercooling.
331 ORGANIZATION OF PROCESSING TOMATO GERMPLASM BASED ON RAPD BANDING PATTERNS
Authors: Nienhuis James , dos Santos Joao B. , Skroch Paul , Tivang Jan
Published: February 2019

Genetic distance was calculated among 92 tomato, Lycopersicon esculentum, genotypes, which included open pollinated cultivars and commercial hybrids of both fresh market and processing types. Over 800 were screened, and 44 10-mer primers which had clear banding patterns and were polymorphic among cultivars were selected. From each of the primers an average of five polymorphic bands were classified for their presence or absence for each genotype. Genetic distance was calculated as the ratio of discordant to total bands scored. A multidimensional scaling (MDS) plot indicated that the processing cultivars, `UC82' derivatives and fresh market types generally formed separate clusters. Within groups, genetic distance corresponded to known pedigree relationships. The genetic distance between duplicate samples of 10 genotypes ranged from 0.01 to 0.05. The results of this study indicated that RAPDs provide a high degree of resolution for estimating genetic relationships among tomato cultivars.
332 GENETIC SIMILARITIES AMONG CHINESE VEGETABLE BRASSICAS USING RANDOM AMPLIFIED POLYMORPHIC DNA MARKERS
Authors: Ren Jianping , Lamboy Warren F. , McFerson lames R. , Kresovich Stephen , Ren Jianping
Published: February 2019

Fifty-two germplasm accessions of Chinese vegetable Brassicas were analyzed using 112 random amplified polymorphic DNA (RAPD) markers. The array of material examined spanned a wide range of morphological, geographic, and genetic diversity, and included 30 accessions of Brassica rapa (Chinese cabbage, pakchoi, turnip, broccoletto), 18 accessions of B. juncea (leaf, stem, and root mustards), and 4 accessions of B. oleracea ssp.alboglabra (Chinese kale). The RAPD markers unambiguously identified all 52 accessions. Net and Li genetic similarities were computed and used in UPGMA cluster analyses. Accessions and subspecies clustered into groups corresponding to the three species, but some accessions of some subspecies were most closely related to accessions belonging to another subspecies. Using genetic similarities, it was found that Chinese cabbage is more. likely to have been produced by hybridization of turnip and pakchoi, than as a selection from either turnip or pakchoi alone. RAPD markers provide a fast, efficient technique for diversity assessment that complements methods currently in use in genetic resources collections.
342 HEAT SHOCK AND SELECTIVE PRESSURE INCREASES Cucumis sativus SEEDLING TOLERANCE
Authors: Jennings Paul H.
Published: February 2019

We have previously shown that both temperature and chemical shocks are capable of inducing chilling tolerance in 24h germinated cucumber seedlings. Using a heat shock temperature of 50°C. it has been demonstrated that a 2 min treatment is most effective in inducing chilling tolerance as measured by root survival growth. However the induced chilling tolerance is transient and disappears if the heat shocked seedlings are held at 25°C for 12h before chilling at 2°C. Older seedlings (36h of germination) are more sensitive to chilling but are still capable of chilling tolerance induction by heat shock. Using chilling as a selective pressure, it is possible to increase chilling tolerance of 24h germinated seedlings.
355A COMPARISON OF REGIONAL CONSUMER PREFERENCES FOR PACKAGING OF NURSERY STOCK
Authors: Khatamian Houchang , Stevens Alan
Published: February 2019

During the Spring of 1992 a survey of over 2000 respondants was conducted as personal interviews at Flower/Garden Shows in Atlanta, Kansas City, Los Angeles, Philadelphia and Portland.

When asked how the plants you buy are packaged? Nine percent of the Los Angeles (LA) sample said they purchased trees as balled and burlapped (B & B) while over 40% of the consumers from the other regions purchased trees as B & B. Over 40% of all respondents purchased shrubs in “container”.

When asked how would you like to have landscape plants packaged? While only 31% of the LA sample chose to purchase trees as B & B, over 70% of the consumers from other regions preferred to buy in a B & B form. More than 50% of all respondents also preferred to purchase trees in “Container”. By a two to one margin consumers chose to purchase ornamental shrubs in “Container”. Regardless of the region of the country, “bare-root” and “plastic package” were least desired. About 1/2 of the respondents were couples, 80% owned their own homes, over 50% had an income of $25,000 to $75,000 and more than 75% did own plantings.
358 WOODY ORNAMENTAL TRIAL NETWORK IN QUEBEC
Authors: Richer-Leclerc C. , Rioux J.-A.
Published: February 2019

The “Réseau d'esssais des plantes ligneuses ornementales du Québec” (REPLOQ) is a research project initiated in 1982 with the mandate to elaborate, develop and coordinate a cooperative research project to evaluate the winter hardiness of ornamental plants. Systematic evaluation trials provided information on growth potential and hardiness of woody trees and shrubs evaluated over a five year period in the principal growing regions of Québec. Zonal range covered was 2 to 5b in the Canadian system. Adequate field testing is critical for new introductions and, since 1984, more than 400 species and cultivars have been introduced in 8 evaluation sites. Results were published on several forms: technical factsheets provide cultural and production recommendations for the species and cultivar evaluated in each climatic zone. Propagation methods as well as their potential for ornamental purpose were described. In the 1984 plantation, Malus baccata and Quercus macrocarpa showed a similar potential for acclimation, but Malus baccata could be produced advantageously in any area, while the production potential of Quercus macrocarpa was enhanced by the summer heat of the wannest region. In this group of plants, Acer saccharinum was the species with the greatest number of plants suffering winter damage and could not be grown without risk anywhere in the area studied. Acer platanoides was severely damaged in the coldest of the eight evaluation sites and should not be cultivated there.
361 IN VITRO CITRUS BREEDING FOR SCION IMPROVEMENT
Authors: Fo Francisco A. A. Mourão , Grosser Jude W. , Gmitter Frederick G.
Published: February 2019

Protoplast culture following polyethylene glycol (PEG)-induced fusion resulted in the regeneration of somatic hybrid plants from the following combinations: `Succari' sweet orange (C. sinensis L. Osbeck) + `Ponkan' mandarin (C. reticulata Blanco), `Succari' sweet orange + `Dancy' mandarin (C. reticulata), `Succari' sweet orange + `Page' tangelo [a sexual hybrid between `Minneola' tangelo (C. reticulata × C. paradisi Mcf.) × `Clementine' mandarin (C. reticulata)], `Valencia' sweet orange (C. sinensis) + `Page' tangelo. `Succari' and `Valencia' protoplasts were isolated -from ovule-derived embryogenic cell suspension cultures and from seedling leaves for the other parents. Somatic hybrid plants were Identified on the basis of leaf morphology and electrophoretic analysis of isozyme banding patterns. Root tip cell chromosome counting is being performed on all plants. Other putative somatic hybrids Include: `Succari' sweet orange + `Minneola' tangelo; `Succari' sweet orange + `Murcott' tangos (C. sinensis × C. reticulata); `Valencia' sweet orange + `Murcott' tangor; and `Valencia' sweet orange + `Dancy' mandarin. These plants may have direct cultivar potential, but there primary use will be for interploid hybridization with selected monoembryonic scions to produce improved seedless triploids.
362 PRODUCTION OF SEVEN NEW INTERGENERIC SOMATIC HYBRIDS FOR CITRUS ROOTSTOCK IMPROVEMENT
Authors: Fo Francisco A. A. Mourão , Grosser Jude W. , Gmitter Frederick G.
Published: February 2019

Protoplast culture following polyethylene glycol (PEG)-induced fusion resulted in the regeneration of somatic hybrid plants from the following combinations: `Succari' sweet orange (C. sinensis L. Osbeck) + Severinia disticha; `Hamlin' sweet orange (C. sinensisj + S. disticha: `Valencia' sweet orange (C. sinesis) + S. disticha; `Nova' tangelo (C. reticulata hybrid) + S. disticha; `Succari' sweet orange + S. buxifolia; `Nova' tangelo + Citropsis gilletiana; and `Succari' sweet orange + Atlantia ceylanica. `Succari', `Hamlin', `Valencia', and `Nova' protoplasts were Isolated from ovule-derived embryogenic callus and/or suspension cultures whereas protoplasts of S. disticha, S. buxifolia, C. gilletiana, and A. ceylanica were isolated from leaves of potted trees in a greenhouse. Plants were regenerated via somatic embryogenesis and somatic hybrids were identified on the basis of leaf morphology. Electrophoretic analysis of isozyme banding patterns and root tip chromosome counts are being performed. Somatic hybrids with S. disticha are apparently weak whereas the other somatic hybrid plants with S. buxifolia, C. gilletiana, and A. ceylanica exhibit adequate vigor. These are more examples that the the techique of protoplast fusion can be an important tool in overcoming barriers to hybridization of sexually incompatible species.
365 BIOSYSTEMATICAL CLASSIFICATION OF GENUS ROSA USING ISOZYME POLYMORPHISMS
Authors: Kim Young-ju , Byrne David H.
Published: February 2019

Isozyme analysis has been used for cultivar identification, but little has been done with the genus Rosa. One hundred and sixty rose accessions (species, cultivars, and hybrids) were characterized for isozyme phenotypes using starch gel electrophoresis. Six enzyme systems were stained on three electrode buffer systems. ACP, MDH, and 6PGD were run on morpholine citrate (pH 6.1) and histidine (pH 5.7), PGI and PGM were run on histidine (pH 5.7) and lithium borate (pH 8.3), and SKDH was run on morpholine citrate (PH 6.1) and lithium borate (PH 8.3). The most variable isozymes were MDH and 6PGD. MDH and 6PGD revealed 10 and 9 bands, respectively. This study showed that isozyme variability exists in roses and can be useful in their classification into species groups.
368 TESTING SPRAY CHEMICALS FOR PHYTOTOXICITY ON CITRUS
Authors: Albrigo L. Gene , Grosser Jude W.
Published: February 2019

In Florida, pesticides, nutritional and growth regulators are often sprayed in tank mixes to reduce sprayer use. Many individual spray components are phytotoxic and result in spray burns in combination or if applied with adjuvants. The toxicity level of standard spray materials is not known and new product testing for phytotoxicity is not routine. Three tests were developed to allow testing of cellular and whole fruit susceptibility to spray chemicals. Cell suspension cultures initiated from `nucellar derived' embryonic callus of `Hamlin' sweet orange were grown in log phase for 2 weeks with various levels of test chemicals. Fresh weight increase was measured. Peel disks of orange or grapefruit were grown for 4 weeks on solid media. Color changes and callus growth were used to evaluate phytotoxicity. Dilute sprays and droplet applications to on-tree-fruit were used to evaluate individual and combinations of chemicals with and without spray adjuvants. The 3 tests combined effectively demonstrated levels of phytotoxicity and are useful for testing new citrus production chemicals.
371 TRITERPENES IN GRAPEFRUIT EPICUTICULAR WAX
Authors: Nordby Harold E. , McDonald Roy E.
Published: February 2019

The purpose of this study was to identify compounds in the wax of fruit obtained from different canopy positions for possible relationships to chilling injury development. Both exterior and interior canopy grapefruit wax extracts were separated by thin layer chromatography into four lipid classes: alkanes, aldehydes, linear alcohols and triterpenes. The triterpene class consisted of three subclasses: triterpenols (TOH), triterpenones (TON) and triterpenol acetates (TAC). Each triterpene subclass was analyzed by gas chromatography and their component structures estimated by comparison of retention times with authentic standards. Derivatives were prepared for each subclass: TOH were oxidized to TON, TON were reduced to TOH, and TAC hydrolyzed to TOH. Structures were verified by gas chromatography-mass spectra of components and their derivatives as well as spectra of authentic standards and their derivatives. There was a higher level of TON in interior compared with external canopy fruit. The three major TON were a amyrone, β amyrone and friedelin. α amyrone was also shown to be a major component of the wax of `Valencia' orange, a fruit not subject to chilling injury when produced in Florida
372 GRAPEFRUIT CANOPY POSITION AFFECTS CHILLING TOLERANCE AND FLAVEDO LIPID COMPOSITION
Authors: McCollum T.G. , McDonald R.E. , Nordby H.E.
Published: February 2019

The objective of this work was to determine if lipid composition of grape fruit flavedo tissue differed with canopy position and if changes in flavedo lipid composition occurred during the development of chilling injury (CI). `Marsh grapefruit were harvested from interior (IN) and exterior (EX) canopy positions and stored at 5C for up to 8 weeks. During storage, EX fruit developed severe CI, whereas IN fruit developed only trace CI. Electrolyte leakage from EX fruit flavedo increased during storage and significantly greater than from IN fruit At the time of harvest, flavedo oleate and linoleate, on a μg % basis, were higher in IN than in EX fruit During storage at 5C, the amount of oleate in IN fruit flavedo decreased and was similar to EX fruit after 4 weeks at 5C. The relative amount of flavedo linoleate decreased in IN fruit and increased in EX fruit during storage at 5C and following 8 weeks at 5C was higher in EX fruit than in IN fruit At the time of harvest, total lipid P in flavedo was higher in IN fruit than in EX fruit; during storage the amount of flavedo lipid P in IN fruit decreased and was equivalent to EX fruit following 8 weeks at 5C. Total sterols in flavedo did not differ with canopy position and remained constant during storage.
385 SUMMER FORCING AND HARVEST PRESSURES AFFECT ASPARAGUS SPEAR PRODUCTION IN COASTAL SOUTH CAROLINA
Authors: Dufault Robert J.
Published: February 2019

The purpose of this 5-year study was to investigate the effects of different cutting pressures (3, 6, 9, or 12 spears/plant) on aspargus harvested in spring or forced in July or August. `UC 157 F1' seedlings were transplanted in 1987 and clear-cut harvested1 from 1989 to 1993. Forcing plots were not spring-harvested, but allowed to produce fern in spring. Summer spear production was forced by mowing all fern and stalks at ground level on the 1st day of each forcing month. Harvested spears were graded and harvesting ended if either 1) 80% of the plants within each plot reached cutting pressure treatment levels or 2) 30 harvests had elapsed: Yields in 1989 were highest and equivalent for the following: spring-harvested at 9 to 12 spears/plant, July-forced at 12 spears/plant, or August-forced at 9 spears/plant. In 1991, forcing in July at 12 spears/plant yielded more than harvesting in spring or August at all cutting pressures. In 1993, August forcing at 9 to 12 spears/plant produced the highest yields with significantly lower yields from July forcing at all cutting pressures. The 1993 spring yields were very poor due to plant death. Stand losses from 1988 to 1993 were 60%, 40%, and 30% in spring, July and August plots, respectively. Cumulative yields over the 5-year-period were greatest and equivalent for July forcing at 12 spears/plant and August forcing at 9 to 12 spears/plant.
386 MECHANICAL ASPARAGUS HARVESTING STATUS--WORLDWIDE
Authors: Marshall Dale E.
Published: February 2019

For over 86 years producers, processors, engineers, and equipment manufacturers have attempted to mechanize the harvest of asparagus. Over 60 U.S. patents have been issued. Probably the most sophisticated harvester tested was started in 1987 by Edgells Birdseye, Cowra, Australia. After successful field tests of the 3-row, selective (fiber optic), harvester for flat-bed green asparagus used in canning, 3 more were built at a cost of $US 4.5 million, and harvested 500 acres until 1991 when the company ceased canning. Recovery was 30 to 80% with 50% being typical. Wollogong University in Australia is now researching a selective (fiber optic), harvester for flat-bed green asparagus. It utilizes multiple side-by-side 3 in. wide by 24 in. dia. rubber gripper discs which rotate at ground speed. No harvester prototype has been commercially acceptable to the asparagus industry due to poor selectivity, low overall recovery (low yield relative to hand harvest), mechanical damage to spears, low field capacity per harvester, or overall harvesting costs that exceed those for hand harvesting. The reality may be that asparagus production will cease in the traditional geographical areas where growing costs and labor costs are high, although niche fresh markets may help some growers survive.
388 EFFECTS OF DEHAULMING ON CANOPY GROWTH AND TUBER YIELD OF `YUKON GOLD'
Authors: Okeyo James A. , Morse Ronald D.
Published: February 2019

Seed tubers of `Yukon Gold' (Solanum tuberosum L.) exhibit strong apical dominance, resulting in relatively poor stem emergence. Cutting seed tubers to overcome apical dominance in `Yukon Gold' results in irregular, uneven stem emergence. In 1992 and 1993, experiments were conducted to evaluate the effects of dehaulming (excising stems to ground level after field emergence) whole, cross- and longitudinal-cut seed tubers of `Yukon Gold' on canopy growth and tuber yield. For all seed piece types, dehaulming during the first week of field emergence produced uniform plant stands and increased yields of U.S. no. 1 tubers by 16 and 42% and large tubers (> 6.4 cm dia.) by 340 and 64% in 1992 and 1993, respectively. Our data indicate that tuber bulking rate was increased by dehaulming. The possible causes and implications of increased tuber bulking rates in dehaulmed potato plants are discussed.
394 HIGH-AND-LOW RESOLUTION ANALYSIS OF GROWTH IN SNAPDRAGON (Antirrhinum majus cv. Giant Tetra) AND ZINNIA (Zinnia elegens cv. Pompom)
Authors: Neily Will , Hicklenton Peter R. , Kristie David N.
Published: February 2019

Stem elongation rates (SER) in snapdragon end zinnia were recorded in 3 DIF regimes (+5, -5, and 0; Daily average: 18C) using both high resolution (linear transducers), and low resolution techniques. Three developmental stages were chosen for study: Stage 1 was vegetative growth, preceding the formation of a flower bud. Stage 2 was the period from bud formation to preliminary expansion. Stage 3 was the period just before anthesis.

Low resolution measurements showed a decrease in snapdragon height in response to a negative DIF. A negative DIF was less effective in reducing zinnia height especially after the third developmental stage. Final plant height for both species was not affected by placing plants in the 3 DIF regimes for 1 week during the growth cycle.

Snapdragon and zinnia displayed unique diurnal SER patterns. Snapdragon showed a large peak in SER at the start of the dark period followed by a gradual decline. SER increased again during the light period. Most growth in vegetative zinnias occurred around the light/dark transition. This peak growth tended to shift to the night period as buds were formed and flowering proceeded. High resolution measurements revealed a reduction in SER for both species at negative DIP; greatest decreases occurred during the night.

DIF exerts an influence on diurnal SER in both snapdragon and zinnia, despite well defined differences in SER patterns. Negative DIF suppresses the SER of both species at all 3 developmental stages, but must be applied consistently in order to produce significant differences in final plant height.
395 FAR-RED LIGHT REVERSES GROWTH-REGULATING ACTION OF NEGATIVE DIF
Authors: Roberts Glenn L. , Tsujita M.J. , Blom T.
Published: February 2019

Lilium hybrid `Enchantment' bulbs were grown at a -4C or +4C DIF in growth chambers set at 100 μmolm-2s-1 PPF, with or without one hour red or far-red light extensions to each end of an eight hour photoperiod. Far-red light extensions completely reversed the growth regulating effect of negative DIF temperatures. Negative DIF treated plants given far-red extensions were 43% taller than plants with no light extensions and 15% taller than plants given red light extensions. Prephotoperiod red or far-red extensions did not increase stem elongation over similar plants given no light extension, but postphotoperiod far-red extension stimulated stem elongation up to 52%. Red light extensions caused a less dramatic increase than far-red in some cases. The phenomenon is not photoperiodic since lengthening the photoperiod to ten hours caused no appreciable increase in stem elongation. Total 24 hour accumulated energy also proved not to be involved in the process.
397 LIFE CYCLE AND FLORAL INITIATION OF ORNAMENTAL ALLIUM SPECIES
Authors: Kamenetsky Rina , Blaustein Jacob
Published: February 2019

The annual life cycle and development of the monocarpic shoot of some ornamental Allium species from Central Asia and the Mediterranean area have been followed from the time of meristem dome initiation in the axil of a mother plant leaf, through formation of scale, leaf and flower primordia. There are three periods of meristem activity from apex initiation to flower formation. Detailed analysis of inflorescence development has been carried out by Scanning Electronic Microscope (SEM). The life span of the Allium monocarpic shoot can be as long as 18 months. Climatic variations between Central Asian and Mediterranean areas lead to differences in the time of leaf sprout and flowering of species from the same taxonomic group. The principal mechanism of floral initiation is similar for species from both areas. Knowledge of the structure and development of the shoot will be useful for improvement of an optimal program of ornamental Allium cultivation.
402 PB 007 THE DEVELOPMENT OF A MANUAL OF SUSTAINABLE TREES AND SHRUBS FOR SOUTHERN NEW ENGLAND
Authors: Maynard Brian K. , Casagrand Richard A. , Clark Roberta A.
Published: February 2019

The development of a manual and database of recommended trees and shrubs was undertaken as a collaborative effort of the University of Rhode Island, University of Massachusetts Cooperative Extension and regional nursery stock producers. Initial selection was limited to species exhibiting few or no pest and disease problems, and without site requirements or other factors that could lead to higher maintenance in established landscapes. The preliminary list was reviewed by more than 30 representatives of regional arboreta, universities, growers, landscapers and arborists. In its third printing, the manual includes lists of recommended species, excluded species (with explanations), species for particular situations, and a guide to sustainable landscaping. The consortium brought together to create the manual is also developing a point-of-sale logo and poster to advertise recommended plant species and sustainable landscaping. This project has raised important issues about the interface between the industry and academia in promoting new and less readily available plants.

The database is maintained in FileMaker Pro (MAC), and will be made available in several DOS or MAC formats to those supplying a unformatted3.5” DD or HD disk.
409 PB 048 INCREASED ENROLLMENT AND MULTIPLE ACADEMIC PROGRAM SITES TYPIFY FLORIDA'S ENVIRONMENTAL HORTICULTURE UNDERGRADUATE PROGRAMS
Authors: McConnell Dennis B. , Fitzpatrick George F.
Published: February 2019

Environmental Horticulture-undergraduate student enrollment at the University of Florida (UF) Gainesville campus decreased from 88 students in 1980/81 to 34 students in 1989/90. In 1983/84 a resident instruction program in Environmental Horticulture for placebound students was initiated by UF at the Ft. Lauderdale Research and Education Center. Enrollment rapidly increased from 6 students in 1984 to 67 students in 1989, with an average student credit load of 3.5 credits per semester. In 1990/91 increased student recruiting efforts were made with a common undergraduate handbook, recruiting brochure, and guides for academic program specializations developed to serve both locations. These efforts and others have increased enrollment at both sites. Currently there are 73 students in the Environmental Horticulture program at Gainesville and 87 students at Ft. Lauderdale. Students may begin their academic program at one location and transfer to the other site to complete their undergraduate requirements for the Bachelor of Science degree. A Bachelor of Science program in Environmental Horticulture will be initiated in the fall of 1994 in Milton, Florida, a small community in northwest Florida.
412 PB 057 MODEL FOOD WASTE PROCESSING PILOT FACILITY SITE TO DETEMINE MONITORING STANDARDS FOR THE COMMERCIAL OPERATION OF FOOD WASTE COMPOSTING SITES IN ILLINOIS
Authors: Williams David , Jaminski John , Bumpus Pat
Published: February 2019

Food wastes were collected daily Monday through Saturday with approximately 25 tons of food waste delivered to the composting site each week. Collections sites included restaurants, super markets and a hospital. All food wastes were collected behind the counter to reduce paper and other extraneous materials. Food wastes were mixed with bulking agents in a ratio of 1 part leaves, 1 part woodchips to 1 part food waste by volume. Daily a bed of leaves and wood chips was prepared and covered with food waste, in rum the food wastes were capped with a mixture of wood chips and leaves to form a windrow. The windrow was turned three times a week with a scat style commercial compost turner. Oxygen content and temperature of the windrow were recorded daily. C:N ratio, pH, soluble nitrogen and volatile organic acids were determined monthly. At the end of the composting process, 90 days, Ni, Cd, Fe, Pb, Cr, Ar and Se levels in the compost were not present at toxic levels. Finished compost rested negative for salmonella and Fecal coliform pathogens.
422 PB 127 PERFORMANCE OF NITRATE -N FERTILIZERS ON BERMUDA GRASS IN HUMID TROPICAL CONDITIONS
Authors: Hamilton Mark D. , Cruz Frank J. , McConnell James
Published: February 2019

The performance and leaching behavior of six nitrogen fertilizers on bermuda grass were studied under humid tropical conditions. The grass was established in 20 × 36 cm pots filled with 8 cm pea gravel and 28 cm of silica sand. Ammonium nitrate was applied to the turf at monthly rates between 0.25 and 6 lb/1000ft2. Performance was gauged by clipping dry weights, image analysis for greeness, and visual ratings. Leachates were checked for nitrate levels. A rate of 2 lbs/1000ft2 produced quality turf while yielding a minimum of nitrate leaching. Rates of 6 and 4 lb./1000ft2/mo. resulted in the highest readings without an increase in quality. Rates less than 2lb/1000ft2 had leachate nitrate less than 9 ppm but produced turf of unacceptable quality.

Nutralene, Nitroform, sulfur coated urea, IBDU, and AN were applied at a rate of 2 lb./1000ft/mo. The slow-release forms were applied as a 3 month dose. Performance was determined as above and nitrate leaching was monitored by weekly collections. Nutralene, SCU and Nitroform had peak nitrate levels 2 weeks after application, IBDU had peak nitrate levels after 4 weeks. Turf quality diminished at 6 weeks.
423 PB 130 FERTILIZER FORMULATIONS AFFECT LOWBUSH BLUEBERRY LEAF NUTRIENT CONCENTRATIONS
Authors: Smagula John M. , Yarborough David
Published: February 2019

Experimental plots in a commercial lowbush blueberry (Vaccinium angustifolium Ait.) field deficient in N and P received preemergent 33.6 and 67.2 kg/ha rates of N (urea), P (23 % phosphoric acid), N+P (DAP), N+P+K (S-10-5) or N+P+K (fish hydrolysate, 2-4-2). A RCB design with eight replications of 12 treatments was used. Fertilizer containing N alone was as effective in raising N leaf concentrations, as those containing N and P. However, leaf phosphorus concentrations were raised more by fertilizer providing N and P than only P. Fish hydrolysate fertilizer was as effective as 5-10-5 in raising leaf N, P and K concentrations in prune and crop year leaf samples.
425 PB 136 FERTILIZATION AND IRRIGATION AFFECT AZALEA GROWTH
Authors: Yeager Thomas H.
Published: February 2019

Multiple branched liners of `Mrs. G. G. Gerbing' azaleas (Rhododendron L.) were greenhouse-grown for 16 weeks in 3-liter containers with a common nursery medium. The growth medium of each plant was amended with either 0.5, 1.5, or 2.5 g N from Osmocote 14N-6P-11.6K and irrigated with either 920 ml water twice a week or evapo-transpiration (ET) plus 10%, 30%, or 50%. Shoot dry weights (35 and 35 g, respectively) for plants irrigated with ET plus 30% or 50% and fertilized with 1.5 g of N were larger than plants fertilized with 0.5 or 2.5 g N and irrigated with ET plus 10%, 30%, or 50%. Shoot dry weights of plants irrigated with ET plus 30% or 50% were similar to plants irrigated with 920 ml twice a week when plants received 1.5 g N. Plants that received 920 ml twice a week and 2.5 g N had larger shoot dry weights than plants irrigated with ET plus 10%, 30%, or 50% and fertilized with 2.5 g N. Shoot dry weights increased from 17 to 46 g for the 0.5 and 2.5 g N treatments, respectively, when plants were irrigated with 920 ml.
429 PB 168 NET AMMONIUM UPTAKE BY ROOTS OF FIELD-GROWN PEACH TREES IS INVERSELY RELATED TO TREE NITROGEN STATUS
Authors: Niederholzer F.J.A. , Weinbaum S.A.
Published: February 2019

The relationship between nitrogen (N) status and N uptake capacity has not been assessed in fruit trees. Determination of root uptake capacity by depletion of unlabeled N from external solution is less costly than methods using 15N, but is reportedly not suited for excised root studies due to reductions in uptake rates with time (Pearcy, R.W. et al. (eds). 1989. Plant Physiological Ecology, p. 195. Chapman and Hall. New York.). We tested two hypotheses: I) excised peach root NH4+ uptake rates are constant over several hours exposure to NH4+ solution and 2) excised peach root NH4+ uptake rates are negatively correlated with tree N status. Mature, N deficient, field grown `O'Henry' trees on `Lovell' peach (Prunus persica L. Batch.) rootstocks and growing in Winters, CA received (NH4)2SO4 at a rate of 200 kg N/ha on September 29, 1993. An equal number of control trees received no N fertilizer. Foliar N deficiency symptoms of fertilized trees disappeared within 3 weeks of fertilization. On Nov. 9, 1993 (prior to leaf fall), excised roots were obtained from two fertilized and two unfertilized trees. Root NH4+ accumulation rates per unit root dry weight or root length were constant over 5 hours of exposure to 70 μM NH4+ (initial concentration) for both fertilized and unfertilized trees. Unfertilized tree root NH4+ uptake rates were significantly greater than those of fertilized trees on a root dry weight or length basis. Excised root NH4+ uptake may prove to be a sensitive index of fruit tree N status.
432 PB 177 ADDITIONAL SYMPTOMS OF BORON DEFICIENCY IDENTIFIED IN ALMOND
Authors: Connell Joseph H. , Uriu K. , Micke W. , Uyemoto J.
Published: February 2019

Boron(B) deficiency in almond (Prunus dulcis Mill.) is characterized by leaf tip scorch, leaf drop, twig dieback, brown gummy areas in the endocarp, and embryo abortion followed by nut drop in May. Additional symptoms revealed by our work include failure of flowers to set nuts and lateral bud drop. Lack of production in part or in all of the free canopy causes spurs to elongate leading to a “willow twig” symptom on the small fruitwood. This can be confused with the nonproductive “bull” syndrome or with virus bud failure (ABFV or PRSV). Comparative leaf, pericarp, or kernel analysis in May gave a better indication of low B than did leaf analysis in August. In August, analyzing the hulls (mesocarp and exocarp) gave better separation between deficient and adequate trees than did leaf, kernel, or shell analysis. B critical levels for almond leaves should be re-evaluated since deficiency symptoms occur at currently accepted “adequate” levels.
440 PB 241 FIELD PERFORMANCE OF DRYLAND GUAYULE GENOTYPES IN SOUTH TEXAS
Authors: Latigo G.V. , Smart J.R. , Kuti J.O.
Published: February 2019

Guayule (Parthenium argentatum Gray) is a promising alternative to rubber tree (Hevea brasiliensis Muell. Arg.) for production of natural rubber in semiarid regions. For guayule to be commercially viable, substantial improvement in rubber yield is needed. Field studies were conducted on a dryland site in south Texas to evaluate productivity of selected guayule genotypes from Arizona and California. After 34 months of growth, no significant differences (p= 0.05) were found among the genotypes for rubber yield. However, rubber yields for most of the genotypes increased more than 3-fold from that of last year (1992) yields. Genotype `N9-5' from Arizona had the highest yield (1,239 kg ha-1). Survivability of the genotypes has progressively decreased over the years and survival rates for this year (1993) ranged from 48-25%.
449 PS 288 EVALUATION OF SWEETPOTATO GERMPLASM FOR RESISTANCE TO THE SWEETPOTATO WEEVIL
Authors: Thompson Paul G. , Schneider John C. , Graves Boyett
Published: February 2019

One hundred one accessions from the U.S. germplasm collection were evaluated in field trials for sweetpotato weevil resistance. Weevils were collected from 4 separate Mississippi locations during the winter of 1992-93. They were increased in culture and 6 adult females and 6 males were applied to the crown of each plant percentage of uninjured storage roots ranged from 53 to 99. The most highly resistant control, Regal, had 79% and the most susceptible, Centennial, 60% uninjured roots. Uninjured root numbers ranged from 0.03 to 3.82 per plant. Regal had 2.1 and Centennial 1.88 uninjured roots per plant. Seventy-five accessions produced higher percentages of uninjured roots than Regal. However, 48 of those accessions produced less than one root per plant and previous results indicated that estimates with low storage root numbers lack precision. Fourteen accessions produced as many or more roots than Regal and also higher percentages and numbers of uninjured roots.
453 PB 300 RUST REACTION TYPES AND LEAF PUBESCENCE IN DRY BEAN LINES FROM MALAWI
Authors: Bokosi J. M. , Coyne D. P. , Steadman J. R. , O'Keefe D.
Published: February 2019

Twenty-four diverse bean (Phaseolus vulgaris L.) lines (Malawi) derived from single plant selections from landraces were evaluated for bean rust (Uromyces appendiculatus) resistance and leaf pubescence in the greenhouse (NE). A randomized complete block design was used. Each line was inoculated on the primary leaf (35-60% leaf expansion) 7 days after planting and on the 4th trifoliolate leaf (10-20% leaf expansion) with two rust strains, D82VC74fh(Dominican Republic) and A88TI-20a (Tanzania). Rust uredinia size was recorded on the 14th day after inoculation. Three lines, `Nasaka', 16-6, and `Kamtsilo' had specific resistance (SR) to one or the other of the strains but none to both strains. Many lines were susceptible on the primary leaves but had moderate to highly resistant reactions on the 4th trifoliolate leaves indicating adult plant resistance (APR). APR was the main type of rust resistance for most of these 24 lines. Many of these APR lines were glabrous. No association was observed between APR and pubescence.
456 PB 329 REPRODUCTIVE BIOLOGY OF VIGNA CARACALLA (=PHASEOLUS CARACALLA)
Authors: Anderson Neil O. , Ascher Peter D.
Published: February 2019

The snail flower, V. caracalla, was a popular ornamental flowering plant in conservatories at the turn of the century. It's popularity was due, in part, to its showy, orchid-like flowers whose fragrance rivals Stephanotis The indeterminate, vining growth habit can produce plants > 20 feet in height. V. caracalla is of interest for genetic and evolution studies since it is an ancestral species and possesses diagnostic traits of both Phaseolus (coiled style, leaf length/width ratios) and Vigna (> 10 seeds/ovary, long seed pods). However, its reproductive biology and use as an intergeneric hybrid bridge is unknown. Plants were examined for male and female fertility, self compatibility, and cross compatibility. Genotypes were self-incompatible; with one exception, self seed set did not occur following artificial manipulation. Selfed flowers abscised within 1-2 days post-pollination. Accessions were cross-compatible and highly fertile. To date, intergeneric hybridizations performed with P. coccineus --theancestral Phaseolus --have aborted following fertilization.
458 PB 335 HERITABILITY ESTIMATES OF POWDERY MILDEW RESISTANCE IN A TWO-YEAR-OLD LILAC POPULATION
Authors: Johnson Randy
Published: February 2019

Twenty-one control-pollinated families of lilac (Syringa) were evaluated for the presence of powdery mildew (Microsphaera syringae). Because disease developed first in the lower portions of the plant and moved up, infection was scored from the lowest (1 =only on the lower quarter of the plant) to the highest quarter of the plant (4=present on all quarters of the plant). Family means for mildew score ranged from 2.3 to 3.8 and averaged 3.1, and for height ranged from 59 to 107 cm and averaged 82 cm. Narrow sense and broad sense he&abilities were estimated to be 0.08 and 0.27 respectively. Since any selections will be clonal, this relatively large proportion of non-additive variance can be fully utilized. There was a significant positive correlation between family means of height and mildew score (0.58); however, the phenotypic correlation between height and mildew score was -0.11. For this population the genetic correlation between mildew infection and height was positive (the taller families on average had mildew farther up the plant), but the environmental correlation was negative.
459 PB 338 SELF INCOMPATIBILITY (SI) IN DISTYLOUS LYTHRUM ALATUM, WINGED LOOSESTRIFE
Authors: Anderson Neil O. , Ascher Peter D.
Published: February 2019

Lythrum species (Lythraceae), found both in the Old and New Worlds, possess heterostyly (macroscopic differences in anther and style lengths). SI is linked with heterostyly in tristylous L. salicaria, allowing for visual identification of compatibility relationships. Five Minnesota populations of distylous L. alatum (short & long styles/anthers) were examined for fertility and linkage between distyly and SI. Pollen was not inhibited from germination, stigmatic penetration, or stylar growth in compatible crosses. Average cross-compatible seed set for each population was 7-33 seeds/capsule for short- and 27-69 for long-styled plants. With the exception of the Iron Horse Prairie population, there were no significant differences in mean seed set/capsule between genotypes, style morphs, or their interaction for compatible crosses. Zero self seed set predominated, although 0.8±1.8 seeds/capsule were produced by short styles and 1.2 ±2.3 by long styles from Iron Horse Prairie. In those individuals that were SI, pollen tube growth was inhibited following self pollinations.
474 PB 370 EFFECT OF PRIOR INOCULATION OF LEAVES OF DRY BEANS WITH THE COMMON BLIGHT PATHOGEN ON THE DISEASE REACTION OF SUBSEQUENTLY INOCULATED LEAVES AND PODS AND TEE REACTION OF DETACHED VERSUS ATTACHED PODS
Authors: Ariyarathne H. M. , Coyne D. P. , Vidaver Anne K. , Eskridge K. M.
Published: February 2019

Breeding for resistance is a major method to control the common bacterial blight disease caused by Xanthomonas campestris pv phaseoli (Xcp) in common bean (Phaseolus vulgaris L.). It is necessary to determine if prior inoculation of the first trifoliolate leaf with Xcp will influence the subsequent reaction in other plant parts through induced resistance. It is difficult to get an accurate estimate of heritability (H) of disease reaction in pods since environment (E) greatly affects the H estimate if flowering occurs over extended time periods. Thus the disease reaction in attached pods vs detached pods was also observed. Four common bean lines were used in a split plot design with two replications. Two bacterial strains were used for inoculations. Two growth chambers were used as replicates. The first trifoliolate leaves, later developed leaves and attached pods and detached pods were inoculated. No effect of prior inoculation on the disease reactions of subsequently inoculated leaves and pods were observed indicating that the different plant parts can be inoculated at different times. Detached and attached pods showed similar disease symptoms. The former may be used to reduce E variance and improve H estimates.
477 PB 379 GENETIC DIVERSITY AMONG BOTANICAL VARIETIES OF CUCUMBER (Cucumis sativus L.)
Authors: Staub J. E. , Liu Jinsheng
Published: February 2019

The genetic diversity among Cucumis sativus var. sativus (commercial cucumber) (1), var. anatolicus (2), var. cilicicus (3), var. europaeus (4), var. falcatus (5), var. indo-europaeus (6), var. irano-turanieus (7), var. izmir (8), var. sikkimensis (9), var. squamosus (10), var. testudaceus (11), var. tuberculatus (12), var. vulgatus (13), and var. hardwickii (14) were assessed using 7 morphological characteristics and 9 isozyme loci to determine their potential use for plant improvement. Results of morphological comparison below. Isozyme and morphological analysis did not result in similar dendrogram depictions. Varieties 13 and 3 might have potential in plant improvement based on yield performance.