ASHS Press Releases

New breed of pumpkin good news for growers and consumers in southeast US

A new, virus-resistant pumpkin, specifically developed for ornamental fall and Halloween displays. Click here for more information.

Statesboro, GA — Move over ‘Longface’, ‘Spooktacular’ and ‘Trickster’ - there’s a new face in the pumpkin patch. Welcome ‘Orange Bulldog’, a new variety of the familiar fall fruit that may soon be available to consumers and wholesale pumpkin growers. Researchers at the University of Georgia recently introduced the new, virus-resistant pumpkin, specifically developed for ornamental fall and Halloween displays.

Dr. Gerard Krewer from the Department of Horticulture at the University of Georgia’s College of Agriculture and Environmental Sciences, collected pumpkin seeds in remote areas of Brazil in 1996. The Brazilian seeds were then planted in laboratories, hybridized, and ultimately used to develop ‘Orange Bulldog’.

Dr. George Boyhan, Assistant Professor and Extension Horticulturist at the University of Georgia and lead author of the study published in the October 2007 issue of HortScience, explained that pumpkins have not been readily available in southern states because conventional pumpkins are highly susceptible to viruses and often die before they produce fruit. The research team set out to develop a virus-resistant pumpkin with bright orange color and an open cavity that would be suitable for Halloween carving. According to Boyhan, ‘Orange Bulldog’ seeds “consistently produced fruit during fall production, whereas commercial pumpkin cultivars often succumb to severe virus infections before fruiting.”

Although ‘Orange Bulldog’ is not yet available to growers or the public, Boyhan’s team hopes that a commercial supplier will soon handle the seeds and make the new pumpkin available to pick-your-own pumpkin growers and consumers.

The complete study is available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/42/6/1484

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education and application. More information at ashs.org

George E. Boyhan, Gerard Krewer, Darbie M. Granberry, C. Randell Hill, and William A. Mills
HortScience Oct 1 2007: 1484–1485. [Full Text] [PDF]

Researchers Find Most-effective Seed Mixture, Planting Times for Fall Sports Fields

MADISON, WI — A study published in the February 2008 issue of HortScience offers new information that can help schools and contractors get outdoor athletic fields ready for fall sports more quickly. Results of the research study will help schools and communities pare down the usual 9- to 12-month waiting period between planting new fields and opening the fields to autumn football traffic.

Dr. John Stier, Associate Professor of Horticulture at University of Wisconsin-Madison, led the 2-year study of seed mixtures and planting times. He noted that football fields are usually planted using slow-establishing Kentucky bluegrass seed mixed with a lower proportion of perennial ryegrass seed. The objective of this study, explained Stier, was to evaluate the effects of planting time and seed mix on three different blends of the two seeds.

The researchers also studied each seed blend’s ability to stand up to “football-type traffic”. “We were interested in determining the amount of time needed for athletic fields to establish before they could successfully support autumn sports. We also wanted to see if the amount of time (to establish the fields) was affected by grass types and mixtures, and how planting time affected the relative proportions of different grass species that became established.”, stated Stier.

During each year of the project, field plots were seeded three times: in late summer, as a dormant planting in late fall, and in the following spring. Each plot was subjected to simulated football traffic (simulating either one or four weekly games) from mid-August through mid-November of the year in which spring seeding occurred.

According to Stier, all planting dates provided acceptable turf quality by September, regardless of seed type. However, Kentucky bluegrass-based mixtures planted during the summer provided better turf quality than mixtures planted in the spring. Dormant-seeded mixtures provided the poorest turf quality. The team found that turf seeded with 100% perennial ryegrass was less sensitive to planting dates than Kentucky bluegrass turf. Summer and spring plantings provided similar quality and dormant seedings resulting in superior quality to Kentucky bluegrass-based dormant seedings.

Additionally, simulated traffic studies revealed that different levels of traffic did not affect turf species proportions. The most consistently desirable results were obtained with a mixture containing 70%-80% Kentucky bluegrass and 30%-20% perennial ryegrass. The best results for mixtures dominated by Kentucky bluegrass came from fields seeded in late summer.

Stier added that perennial ryegrass could be planted in spring and provided ideal ground cover with few weeds, but mixtures in which Kentucky bluegrass seed comprised 50% or more of the turf needed to be planted the preceding summer. Dormant seedings did not perform well, leading to relatively poor ground cover and significantly higher weed populations.

Summarizing the impact of his team’s research, Stier said: “The research outcomes can allow school systems to prepare better bids for construction and renovation of sports fields, making the fields more likely to meet expected performance standards and ultimately reduce costs to the school districts.”

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The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/43/1/240

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education and application. More information at ashs.org

John C. Stier, Eric J. Koeritz, and Mark Garrison
HortScience Feb 1 2008: 240–244. [Abstract] [Full Text] [PDF]

Teen helps design classroom DNA experiments using common food dyes

Andrew N. Trigiano, a middle school student, completing an electrophoresis experiment with food dyes. Click here for more information.

KNOXVILLE, TN — Agarose gel electrophoresis” Most teenagers wouldn’t have a clue what this scientific term means, but middle school student Andrew Trigiano knows the protocol inside and out. When Andrew was 12, his father Robert Trigiano, a professor at the University of Tennessee, was looking for an interesting science project for his son. Setting out to compare differences in popular brands of Easter egg dyes, Trigiano’s project soon grew into a full-blown scientific study and set of replicable classroom experiments.

One of the most frequently used tools in biochemistry and biotechnology, agarose gel electrophoresis is a common forensic technique often used in genetic or DNA fingerprinting. The procedure is achieved by moving negatively charged nucleic acid molecules through a gelatinous substance known as agarose by using an electric field.

Andrew, in collaboration with his father and other researchers, completed the study, which is published in the January 2008 issue the American Society of Horticultural Science’s journal HortTechnology. The youngest author ever to publish in an ASHS journal, Andrew was only 12 when he began the research project and 14 when the study was published.

The resulting experiments were developed for use in middle and high school classrooms or for teachers and undergraduate students who have limited hands-on experience with this technique. As Dr. Trigiano explained, “one experiment, electrophoresis of common food dyes, was designed for secondary and undergraduate students but can be used as an inexpensive means for introducing the main concepts of electrophoresis to anyone. Popular brands of food dyes (red, blue, yellow, and green) purchased at local markets are mixed into a 60% glycerol/water solution and are separated on 1% agarose gels. Mixed colors are separated into primary colors (e.g., green into blue and yellow) and some apparently single dyes often have extra “surprise” components.”

Explaining another experiment from the study, Trigiano continued: “The second laboratory exercise requires more extensive equipment and a more advanced set of skills, but the exercise has been completed successfully by middle school-level through graduate-level students and teachers. In this exercise, the internally transcribed spacer region of the ribosomal subunit for a fungus, plant, and insect are amplified and separated electrophoretically on agarose gels. A simple crime is solved using polymerase chain reaction (PCR) and DNA fingerprinting.”

The experiments outlined in the study provide students with hands-on practice assembling master mixes for PCR, using pipettes, and performing the various steps involved in PCR amplification. Instructions for both exercises are formatted in easy-to-follow procedure boxes, and a downloadable presentation is available on the web. The cost of supplies is about one dollar per student, making these exercises relatively inexpensive to conduct.

Dr. Trigiano hopes the experiments will be a vehicle to introduce electrophoresis to students of all ages. “The experiments are fun, engaging and inexpensive compared to most commercially available kits. The downloadable PowerPoint presentation also helps explain the process visually. The techniques are easily understood and completed by students of all ages with a minimum of equipment and other resources.”

Trigiano attributes his son Andrew for much of the research study’s success. “Andrew did most of the PowerPoint presentation, the dye figures in the article, much of the experimentation with the dyes and helped develop the dye-based forensic exercise.” From the results, it’s clear that this teenager has science in his DNA.

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The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/18/1/177

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education and application. More information at ashs.org

Strawberry producers searching for safe pesticides, effective growing methods

Researchers study new methods of weed control in strawberry nurseries. Click here for more information.

VALLADOLID, SPAIN — Methyl bromide, an odorless, colorless gas used as an agricultural pesticide, was introduced in the 1980s as an effective way to control weeds and increase fruit yields. Agricultural production nurseries around the world relied on methyl bromide (MB) to produce healthy plants for export and domestic sales. In 2000, the widely used pesticide was classified as an ozone-depleting substance, and in 2005 MB was banned in the United States and all European Union countries.

In response to the need for safe and effective alternatives to methyl bromide, researchers at the Instituto Tecnologico Agrario de Castilla y Leon in Valladolid, Spain, undertook a 3-year project to study new methods of weed control in strawberry nurseries. Results of the comprehensive research project were published in the February 2008 issue of HortScience.

According to lead researcher Eva García-Méndez, “the phaseout of methyl bromide requires effective alternatives for soil disinfestation, particularly in high-elevation strawberry nurseries.” In the study, MB alternatives were evaluated for weed control and plant yields at strawberry nurseries participating in Spain’s Methyl Bromide Alternatives Project (INIA). Two types of field trials were carried out: replicated experiments and commercial-scale field demonstrations.

In the replicated experiments eight fumigant treatments were evaluated each year, including the nonfumigated control and commercial standard methyl bromide plus chloropicrin mixture. Other treatments evaluated included: dazomet, chloropicrin alone, metam sodium plus chloropicrin, chloropropene:chloropicrin, DMDS plus chloropicrin, and propylene oxide. The best alternative treatments from the replicated experiments were then tested in the demonstration phase of the project.

The researchers discovered that several of the chemical alternatives they evaluated controlled weeds as consistently as MB, but all of the alternatives studied were less consistent than MB in terms of plant yields. They also found that the use of some types of barrier films increased the performance and consistency of alternative pesticides and that environmental factors such as weather, soils, and rotational crops contributed to inconsistencies in weed control and runner yields at high-elevation nurseries.

In summary, García-Méndez stated: “Replacements for methyl bromide will require more than one fumigant component as well as a higher level of management of pest populations in the fields during rotational crop production. It is necessary to continue evaluation of alternative fumigants for strawberry nurseries to focus on commercial field-scale demonstrations. Moreover, European Union regulatory restrictions may require the use of non-chemical alternatives in the near future. The need for evaluations of chemical and non-chemical soil disinfestation methods is urgent.”

The complete study and abstract are available on the ASHS HortScience electronic journal web site:http://hortsci.ashspublications.org/cgi/content/abstract/43/1/177

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. Society website - ashs.org

University extension services perceived as more credible, but need to become more convenient

Research shows benefits, detriments of silicon supplements for ornamental flowers

Helianthus L. - sunflower Click here for more information.

STILLWATER, OK — Vibrant, showy sunflowers are revered worldwide for their beauty and versatility. While many varieties of sunflower are grown specifically for their nutritional benefits, ornamental sunflowers have become standards for commercial growers and everyday gardeners. As sunflowers’ popularity grows, scientists are looking for new supplements and growing methods to enhance production and quality of this celebrated annual.

Horticulturists have found ample evidence that plants depend on “essential nutrients”; naturally occurring elements that are found in normal plant tissue that are essential for the completion of the life cycle of the plant. Although silicon, a predominant element in mineral soil, is not considered to be an essential nutrient for most plants, there has been limited evidence that silicon supplements affect the aesthetic qualities of ornamental flowers and crops.

Drs. Sophia Kamenidou and Todd J. Cavins, formerly of the Department of Horticulture and Landscape Architecture at Oklahoma State University, published a research study in the February, 2008 issue of HortScience in which they examine the effects of silicon supplements on sunflowers grown in greenhouse environments.

“In greenhouse production, most floricultural crops are cultivated in soilless substrates, which often supply limited amounts of plant-available silicon. The goal of this study was to determine the effects of silicon supplementation on greenhouse-produced ornamental sunflower (Helianthus annuus L. ‘Ring of Fire’).”, explained Cavins. “This is one of the first studies to highlight supplemental silicon impact on horticultural traits. Most previous research on silicon has focused on disease suppression in hydroponic vegetable production. This is also one of the few examples of detrimental effects seen from high silicon concentrations.”

Depending on the source and concentration of silicon used, several horticultural traits were improved as a result of silicon supplementation. “We observed thick, straight stems, increased flower and stem diameters, and increased height in some of the treatments, upgrading sunflower quality compared with untreated controls. However, growth abnormalities were observed when concentrations of silicon at 100 and 200 mg per liter were supplied as potassium silicate substrate drenches. In these treatments, plants appeared stunted with deformed flowers and were delayed in flowering. Consequently, the effects of silicon supplementation on greenhouse-produced sunflowers can vary from beneficial to detrimental depending on the applied source and concentration.”, stated Cavins.

Summarizing the study outcomes, Cavins said, “Silicon is a key component in mineral soil, but it has been overlooked for years since it is not considered an essential element for plant growth and development. Sunflowers are capable of accumulating silicon from multiple sources and we found major benefits to some silicon supplements, such as increased stem diameter and improved quality.”

The complete study and abstract are available on the ASHS HortScience electronic journal web site:http://hortsci.ashspublications.org/cgi/content/abstract/43/1/236

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. Society website - ashs.org