bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Pollination on Peroxidase Activities and Isozymes during Southern Highbush Fruit Development
Authors: Huang Yuehe , Lang Gregory A.
Published: February 2019

Five-year-old `Sharpblue' southern highbush (Vaccinium corymbosum) plants were self- and cross-pollinated (`O'Neal') to study peroxidase activities and isozyme patterns during fruit development. Both soluble and bound peroxidase activities were present throughout development. Activities were very high during early fruit development, with peaks at 10 and 20 days after self- and cross-pollination, respectively. Activity was much higher for cross-pollinations. During rapid fruit development, peroxidase activities were low. During ripening, the activity of soluble peroxidases increased, then declined in both treatments. Bound peroxidase activity increased during the color transition from blue to dark blue, with the increase being much greater in self-pollinated fruits. Banding patterns of both soluble and bound isoperoxidases varied by pollination treatment as well as fruit developmental stage. Pollen sources alter peroxidase isozymes and activities in developing fruits. During fruit ripening, soluble peroxidase activity appears to be associate with the color transition from light blue to blue, while bound peroxidase activity appears to be associated with the color transition from blue to dark blue.
Effects of Light Quality on Growth and Quality of in Vitro Plantlets during Low-temperature Storage
Authors: Kubota Chieri , Rajapakse Nihal C. , Young Roy E.
Published: February 2019

Broccoli `Green Duke' plantlets, which were ready for transplanting after 2 weeks of photoautotrophic (sugar-free) culture under the conditions of 1100 μmol·mol–1 CO2 (outside the vessel), 22±4C air temperature, and 140 μmol·m–2·s–1 photosynthetic photon flux (PPF), were stored for 6 weeks at 5C in darkness or in white, red, or blue light at 2 μmol·m–2·s–1 PPF. Photoperiod was set at 24 h/day during storage. Spectral quality significantly affected plantlet quality: stem length was longer and chlorophyll concentration of leaves was lower in red or in blue light than in white light or in darkness after 6 weeks in storage. Regardless of the spectral quality, light in storage maintained plantlet dry weight at a level comparable to that before storage, while dry weight was reduced significantly in dark-stored plantlets. Spectral quality did not significantly affect the photosynthetic and regrowth potential of plantlets. All plantlets stored in light, regardless of light spectra, showed comparably high photosynthetic ability after storage and had similar dry weight, number of leaves, and stem length after 9 weeks of transplanting to the greenhouse under natural light.
Respiration of `Hass' Avocados in Response to Elevated CO2 Levels
Authors: Lange Diana Dostal , Kader Adel A.
Published: February 2019

Stress levels of carbon dioxide can be effective in the retardation of ripening and control of decay-causing pathogens and insect infestation of some horticultural perishables. Our objective has been to identify key mitochondrial enzymes and pathways that regulate the fruit's response to CO2 actions. Oxygen uptake of fruit stored in air + 20% CO2 (16.8% O2) was depressed compared to the airstored fruit, whereas the fruit stored in air + 40% CO2 (12.6% O2) had an elevated respiration rate. Climacteric fruit treated with 20% CO2 at 10C had increased pyruvate dehydrogenase (PDH) activity, decreased cytochrome oxidase (CytOx) activity, and double the alternative oxidase (AltOx) activity compared to air-stored fruit. Air + 40% CO2-stored fruit had reduced PDH and CytOx activities, and 50% more AltOx activity than the control fruit. Mitochondria were treated directly with the same CO2-enriched atmospheres to measure the catalytic effects of CO2. Total O2 uptake was decreased in both CO2 atmospheres and the cytochrome/alternative pathway ratio was greater than with mitochondria held in air. Nuclear magnetic resonance analysis of whole fruit confirmed that these CO2 atmospheres decrease the intracellular pH several 0.1 pH units with 2 h.
Modeling the Accumulation of Volatiles in the Interstices of Fruit Interiors and the Fruit Cuticle
Authors: Beaudry Randolph M.
Published: February 2019

A theoretical model was developed that predicts how volatiles synthesized by fruit accumulate in the fruit interior and the fruit cuticle. Model inputs include temperature, rates of volatile synthesis, solubility of the volatile in the cuticular material, and the permeability of the volatile through the cuticle. The model indicated that the accumulation of volatiles was highly temperature-dependent and dependent upon the nature of the interaction between the volatile and the cuticle. For volatiles whose cuticular permeability declined rapidly with temperature, the concentration in the fruit and fruit cuticle tended to increase with decreasing temperature. This accumulation of volatiles in the fruit and fruit cuticle with decreasing temperature was enhanced by a decrease in the heat of solution (i.e., temperature sensitivity of solubility) and diminished by an increase in the Q10 Of the rate of volatile synthesis (i.e., the temperature sensitivity of the rate of synthesis). The model suggests that storage temperature can influence volatile retention and, hence, the volatile profile.
Consumer Evaluation as an Adjunct to F1 Hybrid Seed Development of Hexaploid Chrysanthemums (Dendranthema grandiflora Tzvelv.)
Authors: Anderson Neil O. , Ascher Peter D. , Luby James J.
Published: February 2019

The change from asexual to sexual propagation for annual and perennial bedding plants has been successfully accomplished for floral crops, e.g., Pelargonium. Seed-propagated cultivars do not necessarily possess the clonal uniformity of vegetatively propagated cultivars. In the development of F1 hybrid garden chrysanthemums, this lack of uniformity was assessed with the use of consumer sensory evaluations. Seedlings (n = 10–20 plants/cross) were transplanted for field trials in St. Paul and five Minnesota branch stations each year during 1988–94 to test for G × E. Early flowering F1 hybrids, developed from inbred parents with general combining ability, were evaluated for flowering earliness, plant uniformity, and a general rating. Consumer rankings of top performers were not significantly different (5% level) from mum breeders. The top performers for all three ratings were selected each year for repeat evaluation the next year. The two highest performing F1 hybrids were submitted for All American Selection Trials in 1995.
Genetic Analysis in Nicotiana alata: The Inheritance of Flower Doubleness
Authors: Zainol Rozlaily , Stimart Dennis P.
Published: February 2019

Genetic analysis of a white double-flowering Nicotiana alata is being investigated. Self-pollination of the double-flowering plant produced all double progeny. Reciprocal hybridization of the double-flowered selection with N. alata cultivars produced nondouble F1 progeny that segregated 3:1 (nondouble to double) in the F2 generation. Reciprocal backcrosses of F1 plants to the parents resulted in nondouble progeny when backcrossed to the nondouble parent and 1:1 segregation when backcrossed to the double parent. Intercross of F1 plants resulted in progeny segregating 3:1. Double flowering habit has been transferred to white, red, salmon, green, and bicolor N. alata. Results suggest double flowering is under nuclear control regulated by a recessive allele.
Growth of Norway and Sycamore Maple Taxa in Tennessee
Authors: Witte W.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Commercially available Norway and sycamore maple taxa were established as 10 single-plant replications in a cultivar trial at the TSU–NCRS in 1993 and Spring 1994. Each plant was fertilized regularly and drip irrigation was begun Summer 1993. Vegetation within tree rows was controlled with preemergent and postemergent herbicides, while grassed middles were mowed. Growth data was recorded in Fall 1993 and 1994 and height and caliper increment calculated for the 1994 season. In this group of 29 taxa, 9 cultivars were in the group with most height growth: `Columnare', `Pond', `Deborah', `Crystal', `Parkway', `Columnarbroad', `Schwedleri', `Summershade', and `Fairview'. With some exceptions, cultivars with the most height growth tended to have the most caliper growth, while those with the least height growth tended to have the least caliper growth, with the notable exception of `Columnar'. Data will also be presented on insect and disease ratings.
Horticultural Crops Germplasm in the S-9 Plant Germplasm Collection
Authors: Jarret R.L. , Lovell G. , Spinks M.
Published: February 2019

The S-9 Plant Germplasm Collection maintains and distributes germplasm of various horticultural crops, including pepper (Capsicum spp.), watermelon (Citrullus lanatus), okra (Abelmoschus spp.), eggplant (Solanum melongena), miscellaneous Solanum spp., sweetpotato (Ipomoea batatas spp.), luffa (Luffa spp.), gourds (Lagenaria and Momordica spp.), squash (Curcurbita moschata), pumpkin (Curcurbita maxima), marigold (Tagetes spp.), Stokes' aster (Stokesia laevis), hibiscus (Hibiscus spp.), Engelman daisy (Engelmannia pinnatifolia), pampasgrass (Cortaderia selloana), ornamental bamboo (Bambusa spp.), and other ornamental grasses. Seed or other propagules of these plant materials are available for research purposes. Detailed information on individual collections and general information on the USDA National Plant Germplasm System will be presented.
Evaluations and Plant Descriptors of New Collections of Lesquerella fendleri
Authors: Dierig David A. , Thompson Anson E. , Coffelt Terry A. , Arnold Stacy E. , Dahlquist Gail H.
Published: February 2019

Lesquerella fendleri (Gray) Wats. (Brassicaceae) is a potential oilseed crop with many commercial applications, primarily as lubricant additives, but also in resins, waxes, plastics, and cosmetics. This species is native to the southwestern United States where new populations have been collected over the past 2 years to increase germplasm diversity for plant breeding. Some of these new accessions were evaluated and seeds increased at Phoenix, Ariz., over the 1994–95 season. Measurements of stand establishment; plant height and width; leaf, shoot, and flower characteristics; and growth habit were taken over the season. Plants were also examined for autofertility and male sterility. Seed-oil characteristics, seed size and yield, glucosinalate content, and seedcoat gum content will be measured at harvest. Plant descriptors for Lesquerella have been developed as a result of these measurements. Following seed increase, germplasm will be entered into the National Plant Germplasm System. This information will be useful in determining the most promising material for plant breeding.
Storage and Modified-atmosphere Packaging of Chinese Chestnuts (Castanea mollissima)
Authors: Talasila P. Chowdary , Cameron Arthur C. , Taylor Lee J.
Published: February 2019

The shelf life of chestnuts is limited by water loss. Polymeric packages have been used to prevent dehydration, although little specific information is available on the use and design of MA packaging for extending shelf life. To investigate the product response to MA conditions, a range of O2 levels were generated inside low-density polyethylene (LDPE) packages containing chestnuts. The respiration rate decreased with decreasing O2 levels below 16 kPa at 0C. A rapid increase in RQ and ethanol were noticed when the chestnuts were exposed to O2 levels below 1 kPa at 0C, indicating a shift to fermentative metabolism. In a flow-through system, the respiration rate at 0C and the Q10 were measured as 108 nmol·kg–1·s–1 and 2.5, respectively. Chestnuts were stored at –2, 0, 5, and 20C in LDPE packages for 6 months and quality was periodically evaluated. Off-flavors were noticed from chestnuts stored in O2 levels below 1 kPa at 0C on day 38. Chestnuts stored at 0C but at higher O2 levels were acceptable for 5 months. Chestnuts stored at –2C were still acceptable after 6 months of storage.
Cell Membrane Stability and the Role of Calcium Infiltration in Postharvest Quality of Apples
Authors: Picchioni G.A. , Watada A.E. , Conway W.S. , Whitaker B.D. , Sams C.E.
Published: February 2019

Postharvest CaCl2 pressure infiltration improves firmness and storage quality of apples but is still in the experimental stages. Its effectiveness could be increased if we had a better understanding of how Ca affects the tissue at the cellular level. `Golden Delicious' fruit were harvested from a commercial orchard and were pressure-infiltrated with CaCl2 (0%, 2%, or 4% w/v), stored for 6 months at 0C, and then for 7 days at 20C. Between harvest and the end of storage at 20C, the net breakdown of galactolipids and phospholipids decreased with increasing CaCl2 in infiltration solutions. During 0C storage, CaCl2-infiltrated fruit maintained greater concentrations of conjugated sterol lipids, and these lipid classes are thought to be closely associated with the plasma membrane. As membrane lipid alterations are viewed as a central factor in the senescence of fruits, Ca (from postharvest infiltration) may serve a major role in regulating fruit quality losses through its interactions with cell membranes.
Operator and Instrument Affect Apple Firmness Readings
Authors: Lehman-Salada Laura
Published: February 2019

Apple flesh firmness, a common indicator of maturity and postharvest quality, can be measured destructively using several instruments. This study compared readings obtained with a Magness-Taylor tester, an Effegi device, and an electronic tester with Magness-Taylor testing in the on or off mode. Three trained operators measured firmness of 50-apple samples of three cultivars with a wide range in suspected maturity. In the instrument test, each operator measured firmness using a different instrument or mode on one half of each apple. In the operator test, the firmness of each apple was measured three times (once by each operator). Both soft and firm lots had consistent operator and instrument differences in readings. Ignoring the operator differences, five out of six comparisons of instrument and mode produced significantly different readings. Operator differences between instruments and modes were also significant in many instances. The results suggest that a single instrument and operator should be used in long-term experiments when multiple determinations of apple flesh firmness are planned.
Free Volume Changes in Modified-atmosphere Packages Containing Fresh Produce: Measurement and Control
Authors: Talasila P. Chowdary , Cameron Arthur C.
Published: February 2019

Flexible modified-atmosphere (MA) packages of fruits and vegetables can shrink or expand with time depending on the net flux of gas from the package to the surroundings. Excessive shrinkage can cause product damage if the tissue is fragile. However, reducing free volume should reduce the amount moisture loss and condensation. It would be useful to understand the factors that determine the rate and direction of free volume changes when applying MA packaging technology to fruits and vegetables. Free volume was measured in packages using a simple procedure based on dilution of injected ethane gas. The free volume in low-density polyethylene packages containing cut broccoli at 0C changed from 284 cc to 148 cc in 33 days. A computer model was developed to estimate changes in package free volume for different situations. The model predicted that the rate of shrinkage will be less if packages are flushed with a low permeable gas. Flushing with a highly permeable gas such as CO2 will increase the rate of shrinkage. The rate of package shrinkage will be less if made with films that have low permeability to N2.
Effects of Preemergence Herbicides on Weed Control and Yield and Vase Life of Leatherleaf Fern
Authors: Stamps Robert H.
Published: February 2019

Six preemergence herbicides were applied twice a year at 1x and 2x rates for 2 years to leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] starting from the time of rhizome planting. Predominant weeds present were Cardimine hirsuta, Erechrites hieracifolia, Oxalis stricta, and Phyllanthus tenellus. All herbicides, except pendimethalin and oxadiazon at the 1x rates, reduced weed biomass by 60% to 99% compared to the unweeded control during the fern bed establishment phase (year 1). During that period, hand-weeding times were reduced (51% to 95%) by prodiamine and dithiopyr at both rates, and oxadiazon and pendimethalin at 2x rates. During year 2, herbicides were of greatly reduced benefit due to reduced weed growth caused by the increasingly competitive fern. After 2 years, only 2x dithiopyr-treated plots had reduced yields compared to the hand-weeded controls. Herbicide treatments had no detrimental effects on frond postharvest longevity. In fact, fronds harvested from the 1x isoxaben-treated plots exhibited increased vase life compared to the controls.
The Effect of Genotype on Winter Production of Collard and Kale in the Southeastern United States
Authors: Farnham Mark W. , Garrett T.
Published: February 2019

Collard and kale (Brassica oleracea L. var. acephala) cultivars and several landraces obtained from southeastern growers were tested for potential winter production. Collard and kale entries were grown in four winter environments in South Carolina from 1993 to 1995. Transplants were set in the field during November or December, and leaf production and plant fresh weight were monitored through the winter. When plants reached a 22-leaf stage, a plot subsample was harvested and weighed. The date at which 50% of the plants per plot had bolted was also recorded. Essentially all entries survived the conditions of four winter environments. However, whether an entry reached harvest size depended on its date of bolting. Collard entries typically bolted earlier than kale entries, and most kale and several collard entries attained harvestable-size before bolting. The ranking of genotypes for days to 50% bolting was consistent among environments. `Blue Max' and a landrace of collard, and `Squire' and `Blue Knight' kale usually never reached 50% bolt.
Arkansas Blackeye #1: A New Southernpea
Authors: Morelock T.E. , Motes D.R. , Gonzalez A.R.
Published: February 2019

Southernpeas (Vigna ungurculata) are a popular crop in the southeastern United States. They are an important crop to Arkansas processors, market gardeners, and home gardeners. While the bulk of the acreage produced in the state is pinkeye purple hull types, there is a demand for other horticultural types. At present, there is not a well-adapted blackeye that is available to producers in the state. For that reason, Arkansas Blackeye #1 is being released. Arkansas Blackeye #1 has been widely tested under the designation Arkansas 91-245. It produces a medium-sized bush plant that is well suited to conventional or narrow row spacing and matures 2 to 3 days earlier than Coronet under Arkansas conditions. Arkansas Blackeye #1 produces yield similar to the best pinkeye purple hull types. Samples have been canned by the Food Science Dept. at the Univ. of Arkansas and the canned samples have compared favorably to the industry standards.
Barriers to Introgression into Tomato of Intergeneric Fusion Hybrids of Solanum ochranthum and Tomato
Authors: Stommel John R. , Kobayashi Ruth S. , Sinden Stephen L.
Published: February 2019

Somatic fusion hybrids created between tomato and Solanum ochranthum, a wild nontuber-bearing diploid species that is genetically isolated from tomato, were evaluated in an effort to introgress traits from S. ochranthum into tomato. Pollen stainability and pollen tube growth examination demonstrated that little or no viable pollen was present in tetraploid and hexaploid fusion hybrids. Aneuploidy was noted in a small percentage of these hybrids. Use of tetraploid and hexaploid fusion hybrids as female parents in backcrosses to diploid and tetraploid tomato was studied. Chemical treatments that induce either chromosomal recombination or reduction may be advantageous for overcoming difficulties in introgression of these wide hybrids into tomato.
Michigan Asparagus Clone Trial
Authors: Ball T. , Smeenk J. , Sink K.C.
Published: February 2019

Outstanding asparagus crowns were identified in established Michigan asparagus fields, MSU germplasm, variety trials, or were provided by commercial sources. The single-crown selections were micropropagated to provide cloned plants for the trials. Field trials consisting of four replications of 12 plants each were established at two locations. Crowns were planted 8 inches deep and spaced 18 inches apart in rows 4.5 or 5 feet apart. Five, 37, and 25 selections were planted in 1998, 1989, and 1991, respectively. Plots were not harvested until 2 years after planting, when they had partial harvests of six pickings. In the third and following years, plots received full harvests of 20 to 25 pickings. In the third full harvest at the Hart location, clones Hart-2 and Hart-3 yielded 6989 and 6875 lb/A, respectively, and were significantly more productive than Syn4-56, which had 3720 lb/A. At Benton Harbor, Hart-4 produced 4184 lb/A, significantly higher than the Syn4-56 yield of 3088 lb/A at that location. These significant differences were not observed until the second full harvest.
Fertility Losses in Congruity Backcross (CBC), Intraspecific Phaseolus vulgaris Hybrids
Authors: Anderson Neil O. , Ascher Peter D. , Hoover Emily E.
Published: February 2019

Decreases in fertility are most common among interspecific, wide crosses of Phaseolus; intraspecific hybrids are less likely to exhibit sterility. Intraspecific CBC hybrid pedigrees were created to test for comparative fertility losses. Eight P. vulgaris cultivars from different centers of origin, polymorphic for seed proteins (15, 20, 50 kDa), were used to create 16 CBC populations: dry (`Cuarenteño', `Great Northern Harris', `Sulfur', `Swedish Brown') and snap beans (`Purple Pod Pole', `Romano Bush', `Royal Burgundy Bush', `White Half Runner'). Despite repeated attempts, two crosses failed to produce primary hybrids. Primary hybrids had decreased percent stainable pollen from the parents. Female sterility was more severe, necessitating the screening of the F1–F3 before producing the next CBC. Yield was significantly lower than midparent values for all F3 CBC pedigrees. In several cases, phaseolin was no longer the major seed protein. Other hybrid breakdown symptoms were similar to those found with wide crosses, indicative of incongruity between centers of origin.
Methanethiol Production by Brassica Vegetables Held in Anaerobic Atmospheres
Authors: Forney Charles F. , Jordan Michael A.
Published: February 2019

Methanethiol (MT) is a volatile compound responsible for the strong off-odor that is evolved when fresh broccoli is held under anaerobic atmospheres. Inductive atmospheres can develop in modified-atmosphere packages, resulting in reduced quality. To determine if related vegetables are capable of producing MT, 12 different vegetables from the genus Brassica were cut into ready-to-eat forms. Fifty-gram samples of these cut vegetables were sealed in 500-ml glass jars and flushed with N2. After flushing, jars were held for 24 h at 20C in the dark. Headspace samples from the jars then were analyzed for MT and other volatiles using a GC-MS> The concentration of MT was greatest in jars containing broccoli florets. Broccoli flower buds removed from florets produced 40 times more MT than peduncle and stem tissues (38.3 vs. 0.87 mmol·m–3). Headspace concentration of MT (mmol·m–3) in jars containing these different vegetables was: broccoli florets, 22.7; pak choi leaf blades, 17.8; savoy cabbage, 12.4; broccoflower, 7.5; green storage cabbage, 5.2; red cabbage, 2.7; kale, 0.81; Brussels sprouts, 0.36; pak choi petioles, 0.28; rutabaga root, 0.26; cauliflower florets, 0.18; Chinese cabbage, 0.03; and kohlrabi tubers, 0.02. In addition to MT, ethanol, dimethyl disulfide, and dimethyl trisulfide were detected in the headspace over each of the 12 vegetables. The contribution of these induced compounds to off-odor development in packaged, precut vegetables will be discussed.
Ethylene Production in Watermelon Fruit Varies with Cultivar and Fruit Tissue
Authors: Perkins-Veazie P. , Collins J. K. , Cartwright B
Published: February 2019

To determine whether ethylene production was related to locular tissue breakdown in watermelon, plugs from ripe `Jubilee', `Black Diamond', `Tiger Baby', `Mirage', and `King of Hearts' were taken from the skin (epidermis and hypoderm), rind (hypoderm and mesocarp), and placenta (locular and heart) tissues. ACC oxidase activity was <0.05 nmol·g–1·h–1 in locule and heart locations for all cultivars. Skin tissue had the highest activity, ranging from 0. 1 8 for `Jubilee' to 0.5 to 0.62 nmol·g–1·h–1 for the other four cultivars. ACC (1-aminocyclopropane-1-carboxylic acid) and ACC oxidase activity were measured in unripe, ripe, and overripe `Jubilee' melons. ACC oxidase activity from skin tissue was lowest in unripe (0.05 nmol·g–1·h–1) and highest in overripe (0.13 nmol·g–1·h–1) melons, and was 0.05 nmol·g–1·h–1 or less in all other tissues. Free ACC was highest in the skin tissue (1.3 nmol·g–1·h–1), but there was no difference in ACC content with stage of ripeness for any tissue. Results indicate that ethylene may be transported from the outer skin and rind tissues to locular areas and that wounding of the skin tissue could lead to deleterious ethylene production.
The Use of Immunoassays for the Detection and Quantification of Pesticides in Fresh and Processed Fruits and Vegetables
Authors: Yahia Elhadi M. , Valenzuela Q. Ana Isabel , Ri vera D. Marisela
Published: February 2019

There is a continuous need for the monitoring of agrochemicals in foods. For this purpose, there is a need for sensitive and inexpensive techniques. The recent use of immunoassays for the detection and quantification of environmental residues is advantageous as being specific, sensitive, fast, and potentially inexpensive compared to traditional methods. In this work, we have used an immunoassay method to quantify 13 pesticides in eight fresh and processed fruits and vegetables consumed in northwestern Mexico. The concentrations detected were much lower than the maximum permitted levels in all products analyzed. Minimum concentration detected was 0.1 ppb of chlorothalonil in tomato fruit. The maximum concentration detected was 386 ppb of benomyl in Mexican-produced apples.
Ethanol Accumulation as an Indicator of Sensitivity of Different Horticultural Produce to 30% CO2 in Air Storage at 7C
Authors: Yanez-Lopez L. , Buescher R.W.
Published: February 2019

Controlled atmospheres (CA) have been used as auxiliary to refrigeration for the storage and transportation of food crops. Commodities sensitive to high levels of CO2 experience fermentation. This study was focused upon the effects of CO2-enriched atmospheres on ethanol (ETOH) accumulation as an indicator of the sensitivity of 22 different produce to short-term exposure to 30% CO2 in air for 2 days at 7C. Commodities were obtained from a wholesale or grocer supermarket. ETOH was determined by gas chromatography (GC). Differences in response to 30% CO2 in air were observed among commodities. Kiwi fruit and broccoli had initial low levels of ETOH, which greatly increased after the first day of storage. Cherries and spinach maintained approximately a constant increase in ETOH accumulation during the whole period of storage. Pickling cucumber and zucchini squash had high ETOH accumulation at the early period of storage, which was even higher by the second day of exposure to 30% CO2 in air. In most of the commodities under study ETOH accumulation increased as a response to 30% CO2 levels in air. There was no apparent influence of plant organ on ETOH accumulation.
Comparison of Assays for the Quantitation of Superoxide Dismustase in Apple and Potato Tissues
Authors: Vaughn Steven F.
Published: February 2019

The enzyme superoxide dismutase (SOD; EC 1.15.1.1) catalyzes the conversion of the superoxide radical (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}) to O2 and H2O2. SOD is thought to be critical in delaying aging and senescence in plant tissues such as apple fruit and potato tubers. A variety of assays have been reported for the quantitation of SOD based on the inhibition of O2-driven reactions. Four assays were examined, including 1) the reduction of nitro blue tetrazolium (NBT) by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}generated by the reaction of cysteine and FeCl3; 2) the reduction of NBT by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}generated by photochemical activation of riboflavin; 3) the inhibition of nitrite formation from hydroxylammonium chloride (nitrite subsequently converts sulfanilic acid to a diazonium compound, which reacts with α-naphthylamine to form a red azo compound); and 4) the autoxidation of hematoxylin to hematein by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2}^{-}\) \end{document}. In all cases, the production of colored compounds was inversely proportional to SOD activity. Although all of the assays were successful in quantitating SOD activity, assays 1 and 4 appeared simplest to use and had the fewest drawbacks.
Acylsugars of the Wild Tomato [Lycopersicon pennellii (Corr.) D'Arcy] Alters Settling and Reduces Oviposition of Bemisia argentifolii (Silverleaf Whitefly)
Authors: Liedl Barbara E. , Lawson Darlene M. , White Kris K. , Shapiro Joseph A. , Carson William G. , Trumble John T. , Mutschler Martha A.
Published: February 2019

Acylsugars, the primary components of the exudate secreted by type IV trichomes of Lycopersicon pennellii (Corr.) D'Arcy LA716, mediate the resistance of this accession to silverleaf whitefly, Bemisia argentifolii Bellows & Perring, n. sp. Reduction in the settling of the adult silverleaf whiteflies correlates with the concomitant increase in applied acylsugars. Oviposition of B. argentifolii is also affected by acylsugars, resulting in a reduction in the number of eggs and nymphs found; however, acylsugars do not affect hatching of nymphs. The threshold amount of acylsugars required for deterring settling and oviposition is under the amount of acylsugars (50 to 70 μg·cm–1) required for control of other insects.
Implementation of Brassica spp. as Trap Crops and as Beneficial Insectaries for Caterpillar Management in Cabbage Ecosystems
Authors: DeFrank Joseph , Luther G.C. , Valenzuela H.
Published: February 2019

Experiments conducted over 3 years have determined the potential of utilizing Indian mustard and `Tastie' head cabbage multi-species borders as trap crops for management of caterpillar pests of head cabbage in Hawaii. `Scorpio', a cultivar that showed less feeding damage than `Tastie', was used as the main crop. The studies point toward the use of isolated patches of multi-species attractant crops separated from the main crop by a buffer of non-host crops such as sweet corn. A sweet corn buffer was effective in preventing insect movement between plots. Initial studies showed the high susceptibility of Indian mustard to white rust (Albugo candida), to be a constraint to its use as a trap crop. Follow-up studies found that `Excel' and `Parkland' mustards may be adequate substitutes for mustard crop due to their attraction of caterpillars and their tolerance to white rust. Gradient experiments conducted on 60 × 30-m plots indicate that the trap crop may be effective for a distance of 25 to 30 m in terms of attraction of caterpillars and dispersal of beneficials into the main crop. A record was also made of growth, flowering patterns, and of beneficials hosted by 12 different Brassica cultivars during the winter and spring growing seasons.
Commercial Outlook and Adoption of Landscape IPM Tactics in Central New Jersey
Authors: Smith-Fiola Deborah C. , Way Robert G.
Published: February 2019

The largest agricultural industry in New Jersey is the commercial landscape/nursery/turfgrass industry; it is also one of the highest users of pesticides. In the lawn care industry alone, >906,000 lb of pesticides (active ingredients) were used in 1990. A proven way to commercially reduce pesticide usage while maintaining landscape quality is through Landscape Integrated Pest Management (LIPM) tactics; however, adoption of LIPM nationally has been slow. In 1994–95, a survey of 525 landscape contractors, arborists, groundskeepers, and turfgrass professionals was conducted to determine attitudes towards adoption of LIPM tactics. Customer perceptions, products utilized, educational needs, and attitudes toward alternative control tactics were assessed. Results show the majority of landscapers do not wish to spray pesticides, and do utilize good horticultural methods. However, purchasing traditional pesticide products that are cost-effective and proven are favored relative to environmentally “safe” and new. Concerns constraining LIPM adoption include potential for customer dissatisfaction, recovering monitoring costs, increased knowledge requirement for LIPM tactics, and fear of inadequate control.
Chemical Control of the European Asparagus Aphid (Brachycorynella asparagi Mordvilko) in Northwestern Mexico
Authors: Lopez-Carvajal Arturo , Grijalva-Contreras R. Leonel , Robles-Contreras Fabian
Published: February 2019

Asparagus growers in the Caborca, Sonora, area consider disulfoton the only efficient insecticide for the control of the European asparagus aphid (EAA); therefore, this is the only insecticide used to control this pest. However, it is prohibited in Mexico. Therefore, during Fall 1991 in a commercial plantation of asparagus, six conventional and one microbial insecticides were evaluated. All the insecticides: chlorpirifos (480 g a.i./ha), dimethoate (400 g), malathion (2000 g), pirimicarb (375 g), oxamil (480 g), disulfoton (1000 g), and two doses of the fungus Verticillium lecanii (300 and 600 g) had a significant control (P ≤ 0.05) in relation to the untreated check. However, chlorpirifos, malathion, disulfoton, and Verticillium (600 g) were more consistent, fast-acting, and registered from 90% to 100% control of the EAA for at least 51 days after application; 73 days after the application, control ranged from 16% to 57%, except oxamil, which registered 71% control.
Irrigation Affects Yield and Sweetpotato Weevil [Cylas formicarius elegantus (Summers)] Infestation of Sweetpotato
Authors: Crossman S.M.A. , Palada M.C. , Kowalski J.A.
Published: February 2019

A study was conducted to evaluate the effect of irrigation on yield and sweetpotato weevil (SPW) infestation of sweetpotato storage roots. Sweetpotato was grown in plots under controlled soil moisture regimes. The treatments were rainfed (no applied irrigation) and irrigation applied to maintain soil moisture levels at 20, 40, and 60 kPa, based on tensiometer readings. The 40- and 60-kPa treatments produced the highest yield of root biomass. Irrigation applied at 40 kPa produced significantly more medium-sized storage roots (8.1 t·ha–1) than the rain-fed treatment, which produced 4.4 t·ha–1. All of the irrigation treatments produced significantly more marketable storage roots with a lower mean damage index (MDI) than the rain-fed treatment. There was an inverse relationship between MDI and soil moisture levels among the irrigation treatments. A significantly higher percentage of storage roots (51.5%) from the 20-kPa treatment were rated in the Damage Index (DI)-1 (uninfested roots) category than from the rain-fed treatment (27.7%). Additionally, the percentage (29.4%) of storage roots from the rain-fed treatment rated in the DI-6 (most severe) category was significantly higher than the applied irrigation treatments, with 13.9%, 13.9%, and 6.0% respectively, for the 60-, 40-, and 20-kPa treatments. Irrigation therefore has potential to increase sweetpotato yields while reducing SPW infestation levels.
Conditioning Treatments Affect Growth and Spider Mite Infestation of Greenhouse-grown Bedding Plants
Authors: Latimer Joyce G. , Oetting Ronald D.
Published: February 2019

Two weeks after planting, plugs of New Guinea impatiens (Impatiens × hybrida), marigold (Tagetes erecta), or ageratum (Ageratum Houstonianum) were subjected to eight conditioning treatments: untreated, low N (50 ppm), high N (500 ppm), ebb/flow watering, drought, brushing (40 strokes twice daily), daminozide (5000 ppm), or paclobutrazol (45 ppm). Fertilizers were applied three times per week at 250 ppm N for all plants not treated with high or low N. Five adult twospotted spider mites were placed on each plant 1 week after treatment. New Guinea impatiens height was reduced by low N, brushing, or paclobutrazol at 4 weeks after treatment. Spider mite populations were reduced only by brushing. Marigold height was reduced by low N, drought, or brushing, but spider mite counts were reduced by brushing or paclobutrazol. Height of ageratum was reduced by low N, daminozide, or paclobutrazol, but spider mite counts were reduced by ebb/flow or brushing at 4 weeks after treatment.
Dispersal of Perillus bioculatus, a Stinkbug Predator of the Colorado Potato Beetle
Authors: Lachance Simon , Cloutier Conrad
Published: February 2019

Predators and parasitoids used for biological control must possess good dispersal potential in order to ensure spatially uniform and cost-effective control. The rate of dispersal of Perillus bioculatus (F.) (Hemiptera: Pentatomidae), a predator of the Colorado potato beetle (Leptinotarsa decemlineata), was measured following central release in 0.025-ha potato plots. Factors influencing predator dispersal were also studied under controlled conditions in plant growth chambers. Temperature, predator size as affected by instar, and physiological age with respect to the completion of feeding during the intermolt stage were found to be significant factors. Predator density was also evaluated because of the strong tendency for this species to aggregate, thereby influencing dispersal. Results can be used to develop predictive models for inundative releases of P. bioculatus.
Effect of Blue Light on Flowering in Dendranthema grandiflora and Diapause Induction in Orius insidiosus
Authors: Stack Philip A. , Drummond Francis A.
Published: February 2019

Orius is an effective predatory bug of western flower thrips on chrysanthemum. However, long days are required to prevent reproductive diapause in Orius, which is counter to the short-day flowering response in Dendranthema. Two cut flower cultivars (`Manatee Iceberg' and `Naples') and a pot cultivar (`Boaldi') were given short days, long days with broad spectrum light, and long days with supplemental blue light (430–480 nm) at critical threshold levels. Blue light at intensities of 2 to 5 μmol·m–2·s–1 had no effect on flower induction, size, or dry weight or leaf dry weight compared to the short-day control. Increasing intensity and blue light exposure reduced flowering in the cut mum cultivars. At 25C, 77% of Orius females were reproductive in blue light compared to 75% in broad spectrum and 46% in short days. Spectral quality had no effect on fecundity, survival, or insect development rate. At least 90% of Orius reproduced with blue light at 19, 22, 25, and 28C. These results indicate possibilities for providing favorable conditions for biocontrol of arthropod pests on short-day crops.
An Outbreak of a New Whitefly in Guam
Authors: Marutani M. , Yudin L. , Nafus D. , Cruz F. , Santos V.
Published: February 2019

The outbreak of a new whitefly was first reported in Summer 1993 at two sites in the southern part of Guam. Vegetable crops heavily damaged by this pest included cucumber, yardlong beans, and tomato. At present, the whitefly is found infesting tomato, eggplants, cucumbers, watermelon, and other vegetable crops throughout the island. The whitefly was identified as Bemisia argentifolii with the characteristics of a wide host range and the presence of silvering leaves on cucurbits. A larval parasitoid was recovered from eggplant and tomato leaves. The efficacy of pesticides against the pest is being investigated.
Quality Characterization of Fragaria Cultivars and Selections
Authors: Wang Shiow Y. , Galletta Gene J. , Maas John L.
Published: February 2019

Fruit quality of 24 selected strawberry cultivars and selections were evaluated. There were great variations in the contents of soluble solids, titratable acidity, carbohydrates, organic acids, and ascorbic acid among different cultivars, reflecting primary genetic differences. Fructose, glucose, and sucrose were found to be the three major sugars, comprising >65% of the total soluble solids in strawberry. Fruit contained lower sucrose compared to fructose and glucose, whereas leaves contained comparable amounts of fructose, glucose, and sucrose. Citric acid was the major organic acid in strawberries. Strawberries were also rich in ascorbic acid. Leaves were much higher in ascorbic acid than fruit. There appeared to be no correlation between fruit and leaves on carbohydrate, organic acid, and ascorbic acid contents.
Moderate-chilling Peach Breeding Project for the Coastal Plain of the Southeastern United States
Authors: Beckman T.G. , Okie W.R. , Krewer G. , Sherman W.B.
Published: February 2019

The purpose of this three-way cooperative project is to develop new fresh-market peach and nectarine varieties in the 400 to 650 chill hour range for the early season shipping market. Since 1990, >3000 seedlings have been evaluated, resulting in 48 selections. Additionally, several hundred selections from other programs have been evaluated. `Sunsplash', an attractive, early season, 400 chill hour nectarine, was released in 1993 as a result of this cooperative effort. A novel aspect of the program has been the use of non-melting flesh parents for the purpose of improving handling characteristics. Selections include both yellow- and white-flesh types, peaches and nectarines. Some may be adapted for use in other production areas and are available for testing under non-propagation agreement. Evaluation summaries of selections and standards will be presented.
Variation in Reproductive Traits of Western Trailing Blackberry (Rubus ursinus) in the Pacific Northwest
Authors: Anderson Angela K. , Finn Chad E.
Published: February 2019

The superb flavor of trailing blackberry cultivars, such as `Marion', is derived from Rubus ursinus Cham. & Schlecht. Wild R. ursinus offer a range of horticulturally desirable traits to breeders, from high fruit quality to improved cold hardiness. Current cultivars are derived from relatively few sources of R. ursinus, selected primarily for fruiting characteristics. A replicated field trial of 460 clones, representing 20 populations from southern British Columbia, Washington, and Oregon, was established in 1994. Observations during the planting year have indicated that monitoring variability in the following reproductive traits will be useful in assessing diversity; budbreak, flowering, and fruiting date; lateral length; proportion of reproductive laterals; gender; flower and fruit number; and fruit size. In particular, there are clones that exhibit large fruit size (4 to 5 g), high flower number per lateral, and uniform fruit set. Analysis of these data will contribute to determination of relative genetic distances among the populations and enhance the understanding of the diversity available in R. ursinus.
Use of Epifluorescent Microscopy to Observe Development of Plasmopara viticola on Grape Leaf Disks
Authors: Brown Maurus V. , Moore James N. , Harris William M. , Fenn Patrick
Published: February 2019

Calcofluor and berberine were used to determine the potential of epifluorescence microscopy to observe the interaction between grape leaves and P. viticola. Leaf disks (10 mm in diameter) were inoculated and incubated for 2, 4, and 7 days. Disks were stained with berberine at 0.1% for 1 h, rinsed, placed in 0.1 M Tris (pH 5.8) for 15 min, stained in calcofluor at 0.1% for 25 min, and rinsed. Disks were mounted abaxial side up in 30% glycerin and viewed with an epifluorescence microscope. Various leaf features (e.g., trichomes, stomates) were distinguishable from the fungal structures (e.g., hyphae, sporangiophores). Leaf surface colors were red, orange, brown, green, and yellow, and fungal structures were light to dark blue. Epifluorescence microscopy was a useful means of differentiating leaf and fungal structures.
Performance of Advanced Breeding Selections of Primocane-fruiting Raspberries in New Jersey
Authors: Fiola Joseph A. , Lengyen Robert , Swartz Harry J.
Published: February 2019

A major objective of the MD/NJ/VA/WI Cooperative Raspberry Breeding Program is to develop new primocane-fruiting raspberry cultivars that are early, with large fruit size, and good fresh flavor, relative to the `Heritage' standard. Step I seedling selections were made and tissue culture-propagated. The Step III advanced selection trial, planted in 1993, consisted of two advanced selections, JCR-F1 [Geo-1 (Autumn Bliss × Glen Moy) × Heritage–red], and JEF-B1 (Amity × Glen Eagles–golden), with a `Heritage' check. The planting was a RCB (four replications), with 3-m plots, 60-cm plant spacing, on raised beds with black plastic mulch (establishment year), and trickle irrigation. The 1994 season started dry, and mid-summer was warm and wet, inducing an early harvest overall. JCR-F1 was >2 weeks earlier, 40% higher yielding, with 18% larger fruit size than `Heritage'. JCR-F1 fruit was tall conic, cohesive, and had good flavor; plant vigor was very good. JEF-B1 was 10 days earlier than `Heritage', had 40% larger fruit size, but was 25% lower yielding; plant vigor was also good. The flavor was described as banana and apricot. The planting will be fruited for multiple seasons for continued comparison.
Effects of Harvesting Stages, Preservatives, and Storage Methods on Vase Life and Flower Quality of Cut Snapdragons
Authors: Lee Jong Suk , Kim Young A , Sin Young Mi
Published: February 2019

Cut snapdragons (Antirrhinum majus L. cvs. Fujinoyuki, Oakland, and Bismarck) were harvested at three different stages and pulsed with silver thiosulfate (STS). Then, the flowers were treated with several preservative solutions to test the effects on vase life and flower quality. Proper storage methods were also investigated. The best harvesting time of snapdragon was when seven to nine florets were opened in a spike. The flowers harvested at this stage had more fresh weight, increased number of opened flowers per spike, and longer vase life than those harvested at earlier stages. Pulsing with 0.2 mM STS for 16 h improved flower quality and prolonged vase life. The preservative solution containing 2% sucrose + 150 ppm 8-hydroxyquinone citrate (HQC) + 25 ppm AgNO3 prolonged vase life. However, this solution caused longer internode between florets and excessive elongation of spike. The preservative solution containing 2% sucrose + 150 ppm HQC + 25 ppm AgNO3 + 50 ppm daminozide improved flower quality by prolonging vase life, reducing the length of internode between florets, and preventing excessive elongation of spike. The flowers held in 50% 7-Up had 2 times prolonged vase life compared to water control. The flowers held in 4% ethyl alcohol also had prolonged vase life and increased fresh weight. Ethylene caused floret abscission and STS pretreatment prevented this floret abscission. Ethylene production in cut snapdragons maintained 2 to 6 nl/g fresh weight per h during vase life. The prolonging storage at low temperature (1C) shortened vase life. The flowers pretreated with STS, and then held in preservative solution during cold storage, had better flower quality and longer vase life than those in plain water.