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Archive for category: Upcoming Publications

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Peach Orchard Establishment and Production Planning Budgets for Florida

January 28, 2014

K-9_OlmsteadKim Morgan1 and Mercy Olmstead2*,
1Department of Agricultural and Applied Economics, 314 Hutcheson Hall, Virginia Tech, Blacksburg, VA 24061,
2Horticultural Sciences Department, 2135 Fifield Hall, University of Florida/IFAS, Gainesville, FL 32611

Additional index words. Prunus persica L., Florida peaches, production costs

Diversification of an agricultural enterprise provides growers with alternative approaches to management of financial risk across multiple crops and harvest dates. Citrus growers have been wrestling with disease challenges such as bacterial citrus canker [Xanthomonas campestris pv. citri (Hasse) Dye] and citrus greening (Candidatus Liberibacter asiaticus) that have reduced tree productivity, and thus there is interest in alternative crops. The Florida peach industry has had moderate success as it takes advantage of an early market by having the first domestically produced peach of the calendar year. However, growers considering orchard plantings need firm estimates for establishment and production budgets to secure funding and build sound business plans. Budgets for Georgia and other southeastern states do not necessarily reflect production practices in Florida due to differences in disease management and greater costs for initial infrastructure in Florida. In 2011–12, requests were sent to current growers and those in the establishment phase to gather data on costs, and these were used to establish budgets for Florida peach operations. At the current market price for Florida peaches, it is estimated that growers begin to see a positive return over variable costs in the third year, with 40–60 lb of marketable fruit per tree.

Transgenic Expression in Citrus of Vitis MybA1 from a Bidirectional Promoter Resulted in Variable Anthocyanin Expression and Was Not Suitable as a Screenable Marker without Antibiotic Selection

September 23, 2013

fshs-upcoming-130923aEd Stover*, Yolanda Avila, Zhijian T. Li, and Dennis Gray

Additional index words. citrus breeding, disease resistance, tolerance, huanglongbing

Transgenic strategies offer potential solutions for major problems facing Florida citrus. Intragenics, in which all transgene components are from the target species’ gene pool, may alleviate consumer concerns and might also facilitate deregulation, providing growers with consumer-accepted transgenic solutions more quickly. Resistance to antibiotics is typically used as a selectable marker for plant transformation and this project was initiated as a proof of concept to test a plant gene as a visual screenable marker alternative to antibiotic-resistance. Transformation with Vitis MybA1 has been demonstrated to produce purple shoots in grape and was tested as a surrogate for a citrus Myb that might be used as an intragenic plant-pigmentation marker in citrus transformation. ‘Hamlin’ and Carrizo epicotyls segments were exposed to A. tumefaciens EHA105 containing the DAT or DEAT vector with Vitis MybA1 driven by the D35S promoter and neomycin phosphotransferase II (NptII, conferring kanamycin resistance, originally isolated from E. coli), driven by the Nos promoter. Transformation was compared with and without kanamycin (100 mg·L–1 = 0.00083 lb/gal) in the shoot regeneration medium with the DEAT vector. In sum, over 16 separate experiments, more than 1300 explants each of Carrizo and ‘Hamlin’ were treated. In all cases, 6–20 fold more shoots resulted when kanamycin was excluded from the medium, since there was no negative selection against non-transformed shoots, but no shoots with red pigmentation were recovered. When kanamycin was included, 28% of resulting ‘Hamlin’ shoots (6 out of 21) and 57% of Carrizo shoots (321/405) displayed anthocyanins. Phenotypes recovered included plants with blotchy reddish leaves and plants with cupped leaves. Pigmented ‘Hamlin’ shoots were very weak and subsequently died. Several deep red Carrizo transformants resulted with potential as research tools and ornamentals.

Local Food Systems in Florida: Consumer Characteristics and Economic Impacts

September 10, 2013

fshs-upcoming-wp1Alan W. Hodges* and Thomas J. Stevens

Additional index words. marketing, market channel, value, household survey

Consumption of local foods has developed rapidly over the past 10 years in response to concerns about food safety and quality; however, consumer behavior for purchasing local foods has not been widely studied. In a 2012 survey of 7,500 Florida households, a majority of respondents defined “local” foods as originating within a radius of 100 miles of home or within the state of Florida, while a minority defined it as within my county, city, or town. A majority of respondents purchased local foods at retail grocery stores or farmers’ markets. The total value of all foods purchased annually through local market channels in Florida was estimated at $8.314 billion, averaging $1,114 per household, or 20.1% of total food purchases for at-home consumption. Fruits and vegetables were the most commonly purchased types of local foods. These values are much higher than has been reported previously in the literature, and suggest that local food systems in Florida are better developed than most other areas of the United States. The total economic impacts of local food purchases in Florida, including indirect multiplier effects calculated with a regional economic model, were estimated at 183,625 jobs and $10.47 billion in GDP.

Preliminary Study of the Differential Gene Expression in Jatropha curcas L. In Vitro Cultures Exposed to Microgravity

September 10, 2013

fshs-upcoming-wp5Ania Pinares, Wagner A. Vendrame*, and Alba Myers

Additional index words. jatropha, gene expression, space biology

Jatropha (Jatropha curcas L.) has been identified as a suitable species for biofuel production. However, breeding and genetic improvement programs are necessary. Microgravity is a unique environment for the assessment of genetic variation aiming at genetic improvement. The goal of this study was to evaluate the differential gene expression in in vitro jatropha cultures exposed to microgravity. Specific objectives included the evaluation and ranking of RNA isolation methods according to RNA quality and quantity for microarray analysis. In vitro cultures of two jatropha accessions (Brazil and India) were initiated from cotyledon (CO), leaf (L), and stem (ST) sections. Groups of eight petri dishes containing treatments (accession × explant tissue) were arranged in flight hardware and exposed to microgravity for periods varying from 14 to 111 d. Once returned, cultures were processed for RNA isolation and microarray analysis. Gene expression comparisons were performed between ground and orbit samples for the effects of medium and microgravity exposure time. The Plant Reagent protocol gave the highest mean yield in micrograms of RNA and it was almost 30 times greater than the mean concentration given from RNeasy mini kit protocol. The A260/280 ratio mean for the Plant Reagent protocol was higher than 2.0, which is a ratio generally accepted as “pure” for RNA. For all comparisons performed, between 9 and 522 genes were differentially expressed. Over 20% of those genes were expressed at higher levels by more than 2-fold. Differential gene expression was affected by culture medium, with higher levels of expression observed in orbit. Gene expression was also affected by exposure time to microgravity, with periods of 111 d showing higher expression levels. There were 29 genes with high expression levels that were expressed in at least two comparisons. Those genes showing differential gene expression and their importance are discussed. Differential gene expression in microgravity may assist in future jatropha genetic improvement programs.

Comparing the Effects of Environmental and Economic Benefits Related Information on Consumers Preferences and Demand for Ornamental Plants

September 10, 2013

fshs-upcoming-wp2Hayk Khachatryan*

Additional index words. purchase decisions, plant benefits, information effects

The effects of plant benefits information on consumer preferences and demand is investigated using data from an Internet survey conducted in the U.S. (N=1151). A number of recent research efforts identified consumer profiles based on socio-demographic measures such as income, education, gender, race, and preferences for product-specific characteristics and attributes such as new colors, scents, and vase life guarantees, to name a few. Further, research literature supports claims that being around plants contributes to concentration, boosts creativity, and accelerates the healing process. Other benefits that were discussed in recent studies include household energy savings through reduced solar radiation effects and potential increase in property values. However, the effects of environmental and economic benefits related information, on consumer preferences and demand for ornamental plants remains less investigated. The present study addresses this research gap by investigating the influence of environmental and economic benefits related information on consumer willingness to purchase more plants. The results showed that environmental benefits related information (relative to economic benefits) has a higher impact on purchase intentions and may offer a greater potential to increase consumers’ likelihood of purchasing more plants in the future.

In Vitro Growth of Jatropha curcas L. Cell Cultures in Microgravity

September 10, 2013

fshs-upcoming-wp4AlbaMyers, Wagner A. Vendrame*, and AniaPinares 

 Additional index words. Jatropha curcas, micropropagation, space biology

Jatropha is a species identified for biofuel production. Microgravity offers a unique environment for genetic variation studies and in vitro cell cultures are suitable for space-based experiments. The main objective of this study was to compare the in vitro growth of jatropha cell cultures between orbit and ground. The effects of genotype, culture medium, and explant type were evaluated. In vitro cultures were initiated from three jatropha accessions: Brazil, India, and Mexico. Cotyledon, leaf, and stem sections were utilized as explants. A basal Murashige and Skoog (MS) medium was used, modified with either 4.5 μM TDZ (MS1) or 0.75 μM IBA + 3.6 μM 6-BA (MS2). Cultures were maintained in petri dishes, in the dark, at 25 ± 2 °C, arranged in Group Activation Packs (petriGAPs) flight hardware. Control petriGAPs were maintained on the ground. Spaceflight experiments were conducted in the International Space Station for 111 d (STS-133) and in the mid-deck of the space shuttle Atlantis (STS-135) for 14 d. In vitro jatropha cultures showed normal growth in microgravity. The MS1 medium produced structures similar to globular stage somatic embryos, while the MS2 medium produced mostly callus. The genotype had an effect on somatic embryo formation and subsequent shoot regeneration, and cultures from Brazil had the best regeneration capability. Stem sections showed the best capability to form somatic embryos in vitro. Cultures exposed to microgravity showed efficient development of embryogenic cultures. Future efforts should focus on improved root formation and plantlet regeneration.

Developing Regional Food Hubs in Central Florida

August 9, 2013

nr-14John Rife* East End Market, 3201 Corrine Drive, Orlando, FL 32803

Additional index words. source identified, localized, food system

This paper provides a survey of organizations, businesses, and initiatives engaged in building capacity for Central Florida’s localized food system by developing regional food hubs. Regional food hubs aggregate food system services like procurement, processing, distribution, warehousing, marketing, and retailing of localized and source-identified food products. The results of the survey show that, while no single entity vertically integrates all of these services, the handful of existing initiatives in Central Florida are nonetheless building noticeable capacity for the region’s source-identified food products.

Teaching Tree Management Programs to the Miami Downtown Development Authority—Downtown Enhancement Team–a Successful Approach

August 9, 2013

Henry Mayer1* and Jennifer Rodero, University of Florida, IFAS, Miami Dade County Extension, 18710 SW 288 Street, Homestead, FL 33030 2Miami Downtown Development Authority (DDA), 200 S. Biscayne Boulevard, Suite 2929, Miami, FL 33131

Additional index words. planting, pruning plants

ogl-18The city of Miami has one of the highest poverty rates and one of the lowest median incomes among large U.S. cities, according to the Census Bureau’s American Community Survey ( http://www.census.gov/acs/www/). This survey places Miami’s poverty rate at 26.9%, well above the state average of 12.6%, Miami–Dade County’s 18%, and the national average of 13.3%. During 2012, at a request from the Miami Downtown Development Authority (DDA), the Commercial Urban Horticultural Agent put together 3-h training workshops to teach entry-level employees from the Downtown Enhancement Team (DET) some techniques to plant and maintain trees in downtown Miami. The Miami DDA, in partnership with Camillus House, assists formerly homeless persons to give back to the community and reenter the workforce through employment with the DET. The tree management training programs are an important resource for the DET program. According to the DET supervisors, as a consequence of the workshops the participants are more confident in performing landscape maintenance, planting trees, and planting shrubs. They also take initiative and assist/correct others who have not been trained and show them how to do the planting or pruning. The workshops have also increased the survival rate of the trees and shrubs being planted in the downtown area. Due to the success of the program, these workshops will continue in 2013.

CISMA—Resource Networking to Control Invasive Plants and Animals

August 7, 2013

NR-9-LollarMatthew C. Lollar*, Gabrielle Milch, and Dennis Mudge

Additional index words. nonnative, Cooperative Invasive Species Management Areas

Situation/objectives: Nonnative invasive species cost land owners and tax payers millions of dollars annually in Florida. Pressure from numerous sources (including agriculture) caused legislation to form CISMAs (Cooperative Invasive Species Management Areas) to address the problem. The Central Florida CISMA Steering Committee formed in 2008, bringing with it solutions as well as new problems. Extension Agent facilitation and participation began to address the objectives of invasive species management and public perceptions of the Agricultural Community. Educational method: Three County Extension Agents were to join the Steering Committee and do “classic community resource development work” while networking with new audiences to address environmental issues. Results: Public environmental agency staff, private environmental concern groups, leaders from the farm industry, Disney, parks, private landowners, Deseret Ranch, and other interested parties are now networking through cooperative educational programs and addressing serious and potentially confrontational issues in a positive manner. The concerns of the committee have shifted from criticizing agriculture and County Extension Programs, to addressing the issues of invasive exotics on public lands through educational programs and work days. Conclusion: UF/IFAS Extension’s future depends, in part, on networking with environmental issue work groups, which can become challenging. Extension Agents are still best at leading issue-based programming, especially when agriculture is threatened. Multiple CISMA trainings are conducted annually, which provide Pesticide Applicator CEUs. The Central Florida CISMA has been rewarded with numerous grants from the U.S. Fish and Wildlife Service and the Florida Exotic Pest Plant Council (FLEPPC).

Extension Model to Improve Asian Citrus Psyllid Control in Citrus Health Management Areas (CHMAs)

August 7, 2013

C-11-JonesMoneen M. Jones*, Philip A. Stansly, and Joseph Russo

Additional index words. Citrus Health Management, Asian Citrus Psyllid, Huanglongbing, mapping

Citrus health management areas (CHMAs) have been implemented throughout Florida to provide regional coordination to manage Asian citrus psyllid (ACP) and spread of Huanglongbing disease (HLB). During the fourth season (2011–12), we provided Gulf CHMA updates and interactive maps with ACP density and “hot spots” on our website (www.imok.ufl.edu) using data from Citrus Health Research Program (CHRP) (www.flchma.com). Ring color of the proportional circle map designated the cycle, and ring size represented psyllid density. The map was readable by anyone with Adobe Reader and provides information for Cycle #, Cycle Date, County Name, and ACP density. The .pdf format allowed a grower to click on and off different cycle layers for comparison between two or more sets of data simultaneously and spatially. This project included development and testing of a spray app that will suggest the best insecticide for use by growers and consultants. Data would be converted to a map layer and used to determine which growers may need help and what chemicals appear to be failing—a precursor to predicting ACP resistance. Funding is currently being sought to continue this effort. We expect to build better working relationships with growers by offering individual support to their economic efforts, ACP management, and HLB control.