bluuebunny/crossref_metadata_2025 huggingface dataset:
293 Genotypic and Temporal Variation in Nitrate Uptake Rate by Kentucky Bluegrass
Authors: Jiang Zhongchun , Sullivan W. Michael , Sawyer Carl D. , Hull Richard J.
Published: February 2019

Turfgrass cultivars that have superior nitrate uptake ability are needed for the protection of ground water from pollution by excess nitrate. Information on temporal variation of nitrate absorption is also needed to enhance the environmental safety of turfgrass N fertilization programs. Our objectives were to evaluate Kentucky bluegrass (Poa pratensis L.) cultivars for their differences in nitrate uptake rate (NUR) and temporal variation in NUR. Six cultivars (Barzan, Blacksburg, Connie, Dawn, Eclipse, and Gnome) were propagated from individual tillers and six plants of each cultivar were generated from one mother plant. Plants were grown in silica sand, mowed weekly, and watered daily with half-strength modified Hoagland's nutrient solution containing 1 mM nitrate. When 5 months old, the plants were excavated, the roots were washed to remove sand, and the plants were transferred to 120-mL black bottles. After 24 hours in tap water, the plants were supplied with half-strength nutrient solution containing 0.5 mM nitrate, and the solutions were replaced daily for 8 days. NURs expressed as micromoles per plant per hour were calculated from solution nitrate depletion data. Significant genotypic differences in NUR were found: `Blacksburg' > `Connie' > `Dawn' > `Barzan' = `Eclipse' > `Gnome'. Significant temporal variation in NUR was also found, with NUR on the second day more than the first day after tap water. A significant interaction was noted between genotype and time. Temporal variation was greatest in `Blacksburg', while none noted in `Connie' and `Eclipse'. In `Barzan' and `Gnome', NUR on the last day was higher than the first day.
294 Quantifying the Effect of Application Date of Paclobutrazol Drenches on Poinsettia Stem Elongation and Bract Size
Authors: Korczynski Pamela , Faust James E. , Klein Robert
Published: February 2019

Paclobutrazol drenches (1 ppm, 118.4 mL per pot) were applied to Poinsettia `Freedom' Red' on 1, 11, 21, and 31 Oct. in 1997 and 1998. Plant heights were recorded twice weekly throughout the experiment, and internode length and bract area were measured at harvest. The total bract area of the three true bracts and the top three transitional bracts was reduced by 5.8%, 13.6%, 4.2%, and 2.3% for the 1, 11, 21, and 31 Oct. application dates, respectively; however, all plants were highly marketable. At the time of each drench application, the most newly unfolded leaf was marked. The internode lengths for the three internodes below this leaf and the internodes that developed after the drench application were typically between 5 and 10 mm in length, while the internode lengths of the control plants were typically 10 to 25 mm, depending on node number. Plant height increased 62, 51, 47 and 19 mm following application on the 1, 11, 21, and 31 Oct. application dates, respectively. The 1, 11, 21, and 31 Oct. drench applications reduced total stem elongation from 1 Oct. to anthesis by 64%, 49%, 28%, and 15%, respectively. Paclobutrazol drenches did not affect time to anthesis.
304 Influence of Late Thinning with NAA and Carbaryl in the Apple Cultivar Braeburn
Authors: Garriz P. I. , Colavita G.M. , Alvarez H.L. , Alvarez A.J.
Published: February 2019

NAA (1-naphthaleneacetic acid) is widely used for thinning apples; however, its mechanism of action is not well understood. Postbloom application of NAA is cultivar-specific and may, in addition to causing fruit abscission, show unwanted side effects. The response of 5-year-old `Braeburn'/MM 111 apple (Malus domestica Borkh.) trees trained to palmette leader to NAA used alone or in combination with carbaryl (1-naphthyl-N-methylcarbamate) was evaluated in late thinning trials. The experiment was conducted at the Comahue National Univ. (lat. 38°56′S long 67°59′W), during the 1997-98 growing season. Treatments were 1) control, 2) NAA (13 ppm), and 3) NAA (6.5 ppm) + Carbaryl (600 ppm). Whole sprays were applied 17 Oct. at 22 days after full bloom (DAFB) to five trees per treatment. Fruit diameter (FD) was recorded twice weekly (n = 20 per date and treatment). At 169 DAFB, cropload and fruit fresh weight (FW) were determined. Fruit were then graded into size categories. Analysis of variance was used and mean separations were computed with Student's t test. Good thinning resulted from NAA applications; however, this did not reflect in increased mean FW. The number of fruit ≥70 mm was increased by 6.67%. Cropload was overthinned by NAA + carbaryl. Mean FW was slightly greater than control (185.15 and 172.45 g, respectively) and this treatment resulted in 90 % of the fruit ≥70 mm compared to 75 % from control. The following potential model best fitted the fruit growth pattern on non-thinned trees: FD =2.9077 DAFB0.6307 (R2=0.98, P≤0.001). More work needs to be done to establish the most effective timing and concentration of spray for `Braeburn' to give the maximum crop of large fruit on a regular cropping basis.
311 Growth and Mineral Nutrition of Tomato Seedlings under Diurnal Temperature Variation of the Root and Shoot
Authors: Gent M.P.N. , Ma Y.-Z.
Published: February 2019

Does heating roots only in the day improve growth and nutrient status of seedlings grown under a day-to-night difference (DIF) in air temperature? To answer this question, tomato seedlings (Lycopersicon esculentum Mill) were grown in early March or April in greenhouses heated to give either a 14 °C DIF or a 5 °C DIF with a 18 °C mean. The roots were in peat-vermiculite medium that was unheated or heated to 21 °C, constantly or only in the day, or only in the night. Growth was faster and there were higher concentrations of elements in leaves under 5 °C compared to 14 °C air DIF. Any root-zone heating increased growth and nutrition compared to no heating. Under both air conditions, the trend in root temperature treatments was constant > day > night. In general, there was no benefit of heating the roots only in the day, compared to constant heating of the root zone, even with a large diurnal variation in temperature of the shoot. The only nutrient to respond differently to root heating under 5 °C compared to 14 °C air DIF was nitrate in leaves. Under a 14 °C air DIF, heating roots in the day resulted in the highest nitrate concentration, whereas constant root heating was optimal under a 5 °C DIF. Research supported in part by grant 93-37100-9101 from NRI Competitive grants program/USDA.
322 Influence of Mycorrhiza and an Isoflavonoid on Plant Growth and Gas Exchange of Potatoes Started from Minitubers
Authors: Davies F.T. , Egilla J.N. , Miller J.C. , Grossi J.A. Saraiva
Published: February 2019

The influence of the mycorrhizal fungus Glomus intraradices and reduced levels of G. intraradices treated with the isoflavonoid formononetin was tested on growth and gas exchange of container-grown potato plants. Tissue culture-produced minitubers of Solanum tuberosum cv. Russet Norkotah and Russet Norkotah selection TX112 were subjected to four treatments: 1) G. intraradices at 750 propagules per container, 2) G. intraradices at 376 propagules per container, 3) G. intraradices at 376 propagules per container treated with the isoflavonoid formononetin, and 4) noncolonized plants. Plants were grown under glasshouse conditions in 1500-mL containers containing a sterilized sand: sandy loam soil, and fertilized with Long Ashton nutrient solution modified to supply phosphorus at 11 ug P/mL. The experiment was initiated on 4 May 1998 and terminated on 27 Aug. 1998, during which the plants were exposed to adverse high temperatures (mean high: 30.7 °C). Both cultivars responded similarly to mycorrhizal treatments. Formononetin enhanced growth of myocorrhizal plants and increased total colonization, arbuscule, and hyphae development. Only formononetin-treated mycorrhizal plants had increased shoot growth. Net photosynthesis and stomatal conductance were generally greatest with reduced levels of mycorrhiza and formononetin treated mycorrhizal plants.
332 Effects of Heat Stress on Spinach Seed Germination
Authors: Hum-Musser S.M. , Morelock T.E. , Murphy J.B. , Henry R.L.
Published: February 2019

Seed germination of spinach (Spinacia oleracea L.) is partially inhibited by a high germination temperature (35 °C). Tolerance of high germination temperatures varies widely depending on the variety used. We ascertained that seed germination of these spinach varieties was thermoinhibited at 35 °C and secondary dormancy was not induced as seeds germinated when transferred to optimum germination conditions (20 °C). Treatment with 99% oxygen and 10 ppm kinetin significantly increased germination of thermoinhibited varieties at 35 °C. During heat stress, all organisms produce heat shock proteins (HSPs), which may function as molecular chaperons, are possibly required for the development of thermotolerance, and may be crucial for cell survival during heat stress. Western blotting of SDS-PAGE gels using antibodies to various heat shock proteins indicated that spinach varieties with the highest degree of thermotolerance have higher levels of HSP expression than varieties with the lowest degree of thermotolerance during germination. These results suggest that thermotolerance could be further improved, either through a breeding program or possibly by genetic engineering.
340 Postharvest Life of Antirrhinum majus L. as Influenced by Number of Stomata per Cut Flower Stem
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: February 2019

Leaf impressions were made from two short-lived (4 and 5 d) inbreds, a long-lived (11 d) inbred, and their hybrids (8 and 9 d) of Antirrhinum majus L. using Super Glue and glass microscope slides. Leaves were taken from mid stem, pressed on glass slides (under side down), spread with a small amount of Super Glue, set for 3 to 4 s. Then, the leaf was peeled off leaving a permanent impression in the glue. Slides were placed under a microscope equipped with a video imaging system and computer images were taken to facilitate counting of stomatal complexes. Number of stomata ranged from 10,400 to 21,300 per cm2 of leaf. A LI-COR LI-3100 area meter (LI-COR, Inc. Lincoln, Neb.) was used to measure total leaf area of 40-cm cut flower stems of each accession. Stomata per flowering stem ranged from 1,074,000 to 2,282,000, with the long-lived inbred having the fewest stomata, the hybrids intermediate with 11% to 21% more, and the short-lived inbreds having 40% to 113% more stomata per stem. It appears long postharvest life of A. majus is associated with flowering stems with fewer stomata per cut stem.
346 Effects of Gibberellic Acid and Seed Location on Seed Germination of Echinacea pallida
Authors: Sari Ali O. , Morales Mario R. , Simon James E.
Published: February 2019

Echinacea pallida, one of the three medicinal Echinacea species native to North America, is generally wildcrafted, and low and uneven seed germination are obstacles to its widespread cultivation. Nonstratified E. pallida seeds were treated with 2500, 3500, and 4500 mg/L GA3 to increase seed germination. Treated seeds were directly germinated at 25 °C and 25/15 °C (14/10h) or stored at 5 and 10 °C for 4, 8, and 12 weeks before germination at the same temperatures. Seed germination across treatments was higher at 25 °C (19%) than at 25/15 °C (14%). Application of 2500, 3500, and 4500 mg/L GA3 significantly increased seed germination rate and total seed germination of nonstratified seeds of E. pallida and resulted in 44%, 50%, and 63% total seed germination, respectively, while untreated control seeds germinated at only 9%. The effect of GA3 as a germination stimulant increased with cold storage, with maximum germination (83%) occurring after seeds were treated with 4500 mg/L GA3 and an 8-week cold storage period at 10 °C. The effect of cold storage periods of 4, 8, and 12 weeks and cold storage temperatures of 5 and 10 °C on seed germination were generally similar. Seeds collected from the upper rows of the seed heads germinated significantly higher (10.6%) than those collected from the lowest seed rows (2.4%).
348 Mineral Nutrient Composition of Edible Parts of the Daylily Plant
Authors: Carter Johnny , Singh Bharat P. , Park Young W.
Published: February 2019

In the United States, the common daylily is cultivated as an ornamental. However, in other countries, such as China and Japan, it is an important food crop. With this in mind, a study was conducted to determine the mineral nutrient content of edible parts (flower buds, flowers and tubers) of the daylily plant. Edible parts were analyzed for P, K, Ca, Mg, Mn, Fe, B, Cu, Al, and Na. Results of this study showed that flower buds had significantly higher level of P and Mg than tubers and flowers. The K and B concentration in flower buds were similar to flowers, but significantly greater than in the tubers. The respective Zn concentrations in flowers and flower buds were 32% and 23% greater than those in the tubers. There was no difference in the Mn concentration among the edible parts. Tuber contained significantly higher contents of Ca and Cu than the flowers and flower buds. It also had 10.6-, 14.3-, and 2.8-times greater concentration of Mn, Al, and Na, respectively, than the combined average flower buds and flowers. From this study, daylily appears to have potential as a nutritious food source for human consumption.
363 UV-C Irradiation Reduces Decay and Improves Quality of Fresh-cut Squash
Authors: Erkan M. , Wang C.Y. , Krizek D.T.
Published: February 2019

Exposure of fresh-cut zucchini squash (Cucurbita pepo L., cv. Tigress) to ultraviolet-C (UV-C) irradiation for 1, 10, or 20 min significantly reduced microbial counts and severity of decay during subsequent storage at 5 or 10 °C. However, the respiration rate and ethylene production of the slices were not affected by the UV-C treatments. Slight UV-C damage (reddish brown discoloration) was detected on the surface of 10- and 20-min treated slices after 12 days of storage at 10 °C. Slices stored at 5 °C did not show UV-C damage. Chilling injury was not observed until after 20 days of storage at 5 °C. The symptoms of chilling injury appeared as dried sunken brown spots on the surface of cortex tissue. UV-C treatments did not affect the degree of chilling injury during storage at 5 C. The storage quality of fresh-cut zucchini squash was improved by UV-C exposure primarily because of the retardation of microbial growth and reduction of decay. The influence of UV-C irradiation on sugar and organic acid contents of the fresh-cut zucchini squash will also be discussed.
370 Alternative Coating Formulations for Apples and Their Effects on Quality
Authors: Alleyne V. , Baldwin E.A. , Hagenmaier R. D.
Published: February 2019

Experimental formulations of candelilla, zein, and polyvinylacetate (PVA) were investigated as alternatives to commercial apple-coating formulations of shellac and carnauba wax. Coatings or a deionized water control were applied to `Red Delicious' apples. Effects on quality attributes, internal atmospheres, sensory flavor, and volatile composition were evaluated. Treated fruit were stored at 5 °C for 7 days followed by 14 days at 21 °C. Zein and PVA formulations exhibited gloss levels comparable with commercial formulations. Although shellac-coated apples maintained the highest gloss over the 21-day storage period, gloss of zein-coated apples was comparable to shellac after fruit were removed from storage at 5 °C. On removal from cold storage there was no difference in firmness among coated and uncoated apples, but, after a 14-day period at 21 °C, shellac-coated fruit were significantly firmer than all other treatments. Shellac- and candelilla-coated apples contained higher CO2 than uncoated fruit and lower O2 than all coated fruit except those coated with PVA. PVA-coated apples contained significantly higher ethylene than uncoated fruit. Candelilla coating was most effective in reducing weight loss while PVA and zein had no effect. Shellac and carnauba coatings reduced weight loss relative to uncoated fruit. There were no differences in perception of sweetness, acidity, off-flavor, and overall flavor. Effects of coating formulations on apple flavor volatile composition will be discussed.
374 Evidence that α-farnesene Biosynthesis during Fruit Ripening is Involved in Ethylene-regulated Gene Expression
Authors: Ju Zhiguo , Curry Eric A.
Published: February 2019

In `Delicious' and `Granny Smith' apples, fruit did not produce α-farnesene until internal ethylene reached about 1 μL•L-1. The correlation between internal ethylene and α-farnesene production was highly significant (r2 = 0.71 and 0.76, respectively) and fitted the exponential growth equation. Aminoethoxyvinylglycine (AVG) inhibited both internal ethylene and α-farnesene production, while ethephon stimulated them. When applied to discs from preclimacteric fruit peel, cycloheximide and actinomycin D inhibited ethylene and α-farnesene production. In discs from AVG-treated fruit, ethephon induced α-farnesene synthesis. Cycloheximide, actinomycin D, and silver ion counteracted the stimulation effect of ethephon. When added to discs from preclimacteric fruit peel or AVG-treated fruit peel, hydroxymethylglutarc acid, mevalonic acid lactone, and farnesyl pyrophosphate induced α-farnesene synthesis, which was not affected by cycloheximide or actinomycin D.
378 Does Exposure to Hormic Dose of UV-C Light Affect the Ripening of Tomato Pericarp Disc?
Authors: Kalantari S. , Samson G. , Makhlouf J. , Arul J.
Published: February 2019

The application of ultraviolet light on fruit and vegetables is a promising new method to control storage diseases and to delay the onset of senescence. In this investigation, we studied the effects of hormic dose (1,4 Merg•cm-2) of UV-radiation on the ripening of tomato pericarp discs by measuring different characteristics of ripening and senescence during storage. We observed that UV-treatment induced significant delays of the red color development, chlorophyll degradation, and lycopene production compared to control discs. UV-treatment also retarded the decline of the chlorophyll-a fluorescence ratios Fv: Fm and *F : Fm′, two characteristics related, respectively, to the maximum and operational quantum yield of photosystem II electron transport. Furthermore, the climacteric ethylene peak was delayed in the treated discs. However, UV-treatment did not alter textural changes, and the respiratory climacteric peaks were observed concomitantly for both treated and untreated tomato discs. However, the respiratory rate was consistently higher in treated discs. These results indicate that UV irradiation of tomato pericarp discs delays some processes of ripening associated with chloroplast to chromoplast transition whereas other ripening processes seem unaffected.
388 Measurement of Strawberry Fruit Firmness and Drip-loss
Authors: Moore Patrick P.
Published: February 2019

Strawberry fruit of 16 clones was harvested from 45 plots in 1997. Fruit from 35 plots, 12 of the clones sampled in 1997 plus four additional clones, was harvested in 1998. Fruit was harvested on three to five dates in 1997 and three to seven dates in 1998 with 160 samples in 1997 and 165 samples in 1998. Fruit firmness was determined for five fruit from each plot at each harvest with a penetrometer and fruit from the same harvest was sliced, sugared, and frozen. Drip loss was determined later for the frozen, sliced samples. There were statistically significant correlations between firmness and drip-loss (r = -0.27, n = 160, P < 0.01 in 1997 and r = -0.44, n = 165, P < 0.001 in 1998); however, firmness did not adequately predict drip-loss. There was considerable variation in drip loss from harvest to harvest, which was associated with weather conditions or precipitation/irrigation. The drip loss in 1997 was not significantly correlated with the drip loss for the same plots in 1998 (r = -0.26, n = 24, ns); however there was a significant correlation between firmness in 1997 and 1998 (r = 0.52, n = 24, P < 0.05). These findings have implications for evaluation of fruit in a strawberry breeding program for a processing industry.
393 The Potential of Saprophytic Yeasts Antagonistic to Aspergillus flavus in Reducing Aflatoxin Contamination of Tree Nuts
Authors: Hua S.-S.T. , Baker J.L. , Flores-Espiritu M.
Published: February 2019

California is the major state for producing almonds, pistachios, and walnuts, with a total market value of $1.6 billion. Both domestic and export markets of these nuts presently allow a maximum level of aflatoxin B1 contamination in the edible nuts to be 20 ppb. Even very low degrees of infection of the nuts by A. flavus can result in aflatoxin levels above the mandatory standards. Biological control to reduce the population of and to inhibit the biosynthesis of A. flavus in orchards may be useful to decrease infection and thus aflatoxin content in the edible nuts. Certain saprophytic yeasts were shown to effectively compete with postharvest fungal pathogens such as Penicillium expansum and Botrytis cinerea. The potential of saprophytic yeasts to reduce aflatoxin contamination in tree nuts has not been hitherto extensively explored. A safe visual bioassay for screening yeasts antagonistic to A. flavus has been developed. The nor mutant of A. flavus has a defective norsolorinic acid reductase and blocks the aflatoxin biosynthetic pathway, resulting in the accumulation of norsolorinic acid, a bright red-orange pigment. We used the nor mutant in the assay to screen yeasts strains for their ability to inhibit aflatoxin production by visually scoring the accumulation of this pigment as well as the growth and sporulation of the fungus. Yeast strains that reduced the red-orange pigment accumulation in the nor mutant were identified and shown to inhibit aflatoxin biosynthesis of several toxigenic strains of A. flavus.
402 Lettuce Seed Germination and Endo-mannanase Activity are Stimulated by Ethylene at High Temperature
Authors: Nascimento Warley M. , Cantliffe Daniel J. , Huber Donald J.
Published: February 2019

Temperatures above 30 °C may delay or inhibit germination of most of commercial lettuce cultivars. Ethylene enhances lettuce seed germination at high temperatures. Enzyme-mediated degradation of endosperm cell walls appears to be a crucial factor for lettuce germination at high temperature. The galactomannan polysaccharides in lettuce endosperm cell wall are mobilized by endomannanase. The role of endo-mannanase during germination of lettuce seeds at high temperature (35 °C) and the possible role of etlene in enzyme regulation were investigated. Seeds of thermotolerant (`Everglades'-EVE) and thermosensitive (`Dark Green Boston'-DGB) lettuce genotypes were incubated at 20 and 35 °C in water, 10 mM of 1-aminocyclopropane-1-carboxylic acid (ACC), or 20 mM of silver thiosulphate (STS). Also, seeds were primed in an aerated solution of polyethylene glycol (PEG), or PEG+ACC, or PEG+STS. Untreated seeds germinated 100% at 20 °C. At 35 °C, EVE germinated 100%, whereas DGB germinated only 33%. Seed priming or adding ACC during imbibition increased germination of DGB to 100% at 35 °C. Adding STS during imbibition led to a decrease in germination at 35%C in EVE and completely inhibited germination of DGB. Priming with STS led to reduced germination at 35%C of both genotypes. EVE produced more ethylene than DGB during germination at high temperature. Providing ACC either during priming or during germination led to an increase in endo-mannanase activity, whereas STS inhibited mannanase activity. Higher endo-mannana activity was observed in EVE than DGB seeds. The results suggest that ethylene might overcome the inhibitory effect of high temperature in thermosensitive lettuce seeds via weakening of endosperm due to increased endo-mannanase activity.
405 Glycinebetaine Accumulation in Red Beet under Salinity
Authors: Subbarao Guntur V. , Wheeler Raymond M. , Levine L.H. , Stutte Gary W.
Published: February 2019

Accumulation of glycinebetaine occurs in Chenopodiaceae members and is thought to assist in osmotic adjustment and protect cytoplasm from sodium toxicity. Red beet has an ability to tolerate high tissue sodium levels, which may result in increased glycinebetaine production. To test this hypothesis, two cultivars of red beet ['Scarlet Supreme' (SS) and `Ruby Queen' (RQ)] were grown under nonsaline (4.75 mM Na) and saline (54.75 mM Na) conditions in a recirculating hydroponic system for 42 days at elevated CO2 (1200 μmol•mol-1) in a growth chamber. Leaf glycinebetaine level, relative water content, and osmotic potential were measured at weekly intervals. Leaf glycinebetaine levels increased with plant age and reached a maximum of 67 μmol•g-1 dw under nonsaline and 101 μmol•g-1 dry weight (dw) under saline conditions at 42 days in SS; in RQ, the glycinebetaine levels reached a maximum of 91 μmol•g-1 dw under nonsaline and 121 μmol•g-1 dw under saline conditions by 26 days. The mean glycinebetaine levels were increased over two-thirds under saline conditions in both the cultivars. RQ accumulated significantly higher (37% more under nonsaline, and 46% more under salinity) glycinebetaine than SS. The turgid leaf osmotic potential of RQ was consistently higher than SS under nonsaline (2.23 MPa in RQ vs. 1.82 MPa in SS) and saline (2.48 MPa in RQ vs. 2.02 MPa in SS) conditions. The results indicate that higher glycinebetaine levels in the leaf could result in better osmotic adjustment, and glycinebetaine accumulation in red beet can vary among cultivars and is strongly affected by external salinity.
410 Interactive Effects of Harvest Maturity, Controlled Atmosphere, and Surface Coatings on Mango (Mangifera indica L.) Flavor Quality
Authors: Baldwin E.A. , Malundo T.M.M. , Bender R. , Brecht J.K.
Published: February 2019

Mango fruit, cv. Tommy Atkins, were harvested from two grove sites in south Florida at mature green (MG) and tree ripe (TR) maturities. The fruit were either coated with one of two coatings (NS = Nature Seal® 4000, a polysaccharide coating, or CW = carnauba wax) or left uncoated (control) and stored in humidified air or held in a controlled atmosphere (CA = 5% O2 plus 25% CO2) at 12 °C for 21 days followed by 2 days in air at 20 °C. There were 12 fruit for each treatment/maturity stage combination replicated by grove site. After storage, the pulp was homogenized for later consumer or descriptive panel analysis. Measurements for total soluble solids (SS), pH, titratable acidity (TA), and flavor volatile compounds were also made. TR-harvested fruit were sweeter and generally more aromatic than MG-fruit as determined by sensory and/or chemical analysis. NS-coated fruit were more sour, bitter, and astringent compared to controls and CA-treated fruit. NS-coated fruit received lower overall consumer scores than CW-coated fruit, but were not different from controls or CA-treated fruit. This was reflected also in descriptive panel ratings. There were no differences based on storage treatment for SS, pH, or TA; however, NS-coated fruit were higher in acetaldehyde, methanol and ethanol compared to control or CA-treated fruit. Correlation and regression analysis showed significant relationships between sensory and chemical data.
412 Quality of Packaged Fresh-cut Cantaloupe
Authors: Hakim A. , Purvis A. , Khatoon M.
Published: February 2019

Cantaloupe at commercial stage of maturity were sliced, i.e., prepared as minimally proceed, rinsed with or without sodium hypochloride solution (50 ppm), and drained. They were stored in perforated polyethylene package (PE) at 1 °C in air and controlled atmosphere (2 % O2 and 5 % CO2) for 5 and 10 days. Fresh-cut cantaloupe slices were analyzed initially and after 5 and 10 days of storage for weight loss, lycopene content, fungus infection, flavor and taste, TSS, pH, ethanol, firmness, and electrolyte leakage. Fruit stored in CA exhibited lower weight loss, higher lycopene content, less fungus infection, better flavor and taste, more firmness, higher TSS content, and lower electrolyte leakage than store in air. When compared to fruit treated with sodium hypochloride, lower lycopene content, higher fungus infection, inferior flavor and taste, more softness, and higher electrolyte leakage were detected in fruit that were not rinsed with sodium hypochloride solution. Extended storage time resulted in higher weight loss, increased fungus infection, bad taste, off-flavor, more softness, lower TSS content, and higher leakage value. This study indicates that it is possible to extend the shelf-life of fresh-cut cantaloupe slices from 5 to 10 days if kept at 1 °C in 2% O2 and 5% CO2 in PE package.
420 Integrating Extension Field Faculty Into Academic Homes: The Oregon State University Experience
Authors: Olsen J.L. , Boyer C.D.
Published: February 2019

In 1993, then OSU President John Byrne declared that: “All Extension Service faculty, county agents as well as specialists, will be assigned academic colleges, and will have an academic appointment in the appropriate college.” The selection of the academic home would involve a mutual agreement between the individual and the department and would take into consideration the faculty member's academic training, experience, and work assignment. The implementation of this decision was completed by July 1995. In the College of Agricultural Sciences, this assignment of faculty to academic homes was accommodated by adding county agents to the faculty of existing departments. The Dept. of Horticulture faculty numbers nearly doubled, with an increase from 34 to 58. The department head is now very involved in the annual review and salary administration of extension field faculty. Campus-based faculty are now involved in all of the hiring, promotion, and tenure decisions for extension field faculty and vice versa. Field faculty participate in departmental decision making. The change in the number and diversity of faculty in the department is a unique effort to unify programmatic focus for extension, research, and teaching at OSU. As a work in progress, many issues are being addressed including full faculty participation in the decision-making process, communication, evaluation of scholarship, and building departmental community. Successes, pitfalls, and challenges ahead will be discussed and illustrated.
427 Factors Determining Consumer Preferences for Colored Bell Pepper
Authors: Frank Chris , Simonne Eric , Nelson Robert , Simonne Amarat , Behe Bridget
Published: February 2019

Most bell peppers produced and consumed in the United States are green in color. However, red, yellow, orange, brown, white, black, and purple bell pepper are also available. While bell pepper consumption has been increasing in the past 10 years, limited information is available on how color, retail price, and vitamin C influence consumer behavior. A conjoint analysis of 436 consumer responses showed that color (75%) and retail price (23%) were more important than vitamin C (3%) in shaping consumer purchase decision. Six consumer segments were identified. Segments II to V preferred green bell pepper, while segments I and VI favored the orange and brown color, respectively. Demographic variables were not good predictors of segment membership. However, previous purchases of bell pepper significantly affected the probability of membership in at least one segment. These results suggest that while green is the preferred color, a market exists for orange, red, and yellow peppers. Results on price sensitivity suggest that profits at the retail level are likely to increase by increasing the price of green peppers, and decresing that of the colored ones.
433 Offering a Horticultural Laboratory Experience at a Distance
Authors: McKenney C.B. , Durham R.E. , Peffley E.B.
Published: February 2019

The horticulture faculty at Texas Tech Univ. has developed an introductory horticulture laboratory course offered asynchronously through several media. A print version has been developed as a traditional correspondence course. Students can also choose to access the course over the World Wide Web with laboratory instruction provided from an accompanying CD-ROM. The course is based on an introductory horticulture textbook and is supplemented by additional information. Students conduct the laboratory exercises at a location of their choice and return photographs or video tapes of their results along with a formal lab report. Self-help exercises, worksheets, and proctored exams are submitted by correspondence or electronically via the World Wide Web. The most challenging aspect of this project was the development of laboratory exercises that ensured adequate experiential learning. This was accomplished by using easily accessible materials for laboratories that would allow students to apply the scientific method. A CD-ROM version of the lab includes compressed video segments used to demonstrate laboratory techniques. Details of these laboratory components and samples of student work will be presented.
441 Best Grapefruit Harvest Time for Potential Health Benefit of Pectin
Authors: Liu Y. , Patil B.S. , Ahmad H. , Gardiner D.T.
Published: February 2019

Pectin is a class of complex polysaccharides that function as hydrating agents and cementing materials for the cellulose network. Pectin has various health benefits, such as decreasing serum cholesterol levels, alleviating diabetes mellitus, and preventing cancer. It has been reported that the cancer prevention effect is closely related to the structure of pectin (galactose-rich, molecular weight <10,000, and methylation degree 50% to 70%). This study was conducted to investigate the variation of grapefruit pectin content due to harvest time. `Rio Red' grapefruit on sour orange rootstock grown at Texas A&M Univ.-Kingsville Citrus Center were harvested every 2 months and analyzed for pectin content, galacturonic acid concentration, methylation degree, and neutral sugar composition. Results showed that lamella contains more pectin than flavedo and albedo. In the lamella, the edible section, the uronic acid content ranged from 85% to 90% from August to April the following year. Methylation degree increased from August (31.89%) to April (46.99%). Total neutral sugar content of lamella pectin decreased from 110.54 to 61.77% mg·g -1. Galactose, arabinose, and rhamnose are the major sugar contents of pectin (85%), and glucose content increased with the season from 3.14 to 13.34 mg·g-1. Molecular weight of pectin was also determined.
442 Enhancing Citrus Nutraceuticals through Variable Nutrient Rates
Authors: Patil Bhimanagouda S. , Alva Ashok K.
Published: February 2019

Accumulating epidemiological evidences indicate that citrus phytochemicals have prevented chronic diseases such cancer and heart diseases. To enhance nutraceutical levels, field experiments were conducted using `Ruby Red' grapefruit on Carrizo citrange rootstock to evaluate the effects of variable fertilizer rates on nutraceutical contents. The trees received annual nitrogen rates from 0 to 280 kg·ha-1 (using a 1 N: 0.25 P: 1 K blend) under optimal irrigation schedule. Subsamples of fruit were analyzed for nutraceutical levels. HPLC analysis showed that naringin concentrations of the fruit collected from the trees treated with different levels of nitrogen differ significantly, and naringin levels decreased with increased nitrogen levels. Fruit from the control treatment had 1316 mg·mL-1 of naringin compared to the fruit collected from 280 kg N/ha per year trees (1056 mg·mL -1). A similar trend was observed with tasteless flavonoid naringenin rutinoside (narirutin). Total vitamin C [ascorbic acid (AA) plus dehydroascorbic acid (DHAA)] content from the fruit collected decreased with the nitrogen levels increased. These results demonstrate that increased fertilizer rates have an influence on the nutraceutical levels; therefore, there is a potential for further investigations on fine tuning the preharvest production programs to improve the nutritional value of the fruit.
458 Inheritance of Tree Size in Pistachio (Pistacia vera L.)
Authors: Chao Chih-Cheng T. , Parfitt Dan E. , Ferguson Louise , Kallsen Craig , Maranto Joe
Published: February 2019

Trunk cross-sectional area from a population of 6192 pistachio trees was used to estimate tree growth from 1995 to 1997. The narrow-sense heritabilities of trunk cross-sectional area were near zero across multiple locations based on analyses of progenies from 20 half-sib families. However, within individual location, there were values from 0.20 to 0.56 for 1995, 1996, and 1997, respectively. Broad-sense heritability estimates were considerably higher, from 0.36 to 0.64 at multiple locations and 0.51 to 1.35 for individual locations. These results suggest that dominance and significant interaction effects, epistatic and genotype by environment, were important. Breeding strategies should emphasize selection of superior parents based on individual performance, and parents should be selected in the environment in which the progeny are intended to be used.
467 Overcoming Dormancy, Advancing Budbreak, and Advancing Fruit Maturity in `Bing' Sweet Cherry (Prunus avium L.): Surfactants/ Dormant Oils + Calcium Ammonium Nitrate or Hydrogen Cyanamide
Authors: Weis K.G. , Southwick S.M. , Yeager J.T. , Rupert M.E. , Moran R.E. , Grant J.A. , Coates W.W.
Published: February 2019

In continuing trials (1995-current), we have used a variety of treatments to overcome inadequate chilling, coordinate bloom, improve leaf out and cropping, and advance/coordinate maturity in sweet cherry, cv. Bing. Treatments have included hydrogen cyanamide (HCN, Dormex) and various surfactants or dormant oils combined with calcium ammonium nitrate (CAN17). Chill hour accumulation, (required chilling for `Bing' = 850 to 880 chill hours) has varied greatly in each dormant season from 392 (Hollister, 1995-1996) to adequate, depending both on the season and location (central valley vs. coastal valley). In 1998, 4% HCN advanced budbreak significantly compared to any other treatment, although other chemical treatments also were more advanced than the untreated control. Dormex advanced completion of bloom 11% to 40% more than other treatments, although other dormancy-replacing chemicals were at least 16% more advanced in petal fall than the untreated control. Dormex contributed to slightly elevated truss bud death, as did 2% Armobreak + 25% CAN17. In 1998, fruit set was improved by 2% Armobreak + 25% CAN17 (79%) compared to the untreated control (50%); all other treatments statistically equaled the control. Fruit set was not improved by Dormex, although bloom was advanced by a few days in this treatment. As fruit set was increased by treatments, rowsize decreased (as did fruit weight), as expected, but no treatment resulted in unacceptable size. In 1997, fruit set was also improved by 2% Armobreak + 25% CAN17; however, fruit set was so low overall in that year that no real impact was found. In 1997 and 1998, 4% HCN advanced fruit maturity compared to other treatments, with darker, softer, larger fruit at commercial harvest. These and additional results will be presented.
502 Intermittent CO2 Enrichment for Hydroponic Lettuce Production
Authors: de Villiers David S. , Langhans Robert W. , Both A.J. , Albright Louis D. , Scholl Sue Sue
Published: February 2019

CO2 enrichment increases efficiency of light utilization and rate of growth, thereby reducing the need for supplemental lighting and potentially lowering cost of production. However, during warmer periods of the year, CO2 enrichment is only possible intermittently due to the need to vent for temperature control. Previous research investigated the separate and combined effects of daily light integral and continuous CO2 enrichment on biomass accumulation in lettuce. The current research was designed to look at the efficiency with which lettuce is able to utilize intermittent CO2 enrichment, test the accuracy with which growth can be predicted and controlled, and examine effects of varying CO2 enrichment and supplemental lighting on carbon assimilation and plant transpiration on a minute by minute basis. Experiments included application of various schedules of intermittent CO2 enrichment and gas exchange analysis to elucidate underlying physiological processes. Same-day and day-to-day adjustments in daily light integrals were made in response to occasional CO2 venting episodes, using an up-to-the-minute estimate of growth progress based on an integration of growth increments that were calculated from actual light levels and CO2 concentrations experienced by the plants. Results indicated lettuce integrates periods of intermittent CO2 enrichment well, achieving expected growth targets as measured by destructive sampling. The gas-exchange work quantified a pervasive impact of instantaneous light level and CO2 concentration on conductance and CO2 assimilation. Implications for when to apply supplemental lighting and CO2 enrichment to best advantage and methods for predicting and controlling growth under intermittent CO2 enrichment are discussed.
503 Evidence for Toxic Effects of Cellulose Acetate in UV Exclusion Studies on `Ashley' Cucumber Seedlings
Authors: Krizek Donald T. , Mirecki Roman M.
Published: February 2019

Cellulose diacetate has been widely used in UV-B enhancement studies under field and controlled-environment conditions since the early 1970s to remove wavelengths below ≈290 nm, without any evidence of toxicity effects. However, while conducting UV-B exclusion studies in window boxes covered with cellulose diacetate (CA) or in Plexiglas chambers lined with CA, there was marginal chlorosis and cotyledon epinasty in `Ashley' cucumber, which is normally resistant to elevated UV-B, while seedlings exposed to open sunlight and those grown under polyester (PE) film to exclude UV-B were free of visible injury. These findings suggested that the CA filter itself may be causing toxicity. To test this hypothesis, a UV exclusion study was conducted in which CA or Teflon (T), both UV-B and UV-A transmitting films, were used to cover window boxes in the following four combinations (top/bottom): CA/CA, CA/T,T/CA, and T/T. When CA was used as the bottom filter (CA/CA and T/CA), the plants showed significantly greater leaf injury and a 2- to 3-fold reduction in growth than when T was used as the bottom filter (CA/T and T/T). These findings suggest that toxicity is caused by CA itself rather than by solar UV-B radiation, possibly as a result of outgassing of phthalates known to be used as plasticizers in the manufacture of CA. Further evidence that CA was responsible for leaf injury was provided by a companion study in which T was replaced by PE and damage was still observed, although no significant growth effects of CA position were observed.
505 Analysis of Leaf Development Rates as Affected by Environment Conditions for Modeling Vegetative Propagation of Sweetpotato
Authors: Kubota Chieri , Yamaguchi Ayami , Kozai Toyoki
Published: February 2019

For vegetative propagation of sweetpotato, single or multi-node leafy cuttings are used as propagules. A quantitative understanding of leaf development and the effects of environment conditions on leaf emergence and expansion rates is important for predicting the number of propagules produced after a given production period. Single-node cuttings each with a fully expanded leaf were grown under two levels of photosynthetic photon flux (PPF, 160 and 250 μmol·m–2·s–1) and photoperiod (10 and 16 h/day). The time courses of the number of leaves larger than the standard leaf area (As) were obtained by analyzing the time courses of leaf blade length recorded every day on each leaf. The number of leaves larger than a given As increased almost linearly after the first leaf reached to the As. PPF and photoperiod affected both the duration until the appearance of the first leaf with As and the leaf development rates (leaves per day). The effects of PPF were more pronounced than photoperiod for the development rate of the leaves regardless of As. Results obtained in these experiments were incorporated into our previously developed model, and the number of propagules produced under different environment conditions was predicted. Such techniques need to be used effectively for planning and environment control of vegetative propagation.
506 Plant Density and Shoot Pruning Management on Yield of a Summer Greenhouse Sweet Pepper Crop
Authors: Jovicich Elio , Cantliffe Daniel J. , Hochmuth George J.
Published: February 2019

In greenhouse crops, fruit yield and quality can be increased by managing shoot pruning and plant density. The effect of plant population density (2, 3, and 4 plants/m2 as function of in-row plant spacings of 66.5, 44.3, and 33.3 cm, respectively), and shoot pruning (one, two, and four main stems) was studied for effects on fruit yield, quality and plant growth of greenhouse-grown sweet pepper (Capsicum annuum L. cv. Robusta) during Summer 1998 in Gainesville, Fla. Red fruit were harvested 84 and 118 days after transplanting (14 Apr.). Additional fruit set was inhibited due to the high temperatures. Marketable yield (number and weight) per square meter increased linearly with plant density and was greater on plants with four stems than in those with two or one stem. Extra-large fruit yield per square meter was not affected by plant density, but was higher in four-stem plants. Total marketable yield and extra-large fruit yields per plant were greatest in the four-stem plants at two plants per square meter. The stem length and the number of nodes per stem increased linearly with the decrease in plant spacing. Stem length and number of nodes per stem were greater in single-stem than in four-stem plants. Number and dry weight of leaves, stem diameter, and total plant dry weight were higher in four- and two-stem plants than in single-stem plants. Results indicated that four plants per square meter pruned to four stems increased marketable and extra-large fruit yield in a short harvest period of a summer greenhouse sweet pepper crop in north central Florida.
515 Mapping of Molecular Markers and Seedcoat Pattern Associated with QTL Affecting White Mold Resistance in Common Bean
Authors: Park Soon O. , Coyne Dermot P. , Steadman James R. , Jung Geunhwa
Published: February 2019

White mold, incited by Sclerotinia sclerotiorum (Ss), is an important disease of common bean (Phaseolus vulgaris). Our objective was to identify RAPD markers and seedcoat pattern associated with QTL affecting resistance to Ss isolates 152 and 279 in a molecular marker-based linkage map previously constructed using a recombinant inbred (RI) population from the common bean cross `PC-50' (resistant to Ss) x XAN-159 (susceptible to Ss). White mold reactions were derived from a greenhouse straw test. Continuous distributions for the reactions to Ss isolates 152 and 279 were observed for RI lines, indicating quantitative inheritance. An intermediate (+0.67) Pearson correlation was observed between the reactions to Ss isolates 152 and 279. Low (0.24 and 0.23) narrow-sense heritabilities were found for the reactions to Ss isolates 152 and 279. Three QTL affecting resistance to Ss isolate 152 explained 33% of the phenotypic variation. Four QTL affecting resistance to Ss isolate 279 explained 54% of the phenotypic variation. The seedcoat pattern marker (C) on linkage group I was most consistently associated with resistance to Ss isolates 152 and 279, and explained 10% and 24% of the phenotypic variation for the traits, respectively. This is the first report on detection of QTL for white mold resistance in common bean. The RAPD markers and seedcoat pattern could be useful in breeding for white mold resistance.