U.S. Department Of Agriculture Agricultural Research Service Research Articles

The New USDA: Cultivating Change

In proclaiming the week of August 23–29 National Community Gardening Week, Agriculture Secretary Tom Vilsack noted, “Community gardens provide numerous benefits including opportunities for local food production, resource conservation, and neighborhood beautification. But they also promote family and community interaction and enhance opportunities to eat healthy, nutritious foods. Each of these benefits is something we can and should strive for.” Vilsack’s statement was the latest in a string of signals in the past 7 months that suggest significant changes are afoot at the U.S. Department of Agriculture (USDA). On 29 July 2009 Agriculture Deputy Secretary Kathleen Merrigan inaugurated a new rooftop garden at the offices of the USDA Economic Research Service. In early spring, Vilsack “broke pavement” for a vegetable garden known as the People’s Garden, which was planted in front of USDA headquarters across from the National Mall. And a March 2009 planning meeting to discuss the People’s Garden and other sustainability initiatives, chaired by Vilsack, included people not typically seen at USDA meetings in the past: representatives from community garden associations, local food policy councils, botanical gardens, and the Rodale Institute, a nonprofit organization in Pennsylvania dedicated to organic farming research. Vilsack “talked about sustainability, linking agriculture, food, and human health in a way that you haven’t heard [from USDA],” recalls Rose Hayden-Smith, a fellow at the Minneapolis-based nonprofit Institute for Agriculture and Trade Policy and master gardener for the California Cooperative Extension service.

SPICATIC ACID: A 4-CAROXYGENTISIC ACID FROM A GENTIANA SPICATA EXTRACT WITH POTENTIAL HEPATOPROTECTIVE ACTIVITY

Filariasis and Dengue Fever are two mosquito-borne diseases threatening French Polynesia. The potential vectors for the transmission of these illnesses are Aedes aegypti (L.), the Yellow Fever mosquito, and A. polynesiensis Marks. A research program financed by the Ministry of Health of French Polynesia, the Establishment for Prevention and the Laboratory of Ecophysiology and Biotechnology of Halophytes and Marine Algae was undertaken with the ultimate goal of developing improved insect repellents and lures for insect traps. This goal became even more urgent due to the threat of mosquito-borne diseases. Several natural products from terrestrial plants of French Polynesia were evaluated as spatial repellents against A. aegypti mosquitoes, using a triple cage-dual port olfactometer, and as topical repellents, using a cloth patch assay test with DEET as the positive control. The attraction of A. aegypti to L-lactic acid combined with the natural sample extracts was evaluated using the dual-port olfactometer. A total of 10 aromatic plant species have been collected by the Laboratory of Natural Products of the Institute Louis MalardA©, and these have yielded 10 Essential Oils. 4 more samples of essential oils originating from New Caledonia and Madagascar were also tested. The fine chemical composition of some repellent essential oils were determined by gas chromatography and gas chromatography coupled with Mass Spectrometry at MalardA© and at Montpellier. Their major volatile components are still to be tested and the preliminary results are presented. Bioassays were performed with Ae. aegypti mosquitoes at the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS). This mosquito is the commonly accepted standard species for laboratory bioassays. Bioassays were conducted in randomized sample order and were distributed among the three cages of the olfactometer over three separate assay periods per day (approximately 08.00, 11.00, and 13.00 local time). Each sample was analyzed at least 3 times to improve the statistical precision of the results. The cloth patch repellency assays were conducted using 5-6 individuals to provide adequate precision of the duration and minimum effective dosage measures of the repellent efficacy.

FIFTEEN YEARS AND 120 GENOTYPES LATER WHAT HAVE WE LEARNED ABOUT TRIALING BLUEBERRY CULTIVARS IN THE PACIFIC NORTHWEST?

The U.S. Department of Agriculture Agricultural Research Service (USDAARS), in cooperation with Oregon State University (OSU) and the Oregon Blueberry Trial Support Group, has been running an extensive selection and cultivar evaluation trial at the OSU North Willamette Research and Extension Center (NWREC) in Aurora Oregon. Since the initial planting in 1990, over 120 genotypes have been evaluated. Over the years, the evaluation approach has been streamlined and improved based on experience and data analyses. The very practical things that have been learned include: 1) netting is essential for evaluating genotypes ripening in June and July; 2) a randomized complete block design, while not as ideal as a completely randomized design for detecting genotypic differences, is better from a practical standpoint when managing the best way to add new genotypes to the planting; 3) three replications were sufficient to detect differences that were meaningful to growers, about 2.69 t/ha vs. 1.80 t/ha with five replications; and 4) good harvests in years 4, 5 and 6 after planting was highly correlated with performance of total yield over years 3–9. As far as blueberry type was concerned, northern highbush blueberries were well adapted to the NWES site but most southern highbush were not. The southern highbush, with the notable exception of ‘Legacy’ and ‘Ozarkblue’, grew well but tended to be very low yielding due in part to mid-winter flowering. Rabbiteye blueberries grew well although their fruit quality was generally poorer than highbush blueberries. Rabbiteye cultivars that overlap with the highbush ripening season are not of much interest, whereas cultivars like ‘Powderblue’, which has good quality and ‘Ochlockonee’ that is very late ripening have excellent potential for late-season markets. INTRODUCTION New and potentially better blueberry cultivars are being developed around the world. In past decades, potential new cultivars were planted at many locations over several years before they were released to growers as cultivars for commercial planting. Now, with public research programs, primarily at land-grant universities, struggling with funding and the incredible growth of the blueberry industry new cultivars are more likely to be tested on commercial farms without extensive testing at research stations. The Oregon blueberry industry through the Oregon Blueberry Commission and an industry driven and funded Blueberry Trial Support Group made a strong commitment to selection and cultivar testing. The first replicated trial of over 40 selections and cultivars was planted in 1990 at the OSU-NWREC. Approximately every 2–3 years a new trial has been established since then although typically with fewer genotypes. The tremendous cost associated with establishing, maintaining and harvesting this trial has forced us to try to figure out ways to reduce costs as much as possible while still collecting data we have confidence in. This discussion has two objectives 1) to give insight into the development of the USDA-ARS/OSU testing strategy and 2) to give some insight into what has been learned a Chad.Finn@ARS.USDA.GOV Proc. IX IS on Vaccinium Eds.: K.E. Hummer et al. Acta Hort. 810, ISHS 2009 72 about the types of blueberries and genotypes that do well in the Pacific Northwest.

Pesticides: In Search of a Better Mosquito Repellent

Insect bites are more than just an itchy nuisance; mosquitoes and ticks spread malaria, West Nile virus, Lyme disease, and other illnesses. The insect repellent DEET keeps insects away, but it wears off with sweat and can cause health problems in sensitive people, including rashes, skin and mucous membrane irritation, dizziness, headaches, disorientation, and nausea. Although DEET shows broad-spectrum activity against biting insects, it apparently does not work as well against malaria-carrying strains of mosquitoes. Finally, DEET smells bad, and it can damage plastic eyeglass lenses and watch faces. Now scientists are studying a new type of repellent that overcomes at least one of these myriad disadvantages, lasting three times longer than DEET. For the past 60 years, the U.S. Department of Agriculture (USDA) has tested tens of thousands of chemicals as possible repellents and catalogued the results. Recently, researchers at the USDA Agricultural Research Service and the University of Florida evaluated the records of several hundred diverse compounds and focused on the most effective ones, all of which were acylpiperidines—chemical cousins of the compound piperidine, which gives black pepper its bite. They selected 11 compounds with confirmed effectiveness, and chemists in the group synthesized 23 more, guide by a computer model that predicts improved performance by altering chemical groups. The mosquito-repelling potency of each compound was tested by volunteers who put their arms inside boxes filled with Aedes aegypti mosquitoes for 1 minute per compound per day, while the researchers recorded how many days it took to be bitten. Under these test conditions, the DEET treatment wore off after 17.5 days on average, whereas several of the test compounds lasted 40 to 50 days, and one remained active for 73 days. The results, reported in the 27 May 2008 issue of the Proceedings of the National Academy of Sciences, “were just phenomenal,” says Ulrich Bernier, the USDA research chemist who conducted the bite tests. Next, Bernier and colleagues will evaluate the effectiveness of the compounds against mosquitoes that transmit malaria, and then against other insect species. The best repellents will then be assessed for skin toxicity. “We hope the acylpiperidines are safer than DEET, but we don’t know yet,” says Bernier. The same USDA chemical collection that contained the acylpiperidines also spawned DEET, which has been the reigning repellent since its commercialization in the 1950s. DEET is a very good repellent, says Bernier, despite its drawbacks. To be economically viable, any competitor not only must repel insects better than DEET, but also overcome its disadvantages. So why haven’t the newly identified compounds been pursued further in the past? Bernier explains that, efficacy-wise, “they were equal to or just a bit better than DEET. . . . It would not be advisable to spend millions of dollars just to introduce a repellent into the market that one advertises as ‘about as good as DEET.’” “There’s always room for new and effective repellents, because consumers want a choice,” says Jonathan Day, a medical entomologist at the University of Florida in Vero Beach. Even during medical emergencies such as an outbreak of West Nile virus, some people refuse to use DEET, according to Day, and newer botanical formulations do not repel insects as well. The acylpiperidines look promising, but it’s a long road from identifying a potential repellent to registration with the Environmental Protection Agency. “Time will tell whether these compounds make it to store shelves,” Day says.

Mosquito repellents from essential oils and crude extracts of plants of French Polynesia

Filariasis and Dengue Fever are two mosquito-borne diseases threatening French Polynesia. The potential vectors for transmission of these illnesses are Aedes aegypti (L.), the Yellow Fever mosquito, and Ae. polynesiensis Marks. A research program financed by the Ministry of Health of French Polynesia, the Establishment for Prevention and the Laboratory of Ecophysiology and Biotechnology of Halophytes and Marine Algae was undertaken with the ultimate goal of development of improved insect repellents and lures for insect traps. This goal is made more urgent by the threat of mosquito-borne diseases. Several natural products from terrestrial plants of French Polynesia were evaluated as spatial repellents against Ae. aegypti mosquitoes using a triple cage-dual port olfactometer and as topical repellents using a „cloth patch assay“ test with DEET as the positive control. In addition, the attraction of Ae. aegypti to L-lactic acid combined with the natural sample extracts were evaluated using the dual-port olfactometer. A total of 25 plant species have been collected by the Laboratory of Natural Products of the Institute Louis Malardé, and these have yielded 9 Essential Oils and 21 crude methanolic extracts. The fine chemical composition of some repellent essential oils were determined by gas chromatography and gas chromatography coupled with Mass Spectrometry at Malardé and at Montpellier. Their major volatile components were tested and the preliminary results are presented. Bioassays were performed with Ae. aegypti mosquitoes at the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS). This mosquito is the commonly accepted standard species for laboratory bioassays. Bioassays were conducted in with randomized sample order and distributed among the three cages of the olfactometer over three separate assay periods per day (approximately 0800, 1100, and 1300 local time). Each sample was analyzed at least times to improve the statistical precision of the results. The cloth patch repellency assays were conducted using 5–6 individuals to provide adequate precision if the duration and minimum effective dosage measures of repellent efficacy.

Southwest Watershed Research Center Data Access Project

Hydrologic data, including rainfall and runoff data, have been collected on experimental watersheds operated by the U.S. Department of Agriculture Agricultural Research Service (USDA‐ARS) in southern Arizona since the 1950s. These data are of national and international importance and make up one of the most comprehensive semiarid watershed data sets in the world. The USDA‐ARS Southwest Watershed Research Center has recently developed an electronic data processing system that includes an online interface (http://tucson.ars.ag.gov/dap) to provide public access to the data. The goal of the system is to promote analyses and interpretations of historic and current data by improving data access. Data are collected from sensors in the field and are transmitted to computers in the office. The data are then processed, quality checked, and made available to users via the Internet. The publicly accessible part of the system consists of an interactive Web site, which provides an interface to the data, and a relational database, which is used to process, store, and manage data. The system was released to the public in October 2003, and since that time the online data access Web site has received more than 4500 visitors.

RESEARCH FROM THE COASTAL PLAIN EXPERIMENT STATION, TIFTON, GEORGIA, TO MINIMIZE AFLATOXIN CONTAMINATION IN PEANUT

Scientists with the U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) and scientists with the University of Georgia located at the Coastal Plain Experiment Station in Tifton, Georgia, have been conducting research on aflatoxin contamination of peanut since the early 1960s. Early efforts were focused on identifying the risk factors for increased aflatoxin contamination and helped to document the importance of drought, high soil temperatures, and pod damage. Later efforts were focused on the development of screening techniques and the identification of sources of resistance to Aspergillus colonization and/or aflatoxin contamination. This laid the foundation for a conventional resistance breeding program and has resulted in the development of peanut breeding lines that have high yield and low aflatoxin contamination relative to standard control cultivars. Recent research efforts include studies on the use of molecular genetic approaches to reduce aflatoxin contamination. This includes the evaluation of genetically engineered peanut and the development of molecular markers.

Organic Research at the USDA, Agricultural Research Service is Taking Root

The U.S. Department of Agriculture/Agricultural Research Service (USDA/ARS) began to coordinate its effort in organic agricultural research in 2000 by initiating a survey to determine the nature and extent of organic research being conducted by agency scientists. The survey revealed that approximately 9% of scientists within the agency were interested in organic agriculture but that less than 4% had actually participated in research in certified or certifiable organic production systems. With few exceptions, scientists conducted research on working or transitioning organic farms. Regardless of whether the research was conducted on farm or on research-station-managed land, farmer participation varied greatly. The USDA/ARS is in the process of coordinating the national organic research effort and has invited organic growers and other professionals to participate in the planning process in order to ensure that organic research at the agency continues to be rooted in its interactions with organic stakeholders.

Identifying the Future Needs for Long-Term USDA Efforts in Agricultural Animal Genomics

Agricultural animal research has been immensely successful over the past century in developing technology and methodologies that have dramatically enhanced production efficiency of the beef, dairy, swine, poultry, sheep, and aquaculture industries. In the past two decades, molecular biology has changed the face of agricultural animal research, primarily in the arena of genomics and the relatively new offshoot areas of functional genomics, proteomics, transcriptomics, metabolomics and metagenomics. Publication of genetic and physical genome maps in the past 15 years has given rise to the possibility of being able finally to understand the molecular nature of the genetic component of phenotypic variation. While quantitative geneticists have been remarkably successful in improving production traits, genomic technology holds potential for being able to lead to more accurate and rapid animal improvement, especially for phenotypic traits that are difficult to measure.Recently, the agricultural research community has been able to capitalize on the infrastructure built by the human genome project by sequencing two of the major livestock genomes (Gallus domesticus and Bos Taurus). The 2005 calendar year is truly unprecedented in the history of agricultural animal research since draft genome sequences were completed for chickens and cattle. In addition, sequencing the swine and equine genome was initiated in early 2006. We now have in place a powerful toolbox for understanding the genetic variation underlying economically important and complex phenotypes. Over the past few years, new challenges have emerged for animal agriculture. Enhancements in production efficiency have not come without some negative side effects on animal well-being and longevity in production environments, including losses in reproductive efficiency, increased stress susceptibility, increased animal waste issues, and increased susceptibility to animal metabolic and infectious diseases. When considered in concert with societal concerns in the areas of natural resource conservation and protection, animal welfare, and food safety, it is clear that publicly supported agricultural research must be focused on enhancing the functionality and well-being of livestock and poultry in environmentally neutral production systems in the future. Realizing the great potential for animal genomics to address these and other issues, a workshop was convened by the U. S. Department of Agriculture (USDA) in Washington, DC in September of 2004. The workshop was entitled "Charting the Road Map for Long Term USDA Efforts in Agricultural Animal Genomics". This paper summarizes the proceedings of the workshop and the resulting recommendations. The need for a cohesive, comprehensive long-term plan for all of USDA's research efforts in animal genomics was evident at the workshop, requiring further integration of the efforts of the USDA's Cooperative State Research, Education, and Extension Service (CSREES) and the USDA's Agricultural Research Service (ARS) to achieve the greatest return on investment.

Inflorescence Identity Gene Alleles Are Poor Predictors of Inflorescence Type in Broccoli and Cauliflower

Broccoli (Brassica oleracea L. var. italica Plenck) and cauliflower (B. oleracea var. botrytis DC) are closely related botanical varieties. The underlying genetic bases of their phenotypic differences from each other are not well understood. A molecular genetic marker enabling B. oleracea germplasm curators and breeders to predict phenotype from seeds or seedlings would be a valuable tool. Mutant alleles at flower developmental pathway loci BoAP1-a, Bo-CAL-a, and glucosinolate biosynthetic pathway locus BoGSL-ELONG have been reported to be associated with a cauliflower phenotype. We surveyed mutant alleles at these three loci in a genetically diverse sample of broccoli and cauliflower accessions from the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) Plant Genetic Resources Unit (PGRU) and the University of Warwick, Genetic Resources Unit of Warwick HRI (HRI). Phenotypic and genotypic data were collected for multiple plants per accession during two field seasons. Simple genetic models assuming dominance or codominance of alleles were analyzed. Goodness-of-fit tests rejected the null model that the mutant genotype was associated with a cauliflower phenotype. A correlation analysis showed that BoAP1-a and BoCAL-a alleles or loci were significantly correlated with phenotype but the fraction of variation explained was low, 4.4% to 6.3%. Adding BoGSL-ELONG to the analysis improved predictive power using the linear regression procedure, Maximum R-square Improvement (max R2). In the best three-variable model, only 24.8% of observed phenotypic variation was explained. Because tested genetic models did not hold robustly for the surveyed accessions, it is likely that there are multiple genetic mechanisms that influence whether the phenotype is broccoli or cauliflower. Our results in commercial cultivars indicate that other genetic mechanisms are more important in determining the horticultural type than are BoAP1-a and BoCAL-a.

PLANT COMPOSITION AND EROSION POTENTIAL OF A GRAZED WETLAND IN THE SALMON RIVER SUBBASIN, IDAHO

Wetlands are dynamic habitats with many unique, important functions including filtering sediments and providing diverse habitats for fish and wildlife. Wetlands in the western United States are particularly important because they offer habitat for a number of protected runs of endangered fish species. Historically, livestock grazing has altered wetland and riparian area form and function by facilitating exotic species invasions, altering spatial heterogeneity of vegetation, and increasing erosion. In this study we examined vegetation structure and erosion potential in a wetland meadow exposed to unregulated grazing along Deer Creek in the Salmon River subbasin, Idaho. We characterized the vegetation composition and structure within the study area and attempted to assess potential erosion conditions using the Revised Universal Soil Loss Equation (RUSLE), an empirical approach developed by the U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS). We found no significant spatial variability in species richness and noted a moderate number of exotic species in the total plant composition. Plant cover was higher near slightly entrenched banks, indicating that uncontrolled livestock were primarily occupying gently sloped streambanks and the interior of the meadow. Based on current vegetation composition and RUSLE results, uncontrolled grazing may be negatively impacting the study area. If uncontrolled grazing were excluded or carefully managed in the wetland meadows of the upper portion of the Deer Creek watershed, a reduction in excess sediments to Deer Creek may occur.

NEW FLIGHT DISTANCE RECORDED FOR COPTOTERMES FORMOSANUS (ISOPTERA: RHINOTERMITIDAE)

The Formosan subterranean termite (FST), Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), was first introduced to New Orleans after World War II inside infested cargo returning from the Orient (La Fage 1987). For the past 60 years, they have spread throughout the New Orleans metro area, displaced native subterranean termite species, and significantly damaged buildings, trees, boats, and railroad ties in the process. To help combat the problem, the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) provided funding for treating buildings in a 50-block area of the French Quarter in New Orleans to determine if an area-wide subterranean termite control program is capable of reducing overall populations. Since 1998, populations have been reduced based on structural inspections, termite activity inside independent monitoring stations installed throughout the French Quarter, and the overall number of alates (winged reproductives) recovered from insect glue boards attached to streetlights throughout the French Quarter (Lax & Osbrink 2003). However, alates are still being captured in significant numbers inside selective areas of the French Quarter and along the borders of this treatment zone. Each year during May and June, untold numbers of male and female alates disperse throughout the area in the early evening and tend to congregate around light sources when present. Information on how far they are capable of flying from a dispersal point was virtually unknown, especially in a large urban area. During field observations in early 2004, it appeared that FST alates were flying across the Mississippi River with the aid of prevailing winds and into the French Quarter. To establish if alates were dispersing into the treatment zone from bordering areas, alates were marked with fluorescent visible powders (Shannon Luminous Materials, Inc., Santa Ana, CA) during two dispersal flights on different evenings at a selected site of known termite activity across the Mississippi River, located directly to the southeast of the French Quarter. In cooperation with USDA-ARS, 445 rectangular (20.7 cm × 10.2 cm) glue boards (TRAPPER® LTD, Bell Laboratories, Inc., Madison, WI) were attached to streetlights along the Riverwalk and throughout the French Quarter to capture potentially marked alates. The glue boards were positioned on the streetlights just below the lantern. Weather conditions, including wind velocity and direction, were recorded each evening with a hand-held weather station (Kestrel® 4000, Nielsen-Kellerman, Boothwyn, PA). Alates were individually marked with a bright orange fluorescent powder with a handheld commercial duster as they were flying in a north to northwest direction over the river. These alates were already in flight at the time of marking and their source could not be located. After marking, every glue board was removed and inspected with a UV black light. New glue boards were used for each dispersal flight event. On 1 June 2004, approximately 50 FST alates were initially marked and a single alate was recovered across the River on a glue board 771 m away (Fig. 1). Then, on 7 June, approximately 50 alates were marked again and two alates were recovered on glue boards 866 m and 892 m away (Fig. 1). The wind direction on 1 and 7 June was from the south and southeast at an average speed of 0.93 m/sec and 0.83 m/sec, respectively. Previously, a wind speed at or below 1.0 m/sec was shown to be one of the most important microenvironmental factors involved in determining dispersal flight activity (Leong et al. 1983).

Harvest Mechanization Progress and Prospects for Fresh Market Quality Deciduous Tree Fruits

Deciduous tree fruit crops such as apple (Malus domestica), peach (Prunus persica), and sweet cherry (Prunus avium) are not mechanically harvested for the fresh market. Attempts to mechanically harvest these fruits by mass removal techniques have not been successful due to excessive fruit damage caused during detachment, fall through the canopy, and collection. Robotic harvesters have not been commercially accepted due to insufficient fruit recovery. A U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) harvesting concept shows promise for harvesting both fresh market quality apples and sweet cherries. Successful mechanical harvesting of fresh market quality deciduous tree fruit will only occur when plant characteristics and machine designs are integrated into a compatible system. Cultivar characteristics that would facilitate machine harvesting are uniform fruit maturity at harvest, firm fruit that are resistant to mechanical damage, and compact growth habit that produces fruit in narrow canopies and on short/stiff limbs. Engineers must develop new detachment principles that minimize the energy input to effect fruit detachment, and develop durable energy-absorbing catching surfaces/conveyors to eliminate damage during collection of the fruit. As technology advances, sorting and sizing systems might be developed that can be operating on the harvester to eliminate culls in the field and deliver only fresh market quality fruit to the packers.

Validation of the USDA/ARS Package Rinse Method for Recovery of Listeria monocytogenes from Naturally Contaminated, Commercially Prepared Frankfurters

The utility of the U.S. Department of Agriculture/Agricultural Research Service (USDA/ARS) package rinse method for recovering Listeria monocytogenes from the surface of contaminated foods was validated in comparison to the standard USDA/Food Safety and Inspection Service (FSIS) product composite enrichment method and two other methods using frankfurters from a lot with a known package prevalence rate of approximately 16% for this pathogen. One hundred packages from this batch of naturally contaminated, commercially prepared frankfurters were examined as follows: (i) the package exudative fluid was removed and tested using the standard USDA/FSIS product composite enrichment method; (ii) approximately 5 to 7 portions of frankfurters were removed to obtain a 25-g composite of meat that was then processed using the standard USDA/FSIS product composite enrichment method; (iii) 50 ml of 0.1% peptone water was added to each package, and the USDA/ARS package rinse method was performed on the remaining contents; and (iv) after removing the rinse fluid, the solid contents remaining in each package were directly enriched using the USDA/FSIS product composite enrichment method. These four methods identified that 7, 6, 15, and 9 of the 100 packages tested positive for the pathogen, respectively. Although no single approach yielded a positive result for every package that tested positive for L. monocytogenes by any one of the four sampling strategies, the USDA/ARS package rinse method was appreciably (P < 0.05) better than either the package exudate enrichment method or the standard USDA/FSIS product composite enrichment method at recovering the bacterium. These findings validate the sensitivity and ease of use of the USDA/ARS package rinse method using naturally contaminated frankfurters and argue strongly for its adoption for routine screening of ready-to-eat products that are prone to surface contamination with undesirable microbes such as L. monocytogenes.

Sensor Development and Radiometric Correction for Agricultural Applications

This review addresses the challenges and progress in sensor development and radiometric correction for agricultural applications with particular emphasis on activities within the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS). Examples of sensor development include on-site development of sensors and platforms, participation in cooperative research and development agreements (CRADA) with commercial companies, and membership on NASA science teams. Examples of progress made in sensor radiometric correction suitable for agriculture are presented for both laboratory and field environments. The direction of future sensor development includes integrated sensors and systems, sensor standardization, and new sensor technologies measuring fluorescence and soil electrical conductivity, and utilizing Light Detection and Ranging (lidar), hyperspectral, and multiband thermal wavelengths. The upcoming challenges include definition of the core spectral regions for agriculture and the sensor specifications for a dedicated, orbiting agricultural sensor, determination of an operational approach for reflectance and temperature retrieval, and enhanced communication between image providers, research scientists, and users. This review concludes with a number of avenues through which USDA could promote sensor development and radiometric correction for agricultural applications. These include developing a network of large permanent calibration targets at USDA ARS locations; investing in new technologies ; pooling resources to support large-scale field experiments: determining ARS-wide standards for sensor development, calibration, and deployment; and funding interagency agreements to achieve common goals.

A Plant-Associated Microbe Genome Initiative

ABSTRACT Plant-associated microorganisms are critical to agricultural and food security and are key components in maintaining the balance of our ecosystems. Some of these diverse microbes, which include viruses, bacteria, oomycetes, fungi, and nematodes, cause plant diseases, whereas others prevent diseases or enhance plant growth. Despite their importance, we know little about them on a genomic level. To intervene in disease and understand the basis of biological control or symbiotic relationships, a concerted and coordinated genomic analysis of these microbes is essential. Genome analysis, in this context, refers to the structural and functional analysis of the microbe DNA including the genes, the proteins encoded by those genes, as well as noncoding sequences involved in genome dynamics and function. The ultimate emphasis is on understanding genomic functions involved in plant associations. Members of The American Phytopathological Society (APS) developed a prioritized list of plant-associated microbes for genome analysis. With this list as a foundation for discussions, a Workshop on Genomic Analysis of Plant-Associated Microorganisms was held in Washington, D.C., on 9 to 11 April 2002. The workshop was organized by the Public Policy Board of APS, and was funded by the Department of Energy (DOE), the National Science Foundation (NSF), U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS), and USDA-National Research Initiatives (USDA-NRI). The workshop included academic, industrial, and governmental experts from the genomics and microbial research communities and observers from the federal funding agencies. After reviewing current and near-term technologies, workshop participants proposed a comprehensive, international initiative to obtain the genomic information needed to understand these important microbes and their interactions with host plants and the environment. Specifically, the recommendations call for a 5-year, $500 million international public effort for genome analysis of plant-associated microbes. The goals are to (i) obtain genome sequence information for several representative groups of microbes; (ii) identify and determine function for the genes/proteins and other genomic elements involved in plant-microbe interactions; (iii) develop and implement standardized bioinformatic tools and a database system that is applicable across all microbes; and (iv) educate and train scientists with skills and knowledge of biological and computational sciences who will apply the information to the protection of our food sources and environment.

Effective aerodynamic roughness estimated from airborne laser altimeter measurements of surface features

Aerodynamic roughness length (z 0) and displacement height (d 0) are important surface parameters for estimating surface fluxes in numerical models. These parameters are generally determined from wind flow characteristics using logarithmic wind profiles measured at a meteorological tower or by balloon release. It would be an advantage to use measurements of land surface characteristics instead of wind flow characteristics to estimate the z 0 and d 0 for large areas. Important land surface characteristics are the size and distribution of roughness elements (obstacles). This research evaluates the use of high resolution laser altimeter data to obtain these land surface characteristics. Data were collected at the US Department of Agriculture, Agricultural Research Service (USDA‐ARS), Jornada Experimental Range in southern New Mexico, USA over a coppice dune dominated area. These dunes are covered by honey mesquite (Prosopis glandulosa Torr.) with flat and mostly bare interdunal areas. For this analysis, three 450 m laser transects with a 2 cm measurement interval were used. The distribution and size of dunes were calculated from these laser transects and used to compute z 0. Analysis gave an average z 0 = 4.3 cm and d 0 = 70 cm for the three laser transects, which compares to z 0 = 7 ± 4 cm and d 0 = 98 ± 48 cm calculated from wind profile data measured at a 10 m tower near the laser transects. These results show that the estimation of z 0 and d 0 for a complex terrain is possible using simple land surface features computed from high resolution laser altimeter data.

The relation of gender, race and socioeconomic status to obesity and obesity comorbidities in a sample of US adults.

To examine the obesity-related chronic diseases in the US adult population according to gender, race and socioeconomic status. Data from the 1994-1996 Continuing Survey of Food Intakes by Individuals (1994-1996 CSFII) conducted by the US Department of Agriculture/Agricultural Research Service (USDA/ARS) were used in the analysis. Relevant data included self-reported weight and height, self-reported physician-diagnosed diabetes mellitus, hypertension, heart disease and high serum cholesterol. Analysis was conducted according to gender, race, income level and education level. There was a graded increase in diabetes, hypertension and high serum cholesterol with increasing body weight in nearly all gender, racial and socioeconomic groups. Among the obese individuals, the prevalence of hypertension was higher in black subjects and the prevalence of diabetes, hypertension and heart disease was higher in individuals with lower education compared to their counterparts. The odds of having diabetes, hypertension, heart disease and high serum cholesterol increased with increasing body weight after adjusting for age, gender, race, income, education and smoking. Although cross-sectional in nature, our results suggest that the disease burden associated with obesity in the population may be substantial. This burden increases with increasing severity of obesity. Our findings support the current opinion that, although the nature of obesity-related health risks is similar in all populations, the specific level of risk associated with a given level of obesity may be different depending on gender, race and socioeconomic condition.

Recovery of Listeria monocytogenes from Vacuum-Sealed Packages of Frankfurters: Comparison of the U.S. Department of Agriculture (USDA) Food Safety and Inspection Service Product Composite Enrichment Method, the USDA Agricultural Research Service (ARS) Product Composite Rinse Method, and the USDA-ARS Package Rinse Method

This study compared three methods for the recovery of Listeria monocytogenes from commercially prepared and vacuum-packaged frankfurters that were inoculated with a five-strain mixture of this pathogen at averages of 22 and 20,133 CFU per package over three trials. The presence and levels of the pathogen were determined by (i) the U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) product composite enrichment method, involving the selective enrichment of a 25-g composite of product and the subsequent plating of this product onto selective agar plates; (ii) the USDA Agricultural Research Service (ARS) product composite rinse method, involving the rinsing of a 25-g composite of product with 0.1% peptone water and the subsequent plating of a portion of the rinse fluid directly onto selective agar plates; and (iii) the USDA-ARS package rinse method, involving the use of 25 ml of 0.1% peptone water to rinse the entire contents of a package and the subsequent plating of a portion of the rinse fluid directly onto selective agar plates. For packages inoculated with 20,133 CFU, L. monocytogenes was recovered at a frequency (percentage of packages positive) of 100% by each of the three methods. The pathogen was recovered at efficiencies (percentages of recovery of L. monocytogenes) of 43 and 94% with the USDA-ARS product rinse method and the USDA-ARS package rinse method, respectively. For packages inoculated with 22 CFU, L. monocytogenes was recovered at frequencies of 17, 10, and 100% by the USDA-FSIS product composite enrichment method, the USDA-ARS product composite rinse method, and the USDA-ARS package rinse method, respectively. The pathogen was recovered at efficiencies of 20 and 95% with the USDA-ARS product composite rinse method and the USDA-ARS package rinse method, respectively. In a related study, the USDA-ARS package rinse method was the only method that detected the pathogen in 60 packages from each of five brands of frankfurters purchased from local grocery stores. These data establish that the USDA-ARS package rinse method is markedly more sensitive, as well as demonstrably more rapid and facile, than either the approved USDA-FSIS product composite enrichment method or the USDA-ARS product composite rinse method in determining the presence or absence of L. monocytogenes and establishing the levels of the pathogen that may be on the surface of ready-to-eat foods such as frankfurters.

Multiobjective calibration and sensitivity of a distributed land surface water and energy balance model

The feasibility of using spatially distributed information to improve the predictive ability of a spatially distributed land surface water and energy balance model (LSM) was explored at the U.S. Department of Agriculture Agricultural Research Service (USDA‐ARS) Walnut Gulch Experimental Watershed in southeastern Arizona. The inclusion of spatially variable soil and vegetation information produced unrealistic simulations that were inconsistent with observations, which was likely an artifact of both discretely assigning a single set of parameters to a given area and inadequate knowledge of spatially varying parameter values. Because some of the model parameters were not measured or are abstract quantities a multiobjective least squares strategy was used to find catchment averaged parameter values that minimize the prediction error of latent heat flux, soil heat flux, and surface soil moisture. This resulted in a substantial improvement in the model's spatially distributed performance and yielded valuable insights into the interaction and optimal selection of model parameters.