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A. Medlicott, J. Brice, T. Salgadol, and D. Ramirez

No systematic curing and storage techniques are currently used with onions in Honduras; postharvest losses occur rapidly. The objective of this study was to evaluate the use of storage bins (maximum capacity 7t) that use forced ambient air ventilation to manipulate the atmospheric conditions around the onions. The desired storage conditions were 26 to 30C and 60% to 75% relative humidity. Ventilation regimes were manipulated in an attempt to obtain these conditions. The rate of deterioration in four varieties of onions over a 3-month period was determined and compared with onions stored under normal ambient conditions. Marketable onions in the forced-air storage bin compared to the controls stored under ambient conditions after 13 weeks were 82% vs. 37% for `Granex 33'; 71% vs. 40% for `Granex 429'; 63% vs. 31% for `Granex 438'; and 90% vs. 44% for `Texas Grano 502'. This represents a significant increase in the number of marketable onions after storage. All losses were increased by rain and tornado damage after 1 month of storage. The methods used to maintain uniform temperature and humidity conditions in the storage bin are discussed together with the problems encountered. The construction and operating costs are given together with the market prices and the required returns to cover the bin costs.

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Xin Zhao, C.B. Rajashekar, Edward E. Carey, and Weiqun Wang

Demand for organically grown produce is increasing, largely due to concerns of consumers about health and nutrition. Previous studies have not shown a consistent difference of essential nutrients, such as vitamins and minerals, between organic food crops and the conventional counterparts. However, to date, little consideration has been given to phytochemicals, secondary plant metabolites with potential health-promoting properties. We first discuss factors that can infl uence the levels of phytochemicals in crops, and then we critically review the results of published studies that have compared the effects of organic and conventional production systems on phytochemical contents of fruit and vegetables. The evidence overall seems in favor of enhancement of phytochemical content in organically grown produce, but there has been little systematic study of the factors that may contribute to increased phytochemical content in organic crops. It remains to be seen whether consistent differences will be found, and the extent to which biotic and abiotic stresses, and other factors such as soil biology, contribute to those differences. Problems associated with most studies tend to weaken the validity of comparisons. Given the limitations of most published studies, needs for future research are discussed.

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Timothy J. Smalley and Frank B. Flanders

The Industry Liaison Committee of the American Society for Horticultural Science conducted a survey of the horticulture industry to systematically determine: 1) industry's perception of university training of recent graduates and 2) industry's perception of educational needs for future graduates. A Delphi survey was sent to experts in the fruit, ornamental, greenhouse, turf, and vegetable industry. The respondents expressed dissatisfaction with the level of competence of recent university graduates in personnel management and marketing. The lack of hands-on training in university courses was viewed as a major problem, but the respondents agreed that internships should provide university students with the necessary practical experience and universities should concentrate on the science of horticulture. The respondents indicated that business management and marketing expertise will be more important in the future than knowledge of production techniques; however, they would not be more likely to hire a business major instead of a horticulture major. The following areas of study were ranked for relative importance to be included in the university curriculum (from most important to least): communication skills, horticultural technology, business management, personnel management, plant nutrition and soil fertility, pest control, plant physiology, environmental awareness, plant physiology, plant pathology, accounting, and equipment use and maintenance. A second round of questioning for this Delphi survey is being conducted and results will be presented to verify preliminary results.

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Margaret Cliff, Katherine Sanford, Wendy Wismer, and Cheryl Hampson

This research used digital images to explore some of the factors responsible for consumer preference of visual characteristics of apples (Malus ×domestica Borkh.). The images systematically varied in color and shape (Expt. A: 9 images) and type, shape, and background color (Expt. B: 10 images), while keeping apple size constant. Visual assessments of the apple images were collected from 144 consumers (Expt. A) and 165 consumers (Expt. B) in British Columbia (BC), Nova Scotia (NS), and New Zealand (NZ) using balanced incomplete block designs. Canadian consumers (BC and NS) preferred red apples over green or yellow. NZ consumers liked equally red and green apples, and preferred both to yellow apples. At all locations, consumers in Expt. A significantly preferred round and conical shaped apples to oblong apples. When the combined effects of type, shape, and background color were evaluated, NZ consumers rated the striped, round apples the highest, and least preferred both round and oblong, blush-type apples with yellow backgrounds. NS consumers tended to prefer blush apples regardless of type and background color, and BC consumers were more accepting of a range of apple types, shapes, and background colors.

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Margaret Balbach

Introductory Horticulture at Illinois State University is approved for inclusion in the University Studies Program. This program is comprised of courses whose content is considered of general importance to the educated layperson, rather than to the specialist in the field. Departments may use the University Studies Program as a means of attracting students to the field. This has been done with fair success with Introductory Horticulture. Because the course must provide personal enrichment, be broad in scope, offer a systematic design for further learning, and assure a breadth of knowledge and understanding, this course has been designed to focus on the economies of the various horticultural industries, how they are related to the socioeconomic history of the various regions of the country and how the marketing of horticultural products and enterprises affects the personal life of individuals. Acceptance of this approach has been two-fold: first: student evaluations are positive, a steady enrollment has been maintained, and the course has steadily provided 10% to 15% of new Horticulture students, and second: the University Studies review committee has twice affirmed the “tenure” of Introductory Horticulture in spite of increasingly stringent guidelines that discourage many traditional science courses.

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Scott Kalberer, Norma Leyva-Estrada, Stephen Krebs, and Rajeev Arora

Winter survival of temperate-zone woody perennials requires them to resist loss of frost hardiness (deacclimation) during winter and early spring thaws. However, little is known about deacclimation response in woody landscape plants. Moreover, what impact, if any, the degree of deacclimation has on reacclimation capacity has not been systematically studied. We used nine genotypes of deciduous azaleas (Rhododendron subgenus Pentanthera) to investigate effects of deacclimating conditions on bud cold hardiness and reacclimation ability. Dormant floral buds, with 3–5 cm stem attached, were collected in late December from field-grown plants, and placed in constant warm [22 °C 15 °C (D/N)] and humid conditions for increasing durations (0-day to 14-day) to stimulate deacclimation. Bud cold hardiness (lt 50) was determined (using logistic regressions) by evaluating immature flower survival at subfreezing treatment temperatures. Results indicated that azalea genotypes from colder provenances showed greater initial frost hardiness. Typically northern genotypes had slow to intermediate deacclimation rates, while rates of southern genotypes were intermediate to rapid. High initial frost hardiness was frequently associated with slow deacclimation. Buds retained the capacity to reacclimate upon cold exposure [2 °C/–2 °C; (12 h/12 h)] even after 8 days of deacclimation. Distinct differences were observed between the two latitudinal ecotypes of R. viscosum with respect to their initial bud hardiness, deacclimation rates, and reacclimation capacities. We suggest that the three attributes, i.e., high initial hardiness, slow deacclimation, and high reacclimation capacity, together may be important for winter-survival of azalea buds.

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David Obenland, Paul Neipp, Sue Collin, Jim Sievert, Kent Fjeld, Margo Toyota, Julie Doctor, and Mary Lu Arpaia

It is commonly believed within the citrus industry that handling, waxing, and storage of navel oranges may have undesirable effects on flavor. However, the effect of each potential influencing factor under commercial conditions is not completely understood. The purpose of this study was to systematically investigate these potential influences on navel orange flavor. Navel oranges were harvested on two separate dates, using three grower lots per harvest date, and the fruit run on a commercial packing line. Fruit were sampled at four different stages of the packing process: in the field bin; after the washer; after the waxer; and after packing into standard cartons. Fruit quality, flavor, and juice ethanol concentration were evaluated immediately after sampling and following 3 and 6 weeks of storage at 5 °C. The overall hedonic score, a measure of flavor, significantly declined from 6.5 to 5.7, as a result of 6 weeks storage. Fruit selected from field bins, from after the washer, and after the waxer were all judged by the taste panel to be equivalent in flavor. The packed fruit were judged to be slightly inferior in flavor. Titratable acidity declined while soluble solids increased as a result of storage; the stage of the packing process influenced neither. Waxing and storage both were associated with higher ethanol levels in the fruit.

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C. Richer-Leclerc and J.-A. Rioux

The “Réseau d'essais des plantes ligneuses ornementales du Québec” (REPLOQ) is a research project initiated in 1982 with the mandate to elaborate, develop, and coordinate a cooperative research project to evaluate the winter hardiness of ornamental plants. Systematic evaluation trials provided information on growth potential and hardiness of woody trees and shrubs evaluated over a 5-year period in the principal growing regions of Québec. Zonal range covered was 2 to 5b in the Canadian system. Adequate field testing is critical for new introductions and, since 1984, more than 400 species and cultivars have been introduced and eight evaluated in each climatic zone. Propagation methods, as well as their potential for ornamental purpose, were described. In the 1984 plantation, 30 ornamental species and cultivars were evaluated. Winter damage data observed on each plant during this period were analyzed by Clusters analysis and five groups of plants were determined. Trees, flowering shrubs, and foliage shrubs were discussed separately and winter damages of each group were submitted to “Correspondence analyses” to identify plant response to climatic conditions. Growth and production potentials were defined by SAS analysis. Hardiness zone of each species was detailed, established, or modified.

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Sandra B. Wilson, Robert L. Geneve, and Fred T. Davies

Interactive web-based questions were developed for students to review subject matter learned in an online plant propagation course. Articulate Storyline software was used to build nearly 250 review questions with five different testing styles to ascertain proficiency in subject areas, including the biology of propagation, the propagation environment, seed propagation, vegetative propagation, micropropagation, and cell culture. Questions were arranged to correspond to the supporting textbook chapters in Hartmann and Kester’s Plant propagation: Principles and practices, ninth edition. These are open access and available to instructors and students worldwide. Users received immediate feedback for each question answered correctly or incorrectly. The system remembers where one leaves off, which enables starting and stopping multiple times within a chapter. Means of pre- and posttest responses to nine content knowledge items showed that students perceived a significant content knowledge gain in the course. These online interactive reviews can be adapted easily to other courses in a variety of fields, including horticulture, botany, systematics, and biology. They can also be expanded to overlay multiple objects and trigger events based on user response. Since inception, the website hosting these online reviews averaged 156 unique visitors per month. Students have reported this to be a useful tool to prepare them for course exams.

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William W. Inman and William L. Bauerle

Recent work has shown that stomatal conductance (gs) and net photosynthesis (Anet) are responsive to the hydraulic conductance of the soil to leaf pathway (Xp). Two tree species with differing xylem structures were used to study the effect of systematic manipulations in Xp that elevated xylem hydraulic resistance. Simultaneous measures of gs, Anet, bulk leaf abscisic acid concentration (ABAL), leaf water potential (L), and whole plant transpiration (Ew) were taken under controlled environment conditions. Quercus shumardii Buckl. (shumard oak), a ring porous species and Acer rubrum L. `Summer Red' (red maple), a diffuse porous species, were studied to investigate the short-term hydraulic and chemical messenger response to drought. Both species decreased Anet, gs, L, and Ew in response to an immediate substrate moisture alteration. Relative to initial well-watered values, red maple Anet, gs, and Ew declined more than shumard oak. However, gs and Anet vs. whole-plant leaf specific hydraulic resistance was greater in shumard oak. In addition, the larger hydraulic resistance in shumard oak was attributed to higher shoot, as opposed to root, system resistance. The results indicate hydraulic resistance differences that may be attributed to the disparate xylem anatomy between the two species. This study also provides evidence to support the short-term hydraulic signal negative feedback link hypothesis between gs and the cavitation threshold, as opposed to chemical signaling via rapid accumulation from root-synthesized ABA.