bluuebunny/crossref_metadata_2025 huggingface dataset:
Diosgenin Production in North America
Authors: Dawson Ray F.
Published: December 2018

Diosgenin is a steroidal aglycone occurring in certain species of Dioscorea native principally to eastern Mexico. In the 1940s, diosgenin became a much-sought-after intermediate for the chemical synthesis of certain corticosteroids and structurally related fertility regulants. Various difficulties of access to native sources led to attempts at plantation production. One of these, supported by the Upjohn Company between 1962 and 1980, was located on the Pacific coast of Guatemala and is described herein from the standpoint of technology development. The Dioscorea plant produces a long, coarse vine that requires support. The deep-growing, fleshy rhizome contains the diosgenin and, at harvest, must be removed from soil depths up to 1 m. Dry rhizome yield depends on supply of readily available (low-tension) soil water. Sites located over abundant water reserves give satisfactory rhizome yields, but diosgenin concentrations fall to uneconomically low levels under such circumstances. By 1980, diosgenin had been displaced by two products of soya oil processing, stigmasterol and sitosterol, which became available as a result of advances in microbial fermentation technology. Consequently, the cultivation of Dioscorea was abandoned.
Variable Yield of Bell Pepper Established on Converted Perennial Pasture Fertilized According to Recommendations
Authors: Russo V.M. , Roberts B.W.
Published: December 2018

Soil conditions may not be adequate for uniform yields when perennial pasture is converted to vegetable production. This occurred with `Pip' bell pepper (Capsicum annuum var. annuum L.) planted in a 0.17-acre field 3 years after conversion from perennial pasture. Depths of the A-horizon and pH levels, as well as concentrations of N, P, and K were variable throughout the field when sampled after the last harvest. Marketable yields from plots established in the field ranged from 4.1 to 14.5 tons/acre. The A-horizon depth, soil pH, and residual N, P, and K levels were correlated with yield at specific A-horizon depths and pH levels. An intensive soil-testing regime likely will be required so that nutrient levels can be maintained to support bell pepper production on soil converted from perennial pasture.
Post-production Performance of Uniconazole-treated Zinnia and Marigold Plugs
Authors: Davis Tim D.
Published: December 2018

Plugs of Zinnia elegans Jacq. `California Giant' and Tagetes erecta L. `Golden Climax' and `Grange Lady' were treated with foliar sprays of uniconazole solutions at 0, 5, 25, or 50 mg·liter-1 (spray volume = 120 ml·m-2). Ten days later individual plants were transplanted to OS-liter pots for evaluation of subsequent growth and flowering. All uniconazole treatments reduced height 10 days after application; the extent of reduction depended on uniconazole spray concentration. With zinnia, only the 50-mg·liter-1 foliar spray caused undesirable stunting for at least 1 month after transplanting. None of the uniconazole treatments affected time to anthesis for zinnia. With both marigold cultivars, all uniconazole treatments reduced growth the 2 weeks following transplanting. The highest concentration reduced marigold shoot growth during this period to 25% to 30% of untreated controls. Between 2 and 4 weeks after transplanting growth of all uniconazole-treated marigolds recovered to levels similar to the control. Time to anthesis was increased by the 50 mg·liter-1 treatment for both marigold cultivars. These results suggest that foliar sprays of uniconazole at 5 to 25 mg·liter-1 can control plug height during production without adversely affecting subsequent growth and flowering. with both zinnia and marigold, a single GA3 foliar spray of 100 mg·liter-1 at transplanting partially reversed the adverse post-production effects of the 50 mg·liter-1 uniconazole foliar spray.
Southern Highbush Blueberry Response to Mulch
Authors: Clark John R , Moore J.N.
Published: December 2018

Blue Ridge, Cape Fear, Georgiagem, and O Neal southern highbush blueberry cultivars were grown for 5 years on a fine sandy loam soil in a comparison of plants either mulched with uncomposted pine sawdust and woodchips or nonmulched. Other cultural practices were identical and all plants received the same amount of trickle irrigation. A significant mulch × cultivar interaction for yield and mulch × plant age interactions for yield, individual berry weight, and plant volume were found. Cape Fear was the highest-yielding mulched cultivar, followed by Blueridge, Georgiagem, and O Neal. Mulched plants had higher yields and produced larger plants. Average individual berry weight was greater for mulched plants in the first year of harvest, but not different among treatments in other years. The data reveal that these southern highbush cultivars performed similar to northern highbush (Vaccinicum corymbosum L.) in their need for mulching for adequate production on upland soils.
Advances in Fluid Drilling
Authors: Pill Wallace G.
Published: December 2018

Seed treatments, gels, and planters associated with fluid drilling are reviewed in detail. The future of fluid drilling likely lies predominantly in the sowing of primed seeds rather than germinated seeds in the carrier gel. The primed seeds may be hydrated before fluid drilling to enhance germination and seedling emergence. The gel can carry a variety of chemical or biological additives appropriate for the crop and seedbed conditions. The positional advantage resulting from additive incorporation in the fluid-drilling gel represents a more eflicient, cost-effective, and environmentally sound application method than others such as binding or spraying.
Container Design Influences Physical Parameters of Different Media
Authors: Ruter John M. , van de Werken Hendrik
Published: December 2018

The effect of container design on physical parameters of media with different bulk densities was evaluated. A significant interaction between container design and media for water-holding capacity and air space was found. A container with a polyester fabric bottom had the largest media air space and the smallest water-holding capacity after 24 h of drainage when placed on a column of sand to allow for free drainage from the container medium. For the media tested, a blend of composted pine bark and hardwood bark (PB:HB) appeared to have good physical characteristics for a container medium in the container designs that were evaluated. Container design should be considered when selecting a container medium because physical parameters of a given medium will be influenced.
Transplanting Date Influences Winter Injury and Growth of Two Azalea Cultivars
Authors: Keever G. J. , Cobb G.S. , Foster W.J.
Published: December 2018

Plant response to time of transplanting from 0.53-qt (OS-liter) to l-gal (3.8-liter) containers was influenced by cultivar and severity of winter. Transplanting of `Formosa' from Sept. through Dec. 1983 resulted in injury and death of many plants due to a low temperature of 8F (-13.3C) in Dec. 1983. Injury or death of `Hino Crimson' was higher when plants were transplanted in December. Survival and growth indices of both cultivars were higher when transplanted in January through March. During 1986-87, when minimum temperature was 26F (-3.3C), transplanting between September and April had minimal effect on growth of `Formosa', but plant quality was better when plants were transplanted between December and April. Transplanting date had little effect on size of `Hino Crimson', except smaller plants were produced when transplanted in April; quality was highest of plants transplanted from November through March.
Seed Treatments for Disease Control
Authors: Bennett Mark A. , Callan Nancy W. , Fritz Vincent A.
Published: December 2018

Disease management is an important step in any crop establishment system. Emergence of field-seeded crops may take several weeks for many species and represents a vulnerable stage of plant growth. This paper considers various biological, chemical, and physical seed treatments for improved seed performance. The role of seed quality and cultural practices in seedling establishment also is reviewed. Multidisciplinary approaches to improving horticultural crop establishment are promising.
How to Recognize Wind Damage on Leaves of Fruit Crops
Authors: Newenhouse Astrid C.
Published: December 2018

Plants respond to wind in a manner similar to drought, but, in addition, leaves suffer physical or mechanical damage. Long-term wind stress results in smaller plants, less total leaf area, skewed tree growth because most of the branches grow toward the leeward side, and less yield than plants protected from wind. A simple procedure to simulate abrasion damage to leaves helps growers recognize wind damage to several fruit crops.
A Versatile New Tactic for Fruit Tree Micrografting
Authors: Obeidy Ahmed A. , Smith M.A.L.
Published: December 2018

Micrografting is au effective technique for elimination of viruses, early diagnosis of grafting incompatibilities, rejuvenation of mature tissue, and bypassing the juvenile phase in fruit trees. Current micrografting procedures are difficult, impractical, expensive, and generally result in an inefficient rate of successful graft production. To alleviate some of these limitations, a unique apparatus was designed to splice the in vitro-derived scion and rootstock together during the micrografting process. The dual-layer device was constructed with an outer layer of aluminum foil, with flexibility to facilitate manipulation during the grafting of micro-scale plants. A delicate, absorbent inner layer of paper toweling cushions the plant tissue. It also may be treated with hormones and other compounds. After healing, it is easy to remove the grafting apparatus from the grafted plant without damaging the tissues. This apparatus may be used to unite a scion and a rootstock with different stem diameters. Shoot-tip cultures of `McIntosh' and M.7 apple and `North Star' sour cherry, and in vitro seedlings of lemon, orange, and grapefruit were used as a source of in vitro scions and rootstocks. Successful graft unions were developed, and the grafted plants were transplanted into the greenhouse environment.
Effects of Irrigation on Wine Grape Growth and Fruit Quality
Authors: Hamman Richard Allen , Dami Imed Eddine
Published: December 2018

Field studies were conducted to determine the effect of three drip irrigation regimes on grapevine growth, juice and wine quality, soil moisture, cold hardiness of bud and cane tissues and soluble sugar content of cortical cane tissues of Vitis vinifera, Linnaeus `Cabernet Sauvignon'. This study was developed to help provide some irrigation management strategies that would improve fruit quality and reduce excessive vigor. Irrigation treatments of 192, 96, and 48 L (51, 25, and 13 gal) per vine per week were initiated at bud break until veraison (initiation of berry color) and then reduced by 25% through harvest. Significant differences of fruit weight per vine, crop load, soil moisture, average berry and cluster weight, shoot length and pruning weight per meter of canopy row were observed among treatments. Juice and wine compositions and wine color were also significantly different; however, cold hardiness and soluble sugar contents did not differ between treatments.
Perspectives on Horticultural Therapy in Australia
Authors: Aldous David E.
Published: December 2018

Human awareness of plants in Australia goes back 50,000 years when the aboriginal first began using plants to treat, clothe and feed themselves. The European influence came in 1778 with the First Fleet landing in New South Wales. Australia's earliest records of using horticulture for therapy and rehabilitation were in institutions for people with intellectual disabilities or who were incarcerated. Eventually, legislation created greater awareness in the government and community for the needs of persons with disabilities, and many worthwhile projects, programs and organizations were established or gained greater recognition. Horticultural therapy programs may be found in nursing homes, rehabilitation centers, adult training support services, hospitals, day centers, community centers and gardens, educational institutions, supported employment, and the prisons system. This article reviews the history and development of Australian horticulture as a therapy in the treatment of disabilities and social disadvantaged groups, and includes an overview of programs offered for special populations and of Australia's horticultural therapy associations. It also discusses opportunities for research, teaching and extension for horticultural therapy in Australia.
Consumer Color Preference in New Guinea Impatiens
Authors: Berghage R.D. , Wolnick D.J.
Published: December 2018

Potential consumers were surveyed in the spring of 1996 to gain insight into preferences for flower and leaf color in New Guinea impatiens (Impatiens hawkeri Bull.). Survey participants indicated a preference for bright solid colors, and bicolor flowers. The most preferred solid flower colors were red-violet, and red. The least preferred solid flower colors were pink and blush. Potential consumers ranked bicolor flowers over their solid color counterparts. Red and variegated foliage were preferred to solid green. Foliage with solid red upper or lower surfaces were preferred 2:1 over variegated foliage.
A Review of Human Issues in Horticulture in Finland: Urbanization Motivates a Renewed Appreciation for Plants and Nature
Authors: Evers Aino-Maija , Lindén Leena , Rappe Erja
Published: December 2018

Approaches using human issues in horticulture (HIH) offer new possibilities to develop nearby nature in cities, especially during a period of rapid urbanization in Finland. New initiatives have been developed in school gardening, environmental education, gardening in training programs for disabled people, therapeutic environments in hospitals and institutions, and in the University of Helsinki horticultural education and research programs. At the University of Helsinki, two contact teaching courses and national seminars were organized in 1996 and 1998. Initial studies in the HIH approach have three main themes: 1) gardening as a tool for better quality of life in homes for the elderly, 2) ecology, native plants and extensive maintenance in parks, and 3) the use of horticulture in environment and science education at the lower level of the comprehensive school.
Two Symposia on Human-Horticulture Interactions in the 25th International Horticultural Congress in Belgium
Authors: Matsuo Eisuke
Published: December 2018

In August 1998, there were two symposia concerning human-horticulture relationships held at the International Horticultural Congress. The speakers at the first symposium introduced many activities that are occurring in this field around the world. The second symposium addressed allotment and community gardens. A brief summary of these symposia is presented.
Report of the International People-Plant Symposium in Sydney, Australia, July 1998
Authors: Burchett Margaret
Published: December 2018

Participants from eight countries met in Australia in July 1998 for the International People-Plant Symposium titled “Towards a New Millennium in People-Plant Relationships.” There were about 75 presentations arranged under three general headings: 1) plants, cultural diversity, and environmental quality, 2) plants for human health and well-being, and 3) plant and horticultural education—community and schools. The symposium represented another step in the dissemination of information and awareness on people-plant relationships.
The First Symposium of the Korean Society for Plants, People and Environment
Authors: Sim Woo-Kyung
Published: December 2018

The Korean Society for Plants, People and Environment held its first International Symposium on Plant and People Interactions in Human Health and Quality of Life in May 1998. Three speakers, invited from abroad, were among those who made presentations. A summary is presented.
Effects of Floral and Foliage Displays on Human Emotions
Authors: Adachi M. , Rohde C.L.E. , Kendle A. D.
Published: December 2018

Changes in human emotions were investigated during exposure to three different indoor conditions: floral display present, foliage display present, and no display present. There were 20 subjects (10 males and 10 females) in each condition. The subjects were shown a video that introduced the University of Reading and included scenes of landscapes. It was shown that a floral display had positive effects on human emotions, such as composition and confidence, however, some evidence of a significant increase in annoyance was also found for this treatment. The foliage display had a somewhat negative effect by slightly increasing bad temper, and the foliage display tended to have a positive effect on clearheadedness. Investigations of psychological responses to nature are complex, and many opportunities for more work exist.
Strawberry Cultivar Use in North America
Authors: Hokanson Stan C. , Finn Chad E.
Published: December 2018

Strawberry (Fragaria ×ananassa Duch.) cultivars used by commercial producers in North America often change rapidly due to several factors including modified cultural practices, processing and marketing practices, the desire for new cultivars with larger and higher quality berries, resistant insect and disease pests, loss of traditional chemical control methods, and private sector breeding programs. Within the past decade, the annual plastic-mulched production system has quickly expanded into eastern North America prompting the need for cold-hardy cultivars adapted to that system. The continuing loss of traditional chemical controls for strawberry insects and diseases, including the impending loss of methyl bromide, has prompted the need for increased insect and disease resistance. In addition, consumer demands for a healthier food product with lower chemical residues has heightened this need. Small fruit experts from across North America provided information on the primary strawberry cultivars used in the recent past, the present, and potential cultivars for the future, as well as on current strawberry acreage in their respective states and provinces.
Situation-based and Cooperative Learning in an Upper-division Fruit Production and Physiology Course
Authors: Azarenko Anita Nina
Published: December 2018

A situation-based or modified case study approach to learning has been adopted in an upper division fruit production course that is taught at Oregon State University in the Department of Horticulture. A new case study, which will have a high probability of generating discussion on key pomological themes, is developed each term. On the first meeting day of class, students identify relevant themes in the case study. A modified jigsaw cooperative learning strategy is then used to cover the relevant subject matter throughout the term. While using this strategy, groups of two to three students become experts on a theme and are responsible for sharing their knowledge with their peers. The instructor mentors the experts by reviewing assignments created by them, checking answers to assignments, and administering quizzes on the themes. About midterm, larger groups of six to seven students begin their preparation of an oral presentation and written synthesis of the goals and possible pathways for achieving the targets of the primary stakeholders (i.e., orchardists, field representatives, extension faculty, etc.) that are presented in the case study. The groups make their presentations to the stakeholders at the end of the term. Students are required to prepare an individual written report. This learning approach links theory with practice, gives students practice in extensively analyzing a situation, enables students to become conversant in and knowledgeable of basic pomology, builds positive relationships between fellow students, and provides multiple experiences for communicating information and student's discoveries.
Teaching Integrated Pest Management Using the Learn-by-Doing Philosophy
Authors: Rice Robert P.
Published: December 2018

California Polytechnic State University's (Cal Poly) learn-by-doing philosophy permeates all areas of the environmental horticultural science curriculum by combining an emphasis on the science of horticulture in lecture sessions and the opportunity to engage in activities similar to those used by industry in the lab activities integral in all courses. The course, Disease and Pest Control Systems in Ornamental Plants (EHS 427), has taken this philosophy a step further by using problem-based learning and allowing students to function as pest control advisors and qualified applicators in the class. This approach has resulted in greatly increased student understanding of pest control, improved student morale, and increased interest in integrated pest management careers and research projects.
Student Participation in Syllabus Development as a Student-centered Learning Technique in Horticulture Classes
Authors: McMahon Margaret
Published: December 2018

Student-centered learning means having students actively engaged in many aspects of a course to promote learning. Allowing students to participate in syllabus development is a method that involves students in the course and, in the process, assume responsibility for much of their learning. Students can help set course objectives, decide what is the evaluation criteria and who evaluates, determine and deliver some of the course content, and approve the code of conduct for the class. By helping with the aforementioned areas, students can see the relevance of the course to their needs and interests. They tend to take a greater interest in the course and participate more actively in the class. The process of student involvement in syllabus development requires several steps and utilizes techniques that are presented in the following paper.
Butternut: An Underused Resource in North America
Authors: Ostry M.E. , Pijut P.M.
Published: December 2018

Butternut (Juglans cinerea L.) has many fine qualities as a nut species, however, it has never been commercially important. Although the nut is very edible, only a few cultivars have been selected that have desirable nut size and cracking qualities. In the last 20 years there has been a dramatic decline in the number of butternut in native stands caused to a large extent by the lack of natural reproduction and a damaging canker disease. Evidence suggests that superior, disease resistant trees can be propagated and if isolated from areas where the disease is prevalent, may remain disease-free. It is important that the remaining genetic diversity within the species is maintained. Various butternut conservation practices and research projects to restore butternut populations are underway in the United States and Canada.
Black Plastic Mulch and Between-row Cultivation Increase Black Currant Yields
Authors: Dale Adam
Published: December 2018

Black currant (Ribes nigrum L.) plants of eight varieties were grown either through black plastic mulch or in bare soil and with the area between the rows cultivated or sodded with red fescue (Festuca rubra L.). Over 6 years, black plastic mulch increased yields by 26% over no mulch and cultivation between the rows increased yield by 32% compared to sod. The effect of both treatments was additive, cultivation and black plastic increased yield by 68% over grass and no black plastic. Growers are recommended to plant black currants through black plastic and avoid using sod between the rows.
Evaluation of Phytotoxicity of Diazinon and Captan Formulations on Highbush Blueberries
Authors: Polavarapu Sridhar
Published: December 2018

A common practice in highbush blueberry (Vaccinium corymbosum L.) culture is to use combinations of insecticides and fungicides to reduce the number and cost of pesticide applications. In response to apparent phytotoxicity observed in commercial fields that were treated with combinations of diazinon and captan formulations, phytotoxicity of two formulations of diazinon (Diazinon AG600 and Diazinon 50W) and captan (Captan 80WP and Captec 4L) was investigated on highbush blueberries during 1997 and 1998. Phytotoxicity injury similar to injury observed in commercial fields was reproduced in treatments with diazinon and captan mixtures in all experiments. The Diazinon AG600 and Captec 4L mixture was the most severe and caused significantly more phytotoxic-ity to fruit and leaves than individual treatments of Diazinon AG600, Captec 4L or untreated control. Separation of diazinon and captan applications by 8 h significantly reduced phytotoxicity compared to mixture treatments. Injured fruit and leaves recovered over time and most treatments showed only a mild injury at the time of harvest. Phytotoxicity on fruit and leaves caused by Diazinon AG600 and Captec 4L mixture was significantly affected by application date with the earliest application causing the greatest injury. These data indicate that diazinon and captan mixtures cause phytotoxicity on highbush blueberries and therefore the two should not be applied in combination.
Potassium and Phosphorus Deficiency Symptoms of Ixora
Authors: Broschat Timothy K.
Published: December 2018

Ixoras (Ixora L.) growing in calcareous sandy soils are highly susceptible to a reddish leaf spot disorder. Symptoms appear on the oldest leaves of a shoot and consist of irregular diffuse brownish-red blotches on slightly chlorotic leaves. Symptoms of K deficiency, P deficiency, and both K and P deficiency were induced in container-grown Ixora `Nora Grant' by withholding the appropriate element from the fertilization regime. Potassium-deficient ixoras showed sharply delimited necrotic spotting on the oldest leaves, were stunted in overall size, and retained fewer leaves per shoot than control plants. Phosphorus-deficient plants showed no spotting, but had uniformly brownish-red older leaves and olive-green younger foliage. Plants deficient in both elements displayed symptoms similar to those observed on landscape plants. Symptomatic experimental and landscape ixoras all had low foliar concentrations of both K and P.
What Are Burpless Cucumbers?
Authors: Wehner Todd C.
Published: December 2018

Burpless cucumbers are listed in many seed catalogs as being milder in taste (or easier on the digestion) than the american slicing type. It has been suggested by researchers that burpless cucumbers 1) contain less of a burp-causing compound, 2) are genetically bitterfree, or 3) are just the marketing term for oriental trellis cucumbers sold in the U.S. The objective of this experiment was to determine whether oriental trellis cucumbers cause less burping when eaten, and whether they are genetically bitterfree. An american slicer (`Marketmore 76'), a bitterfree slicer (`Marketmore 80'), and a burpless oriental trellis slicer (`Tasty Bright') were compared. Burpiness of the fruit was determined in the field in two seasons (spring and summer) and two replications. Six judges were grouped into burp-susceptible and burp-resistant. They evaluated the cultivars over two harvests by eating a 4-inch (100-mm) length of one fruit of the three cultivars (in random order) on three consecutive days. Burpiness was rated 0 to 9 (0 = none, 1 to 3 = slight, 4 to 6 = moderate, 7 to 9 = severe). Bitterness of the plants was determined (using different judges) by tasting one cotyledon of six seedlings per cultivar. Cotyledon bitterness is an indicator of plant bitterness; bitterfree plants lack cucurbitacins, and have mild-tasting fruit. Results of taste tests indicated that burpiness ratings were not significantly differentfor burp resistant judges. However, oriental trellis cucumbers were slightly but significantly milder than american slicers for judges susceptible to burping. `Marketmore 76' and `Tasty Bright' were normal-bitter, and `Marketmore 80' was bitterfree. An additional 11 oriental trellis cultivars were also tested for bitterness to determine whether Tasty Bright was typical in bitterness; they were all normal-bitter. In conclusion, oriental trellis cucumbers are not bitterfree, but are slightly milder for burp-susceptible people to eat. Finally, burpless is the marketing term for oriental trellis cucumbers in the United States.
Comparison of Plastic Mulch and Bare-ground Production and Economics for Short-day Onions in a Semitropical Environment
Authors: Vavrina C.S. , Roka F.M.
Published: December 2018

In 4 years of research comparing production of short-day onions (Allium cepa L.) on plastic mulch versus bare ground in southern Florida, greater marketable yields were obtained when onions were grown on plastic mulch. Results showed that in a semitropical environment, white-on-black plastic mulch provided the greatest yield enhancement from increased weight and bulb size. Yield loss due to splitting, while apparent, was not sufficient to reduce the impact of mulch on the increase in individual bulb weight. Adopting plastic mulch for sweet onion production will add between $400 and $500/acre ($988 and $1,235/ha) of additional operating expenses. While this may increase cash-flow burdens and heighten overall financial risks, the added value from increased yields by weight and greater percentages of jumbo sized bulbs suggest that plastic mulch has an excellent chance to increase a grower's overall net return. Using conservative yield and market price assumptions, an economic analysis showed an increase in grower's net return of more than $120/acre ($296/ha).
Effects of Spinosad and Acephate on Western Flower Thrips Inside and Outside a Greenhouse
Authors: Cloyd Raymond A. , Sadof Clifford S.
Published: December 2018

Greenhouse studies were conducted from 1996 to 1998 to determine the efficacy of spinosad, and acephate, against western flower thrips (Frankliniella occidentalis Pergande) on transvaal daisy (Gerbera jamesonii H. Bolus ex. Hook f). In addition, the number of natural enemies inside and outside the greenhouse was determined. Studies were arranged in a randomized complete-block design with four blocks and four treatments per block. Three rates of spinosad, 50, 100, and 200 mg·L-1 (ppm), and one rate of acephate, 600 mg·L-1 were used in all three studies. Plants were artificially inoculated at bloom with 10 adult western flower thrips. The number of live and dead thrips was counted from each plant. In all three studies, both spinosad and acephate controlled thrips. However, there was more variation in the average number of live thrips for acephate than spinosad across years. In all treatments fewer live thrips and more natural enemies were found on plants outside the greenhouse than inside the greenhouse. This suggests that placing plants outdoors allows the natural enemies of thrips to colonize plants and provide supplemental control.
Influence of Stand Deficiencies and Replanting on `Athena' Muskmelon Yields
Authors: Walters S. Alan , Schultheis Jonathan R.
Published: December 2018

Two field studies were conducted in 1997 (Clinton, N.C.) and 1998 (Carbondale, Ill.) to determine if replanting (at 1, 2, 3, or 4 weeks after the initial seeding) into stand deficiencies of 10%, 30%, and 50% affected `Athena' muskmelon (Cucumis melo L. var. reticulatis) melon size and yield. Muskmelon numbers were higher for 1997, but there was no interaction of treatment by year for any of the melon sizes (small, medium, or large) or total melon number. Based on the two experiments conducted, `Athena' muskmelons stand deficiencies up to 30% do not reduce total or marketable numbers compared to a complete stand. Replanting into 10%, 30%, and 50% stand deficiencies increases early-season melon numbers regardless of the replant times. For main-season and total-season harvests, there was no advantage of replanting into 10% deficient stands and in most cases, replanting reduced total and marketable melon numbers. In the 1997 experiment, replanting into 30% and 50% stand deficiencies improved yields but this did not occur in the 1998 experiment. Based on this information, `Athena' muskmelon should be replanted only if a field has a stand reduction of more than 30%. Melon numbers were generally higher if replanted in 1 or 2 weeks after the initial seeding compared to 3 or 4 weeks. However, the timing of replanting does not appear to have significant influence on total or marketable melon numbers.
Integrating Graduate and Extension Education through Total Crop Management Training
Authors: Faust James E. , Will Elizabeth , Williams Millie
Published: December 2018

Graduate students received training in total crop management (TCM) techniques including pest scouting and trapping, nutritional monitoring, and graphical tracking of crop height. In 1995, one student visited five greenhouse businesses biweekly during the poinsettia (Euphorbia pulcherrima Willd.) season to provide TCM training to one greenhouse employee per business. In 1996, a second student visited one greenhouse business every week during the poinsettia crop to conduct the TCM program for that business. The students benefited from the gained practical knowledge of greenhouse production techniques and TCM techniques, and they also benefited from the opportunity to visit commercial greenhouses and interact with staff throughout the production cycle for an entire crop. This program also provided the students with the opportunity to develop their teaching, communication and training skills. The participating growers benefited during this study from receiving useful production information and TCM training. An evaluation of the program conducted in 1998 indicated that four of the five participating businesses continue to use some TCM techniques, while two of the five have fully integrated the TCM program into their normal production routines.
Development of a Bachelor of Science Degree Program in Horticulture at the University of Florida for Place-bound Students
Authors: Klock-Moore Kimberly A. , Fitzpatrick George E. , Schoellhorn Richard K.
Published: December 2018

As the horticulture industry enters the 21st century, advances in horticulture science will continue to be more rapid and frequent creating the need for more innovative approaches in information delivery. Moreover, decentralization continues to be a widespread trend. Land-grant universities have a long tradition of providing outreach, but with the development of new telecommunication technologies, larger audiences now can be reached. Many universities throughout the world have developed distance education programs through the use of modern telecommunication technologies. However, the University of Florida has responded to the needs of place-bound students by developing off-campus resident Bachelor of Science (BS) degree programs in horticulture at three locations in the state. These off-campus programs combine on-site instruction augmented with distance education courses to giveplace-bound students a flexible, efficient, and interactive alternative to degree programs offered at the main campus.
Site-specific Management for the Twenty-first Century
Authors: Robert Pierre C.
Published: December 2018

A better awareness of soil and crop condition variability within fields brought the notion, in the early 1980s that variable management within fields by zones rather than whole fields would increase profitability by doing the right thing at the right place in the right way. At the same time, the microcomputer became available and made possible the acquisition, processing, and use of spatial field data as well as the development of a new kind of farm machinery with computerized controllers and sensors. Precision agriculture (PA) has been considered for most common cropping systems and some specialty crops, worldwide. It is particularly well adapted to high value crops such as many horticultural crops. PA is still in infancy and its adoption varies greatly but precision agriculture is the agricultural system of the future. It offers a variety of potential benefits in profitability, productivity, sustainability, crop quality, food safety, environmental protection, on-farm quality of life, and rural economic development.
Remote Image and Leaf Reflectance Analysis to Evaluate the Impact of Environmental Stress on Grape Canopy Metabolism
Authors: Lang N.S. , Mills L. , Wample R.L. , Silbernagel J. , Perry E.M. , Smithyman R.
Published: December 2018

Research suggests that blackleaf (a leaf disorder in grape, Vitis labrusca L.) is induced by high levels of ultra violet (UV) radiation and overall light intensity, resulting in color changes (purple-brown-black) for sun-exposed leaves of the outer canopy, and a corresponding >50% reduction in photosynthesis. Metabolic indicators (photosynthesis and leaf water potential), percent blackleaf expression, and full spectrum leaf reflectance were mapped within vineyards using global positioning system (GPS) and digital remotely-sensed images. Each image and data record was stored as an attribute associated with a specific vine location within a geographical information system (GIS). Spatial maps were created from the GIS coverages to graphically present the progression of blackleaf across vineyards throughout the season. Analysis included summary statistics such as minimum, maximum, and variation of green reflectance, within a vineyard by image capture date. Additionally, geostatistics were used to model the degree of similarity between blackleaf values as a function of their spatial location. Remote-image analysis indicated a decrease in percent greenness of about 45% between July and August, which was related to a decrease in photosynthesis and an increase in blackleaf symptom expression within the canopy. Examination of full spectral leaf reflectance indicated differences at specific wavelengths for grape leaves exposed to UV or water-deficit stress. This work suggests that remote-image and leaf spectral reflectance analysis may be a strong tool for monitoring changes in metabolism associated with plant stress.
Practical Applications of Remote Sensing Technology—An Industry Perspective
Authors: LeBoeuf John
Published: December 2018

The initial surge of interest in precision agriculture technologies exhibited by innovators and early adopters involved in crop production appears to have crossed over an important threshold. As valuable field experience increases and learning by doing advances, successful applications of management practices are being identified even though few are adequately documented with economic benefits. Access to accurate information pertaining to applications of site-specific management would be expected to motivate more producers to incorporate technology uses with crop production. This next group of producers has been watching technology developments as they preferred to avoid risk and wait for identifiable benefits. Waiting for detailed case studies involving high value fruits and vegetables may be the wrong approach to take. Fierce competition and strict confidentiality are expected in the fresh market industry. Thus, personal experience with technology becomes more relevant to innovative producers than published literature. This is especially true in California where 350 different crops are produced. High resolution imagery from digital aerial and satellite sensors has been used in crop production in California to identify plant stress, direct plant tissue and soil sampling efforts, and provide information for analysis and interpretation of crop growth. Examples of remote sensing imagery that have provided valuable in-season progress reports will be identified. The focus will be on practice, not theory, as seen from an industry perspective.
Modified Atmosphere Packaging—Toward 2000 and Beyond
Authors: Kader Adel A. , Watkins Christopher B.
Published: December 2018

Rapid expansion of modified atmosphere packaging (MAP) for horticultural produce has occurred during the last 10 years, especially for fresh cut (minimally processed) products, but limitations to further expansion reside in both responses of products and available technology. We introduce the workshop on Modified Atmosphere Packaging—Toward 2000 and Beyond by reviewing the current status of MAP technology for fresh and minimally processed products, highlighting research needs and future advances, and providing a list of selected references on MAP published since 1989.
New Film Technologies for Horticultural Products
Authors: Lange Diana L.
Published: December 2018

Modified atmosphere packaging (MAP) is a technology that is currently used for most packaged salads and fresh-cut vegetables, and to a lesser extent, fresh-cut fruit such as cantaloupe (Cucumis melo L.), pineapple [Ananas comosus L. (Merr.)], and apple (Malus ×domestica Borkh.). In addition, about 750 million lb (340,200 Mg) of strawberries (Fragaria ×ananassa Duch.), raspberries (Rubus idaeus L.) and sweet cherries (Prunus avium L.) are distributed in MAP annually. The fresh produce packaging industry has developed new films to respond to increased produce consumption and changes in the use of film packaging within different produce marketing segments. The produce film industry sold 60 million lb (27,200 Mg) of film in 1994, and in 2000 it is forecasted to sell 110 million lb (49,900 Mg), an increase of 83%. The distribution of film usage has also changed since 1994 when film consumption patterns were as follows: 20% [12 million lb (5,400 Mg)] retail, 15% [9 million lb (4,100 Mg)] warehouse clubstores, and 65% [39 million lb (17,700 Mg)] food service. In 2000 it is projected that consumption patterns will be as follows: 25% [27.5 million lb (12,500 Mg)] retail, 20% [22 million lb (10,000 Mg)] warehouse clubstores, and 55% [60.5 million lb (27,400 Mg)] food service. These changes represent a 10% shift in film market segment usage patterns away from food service applications to an increase of 5% for each of the retail and warehouse clubstore segments.
Responses of Horticultural Commodities to Low Oxygen: Limits to the Expanded Use of Modified Atmosphere Packaging
Authors: Beaudry Randolph M.
Published: December 2018

The application of low oxygen through modified atmosphere packaging (MAP) is a technique used successfully to preserve the visual quality of lettuce and some other commodities. The expansion of use of low O2 via MAP to preserve quality of most commodities is limited by technical difficulties achieving target O2 concentrations, adverse physiological responses to low O2, and lack of beneficial responses to low O2. Low O2 often is not used simply because the physiological responses governed by the gas are not limiting quality maintenance. For instance, shelf life may be governed by decay susceptibility, which is largely unaffected by low O2 and may actually be exacerbated by the conditions encountered in hermetically sealed packages. Physiological processes influenced by low O2 and limit storability are discussed. The interdependence of O2 concentration, O2 uptake by the product, and temperature are discussed relative to requirements for packaging films.
Responses of Horticultural Commodities to High Carbon Dioxide as Related to Modified Atmosphere Packaging
Authors: Watkins Christopher B.
Published: December 2018

The tolerances of horticultural commodities to CO2 are outlined, as are also the associated biochemical and physiological aspects of differences in tolerance between and within commodity types. These tolerances are related to responses to the use of modified atmosphere packaging (MAP) during storage. Commodities vary widely in their responses to elevated CO2, and low tolerance to the gas limits its use to maintain quality in some cases. Standard recommendations are generally those established to extend the storage period of any given commodity as long as possible, and safe atmospheres may differ substantially for shorter term exposures used in MAP. Use of MAP for storage of minimally processed products represents an important example of this, as storage periods and quality attributes required for commercial marketing of cut products can be very different from those of the whole product. Factors such as cultivar and postharvest treatment before imposing high CO2 can influence responses of commodities to CO2, but are rarely considered in cultivar selection or in commercial application. A better understanding of the physiology and biochemistry of commodity responses to CO2 is required for increased use of MAP.
Impacts of Modified Atmosphere Packaging and Controlled Atmospheres on Aroma, Flavor, and Quality of Horticultural Commodities
Authors: Mattheis James , Fellman John K.
Published: December 2018

The commercial use of modified atmosphere packaging (MAP) technology provides a means to slow the processes of ripening and senescence during storage, transport, and marketing of many fresh fruit and vegetables. The benefits of MAP and controlled atmosphere (CA) technologies for extending postharvest life of many fruit and vegetables have been recognized for many years. Although both technologies have been and continue to be extensively researched, more examples of the impacts of CA on produce quality are available in the literature and many of these reports were used in development of this review. Storage using MAP, similar to the use of CA storage, impacts most aspects of produce quality although the extent to which each quality attribute responds to CA or modified atmosphere (MA) conditions varies among commodities. Impacts of MAP and CA on flavor and aroma are dependent on the composition of the storage atmosphere, avoidance of anaerobic conditions, storage duration, and the use of fresh-cut technologies before storage.
Long Infection Period for White Pine Blister Rust in Coastal British Columbia
Authors: Hunt R.S. , Jensen G.D.
Published: December 2018

For the white pine blister rust disease (WPBR), reports conflict concerning the time of year the pathogen, Cronartium ribicola J.C. Fisch., infects western white pine (Pinus monticola D. Don) and what needle age increments are most susceptible. To determine timing of infection, western white pine seedling were placed under infected currants (Ribes nigrum L.) for 1-week periods from May to November. Needles became spotted and stems cankered after exposure to diseased currants from early summer until leaf drop in November. To determine what foliage age increment was most susceptible, 5-year-old seedlings were placed in a disease garden, and older trees were inoculated in situ. All age increments of pine foliage were susceptible to infection. For young seedlings, all age increments were about equally susceptible, but on some older seedlings and trees, the current year's foliage appeared more resistant than older foliage.
Developing Blister Rust Resistance in White Pines
Authors: Kinloch Bohun B.
Published: December 2018

After a century since introduction to North America from Europe, white pine blister rust, caused by Cronartium ribicola J.C. Fisch., is recognized as one of the catastrophic plant disease epidemics in history. It has not yet stabilized and continues to spread and intensify. Its nine native white pine hosts comprise major timber producers, important watershed protectors, keystone ecological species, and the oldest trees on earth. All are highly susceptible and some have been damaged severely in parts of their native range, as well as where they have been planted as exotics. Resistance, the most promising approach to control, requires understanding of genetic interactions between hosts and pathogen, a quest that has been ongoing for half a century. Unlike other hosts of spectacular exotic diseases, such as chestnut blight [caused by Cryphonectria parasitica (Murrill) M.E. Barr] and dutch elm disease [caused by Ophiostoma ulmi (Buisman) Nannf.], white pines (Pinus L.) exhibit a surprising number of resistance mechanisms to blister rust, if at only low frequencies. There are three main kinds: