bluuebunny/crossref_metadata_2025 huggingface dataset:
Phasic Development of Fagus sylvatica based on 240 Years of Continuous Tree-height Observations
Authors: Moore F.D. , Nath S.R. , Wang Y-C
Published: February 2019

Duration of growth is dependent on morphological events or changes in growth rate. It is the latter that is associated with phasic development. The most productive phase of plant growth is the linear or constant rate phase, primarily because it endures longer than the exponential phase. The purpose of our research was to objectively determine the true tree-height growth pattern, the linear and stationary phases of height growth, and to mathematically derive the maximum slope (maximum growth rate) of the growth curve, its location (inflection point), and the maximum slope of the logarithmic form (maximum relative growth rate) of the growth curve. The data were composed of 333 tree-height records covering 240 years from 200 beechwoods in the U.K. Height-age data were fitted using a splined function (S) and the Chapman-Richards function (CR). The growth curve and critical points on the curve were derived from the CR model. The linear phase began when trees were 9 and lasted 43 years. However, the stationary phase did not begin until age 162. Anecdotal evidence suggests that very little fruiting occurs before age 50. Based on derived critical points and anticipated source-sink dynamics, the reproductive stage should have taken place during the progressive “deceleration phase” when trees were between 31 (location of the maximum slope, also inflection point) and 162 (from quadratic root). The linear phase ended at 52 years, (coinciding with minimum acceleration) and may prove a more accurate estimate than 31. Maximum slope was 1.2 m per year occurring at age 31. Maximum slope of the log curve was 0.14 m·m–1 per year. The advantage of the CR function and the importance of the derived quantities and growth phases will be discussed.
Treatments to Encourage Earlier Dormancy in Apple
Authors: Stover E.W. , Fargione M.J. , Iungerman K.A. , Stiles W.C.
Published: February 2019

Active growth in late Fall 1993, followed by very low temperatures in November, resulted in widespread loss of scaffolds and leaders of `McIntosh' in the Champlain Valley. Treatments to encourage earlier dormancy are being investigated to address this problem in future seasons. Initial studies showed that 39 mm CuEDTA or 16 mm CuEDTA + 0.25% ultrafine spray oil (sprayed to drip) resulted in 3–4 weeks earlier leaf drop of `Empire' in the Mid-Hudson Valley. Evaluation of cold-hardiness, measured as electrolyte leakage after controlled freezing in a Tenney chamber, indicated greater cold-hardiness from these treatments in early December without reducing mid-winter hardiness. CuEDTA treatments ranging from 4–32 mm, all with 0.25% ultrafine spray oil, were applied to fifth leaf `Marshall McIntosh' on M.9/MM.111 interstems in the Champlain Valley on 12 Oct. 1995. Defoliation was accelerated with each increase in rate examined in this study. The highest rate again advanced defoliation 3–4 weeks compared to controls and increased cold-hardiness on 1 Dec. 19/95 as measured though electrolyte leakage. Evaluation of cold-hardiness in shoots collected on 8 Feb. 1996 showed no significant difference between electrolyte leakage from controls and trees treated with CuEDTA.
Effect of Preplant Fertilization, Annual Fertilization, Irrigation, and Fertigation on `Empire' Apple Fruit Size and Yield
Authors: Robinson Terence L. , Stiles Warren C
Published: February 2019

A field experiment was established in 1992 with `Empire' apple trees on either M.7 or M.9 rootstock. Preplant fertilization with NPKB plus lime compared to the lime only control did not increase tree growth during the first 4 years, but did increase cumulative yield (10%) and average fruit size (7%). The addition of annual applications of ground-applied NKB after planting increased total shoot growth 17%, as well as yield (26%) and fruit size (14%) compared to the lime only control. Trickle irrigation significantly increased trunk cross-sectional area (17%), shoot growth (16%), yield (18%), fruit size (5%), and yield efficiency (7%). The interaction of ground fertilization and trickle irrigation showed that trickle irrigation increased the benefits of ground applied fertilizers. Without trickle irrigation, ground-applied fertilizers increased shoot growth only 6% and yield 14% compared to the unfertilized controls, but, with the addition of trickle irrigation, the ground-applied fertilizers increased shoot growth 21% and yield 21% over the irrigated but unfertilized control. Ground fertilization increased yield efficiency and fruit size by the percentage by whether or not trickle irrigation was present. Fertigation gave similar results as the trickle plus ground fertilizer treatment on tree growth, yield, fruit size, and yield efficiency. Our results indicate that trickle irrigation in the eastern United States can improve tree growth, yield, and fruit size in the first few years after planting. The addition of ground-applied fertilizer or fertigation can improve tree performance even more. However, in the humid New York climate, there does not appear to be a significant benefit from injecting the fertilizer into the trickle water compared to applying the fertilizer on the ground.
Differences in Flower and Spur Characteristics of Apple Cultivars
Authors: Ferree D.C. , Schupp J.R. , Tustin D.S. , Cashmore W.
Published: February 2019

Flower and spur characteristics of eight apple cultivars were determined at bloom and following cell division and related to fruit growth over the season. Flower number per spur was higher in `Jonagold', `Fiesta', `Southern Snap', `Royal Gala', than in `Red Chief Delicious', `Pacific Rose' and `Fuji', and the latter three cultivars also had the lowest total flower dry weight per spur. Generally, pedicel length of the king flower was shorter than the lateral, with `Fuji' having the longest king flower pedicel and `Red Chief' and `Pacific Rose' the shortest. At full bloom, `Jonagold' and `Fiesta' had the most leaves/spur, followed by `Fuji', `Southern Snap', `Royal Gala', `Pacific Rose', with `Red Chief' having fewer leaves/spur than all other cultivars. Leaf area/spur was highest in `Jonagold', `Fiesta', `Royal Gala', and `Fuji', followed by `Southern Snap', with `Red Chief' and `Pacific Rose' having lower leaf areas and fruit set than all other cultivars. At the end of cell division, `Fuji' and `Jonagold' had the highest leaf area per spur and `Fuji' and `Royal Gala' the highest bourse leaf area. `Braeburn' and `Red Chief' had lower bourse leaf areas than all other cultivars. `Royal Gala', `Southern Snap', and `Fuji' had the longest bourse shoots and `Red Chief' the shortest.
Comparison of Soybean Oil and Ammonium Thiosulfate for Peach Bloom Thinning in a Short Bloom Duration Year
Authors: Olien William C.
Published: February 2019

Dormant application of soybean oil formulations (SBO) effectively thin peach flower buds and delay bloom. Alternatively, thinners applied at bloom, such as ammonium thiosulfate (ATS), must be applied before pollination is complete. Consistent thinning with ATS is complicated by bloom duration and weather at bloom. Overall, 1995 peach bloom in South Carolina was delayed and progressed rapidly from 20% to 90% bloom in 2 days. Under these conditions, we compared thinning response of control (untreated), ATS (2%) applied at 70% bloom, SBO concentrations (2.5%, 5%, 7.5%, or 10%) applied 3 weeks before bloom (WBB), and application time of 5% SBO (1, 2, or 3 WBB). SBO was not available for applications earlier than 3 WBB. Treatments were applied by hand gun to six replications of single-tree plots of Redhaven. ATS had no effect on fruit set, yield, or fruit size, contrary to normal bloom years. Flower bud death increased linearly from 8% to 28% with increasing rate of SBO. Delay in SBO application decreased bud death. SBO at 5%-10% rates caused minor delay of 50% bloom, did not effect bloom duration, and increased mean fruit weight over control. Maximum effect was achieved with 10% SBO, reducing fruit number/ha and firmness by 72% and 18% and increasing fruit weight and soluble solids by 67% and 5% from control, respectively. Results show the advantage of bud thinning with SBO during the dormant season in a short bloom duration year.
Growth of Dieffenbachia maculata `Camille' in Growing Media Based on Spaghnum Peat or Coconut Coir Dust
Authors: Stamps Robert H. , Evans Michael R.
Published: February 2019

A comparison was made of Philippine coconut coir dust and Canadian spaghnum peat as components of three growing media for greenhouse production of Dieffenbachia maculata `Camille'. The soilless media were prepared using coir or peat in various amounts (by volume) combined with pine bark, vermiculite, and/or perlite (Media A–50% coir/peat: 25% vermiculite: 25% perlite; Media B–40% coir/peat: 30% vermiculite: 30% bark; Media C–50% coir/peat: 50% bark). Chemical and physical properties of the soils were determined at the beginning and the end of the five-month production cycle. Plant root and top growth and grades were determined at the end of the experiment. Initially, saturated media extracts from coir-containing media had elevated K, Cl, and soluble salts levels compared to peat-containing media; however, by the end of the experiment those levels were lower in coir- than in peat-based media. Water-filled pore space and water-holding capacities were generally higher and air-filled pore space lower in coir- than in peat-based media, probably due to differences in particle size distributions. There were no interaction effects on plant growth between growing media and coir versus peat. Plant root and top growth in Media A > Media B > Media C and plant top growth was greater in coir- than in peat-based media. Differences in growth could be due, in part, to differences in media water-holding capacities.
Relationship between Applied Fertilizer and Accumulated Levels of Nitrogen and Sulfur in a Soilless Mix
Authors: Paparozzi Ellen T. , Conley M. Elizabeth , Stroup Walter W.
Published: February 2019

Three cultivars of poinsettia, Freedom Red, Lilo and Red Sails, were grown in a peat:perlite:vermiculite mix according to a commercial production schedule. Twelve selected nitrogen–sulfur fertilizer combinations were applied (125, 150, 175 ppm N with either 12.5, 25, or 37.5 ppm S, 225 and 275 ppm N with either 37.5 or 75 ppm S). The experimental design was a split plot with cultivars as the whole plot and fertilizer levels as the split-plot factor. Mix samples were taken initially, at production week 7 and at the end of the experiment. Nitrate-nitrogen, sulfate-sulfur and total nitrogen were determined. Data were analyzed using SAS PROC MIXED. Visually all cultivars responded similarly to all treatments and were salable. Thus, levels of N as low as 125 or 150 with 12.5 ppm S produced quality plants. Sulfate-S tended to accumulate in the mix while nitrate-N and total N did not. Both nitrate-N and sulfate-S concentrations were affected by an interaction between the cultivar and the amount of S applied with `Freedom' better able to utilize available sulfur. `Lilo' removed more nitrate-N and total N from the mix than `Freedom' which removed more than `Red Sails', but only at specific levels of sulfur. There was no cultivar by nitrogen interaction for any variable measured.
Efficacy against Silverleaf Whitefly of Insecticidal Dips for Rooted Poinsettia Cuttings
Authors: Bell Michelle L. , Baker James R. , Bailey Douglas A.
Published: February 2019

Since whiteflies preferentially oviposit on the newest leaves, it is the early life stages that are most likely to be present on poinsettia cuttings from infested stock or infested during rooting. This study evaluated efficacy of insecticidal dips against eggs and first nymphal instars of the silverleaf whitefly, Bemisia argentifolii. Dip efficacy was investigated by dipping rooted cuttings of whitefly-infested `Freedom' in the following insecticide emulsions: 2% insecticidal soap (M-Pede), 1% horticultural oil (Ultrafine), fluvalinate (Mavrik), oxythioquinox (Joust), kinoprene (EnstarII), azadirachtin (Margosan-O), fenoxycarb (Precision) and imidacloprid (Merit). Two dip durations, 10 seconds and 1 hour, were tested for each insecticide. Water dips for the two durations were used as control treatments. Fenoxycarb and azadirachtin dips for durations of 10 seconds and 1 hour and oxythioquinox dips for 1 hour resulted in greater egg mortality than the other treatments. No insecticide/dip duration treatment gave 100% mortality of eggs. Dips found to be efficacious killed proportionately fewer eggs than first instar nymphs.
Cloning and Expression of Dehydrin Genes in Blueberry
Authors: Rowland Lisa J. , Muthalif Mubarack , Levi Amnon , Arora Rajeev
Published: February 2019

Previous studies identified three major chilling-responsive proteins of 65, 60, and 14 kDa whose levels increase in floral buds of blueberry during cold acclimation and decrease during deacclimation and resumption of growth. Characterization of these proteins found them to be members of a family of proteins responsive to drought and low temperature stress called dehydrins. The 65- and 60-kDa proteins were purified, digested into peptides, and several peptides from each were sequenced. The sequence information was used to synthesize degenerate DNA primers for amplification of a part of the gene(s) encoding these proteins. One pair of primers amplified a 200-bp fragment, which now has been cloned and sequenced. Within the 200-bp sequence is a motif conserved amongst dehydrins. Hybridization of the 200-bp fragment to RNA blots revealed homology to two chilling-responsive messages of 3.7 and 1.6 kb. The 200-bp fragment currently is being used to screen a cDNA library (prepared from RNA from cold acclimated blueberry floral buds) to isolate the full length cDNA clone.
Isolation and Preliminary Characterization of a Receptor-like Protein Kinase from Cold Acclimated Peach Bark
Authors: Bassett Carole , Nickerson Mike , Artlip Tim , Wisniewski Michael
Published: February 2019

To identify components of a possible signal transduction pathway associated with woody plant cold acclimation, a cDNA library prepared from peach bark collected in December was screened using a small DNA fragment from a maize receptor-like protein kinase (ZMPK1) as probe. Six isolates were obtained and partially sequenced to confirm protein kinase identity. One isolate (PPPKB5) contained a relatively large insert (about 1.9 kbp) and was selected for further analysis. Both strands of PPPKB5 were sequenced and the derived amino acid sequence was compared with a variety of known plant protein kinases, leading to the tentative identification of this clone as encoding a partial cDNA for a serine/threonine class protein kinase. PPPKB5 has a classic protein kinase catalytic domain with all the features required for phosphorylation activity and with greater similarity to the known plant receptor-like protein kinases (RLKs) than other classes of these enzymes. In addition, it contains a potential transmembrane region separating the catalytic portion of the molecule from the receptor region. The receptor region has greatest identity with the class of RLKs known as the S-locus type based on conservation of a stretch of 10 cysteines on the amino-terminal side of the transmembrane region. PPPKB5 shares greater amino acid identity with ZMPK1 (50%) than with the Brassica, rice or Arabidopsis S-locus RLKs (34%–40%). Furthermore, PCR analysis of `Loring' suggests that, like maize ZMPK1, the genomic sequence encoding PPPKB5 contains no introns, in contrast to the genomic sequences of Brassica and Arabidopsis which contain six.
Classification of Cephalotaxus Species Based on rbcL Sequences
Authors: Zhang Donglin , Dirr Michael A. , Price Robert A.
Published: February 2019

Cephalotaxus species are needle evergreens offering the aesthetic qualities of Taxus, yew, yet are heat- and drought-tolerant, sun- and shade-adaptable, and resist deer browsing. They are adaptable to nursery and garden cultivation in USDA hardiness zones (5)6–9. Unfortunately, the various species are frequently confused in the American nursery trade due to their extreme similarity in morphology. Recently, molecular data have been widely applied in the taxonomic studies, especially DNA sequencing. The chloroplast gene rbcL of Cephalotaxus has been sequenced for determining species relationships. The preliminary results show that C. oliveri Mast. has 10 base changes from C. drupacea Sieb. et Zucc., while only one base difference occurred between C. drupacea and C. harringtonia (Forbes) Koch. There are between one and 10 base substitutions among C. fortunei Hooker, C. koreana Nakai, and C. sinensis (Rehd. et Wils.) Li. Compared with other closely related conifers, Cephalotaxus has a substantial number of differences among species except between C. drupacea and C. harringtonia, which may not be distinct species. Detailed data relative to gene sequencing, growth morphology, and horticultural characteristics should lead to correct identification of species and great horticultural uses. Furthermore, the method of rbcL sequence can be applied to distinguish other morphologically homogeneous ornamental plants.
Air and Water Temperature Effects on Growth of Lettuce in a Hydroponic System
Authors: Thompson Helen , Langhans Robert
Published: February 2019

This research explored cool crop production in various climate zones using CEA facilities and hydroponics ponds to control growth rate and quality through root zone temperature control. The precise controls were used to vary air and water temperatures to study the temperature gradient between root and shoot zones. Effect of this gradient was measured by growth rates and final harvest dry weights. Lactuca sativa L. cv. Ostinata seedlings were germinated and grown 11 days in a growth chamber and moved to greenhouse ponds. Air temperatures chosen were 17, 24, and 31°C. These were constant for the 24 days that lettuce grew in the ponds with a 5°C decrease for 14 hours. during the night. Water temperatures of the three ponds in the greenhouse were set and maintained at 17, 24, and 31°C. Maximum final harvest weights were obtained at 24°C air/water 24°C. Final weights for the 17 and 31°C water setpoint were comparable at 24°C air. The 31 °C air /water inhibited quality and final dry weight, while 17 and 24°C water produced equivalent dry weights at 31°C air. At 31°C air heads were tighter at 17 than at 24°C, and loose at 31°C. At air 17 °C maximum weight was at 24°C water and minimum at 31°C water. At 17°C air, the 24°C water plants were of good quality, with thicker leaves but visibly smaller than the 31°C water crop. Significant differences in harvest dry weights were shown at each 7-day harvest beginning on day 14, due to both air and water setpoint factors and there was significant interaction between them.
Growth and Yield Response of Bell Peppers (Capsicum annuum L.) to a Nitrogen Fertigated Plastic-mulched System
Authors: Janik D. , Fava E. , Madramootoo C.A. , Stewart K.A.
Published: February 2019

The yield of bell peppers (Capsicum annuum L. cv. King Arthur) was measured when grown in the field under eight mulching/irrigation/nitrogen fertilization systems, was studied at the Macdonald Campus of McGill Univ., using a randomized block design replicated three times. All treatments received a preplant fertilizer application of 60 kg N/ha with four of the treatments receiving additional fertigation during the season. Of the four treatments receiving fertigation, one silver reflective mulched plot and one black mulched plot received an additional 40 kg N/ha in 4 kg N/ha/week over a 10-week period beginning 12 June weekly up to and including 14 Aug. 1995. The remaining two fertigated treatments only received additional N, when leaf nitrogen, based upon leaf chlorophyll content, dropped below a 95% sufficiency index as measured by a Minolta SPAD 502 meter. Marketable yields of the fertigated plots range between 100%–126% higher than those of the control plot for the entire growing season. However, most notably was the early yields (first three harvests), which ranged from 146%–493% higher than that of the control plot, economically, significantly increasing the producers income. The experiment will be duplicated in Summer 1996 to confirm our findings.
Elevated and Super-elevated CO2 Effects on Stomatal Behavior and Yield of Tomato Cultivated Hydroponically
Authors: Mackowiak C.L. , Stutte G.W. , Wheeler R.M. , Yorio N.C.
Published: February 2019

The growth of candidate crops in high CO2 environments is being investigated as part of NASA's goal of using higher plants for bioregenerative life support systems. Tomato (Lycopersicon esculentum Mill.) cvs. Red Robin and Reimann Philipp were grown in recirculating hydroponics at 400, 1200, 5000, or 10,000 μmol·mol–1 CO2 for 105 days. The plants received a 12/12 hour photo-period at 500 μmol·m–2·s–1 PPF, 26/22°C (light/dark), and 65% continuous relative humidity. Stomatal conductance increased at the highest CO2 levels, which is similar to what we have reported with Soybean, radish, and potato. Fruit number increased with increasing CO2, where Red Robin produced 663 fruit/m2 and Reimann Philipp produced 6870 fruit/m2 at 10,000 μmol·mol–1 CO2. Fruit fresh mass was greatest at 10,000 μmol·mol–1 CO2 for Red Robin (7.4 kg·m–2) and at 5000 μmol·mol–1 CO2 for Reimann Philipp (27 kg·m–2), suggesting that very high CO2 was not detrimental to yields. These findings contrast with those of wheat, soybean, and potato, which have shown slightly depressed yields at CO2 levels above 1200 μmol·mol–1.
Photoautotrophic Micropropagation of Triploid Melon: II. Rooting and Plantlet Growth on Sugar-free Media
Authors: Adelberg Jeffrey , Fujiwara Kazuhiro , Kirdmanee Chalermpol , Kozai Toyoki
Published: February 2019

Two triploid clones of melon from the same tetraploid parent were grown in vitro with and without sugar, rooted without sugar in media both in a laboratory controlled environment chamber (in vitro) and a greenhouse acclimatization unit (ex vitro), and compared for subsequent nursery growth in the greenhouse unit. The clone `(L-14 c B) × L-14' produced more shoots in both photomixotrophic (with sucrose) or photoautotrophic (sugar-free) conditions. Both genotypes were equally likely to root in sugar-free media, and `(L-14 × B) × L-14' rooted as well from either photoautotrophic and photomixotrophic shoots but `(L-14 × B) × Mainstream' rooted less frequently from photoautotrophic shoots. Seventy-six percent (76%) of the shoots were able to root photoautotrophically in vitro, whereas 47% of the ex vitro shoots were rooted. About 85% of plantlets from all treatments survived after transfer to the nursery. After growth in the greenhouse nursery, the sizes of plants (fresh and dry weight, leaf area) were the same for either clone, from either photoautotrophic or photomixotrophic shoots. Also, after growth in the nursery, plantlets that had been rooted in vitro were larger than those rooted ex vitro. Photoautotrophic rooting demonstrates a concept for integrating micropropagation and plug-type vegetable transplant production.
Micropropagation of Two Apricot (Prunus armeniaca L.) Cultivars
Authors: Hassaballa Issam A. , Moughieth M.G. , Hagagy N.A. , Zayed N.S.
Published: February 2019

Shoot tip and single-node cutting explants of `Hamawy' and `El-Amar' apricot cultivars were initiated from forced shoots of field-grown, virus-free trees. Explants were cultured on Murashige & Skoog (MS) Nitsch & Nitsch and Anderson media. Different modifications of MS medium were also evaluated. Antioxidant pretreatment reduced phenolic compounds and decreased necrosis. Modified MS was the best medium for plantlets regeneration, with positive effectiveness of adenine sulfate addition to the modified MS. Shoot multiplication was best on 2.0 mg·L–1 BAP and 1.0 mg·L–1 thidiazuron (TDZ). Also, half-strength MS medium was superior for shoot elongation Surface coverage, 16 hours light/8 hours dark cycle, and 2.0 mg·L–1 IBA induced good rooting. Rooted plantlets were successfully acclimated ex vitro.
A Breeding Program for Cornus florida that Uses Molecular Markers and Seedling Tissue Culture
Authors: Trigiano R.N. , Kaveriappa K.M. , Schlarbaum S.E. , Windham M.T. , Witte W.
Published: February 2019

DNA amplification fingerprinting (DAF) was Used to characterize both parents (different cultivars) in breeding experiments with Cornus florida. Putative hybrids were fingerprinted and true crosses identified by finding unique male parent products in amplification profiles. Both manual and honey bee mediated pollinations successfully produced hybrid seed. Axillary buds from seedlings were used to initiate proliferating shoot cultures on woody plant medium with 4.5 μm BA. Initiation and development of adventitious roots were dependent on IBA (4.1 μm), sucrose (0–2%), and agar (0.2–0.6%) concentrations. About 40–50% of the microshoots produced roots and were acclimatized to greenhouse conditions. Cultures have been maintained without loss of regeneration potential for over 2 years. Clonal material can be reentered into the breeding program or used to evaluate horticultural characteristics in different environments and locales.
World Wide Web Access to Multimedia Resources
Authors: Schrader Wayne L. , Voss Ronald E. , Bradford Kent J.
Published: February 2019

Agricultural producers in the United States require timely and accurate information on critical issues, environmental crises, and best management practices to make effective production decisions and to remain competitive in a global economy. Sources of information (university departments, extension, industry, consultants, scientific and trade publications) often take a single discipline approach that makes it difficult for growers to process and utilize information effectively. The high cost of printed publications make frequent updates impractical, while rapidly changing technologies and issues demand continual publication changes and updates. The rapid development and peer review of multi-discipline, research based information is possible through computer information transfer technology. The Univ. of California's Vegetable Crops Research and Information Center (VRIC) has developed a new World Wide Web site to disseminate peer-reviewed fact sheets, research results, updated publications, and multi-media educational resources relating to critical issues, best management practices, postharvest handling, and marketing of vegetable crops. The website disseminates multi-discipline information originating from the Univ. of California, the USDA, and cooperating agencies and universities. The VRIC website proactively sends peer-reviewed critical issue fact sheets to selected news media, government, industry, and academic contacts. These fact sheets help personnel frequently contacted by the media during crises to answer questions effectively. The website directs visitors to additional agricultural information resources and contains information on careers and educational opportunities available in the field of vegetable crops.
Diffusivity of CO2 and Water Vapors in `Gala' and `Granny Smith' Apples
Authors: Solomos Theophanes , Bouwkamp John C.
Published: February 2019

Previous observations have shown that the diffusivity of water vapors is much larger than the value that is predicted theoretically from the magnitude of the diffusion coefficient of CO2, C2H4, or both. This has been ascribed to the ability of water to diffuse through the cuticle and to the transport of water via the capillaries of cellulase micorfibrels to the surface of the lenticels, where it evaporates. We measured the diffusivity of CO2 in `Gala' and `Granny Smith' apples. The former are more permeable to CO2 than the latter cultivar, in particular after prolonged storage at 2°C. The diffusivity of H2O was 10- to 20-fold larger than that of CO2. Furthermore, the ratio of D(H2O)/D(CO2) was similar for both cultivars. Infiltration of dyes and gas flow through apples submerged in water show that in `Gala' apples, the number of open lenticels is larger than in `Granny Smith'. Thus, the data indicate that lenticels are the main avenue of gas exchange in apples.
Electronic Determination of Blueberry Fruit Quality Using Aroma Sensing Technology
Authors: Phippen W.B. , Ozer N. , Hetzroni A. , Simon J.E. , Bordelon B. , Charles D.J. , Angers P. , Miles G.E. , Malischke L.M. , Trinka D.
Published: February 2019

An electronic sniffer that nondestructively detects aromatic volatiles was used to grade commercially packaged blueberries. A total of 1,358 containers of commercial blueberries entering MBG grading facilities were first “sniffed” using the electronic sniffer, graded by USDA or MGB inspectors, and then subjected to discrimination analyses. The electronic sniffer separated the fresh top grade (grade 1) of fruit from the rest of the grades of blueberries with ≤ 82.79% accuracy when grading into five classes, and ≤89.3% when grading into three quality classes. The sniffer was also able to distinguish hand-harvested fruit from machine-harvested fruit from all cultivars tested (Bluecrop, Jersey, and Elliot). Highest classification accuracy was achieved with four gas sensors operating simultaneously within the sniffer. A stable signal response was achieved in 10 seconds, with each berry pack sampled at 10, 20, 40 and 80 seconds.
A Systematic Approach to the Determination of Maturity Indices for Melting-flesh and Nonmelting-flesh Peach Cultivars for Fresh Market
Authors: Brovelli Ernesto A. , Brecht Jeffrey K. , Sherman Wayne B. , Harrison Jay M.
Published: February 2019

Potential maturity indices were determined for two melting-flesh (FL 90-20 and Tropic Beauty) and two nonmelting-flesh (Oro A and Fl 86-28 C) peach cultivars. A range of developmental stages was obtained by conducting two harvests and separating fruit based on their diameter. Fruit in each category were divided into two groups. One group was used for determining potential maturity indices: soluble solids, titratable acidity, soluble solids: titratable acidity, peel and flesh color on the cheeks (CH) and blossom end (BE), CH and BE texture, ethylene production, and respiration rate. The other group was stored at 0°C for 1 week and ripened at 20°C for 2 days to simulate actual handling conditions, and were presented to a trained sensory panel, which rated the fruit for three textural (hardness, rubberiness, and juiciness) and three flavor aspects (sweetness; sourness; bitterness; and green, peachy, and overripe character). Principal component (PC) analysis was used to consolidate the results of the descriptive sensory evaluation into a single variable that could be correlated with the objective measurements at harvest. The first overall PC explained 40% of the total variation. Following are the attributes that best correlated with PC 1 and, thus, are promising maturity indices: for FL 90-20, peel hue, peel L, and CH texture; for Tropic Beauty, peel L, CH texture, and BE texture; for Oro A, CH texture, BE texture, and CH chroma; for 86-28C, BE texture, CH hue, and CH texture.
A Packaging System for Rapid Measurement and Analysis of Fruit Volatiles and Permeability
Authors: Deng Weimin , Beaudry Randolph M.
Published: February 2019

A simple packaging system was developed to simultaneously measure volatile production by plant organs and the permeability of the packaging film to those volatiles. In this system, apple (Malus domestica Borkk cv Golden Delicious) was packaged in low-density polyethylene (LDPE) bag and placed into a glass jar with a low air flow. The package and jar head spaces were sampled for aroma volatile analysis by gas chromatograph. Analysis was by gas chromatography/mass spectrometry. This system allowed at least 10 volatile compounds and their permeabilities to be measured. This system permits volatile production to be measured for products in the package so the product need not be removed from its storage environment. This may be a useful method for determining the dynamic relationship between flavor volatile synthesis and package atmosphere for packaged produce.
Identification of Random Amplified Polymorphic DNA (RAPD) Markers for Self-incompatibility Alleles in Hazelnut
Authors: Pomper Kirk W. , Azarenko Anita N. , Davis Joel W. , Mehlenbacher Shawn A.
Published: February 2019

Random amplified polymorphic DNA (RAPD) markers were identified for self-incompatibility (SI) alleles that will allow marker-assisted selection of desired S-alleles and assist in cloning the locus responsible for the sporophytic SI displayed in hazelnut (Corylus avellana L.). DNA was extracted from young leaves collected from field-planted parents and 27 progeny of the cross OSU 23.017 (S1 S12) × VR6-28 (S2 S26). Screening of 10-base oligonucleotide RAPD primers was performed using bulked segregant analysis. DNA samples from six trees each were pooled into four “bulks,” one for each of the following: S1 S2, S1 S26, S2 S12, and S12 S26. “Super bulks” of twelve trees each for S1, S2, S12, and S26 then were created for each allele by combining the appropriate bulks. The DNA from these four super bulks and also the parents was used as a template in the PCR assays. Amplification products were electrophoresed on 2% agarose gels and photographed under UV light after ethidium bromide staining. 200 primers were screened and one RAPD marker each was identified for alleles S2 (OPI-07700) and S1 (OPJ-141700).
Founding Parents of Low-Chill Peaches
Authors: Byrne David H. , Bacon Terry A.
Published: February 2019

A computer program was developed to calculate the percent contribution of the founding parents for any given peach or nectarine (Prunus persica) cultivar. The founding parents used most frequently for three low-chill (0 to 500 chill units) peach and nectarine breeding programs (Florida and Pelotas and Campinas, Brazil) were determined. The Florida program used several low-chill honey type peaches (`Hawaiian', `Okinawa') as a source of low chilling and then did extensive crossing with higher quality cultivars developed mainly in the northeastern United States. About 50% of the background of the Brazilian peach releases consists of local selections that were originally brought by the Portuguese explorers. Although each of the Brazilian programs used local peach materials, the local peaches used by each program are different. In addition, the program at Pelotas used germplasm from the Georgia–Florida and New Jersey breeding programs and the Campinas program used `Jewel' (honey peach) and several Florida nectarines (`Sunlite', `Sunred') in their development work. The founding parents among these three programs, although there is some common parentage, are different, and the intercrossing of materials from the various programs would be a useful approach to create more diversity in this germplasm.
Influence of Boron Rate, Timing, and Application Method on Skin Discoloration of `Hernandez' Sweetpotato
Authors: Schultheis Jonathan R. , Campbell C. Ray
Published: February 2019

In the last 3 years, ≤50% of the North Carolina sweetpotato crop has been produced with the variety Hernandez. A brown to black discoloration on the epidermis of the `Hernandez' sweetpotato may develop when maintained in storage for several months. The symptoms resemble blister—blister is caused by a boron deficiency. Preliminary studies in 1994 indicated that boron reduced the discoloration on `Hernandez' but did not eliminate the problem. To help confirm these findings and further define the role of boron in defining skin discoloration, boron was applied in 1995 at several rates (0 to 5.6 kg·ha–1) and stages of plant development using two application methods (foliar or soil). Yields and plant analysis data were obtained. Marketable yields ranged from 18.4 to 29.3 mt/ha. Leaf boron concentration ranged from 50 to 100 mg·kg–1 throughout the production season when 1.1 kg·ha–1 boron was soil applied shortly after planting. Excessive levels of boron (200+ mg·kg–1) were measured in plant tissue when application levels exceeded 2.2 kg·ha–1 regardless of timing. Soil application appeared to be an adequate method for boron application. Roots were examined for symptoms of discoloration after 5 months. Results indicated no affect of boron on incidence or severity of the symptoms.
Surveys and Other Methods Used to Determine User Green Space and Other Requirements: Harmony Playground, Van Saun Park, Bergen County, New Jersey
Authors: Gerber Mary Fennell
Published: February 2019

Harmony Playground is a retrofitted, 2.25-acre site in Van Saun Park, River Edge, Bergen County, N.J. It is part of a 140-acre parcel, the largest in the 8000-acre Bergen County park system. The original playground was opened in 1960 and is visited by one million people annually—county, state residents, out-of-state and foreign visitors. The new playground was designed by Lawrence Porter, CLA, Bergen County Dept. of Parks and was dedicated in Oct. 1994. The facility reflects user demands in priority areas. They include the physical environment (topography, a water resource, shade, and vegetation), visibility, safety, play equipment and numerous amenities. User preference was determined through pre- and postconstruction surveys, interviews, and other measurements conducted by Fennell Gerber during Summer 1993 and Fall 1994. Vegetation and existing conditions are documented also. The landscape architect's use or rejection of the data (in some categories) to execute the design has been documented and analyzed. Vegetation selection is documented as well. User residual fears that surfaced after the completion are noted. While visitors stood in an award-winning facility (Porter was given the New Jersey Chapter American Society of Landscape Architects Honors Award), they expressed lingering concerns demonstrating a common fear and distrust prevalent among public landscape users. The study demonstrates the need for and value of user data. It can be used by designers to create a valid green space without lessening creativity or sacrificing professional integrity. In fact, user input and data used properly to design green spaces increases appropriate use and community support.
Smoking Zucchini—Introducing Commercial Vegetable in Tobacco Country
Authors: Rowell Brent , Snyder John C.
Published: February 2019

“We are a tobacco state” is frequently heard among farmers and agricultural leaders in Kentucky; the state's farm economy has always revolved around burley tobacco production. Tobacco, grown in Kentucky for nearly two centuries, remains the most valuable crop earning approximately $694 million in 1995. Even our unusual terminology of “alternative,” “supplemental,” or “opportunity” crops denotes the prime position of tobacco and attitudes toward vegetable crop production. This long tradition and attitudes associated with it contribute to a serious lack of confidence and low expectations when it comes to diversification with vegetable crops. These low expectations and the consequent circular pattern of experience with vegetable production were revealed in a multidisciplinary, 5-year research project designed to determine opportunities for and constraints to vegetable production in the state. The study showed that nearly half of Kentucky's commercial vegetable growers also were tobacco growers and that there were no fundamental incompatibilities in tobacco–vegetable cropping systems. Although farmers considered lack of markets a major constraint, economic research revealed that growers were often unwilling to use and take the risks associated with existing market structures and channels. As a result of these findings, a major on-farm demonstration program was implemented to raise expectations and break the “circular syndrome”. More recently, new partnerships and collaborative relationships have been established between university horticulture and marketing specialists and the Burley Tobacco Growers Cooperative Association for the promotion of “supplemental crops” among Kentucky's tobacco growers.
Use of RAPD Marker Analysis to Assess Changes in the Genetic Diversity of Potato Genebanks
Authors: del Rio A. , Bamberg J.B. , Huaman Z. , Hoekstra R. , Salas A. , Vega S.E.
Published: February 2019

Effects of genebank seed increases on the genetic integrity and whether germplasm in the genebank still represents the in situ populations from which it was collected are major concerns of the recently formed Association of Potato Intergenebank Collaborators (APIC), a consortium of world potato genebank leaders. This cooperative APIC research used RAPDs and morphological markers 1) to establish genetic relationships between seed increased populations within accessions and (2) to measure genetic differentiation between diploid and tetraploid potato germplasm maintained for many years and current in situ populations from the same collection sites in the wild. Solanum jamesii Torrey (2n = 2x = 24) and S. fendleri A. Gray (2n = 4x = 48), two wild potato species native to North America, were used as plant material. These species represented two major breeding systems found among Solanum species: outcrossing diploids and inbreeding disomic tetraploids, respectively. Comparisons made between populations one generation apart and between sister populations generated from a common source indicated that there has been minimal loss of genetic diversity in captive germplasm using the genebank techniques standard at NRSP-6 and other world potato genebanks. RAPD markers also revealed that significant genetic differences were found between genebank-conserved and re-collected in situ populations for all diploid potato comparisons and for about half of the comparisons within tetraploid potato populations.
Inheritance and Biochemical Analysis of a Carrot Carotenoid Mutant
Authors: Goldman I.L.
Published: February 2019

Pigments in orange carrot tissue, such alpha and beta carotene, are important vitamins in the human diet. Previously identified white or nonpigmented carrot roots, such as those from wild carrot and white derivatives of yellow or orange types, are dominant to the production of pigment, which is recessive. A nonpigmented carrot root was discovered during routine propagation of the inbred line W266 in 1992. Subsequent segregation analysis in the F2 and BC1 generations in three genetic backgrounds demonstrated the lack of pigmentation is due to a single recessive gene (reduced-pigment: rp). Total carotenoid content was reduced 92% in the roots of rprp genotypes compared to RPRP genotypes, however there were no differences in carotenoid content in leaves. Plants carrying rprp also exhibit white-speckled leaves during early stages of development, suggesting rp has an effect on leaf chlorophyll content. This character may prove useful in dissecting the complex inheritance of carotenoids in carrot.
Evaluation of AFLPs as Tags for the MS Locus in Onion
Authors: Sato Yutaka , Havey Michael J.
Published: February 2019

The production of hybrid-onion seed depends on cytoplasmic male sterility (CMS) systems. The male-sterile line is seed propagated using a normal (N) cytoplasmic maintainer line homozygous recessive at the nuclear male-fertility restoration locus (MS). Because of onion's biennial generation time, 4 to 8 years are required to establish the genotype at the MS locus. The development of maintainer lines would benefit greatly from a genetic marker linked to the MS locus. Such a marker would allow breeders to establish the nuclear genotype in seedlings and flower only those plants that are maintainers (N msms) or plants that can be used to develop maintainers (N MSms), reducing the number of plants to be testcrossed or backcrossed to a sterile line. We evaluated restriction fragment length polymorphisms (RFLPs), random amplification of polymorphic DNA (RAPDs), and amplified fragment length polymorphisms (AFLPs) to tag the chromosome region carrying the MS locus. No RAPDs or RFLPs cosegregated with MS. AFLP markers were identified that phenotypically correlated with restoration of male fertility.
Genetic Mapping in Onion: Insight to the Evolution of a Large Diploid Genome
Authors: King Joseph J. , Havey Michael J.
Published: February 2019

The bulb onion (Allium cepa L.) is a diploid with an very large nuclear genome of 15300 Mbp/1C (107× arabidopsis, 16× tomato, 6× maize). We developed a low-density genetic map with morphological, RAPD, and RFLP markers to examine genome organization and to study QTL controlling phenotypically correlated bulb quality traits. A mapping population of 58 F3 families was derived from a cross of the inbreds Brigham Yellow Globe 15-23 (BYG) × Alisa Craig 43 (AC). These inbreds are distinct in solids, storability, pungency, and bulb shape. Analysis of 580 RAPD primers detected 53 (9%) polymorphisms between BYG and AC, but only 12 (2%) segregated at expected ratios among F3 families. Using probes from onion cDNA libraries and four restriction enzymes, 214 RFLPs were identified between mapping parents. A 112-point map includes 96 RFLPs, 13 RAPDs, a locus controlling complementary red bulb color, and two loci hybridizing with a clone of the enzyme alliinase (EC 4.4.1.4), which produces the flavors characteristic of Allium species. Duplicated loci were detected by ≈25% of RFLP probes and were unlinked, loosely linked (2 to 30 cM), or tightly linked (<2 cM). This frequency of duplication was comparable to species with polyploid ancestors (paleopolyploids) and was higher than that found in most true diploids. However, the distribution of duplicated loci suggests that, in contrast to whole genome duplications typical of paleopolyploids, the contemporary size and structure of the onion genome may be a product of intrachromosomal duplications (cryptopolyploidy) and subsequent structural rearrangements.
Influence of Plant Growth Regulators on Postharvest Quality of Zantesdeschia and Preplant Treatment for Preventing Erwinia Infection
Authors: Kuehny Jeff S. , Chang Wen Chy , Branch Patricia
Published: February 2019

Zantesdeschia has been grown for cut-flower production for many years, but more recently it has been grown as a containerized plant. Problems with height control and disease, however, have limited Zantesdeschia production in warmer climates. Our objectives were to evaluate paclobutrazol and uniconazole on control of plant growth of three Zantesdeschia species and evaluate four preplant treatments for preventing Erwinia infection on rhizomes. Paclobutrazol at 1 mg a.i. gave the best control of flower height, foliage height, and plant width. After 20 d in a postharvest chamber, plants drenched with paclobuturazol at 2 mg a.i. and uniconazole at 6 mg a.i. were still suitable plants, plants drenched at 3 and 4 mg a.i. paclobutrazol remained short, and plants drenched at 2 and 4 mg a.i.uniconazole became tall and weak, with flower stems breaking over. Rhizomes were dipped in dimethylbenzyl ammonium chlorides, sodium hypochlorite, 4% formaldehyde, or streptomycin. Streptomycin provided the best control against Erwinia infection followed by formaldehyde. Dimethylbenzyl ammonium chlorides and sodium chloride provided the poorest protection.