bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxic Metals in Different Varieties of Seabuckthorn (Hippophae rhamnoides)
Authors: Lobacheva I. , Letchamo W.
Published: February 2019

Seabuckthorn (Hippophae rhamnoides, L) (Oblepiha, Siberian pineapple, Sandorn, Sha-ji), from the Eleagnaceae family, is one of the most important and leading sources of pharmaceutical, nutritional, and cosmetic products in Tibet, Russia, and China. Hippophae oil is an important component of the cream for protection from cosmic radiation, tan-enhancing, cell tissue regeneration, wound healing, and antiaging properties. It is a good source of natural antioxidants, and is used to boost the body immune system, adaptation to extreme conditions, and increased performance body performance. The fruits, seeds, leaves, and cork contain a large amount of chemical elements, essential oils, vitamins A, B, C, E, carotenoids, flavonoids, palmitic and palmitoleic acids, unsaturated fatty acids, α-sitosterol, proteins, minerals, and many other bioactive compounds. As part of the selection and genetic improvement program to develop superior varieties of higher fruit yield, quality and resistance, varietal difference in the uptake or accumulation of heavy (toxic) metals in the berries was investigated. The variation in the content or accumulation of Zn, Cu, Pb, Cd, and Fe in the berries of three varieties of Hippophae (Chuiskaja, Zivko, and Chechek) with differing morphological, and fruit quality was studied. The plants were grown under similar conditions, at Lisavenko Inst. for fruit trees research in Russia. There was a significant difference in the concentration of the metals among the three varieties. Variety `Tchuiiskaja' was found to have significantly higher concentration (P < 0.05) of Cu, Pb, and Fe. The lowest concentration of the metals was recorded for the variety `Chechek'. The obtained results enable us to suggest, that the Hippophae varieties may significantly vary in the accumulation toxic elements in their berries. This fact should be well considered during selection and improvement program for Hippophae.
Gene Estimation, Associations of Traits, and Confirmation of QTL for Common Bacterial Blight Resistance in Common Bean
Authors: Park Soon O. , Coyne Dermot P. , Jung Geunhwa
Published: February 2019

Common bacterial blight, incited by Xanthomonas campestris pv. phaseoli (Xcp), is a serious disease of common bean(Phaseolus vulgaris L.). Gene estimation, associations of traits, and confirmation of QTL for resistance to Xcp were investigated in a recombinant inbred population derived from the backcross BC2F6 PC-50 (susceptible to Xcp) × XAN-159 (resistant to Xcp). One or two genes from XAN-159 controlled leaf resistance to Xcp. One major gene from XAN-159 was involved in controlling pod resistance to Xcp. Low (+0.24) to intermediate (+0.57 and +0.75) Pearson correlations were observed between leaf and pod reactions to Xcp. Purple flower color was associated with leaf and pod resistance to Xcp but not days to flower. One to 2 QTLs explained from 20 to 51% of the total phenotypic variation for leaf reactions to 5 Xcp strains. Two QTLs explained from 20 to 22% of the total phenotypic variation for pod reactions to Xcp strains EK-11 and DR-7. A marker BC437.1050 was associated with leaf and pod resistance to 5 Xcp strains in nearly all experiments, and accounted for 13% to 45% of the phenotypic variation for these traits. A unassigned marker D13.1000 was associated with only pod resistance to Xcp strains EK-11 and DR-7. Gene number (1 or 2) estimations and number of QTL (1 or 2) detected for resistance to Xcp generally agree. The confirmed marker BC437.1050 is expected to be useful in breeding programs for resistance to Xcp.
Effect of Plant Population on Muskmelon Yield and Quality
Authors: Thornton Allan C. , Schultheis Jonathan R. , Walters S. Alan
Published: February 2019

Muskmelon plant populations and arrangements were evaluated at two sites in North Carolina in 1997. Within-row plant spacings of single rows were 0.15, 0.30, 0.46, 0.61, and 0.76 m, while staggered twin row spacings were 0.30, 0.46, and 0.61 m. The trials were conducted on black plastic with drip irrigation at both locations using the `Athena' cultivar. One trial was seeded 22 Apr., the other was transplanted 21 May. Yield was recorded as fruit number and weight. Soluble solids measurements were also taken. Yields were nearly two times greater when planted on 22 Apr. than 21 May. Yields in the later planting ranged between 13,300 and 18,800 melons per hectare, while yields in the earlier planting ranged between 23,700 and 31,600 melons per hectare. Populations arranged in staggered twin rows on the bed provided no yield advantage compared with single rows. As in-row plant spacing increased, yields of large-sized fruit (>2.0 kg) tended to be greater, while production of smaller size marketable fruit (1.4 to 2.0 kg) tended to be greater as in-row plant spacing decreased. Soluble solids were not affected by plant population.
Plant Population, Seedlings per Hill, Cultivar, and Plastic Mulch Affect Watermelon Yield, Size, and Quality
Authors: Sanders D.C. , Cure J.D. , Schultheis J.R. , Estes E.A.
Published: February 2019

Plant population, seedlings per hill, cultivar and plastic mulch were evaluated in five environments for their affect on watermelon yield, size and quality. `Royal Jubilee' outyielded `Prince Charles' in all environments, and the highest yields were associated with low % culls and high fruit numbers per hectare. Highest yields of marketable fruits (>4.5 kg/melon) were obtained using mulch and areas per plant between 0.4–0.9/m. Unless there is a market for small fruits (<4.5 kg), optimum area per plant was 1 m/plant. Results for one plant/hill at one in-row spacing were similar to those for the alternative planting pattern of two plants/hill at half the in-row spacing, thus supporting the feasibility of using the more economical alterative planting pattern.
Soil Water Measurement as Basis to Optimize Irrigation Scheduling: A Review
Authors: Alva A.K. , Fares A.
Published: February 2019

Supplemental irrigation is often necessary for high economic returns for most cropping conditions even in humid areas. As irrigation costs continue to increase more efforts should be exerted to minimize these costs. Real time estimation and/or measurement of available soil water content in the crop root zone is one of the several methods used to help growers in making the right decision regarding timing and quantity of irrigation. The gravimetric method of soil water content determination is laborious and doesn't suite for frequent sampling from the same location because it requires destructive soil sampling. Tensiometers, which measure soil water potential that can be converted into soil water content using soil moisture release curves, have been used for irrigation scheduling. However, in extreme sandy soils the working interval of tensiometer is reduced, hence it may be difficult to detect small changes in soil moisture content. Capacitance probes which operate on the principle of apparent dielectric constant of the soil-water-air mixture are extremely sensitive to small changes in the soil water content at short time intervals. These probes can be placed at various depths within and below the effective rooting depth for a real time monitoring of the water content. Based on this continuous monitoring of the soil water content, irrigation is scheduled to replenish the water deficit within the rooting depth while leaching below the root zone is minimized. These are important management practices aimed to increase irrigation efficiency, and nutrient uptake efficiency for optimal crop production, while minimizing the impact of agricultural non-point source pollutants on the groundwater quality.
Comparison of Mixtures vs. Monocultures of Cover Crops for Fresh-market Tomato Production With and Without Herbicide
Authors: Teasdale John R. , Abdul-Baki Aref A.
Published: February 2019

Hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), and rye (Secale cereale L.) and mixtures of rye with hairy vetch and/or crimson clover were compared for no-tillage production of staked, fresh-market tomatoes (Lycopersicon esculentum Mill.) on raised beds. All cover crops were evaluated both with or without a postemergence application of metribuzin for weed control. Biomass of cover crop mixtures were higher than that of the hairy vetch monocrop. Cover crop nitrogen content varied little among legume monocrops and all mixtures but was lower in the rye monocrop. The C:N ratio of legume monocrops and all mixtures was <30 but that of the rye monocrop was >50, suggesting that nitrogen immobilization probably occurred only in the rye monocrop. Marketable fruit yield was similar in the legume monocrops and all mixtures but was lower in the rye monocrop when weeds were controlled by metribuzin. When no herbicide was applied, cover crop mixtures reduced weed emergence and biomass compared to the legume monocrops. Despite weed suppression by cover crop mixtures, tomatoes grown in the mixtures without herbicide yielded lower than the corresponding treatments with herbicide in 2 of 3 years. Chemical name used: [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one](metribuzin).
Orchard Groundcover Management Systems Affect Meadow Vole Populations and Damage to Apple Trees
Authors: Merwin Ian A. , Ray John A. , Curtis Paul D.
Published: February 2019

Meadow vole (Microtus pennsylvanicus Ord) populations, feeding activity and damage to young apple (Malus ×domestica Borkh.) trees were monitored for several years in a New York orchard by direct observation, trap counts, and a feeding activity index in various groundcover management systems (GMSs). Meadow vole population density differed among GMSs, with consistently higher densities and more trees damaged in crown vetch (Coronilla varia L.), hay-straw mulch, and red fescue (Festuca rubra L.) turfgrass tree-row strips. Vole densities were high in autumn and low in spring each year. Anticoagulant rodenticides and natural predation did not adequately control voles in GMSs providing favorable habitat. Groundcover biomass per m2 was weakly correlated with vole densities in 2 of 3 years, while the percentage of soil surface covered by vegetation was not significantly correlated with vole populations. Applications of thiram fungicide in white latex paint were better than no protection, but less effective than 40-cm-high plastic-mesh guards for preventing vole damage to tree trunks. A combination of late-autumn trapping, close and consistent mowing of the orchard floor, trunk protection with mesh guards, contiguous habitat for vole predators, and herbicide applications within the tree rows provided effective control of meadow-vole damage to trees at this orchard during 3 years without applications of rodenticide baits. Chemical names used: Tetramethylthiuram disulfide (thiram)
335 Juvenility Influences Cold Acclimation Ability in Rhododendron Populations
Authors: Lim Chon C. , Arora Rajeev , Krebs Stephen L.
Published: February 2019

Winter survival in woody plants is controlled by environmental and genetic factors that affect the plant's ability to cold-acclimate. A juvenile period in woody perennials raises the possibility of differences in cold-acclimating ability between juvenile vs. mature (flowering) phases. This study investigated the yearly cold hardiness (CH) changes of rhododendron populations and examined the relationship between leaf freezing tolerance (LFT) and physiological aging. Naturally acclimated leaves (January) from individual plants (parents-R. catawbiense and R. fortunei, F1, F2, and backcross) and F1 population generated from R. catawbiense and R. dichroanthum cross were subjected to controlled freeze-thaw regimes. LFT was assessed by measuring freeze-thaw-induced ion leakage from leaf discs frozen over a range of treatment temperatures. Data were then plotted with a sigmoidal (Gompertz) curve by SAS, to estimate Tmax—the temperature causing maximum rate of injury. Tmax for the 30- to 40-year-old parental plants (catawbiense, fortunei, and dichroanthum) and the F1 `Ceylon' (catawbiense × fortunei) were estimated to be about -52, -32, -16, and -43 °C, respectively. These values were consistent over the 3-year evaluation period. Data indicated the F2 (50 seedlings) and backcross (20 seedlings) populations exhibited significant, yearly Tmax increment (of ≈5-6 °C) from 1996 to 1998 as they aged from 3 to 5 years old. A similar yearly increase was observed in the 12 F1 progenies (compared 2 to 3 years old) of catawbiense × dichroanthum cross. The feasibility of identifying hardy phenotypes at juvenile period and research implications of age-dependent changes in CH will be discussed.
350 Quality Changes of Spinach Stored in Controlled and Modified Atmospheres
Authors: MartÌnez-Damian Ma. Teresa , Cantwell Marita I.
Published: February 2019

Spinach is not packed commercially in modified-atmosphere packaging due to difficulties in maintaining beneficial conditions during distribution, where temperature fluctuations can occur. However, low O2 and high CO2 atmospheres can be useful to retard yellowing and deterioration. In two experiments we studied developing and full-size leaves stored at 7.5 °C in air and controlled atmospheres of 0.5% O2 + 10%CO2 and 5%O2 + 10% or 20% CO2. Subjective quality evaluations (visual quality, decay, discoloration, off-odors, and yellowing) and objective evaluations (L*a*b* color values, chlorophyll, pH and titratable acidity, ammonia, and ethanol and acetaldehyde) were conducted every 3 days during 15 days. The developing leaves had higher visual quality and lower off-odor scores during storage than did the full-size leaves. In air storage, leaves were below the limit of salability by day 12. The atmospheres containing 10% CO2 were similarly effective in maintaining the visual quality and greenness of the leaves, and reduced off-odors in developing but not full-size leaves. The 20% CO2 atmosphere resulted in some leaf damage. Ammonia concentrations increased during storage, with lowest and highest concentrations in leaves stored in air and 20% CO2, respectively. Tissue pH only slightly increased from 6.5 in air-stored samples, but increased notably during storage in the controlled atmospheres. At 2.5 and 7.5 °C, a plastic film providing a 5% O2 and 6% CO2 atmosphere resulted in better quality spinach than that obtained with either a 10% O2 and 3% CO2 package atmosphere or the commercial perforated polybag.
352 Heat Treatment Enhances the Development of Mealiness in Peaches and Nectarines
Authors: Obenland D.M. , Ryan F.R
Published: February 2019

Previous work by our group has demonstrated the potential feasibility of using high-temperature forced-air (HTFA) treatment for insect disinfestation of nectarines. Fruit quality of nine cultivars tested was unaffected following the application of a HTFA treatment targeted against Mediterranean fruit fly. In an extention of this work, we examined the effect of this treatment on peach and nectarine cultivars that have differing reported susceptibilities to the development of mealiness to determine if HTFA treatment has any effect on the occurrence of this disorder. Fruit were exposed to HTFA over 4 h until the fruit center registered a temperature of 47.2 °C, then stored at 5 °C for 1 to 3 weeks and 2 d at 23 °C, at which time the fruit were visually evaluated for symptoms of mealiness. `Summer Bright', `Ryan Sun', and `Elegant Lady', cultivars susceptible to the development of mealiness, showed a 66%, 24%, and 66% increase in the incidence of mealiness, respectively, due to HTFA treatment. `Summer Grand', a cultivar classified as nonsusceptible, did not develop mealiness in the absence of HTFA treatment, while 81% of the HTFA-treated fruit of this cultivar were classified as mealy following 2 weeks of storage. Enhancement of mealiness in stonefruit by heat is a very detrimental effect that must be carefully considered in the development of HTFA treatments for these commodities.
355 Effect of UV-C on Ripening and Postharvest Quality of Peaches
Authors: Ebel Robert C. , Woods Floyd M. , Himelrick Dave
Published: February 2019

Brown rot of peaches is one of the most devastating diseases that can occur before and after harvest. There has been extensive research that has shown that ultraviolet light (UV-C) kills the fungus that causes brown rot. However, it is has not been determined whether UV-C will also change ripening and fruit quality. We applied UV-C to `Loring' peaches that were harvested 10 days before normal harvest. We intentionally picked the fruit early because we wanted to make sure the fruit had not entered the climacteric. The fruit were treated with UV-C and ethylene, skin color, firmness, and soluble solids were measured. We also held fruit at three storage temperatures to determine whether there may be an interaction between UV-C treatment and storage temperature. Ethylene was slightly higher for UV-C treated fruit at 70 °F (20 °C) and 55 °F (12 °C), but not at 40 °F (4 °C). However, there was very little effect on firmness and soluble solids. There was a slight delay in development of red blush. UV-C had little effect on ripening and peach fruit quality.
358 Quality of Fresh-cut Onions
Authors: Khatoon M. , Hakim A.
Published: February 2019

Sweet onions (Allium cepae) were diced or sliced, ringed with sodium hypochloride solution (50 ppm) for about 2 min, and drained. After that, they were packaged in perforated polyethylene package and stored in an air and controlled-atmosphere (2% O2 and 5% CO2) room at 1 °C for 5 and 10 days. Weight loss, fungus infection, surface discoloration, flavor and taste, ethanol content, TSS, pH, firmness, and electrolyte leakage were determined after storage. Based on weight loss, fungus infection, surface discoloration, flavor and taste, ethanol content, TSS, pH, firmness, and electrolyte leakage, controlled-atmosphere storage, onions diced exhibited better quality retention than those that were stored in air. The overall quality of discs was better than slices. Onion stored for 10 days showed higher weight loss, more fungus infection and surface discoloration, off-flavor, bad taste, higher ethanol content, lower TSS content, less firm and higher electrolyte leakage than those stored for 5 days. So, the quality of fresh-cut onion disks can be maintained properly in a controlled atmosphere with reduced oxygen and elevated carbon dioxide up to 10 days.
360 Quality Deterioration of Fresh-cut Onions
Authors: Camelo Andrés F. López , Cantwell Marita
Published: February 2019

A study on quality changes of fresh-cut onions under different temperatures and handling conditions was conducted. High-quality onions were peeled and diced into 1 x 1 cm pieces. Replicated (3) experimental units (150 g) were stored for 20 days in glass jars in a humidified air flow under the following conditions: 0, 5, and 10 °C. To simulate rough handling, onion pieces were rolled with a rolling pin with enough pressure to induce some damage and stored at 5 °C. Objective (color, soluble solids, and dry and fresh weights) and subjective (visual quality, decay, aroma, and discoloration) measurements were taken every 5 days. Fresh and dry weights as well as soluble solid content decrease with storage time and temperature, but decay and development of off-odors increased. An overall browning was observed at the higher temperatures. Colorimeter readings indicate that b* and chroma increased with storage and temperature, while a* values decreased. No definite trends were observed in L* values, and no major differences were found in the hue, although hue tend to be higher with lower temperatures. Rough handling resulted in a faster quality deterioration rate in comparison with pieces stored at the same temperature. At 0 °C, diced onions could be stored satisfactorily for 20 days, although some quality changes took place. At 5 °C visual quality may be acceptable after 10 days of storage, but discoloration started to show up after 5 days, reducing acceptability. Storage at 10 °C only is possible for very short periods of time. Rough handling increases the rate of quality deterioration.
366 Effects of Postharvest Heat, Methyl Jasmonate Dip, and 1-Methylcyclopropene Vapor Treatments on Quality Maintenance and Decay Development in `Golden Delicious' Apples
Authors: Saftner Robert A. , Abbott Judith A. , Conway William S. , Barden Cynthia L.
Published: February 2019

Air heat, methyl jasmonate dip, and vapor treatments with the ethylene action inhibitor 1-methylcyclopropene (MCP) were used to evaluate their effects on ripening-related characteristics and susceptibility to fungal decay in `Golden Delicious' apples (Malus ×domestica Borkh.) through 5 months of storage at 0 °C and ripening at 20 °C for 7 days. Preclimacteric fruit were treated with MCP vapor at a concentration of 1 μL•L-1 for 18 h at 20 °C, 38 °C air for 4 days, methyl jasmonate dip at concentrations of 10-5 and 10-4 for 3 min at 20 °C, combinations thereof, or left untreated before storage in air at 0 °C. One set of untreated fruit was stored in a controlled atmosphere of 1.5 O2 and 2.5% CO2 at 0 °C. The MCP treatment and CA storage delayed ripening, as indicated by better retention of green peel color and flesh firmness, and the reduced respiration, ethylene production rates, and volatile (both flavor- and superficial scald-associated) levels that were observed upon transferring the fruit to 20 °C. The MCP treatment followed by air storage delayed ripening more than CA storage. The heat treatment also delayed ripening but hastened skin yellowing. While methyl jasmonate dips had no significant effect on ripening, they were the only treatments used that reduced the incidence of postharvest decay and discolored the surface of some fruit. The results indicate that MCP may provide an effective alternative to CA for maintaining quality during cold storage and ripening. The results also indicate that methyl jasmonate dip treatment may reduce postharvest decay of fruit while maintaining fruit quality.
367 Ripening Control of Pyrus communis L. Fruit with 1-MCP
Authors: Mueller R.S. , Murr D.P. , Skog L.J.
Published: February 2019

1-Methylcyclopropene (1-MCP), a gaseous synthetic cyclic hydrocarbon, has been shown to have potential to become an important new tool in controlling the response of plants sensitive to ethylene. Due to its irreversible binding to the ethylene receptor(s) and its subsequent prevention of the physiological action of ethylene for extended periods, 1-MCP may prove also to have effective commercial application in the control of ethylene effects in detached organs such as fruit. Our objective was to investigate the effectiveness of 1-MCP in controlling ripening in pear. Two commercial cultivars (Bosc, Anjou) and one numbered cultivar from Agriculture and Agri-Food Canada's breeding program (Harrow 607) were harvested at commercial maturity. Immediately after harvest, fruit were exposed for 24 h at 20 °C to 1-MCP ranging from 0 to 100 μL•L-1 then placed in air at 0 °C and 90% relative humidity for 5 and 10 weeks. Following treatment and after 5 weeks storage plus a 7- or 14-day post-storage ripening period, fruit softening and ethylene evolution were inhibited and fruit volatile evolution was reduced significantly by exposure to 1-MCP at or above 1.0 μL•L-1 in all three cultivars. Concentrations exceeding 1.0 μL•L-1 were required to maintain initial firmness and inhibit ethylene production after 10 weeks storage in air. Evolution of alpha-farnesene and 6-methyl-5-hepten-2-one was related to low temperature stress and chlorophyll loss as a result of ripening, respectively, and were affected by 1-MCP exposure. The pattern of evolution and amounts of other volatiles was also affected by 1-MCP treatment. These results indicate a huge potential for commercial use and application of 1-MCP in controlling fruit ripening and senescence.
386 Volatiles of E. coli O157:H7 and Foodborne Pathogen Detection on Strawberry Fruit
Authors: Yu K. , Hamilton-Kemp T.R. , Archbold D.D. , Newman M. , Langlois B.E.
Published: February 2019

Strawberry fruit were inoculated with the human pathogen E. coli O157:H7, and the bacteria were recovered from the fruit over a 3-day period of storage at room temperature. The bacterial population was maintained on fruit when the inoculation level was relatively high and increased when the inoculation level was low. The volatile metabolites of E. coli O157:H7 growing on plate count agar (PCA) and on inoculated strawberry fruit were collected by a headspace trapping system and analyzed by gas chromatography and GC-mass spectrometry. E. coli O157:H7 grown on PCA produced a variety of volatile compounds including indole as a major component and a series of methyl ketones. A nonpathogenic E. coli also produced these compounds. However, there was not an appreciable amount of indole collected from E. coli O157:H7 inoculated strawberry fruit as compared to the large amount of volatiles produced by the fruit. Strawberry fruit were able to capture over 95% of the vapor phase indole fed to them from a neat source.
387 Carbon Dioxide Enrichment in Mamoncillo Fruit (Melicoccus bijugatus Jacq.) during Storage
Authors: Manzano-Mèndez Juan E , Bautista Damaso
Published: February 2019

Mamoncillo fruit, which are very perishable, were harvested at mature ripening stage and stored at gas atmospheres containing of 5.1% CO2, 5.6 % oxygen and 89.3% nitrogen, during 17 days at 10 and 15 ± 2 °C. Characteristics studied were the percent soluble solid content, pH, tritatable acidity (expressed as citric acid), reducing sugars, and total sugars. The SST content showed values ranged between 20.37% to 22.30%, which were high values, but did not show significant differences in the treatments. The pH values were between 3.4 and 3.8 and were highly significant in the interaction between temperature and storage time. The tritatable acidity reported values from 0.99 to 2.24 (as percent citric acid), which had similar behavior in the fruit treated or not with CO2. Reducing sugar values were between 7.79 and 17.99 g•100 g-1 (in base to fresh weight), with highest values at higher storage temperature without CO2 atmosphere. Some times these fruit could be sweeter, such as in this case where the total sugar reached the highest values from 12.92 to 20.64 g•100 g-1, resulting in higher value fruit stored during 3 weeks with CO2 treatment at 15 ± 2 °C. Fruit kept good conditions during 3 weeks stored at 15 ± 2 °C.
395 Storage Disorders of Araza Fruit (Eugenia stipitata Mc. Vaugh) Related to Postharvest Treatments
Authors: Hernandez M.S. , Arjona H.E. , MartÌnez O. , Hernandez M.S. , Fernandez-Trujillo J.P.
Published: February 2019

Araza (Eugenia stipitata Mc Vaugh) is a plant from the Myrtaceae family originated from Amazonia. The postharvest behavior of its promissory fruit has been sparingly studied. Weight loss, softening, decay, and chilling injury (skin scald) at temperatures below 10-12 °C limits its shelf-life to less than 10 days. The application of calcium pretreatments slightly improved flesh firmness after 7 days at 20 °C and resulted in skin injury, particularly at concentrations higher than 4% (w/v). A warming treatment of 6, 12 or 18 h at 20 °C was applied to fruit after 6 d storage at 10 °C. Treated fruit had less scald, suppressed decay, and ripened normally after a total of 2 weeks of storage and a shelf life of 3 days.
400 Effects of Hot Air Treatments on the Postharvest Physiology and Quality of Mango Fruit
Authors: Yahia E.M. , Mondragon A. , Balderas M. , Santiago P. , Lagunez L.
Published: February 2019

Heat treatments have several potential positive effects in fruit, including insect and decay control, amelioration of chilling injury, and delay of ripening and senescence. Hot water treatment (46.1°C for 65-90 min, depending on fruit weight) has been used in Mexico and some other countries as a quarantine insect control treatment for mangoes. Hot air treatments can provide several advantages compared to hot water in regard to installations, costs, reduced injury, and compatibility with other systems such as controlled atmospheres. In this work we have investigated the effect of hot air treatments at 44 to 48°C and 50% relative humidity for 160 and 220 min, on the physiology and quality of `Manila' and `Óro' mango fruit stored at 10°C and 85% relative humidity for up to 4 weeks. No injury was observed in both cultivars exposed for 160 min, but some injury was observed when fruit were exposed for 220 min. Some of these fruit also failed to ripen. Heat treatment (especially for 160 min) delayed ripening of fruit, as measured with color and texture changes, compared to the control. Heat treatment changed the protein composition of the fruit and affected the activity of peroxidases.
430 Spacing and Subsoiling Affect Yield and Quality of Gobo (Japanese Burdock)
Authors: Sanders D.C. , Jester W.R.
Published: February 2019

During 2 years, `Takinogawa Long' gobo was seeded with two, three, or four rows per 1.5-m bed at in row spacings of 7.5, 15, 21.5, and 30 cm. Total and marketable yield increased with in-row spacing and marketable yield increased with row number, with greatest yields occurring at 15 cm regardless of row number. Average root weight and yield of forked roots were not affected by row number but increased with in row spacing. Similarly, percent forked roots decreased with more rows per bed. The 15-cm in-row spacing had the greatest yield, but also the greatest weight of culled roots, but none of the populations affected percentage culls. In another study, in-row subsoiling (SS) and in-row banded phosphorus (P) were evaluated. Marketable yield was increased by both SS and P but did not interact. P increased average root weight. Neither SS or P affected forked root yield or cull root yield, but SS decreased forked roots and increased cull production.
435 Addition of Service Learning in Food Crops Curriculum Revision
Authors: Hughes Harrison
Published: February 2019

The food crop concentration in the horticulture major was revised in response to discussions with students, faculty, and county agents to emphasis more service learning. A requirement for an internship or practicum was added. The practicum entails the design, maintenance, and data collection of the vegetable and small fruit display gardens. Emphasis will be on sustainable production and on collection of information for use in extension fact sheets for the citizens of Colorado. Other changes include the modularization of the commodity courses to provide greater flexibility and the addition of a capstone course. The capstone course will involve greater interaction with industry in the state and has a requirement for the development of both an enterprise budget as well as a production plan for a commercial operation.
439 Quantification of the Lachrymatory Factor for Onion Flavor Assessment is Cultivar-dependent
Authors: Kopsell David E. , Randle William M. , Schmidt Norman E.
Published: February 2019

The tearing and burning sensations associated with raw onion consumption are caused by (Z,E)-propanethial S-oxide, the lachrymatory factor (LF). The LF is produced from the hydrolysis of S-1-propenyl-L-cysteine S-oxide (PREN), the dominant flavor compound in onions. Current methodology for LF quantification was optimized for Granex-type onions using a 2-min incubation time to allow for maximum formation. In this study, data were taken on PREN hydrolysis of `Dehydrator #3' and `Granex 33' at harvest and during storage and were compared to LF formation. `Dehydrator #3' PREN hydrolysis was 98% complete 5 s after cellular disruption at each sampling date. However, using the 2-min incubation procedure, only 10.25 μmol of LF was recovered from the hydrolysis of 30.11 μmol of PREN at harvest, thereby underestimating LF for this cultivar. Percent PREN hydrolysis for `Granex 33' was lower than `Dehydrator #3' during the enzymatic reaction at each sampling date, suggesting slower PREN hydrolysis activity. At harvest, 6.96 μmol of LF were recovered from 12.54 μmol of PREN hydrolyzed. After 2 storage months, however, micromol of LF were equal to micromol of PREN. LF quantification is currently being considered by the onion industry as a direct measurement of gross onion pungency. This data suggests that more optimization of LF quantification is needed before it can be applied to a broad range of cultivar types.
460 Introgressing Seedlessness from Vitis vinifera into Vitis rotundifolia
Authors: Lu Jiang , Schell Lloyd
Published: February 2019

Vitis rotundifolia (Muscadine grapes), a native species characterized with multiple resistance to grape diseases and insects, are cultivated throughout the southeastern U.S. for fresh fruit and processing. However, the species falls short of consumer's expectation as fresh fruit due to its seediness and thick skin. However, Vitis vinifera, a predominant Vitis species grown worldwide possesses good fruit characteristics such as seedlessness and edible skin but is susceptible to many diseases. Attempts to produce rotundifolia-vinifera hybrids to combine good fruit quality and disease resistance of both into F1 hybrids have been made by grape breeders for many years. Limited success was only reported when the V. vinifera was used as seed parents. Pollinating seedless vinifera pollen onV. rotundifolia stigma was made in 1993 and 1994. More than 20,000 flowers from 34 cross combinations were pollinated. These crosses were made to see if there is any chance to produce hybrids when muscadine grapes were used as female parent and specifically to introgress the seedlessness from European grapes into muscadine grapes. A few hundred seeds were collected from these crosses and germinated in a greenhouse. Two seedlings were clearly distinguished from the others with morphology intermediate between muscadine and the vinifera grapes, while the rest looked straight muscadine grapes derived from possible contaminated pollination. This conclusion was further confirmed by isozyme and DNA markers. One of the seedlings produced from the cross of `Jumbo' × `Thompson Seedless' grew vigorously and has been setting fruit since 1996. Fruit are mixture of stenospermocarpic and pathonocarpic seedlessness. Fruit setting and pollen viability test indicated that this hybrid is at least partly self-fertile. Many other characteristics of the hybrid, such as leaves, stems, tendrils, time of budbreak, bloom date, and ripen date are intermediate between muscadine and bunch grapes. The hybrid is resistant to Pierce's disease, anthracnose disease, and downy mildew, which are the limited factor to growing V. vinifera in the hot and humid southeastern U.S. This is the first report of a seedless hybrid from V. rotundifolia × V. vinifera.
469 Some Citrus Flower Characteristics Limit Bee Preference of Hybrids and Their Pollination
Authors: Albrigo L.G. , Russ R. , Rouseff R. , Bazemore R.A.
Published: February 2019

Except for `Orlando' and `Minneola' tangelos, most citrus hybrids grown in Florida are small-flowered and produced less than half the nectar of large-flowered cultivars. Sugar contents in large- and small-flowered cultivars were not different in 1997, but the concentration of sugars doubled in 1998 over 1997 for small-flowered hybrids, while nectar volume was about one-half of that in the previous year. Nectar volume of large-flowered cultivars increased slightly in 1998 compared to 1997. Of four aromatic volatiles measured from headspace over flowers, `Robinson' and `Ambersweet' were lowest in total while other cultivars had only some specific differences. Grapefruit flowers produced high limonene levels, while `Sunburst', `Fallglo', and `Valencia' gave off the most myrcene. Bees were tested for flower preference in a round, white screenhouse using a mini-hive and duplicated fresh-cut flower bouquets each day. Bees preferred large-flowered cultivars with more nectar. Some other preferences also were observed. In the field, hedge-rows limited cross movement of bees in mature blocks of hybrids, which limits the number of contiguous rows of the preferred cultivar for good pollinization. Timing of bee hive placement was also critical to get bee movement into the intended block because flowering times differ for some cultivars and bees develop inital preferences.
482 Effects of Plant Growth Regulators on Plant Size, Branching, and Flowering in Petunia × hybrida
Authors: Wang Shi-Ying
Published: February 2019

Five Wave™ petunias, i.e., `Purple Wave™', `Pink Wave™', `Misty Lilac Wave™', and `Rose Wave™', and two hedgaflora petunias, i.e., `Dramatica Cherry™', and `Dramatica Hot Pink™', were investigated to determine the effects of plant growth regulators on plant size, branching, and flowering. Plant regulator treatments consisted of daminozide (B-Nine) spray two times at 7500 ppm, Paclobutrazol (Bonzi) spray two times at 30 ppm, paclobutrazol drench at 5 ppm, paclobutrazol drench at 5 ppm plus spray at 30 ppm, and ethephone (Florel) spray two times at 500 ppm. Plant diameter and central stem height were controlled effectively through daminozide spray and paclobutrazol drench. Plant branching was promoted by ethephone and daminozide. However, time to flowering was delayed significantly in the ethephone treatment. The size of the first flower responded to plant growth regulators negatively. The different responses to growth regulators among different types of petunias and different varieties in the same petunia type will be discussed based on the current trial and other separated experiments.
494 Study on the Effects of Different Pollen Grains of Citrus Cultivars on Some Quantitative and Qualitative Characteristics of `Page' Mandarin in Northern Iran
Authors: Talaie A. , Goleyn B. , Vezvaei A. , Ebrahimi Y.
Published: February 2019

`Page' mandarin is a complex hybrid between `Minneola' tangelo and `Clementine' mandarin. Because of self-incompatibility, this cultivar severely needs pollinizers and, if a suitable pollinizer does not exist, it will produce few and small fruit. In this study, the effects of pollen grains of nine cultivars of citrus ['Sour' orange, `Duncan' grapefruit, `Sweet' lemon, `Salustiana' orange, `Local' mandarin, `Hamlin' orange, `Siavaraz III Locan' orange, `Marrs' orange, and `Shell' mahaleh (natural hybrid)] on the quantitative and qualitative characteristics of fruit (weight, diameter, length, volume, peel thickness, juice content, developed seeds, undeveloped seeds, total soluble solids, acidity, pH, vitamin C, and percentage of final fruit set) were investigated and evaluated. After artificial pollination and during fruit growth and development, seven times abscission and fruit color and diameter were recorded. Fruit were harvested 29 weeks after pollination and were analyzed. The results showed that this cultivar, in addition to the complete self-incompatibility, has the ability of week parthenocarpy, which results in small and low-quality fruit and also parthenocarpy is induced. `Page' mandarin is cross-compatible with some cultivars, such as `Marrs' orange. There is a positive and significant correlation between developed seed number and fruit weight. The pollen of `Siavaraz III Local' orange has the most effects on percentage of final fruit set. The pollen of `Shell' mahaleh (natural hybrid) has the most effect of the quantitative characteristics, and the pollen of `Marrs' orange has the most effects on qualitative characteristics. It was concluded that `Hamlin' orange is the best pollinizer for `Page' mandarin in northern Iran. The results of this study were analyzed with the use of a randomized complete-block design.
499 An Annual Children's Garden for Educational Outreach
Authors: Schoneweis Susan D.
Published: February 2019

Festival of Color, an annual open house and educational outreach event, is sponsored by the UNL Horticulture Dept. and Institute for Agriculture and Natural Resources. In 1995, a children's garden was added to the site to educate, entertain, and motivate families to garden together. Different theme gardens helped over 10,000 attendees learn vegetable and flower culture in 1998. Educational gardens have included: alphabet, pizza, taco, food and fiber, Christmas tree recycling, bees, international cuisine and lemon gardens. Fun themes have included a plant petting zoo, maze, flower “beds,” and a bean tepee. Most attendees are adults, so different home gardening topics are demonstrated in the grown-up section of the garden, including fall gardening, tomato caging, reblooming amaryllis, consequences of saving hybrid seed, and edible flowers. Plants are mulched with wood chips or multi-colored ground corn cobs to ease maintenance, conserve water and demonstrate these benefits of organic mulches. Of surveys returned by 541 first-time attendees, 98% indicated they learned to choose plants based on site/location, 41% said they learned to identify at least one pest, and 42% learned to implement water conserving landscape techniques. Of the 298 surveys by repeat attendees, 86% have learned improved plant selection skills, 63% now use water more efficiently, and 41% can identify some pests in the lawn and landscape.
500 Consumer Viewpoints on Prairie Grass and Wildflower Plantings
Authors: Davis Greg L. , Schimelfenig Julie
Published: February 2019

Public interest in installing landscapes for reduced maintenance remains high. While availability and specification of native and/or adapted landscape plants such as wildflowers and prairie grasses increase, establishment, management, and expectations of such plantings are not well understood. Our objectives in this study were to measure temporal changes of mixed prairie wildflower plantings under various management regimes and to determine consumer expectations and preferences in these plantings. Nine combinations of wildflowers and prairie grasses were planted in June 1997 at the John Seaton Anderson Turfgrass and Ornamental Research Area, Univ. of Nebraska Agricultural Research Development Center near Mead. On-site surveys were conducted during the Festival of Color, a popular outreach event that occurs annually in September at the site. In 1997 and 1998, the festival attracted more than 9000 and 10,500 participants, respectively, of which 750 completed the survey. To determine preferences for planting compositions, plot desirability ratios were calculated from scaled responses. In 1997, respondents preferred the planting composed of only annuals by a ratio of 5.8: 1 (rated desirable vs. undesirable). This result changed dramatically by the second year, in which the desirability ratio for annuals was 0.3: 1, while that of the combination of perennials and annuals was 11.2: 1. Our plant population density and flowering data validate consumers' preference for abundant color. In late summer of the establishment year (1997), the percentage of the plant population in full bloom was highest in the planting of annuals alone as expected and in 1998 was lowest in the annuals.
521 Effects of Apogee on the Growth and Fruit Quality of Three Apple Cultivars in California
Authors: Kelley Kathy , Regusci Carol
Published: February 2019

Apogee at rates of 125 and 250 ppm applied at 2-cm average shoot growth and a split application of 125 ppm applied at 2-cm shoot growth and 2 weeks later reduced vegetative growth of `Pink Lady', `Gala', and `Fuji' in 1997 and 1998. Cultivar response varied with rate and year. Fruit size was significantly increased in `Gala' at the low rate and split low rate applications and in `Fuji' at the low and high rate single application in 1998. There was no effect on return bloom or fruit color.
531 Relating the Accumulation of Heat Units to Changes in the Phenology and Frost Hardiness of Cranberry during Spring
Authors: Workmaster Beth Ann A. , Palta Jiwan P.
Published: February 2019

Little is known about the growth and development of the cranberry plant (Vaccinium macrocarpon Ait.) in response to air and soil temperatures in the spring. During this period, marked changes in cranberry bud hardiness are known to occur (from –20 to 0 °C), with the greatest changes occuring before bud elongation. The ability to predict changes in bud phenology and hardiness in relation to thermal time would be useful to growers in making frost management decisions. To establish a working growth model, canopy air and soil temperatures were continuously recorded in 1996, 1997, and 1998 in a cranberry bed (cv. Stevens) in central Wisconsin. In spring, samples of uprights were randomly collected from several locations within the bed and sorted according to a nine stage bud classification from tight bud to bloom. Controlled freezing tests were performed on uprights from the most advanced stages present that constituted 10% or more of a sample on a given date. Heat units were calculated from hourly canopy air temperatures. Despite the varied weather conditions over the3 years, a distinct relationship existed between the accumulation of heat units and the advancement of the crop. Spring 1998 was very early and resulted in the accumulation of more heat units before initial and advanced bud swell was observed compared to the other 2 years. Initial evaluation suggests that soil temperatures between 5 to 10 °C and photoperiod may play a role in modulating the effect of air temperatures. Further refinement of this model and the predictive value for frost hardiness changes will be discussed.
533 Metabolic Changes Associated with Strawberry Cultivars with Different Tolerances to High Carbon Dioxide during Storage
Authors: Fernandez-Trujillo J.P. , Nock J.F. , Watkins C.B.
Published: February 2019

Several strawberry fruit cultivars were exposed to air or CO2 at 2 °C for up to 9 days. Concentrations of fermentation products and organic acids, and activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), were measured. Acetaldehyde, ethanol, and ethyl acetate concentrations accumulated in CO2-treated fruit of `Honeoye' and `Kent', but not in `Cavendish' or `Annapolis'. We classified the former group of cultivars as intolerant to high CO2 and the latter group as tolerant to high CO2. Activities of PDC and ADH were higher in CO2-treated than air-treated fruit of the tolerant cultivars but not in the intolerant cultivars. Succinate accumulated in fruit of all cultivars, but concentrations were highest in the tolerant than in the intolerant cultivars. These results will be discussed in relation to mechanisms of CO2 action on fruit metabolism.
555 The Impact of Supplemental Calcium Fertilization during Potato Seed Tuber Production on Subsequent Crop Performance
Authors: Gunter Christopher C. , Palta Jiwan P.
Published: February 2019

Tuber tissue calcium has been linked to several potato quality characteristics, including internal defects and the susceptibility of tubers to decay by soft rotting Erwinia species. We were particularly interested in studying the relationship between supplemental calcium fertilization during the seed tuber production cycle to raise the seed piece calcium concentration and the impact on crop performance the following season. The role of seed tuber tissue calcium level on seed piece decay, growth, development, and performance of the plant was evaluated for cultivars Russet Burbank, Dark Red Norland, Atlantic, Superior, and Snowden. This study was performed over four growing seasons. Seed tubers were raised with varying calcium and the following season, individual tubers (over 3,000 total for 4 years of study) were sampled for calcium and hand planted in the field. They were evaluated for seed piece decay and total tuber yield during the growing season. Seed tubers raised with supplemental calcium resulted in significantly higher mean calcium content than the control tubers. In general, calcium-raised seed tubers tended to produce a more vigorous main sprout and higher tuber yield. We also found that there are significant differences among these cultivars for the characteristics measured. Consistently, in all three years, `Atlantic' responded to test conditions with the lowest decay values, and `Dark Red Norland' consistently showed the highest decay values. This suggests that there may be a genetic component involved in these two responses and these genotypic differences could be exploited to improve cultivated potatoes.