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Pasco, WA, United States

Scheele R.D.,Pacific Northwest National Laboratory | Wend C.F.,Northwest Agricultural Products
Annals of Nuclear Energy | Year: 2015

The United States Department of Energy is building the Hanford Waste Treatment and Immobilization Plant (WTP) in south-central Washington State to immobilize a portion of the stored high-level radioactive wastes generated by decades of producing nuclear defense materials. To comply with United States Environmental Protection Agency (EPA) and Washington State air emission regulations, the WTP is planning to use reduced silver mordenite to control releases of any volatilized waste constituent radioiodine (129I t1/2 = 1.7 × 107 a). Because the EPA and Washington State have designated silver as a hazardous or dangerous waste constituent, the disposal form for the waste reduced silver mordenite must comply with their land disposal regulations. We used the mandated EPA Toxic Characteristic Leach Procedure to evaluate and qualify a disposal form for the waste reduced-silver mordenite. Our development effort resulted in a regulation-compliant disposal form which used cast American Society for Testing and Materials (ASTM) Portland Type III cement modified to include calcium iodide to solidify and stabilize the reduced-silver mordenite and control silver release to regulatory levels. © 2015 Elsevier Ltd. All rights reserved. Source

Pusey P.L.,U.S. Department of Agriculture | Wend C.,Northwest Agricultural Products
Biological Control | Year: 2012

Pantoea agglomerans biocontrol strain E325 is the active ingredient in a commercial product for fire blight, a destructive disease of apple and pear initiated by Erwinia amylovora in flowers. Osmoadaptation, involving the combination of saline osmotic stress and osmolyte amendment to growth media, was investigated to improve the epiphytic colonization by E325 on apple flowers, particularly in dry climates. E325 was osmoadapted in nutrient yeast dextrose broth and in the commercial fermentation medium, both amended with NaCl and glycine betaine according to previous research. The bacterium was cultured and freeze dried with cryoprotectants at an ARS-USDA laboratory (Wenatchee, WA) and a commercial facility (Pasco, WA) prior to treating apple flowers in an orchard where relative humidity (RH) averaged <50%. On orchard flowers and on detached crab apple flowers, osmoadaptation generally did not affect colonization of E325 on flower stigmas or nectar-rich hypanthia. The exception was the significant advantage of osmoadapted E325 on hypanthia of detached flowers at 70% RH, resulting in osmotic conditions marginally conducive for bacteria. Osmoadaptation proved most beneficial for increasing E325 survival during freeze drying and storage prior to orchard application. It also complemented cryoprotection, improving overall stability of freeze dried preparations of this biocontrol agent. © 2012. Source

Pusey P.L.,U.S. Department of Agriculture | Wend C.,Northwest Agricultural Products
Acta Horticulturae | Year: 2011

Pantoea agglomerans E325 is a commercially available biocontrol agent for fire blight in the USA. Osmoadaptation, involving the combination of saline osmotic stress and osmolyte amendment to growth media, was investigated as a means of improving the survival of E325 on apple and pear blossoms under dry western conditions. Two complex media, nutrient yeast dextrose broth and the commercial fermentation medium, were supplemented with 0.5 M NaCl and 0.1 mM glycine betaine according to Bonaterra et al. (2005, 2007). E325 was cultured at ARS-USDA laboratory and commercial facility, then freeze dried with cryoprotectants and applied to 'Gala' apple blossoms in an orchard. In 2009, initial population sizes on blossom stigmas, and areas under population-size curves (Aps), were greater for osmoadapted than non-osmoadapted E325. However, comparison of treatments based on areas under the daily-growth curves (Adg) indicated no differences. Results were confirmed by a second trial in 2010. This led us to examine the stability of the E325 preparations prior to field application. Preparations used for field tests continued to be maintained at -20°C and were sampled periodically to estimate viable concentrations. Separate stability tests were also performed involving osmoadapted E325 with and without cryoprotectants. Additionally, we evaluated survival and growth of osmoadapted E325 on both the stigmas and hypanthia of detached crab apple blossoms. Osmoadaptation improved the survival of E325 during freeze drying and subsequent storage prior to application, but did not eliminate the need for cryoprotectants. This production method, however, did not increase the survival of E325 on blossom stigmas under low relative humidity in the orchard (45% average) or laboratory (50 or 70%), but was shown in the laboratory to increase survival and growth in the blossom hypanthium. Further orchard experimentation is necessary to verify this. Source

Wend C.,Northwest Agricultural Products
Acta Horticulturae | Year: 2011

The survival of a biological antagonist such as Pantoea agglomerans E325 or the pathogen Erwinia amylovora on an apple blossom depends upon many environmental factors. In addition commercial orchard practices such as blossom thinning can confound the understanding of this survival. Proper integrated pesticide management programs need to understand this survival so that biological tools to suppress disease can be adequately deployed. Using decision analysis it can be shown that application of antagonist before thinning will result in low antagonist coverage at the end of bloom without post thinning antagonist applications. Post thinning antagonist application at 60% bloom will result in predictions of 49% blossom colonization at full bloom. When the post thinning antagonist application is done at 90% bloom, the overall coverage is predicted to be 80%. One recommendation from this analysis could be that biological antagonists should be applied as recommended early in the orchard but that a second application should be made to blossoms that come after thinning activities in the orchard. Addition of pathogen colonization and risk models will help predict optimum timing of treatments to be analyzed. Source

Northwest Agricultural Products | Date: 2009-07-22

Agricultural biopesticides.

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