Evaluation of spray programs containing famoxadone plus cymoxanil, acibenzolar-S-methyl, and Bacillus subtilis compared to copper sprays for management of bacterial spot on tomato

Bacterial spot caused by Xanthomonas euvesicatoria Jones et al. and Xanthomonas perforans Jones et al. is a major disease on fresh market commercial tomato in Florida. Fourteen field trials were conducted between 1999 and 2005 (10 in south Florida and four in north Florida) testing famoxadone plus cymoxanil (Tanos 50DF^®, E.I. du Pont de Nemours and Company, Wilmington, DE), Bacillus subtilis strain QST 713 (B. subtilis) (Serenade WPO^® or Serenade Max^®, AgraQuest, Inc., Davis, CA), and acibenzolar-S-methyl (ASM) (Actigard 50WG^®, Syngenta Crop Protection, Greensboro, NC) at different rates and in various application programs that were combined and rotated with copper hydroxide and mancozeb for management of bacterial spot. In field applied spray treatments containing famoxadone as a component, all of the programs significantly reduced bacterial spot severity on plants compared to the untreated control plants (UTC) and 97% of the programs were equal for disease suppression conferred by the copper-mancozeb standard. In spray programs containing ASM or B. subtilis plus copper hydroxide, treated plants had significantly reduced disease compared to the UTC plants and were not different from the plants treated with the copper-mancozeb standard. Yield data from small plots was unaffected. Several of the programs which used these compounds in rotation with copper-mancozeb provided similar levels of reduction in the disease severity for bacterial spot while reducing by 50% the amount of copper applied to plants. The effect of famoxadone plus cymoxanil on the survival of Xanthomonas in vitro did not cause a significant reduction in the bacterial population and was not determined to be directly bactericidal. However, greenhouse and field testing supports disease reduction of bacterial spot on plants treated with these compounds. The products tested in these trials may be useful, alternative tools for use in an integrated management program for bacterial spot on tomato.     

Genetic diversity in twenty variants of the avian polyomavirus.

To determine if different pathotypes of the avian polyomavirus (APV) exist and to compare the genomes of APVs originating from different geographic areas, dates, and species of birds, the partial sequences of 18 APVs were determined. New viral sequences were compared with three published APV sequences. Two of the new viruses had identical sequences. Forty point mutations were found at 31 loci. A 27-bp deletion was found in the VP2 and VP3 open reading frames of one virus. A duplication of the putative origin of replication and adjacent enhancer region was previously reported in one APV. Smaller duplications involving the origin in one APV and a second enhancer region in another were discovered. All duplications were in tissue culture-adapted viruses, suggesting they occurred during the isolation process. Excluding duplications and the deletion, maximum variation between viruses was small (11 bp). A maximum parsimony tree was constructed that contained three major branches. The three earliest isolates were on separate branches. The European viruses were confined to branch I, but APVs from the United States were on all three branches. Lovebird, budgerigar, and macaw APVs were also on each of the three branches, suggesting that species-specific pathotypes have not developed. Most nonsynonymous mutations occurred in a small portion of the VP2 and VP3 open reading frames, demonstrating a selection for these mutations. That a glycine at VP2 221 will inhibit virus replication in chicken embryo fibroblasts (CEFs) has been previously reported. In contrast, six of seven of the new APVs isolated in CEFs had a glycine at VP2 221.     

CANINE INTRACRANIAL EPIDERMOID CYST

A 7-year-old intact male pitbull presented with a 2-month history of progressive dysequilibrium. Cerebrospinal fluid analysis was indicative of a central inflammatory or neoplastic disorder. A cerebellar cystic structure was identified on magnetic resonance imaging which was found to be an epidermoid cyst on histopathology.     

ASSESSMENT OF BARIUM IMPREGNATED POLYETHYLENE SPHERES (BIPS®) AS A MEASURE OF SOLID-PHASE GASTRIC EMPTYING IN NORMAL DOGS-COMPARISON TO SCINTIGRAPHY

Barium impregnated polyethylene spheres (BIPS) are radiopaque markers used for investigation of a variety of gastrointestinal disorders. One proposed use of the small (1.5 mm) marker is quantitative assessment of solid-phase gastric emptying, which may offer a simple, inexpensive alternative to nuclear medicine studies. In this study the rate and pattern of gastric emptying of a radiolabeled meal containing 30 small BIPS was evaluated in normal dogs by simultaneous comparison of the radiopaque marker method and a scintigraphic method. Serial scintigraphic images and radiographs were obtained for 8 hours or until 95% of the markers had left the stomach. Emptying curves were constructed and statistical analyses performed. There were significant differences in gastric emptying times and lag phase characteristics between the BIPS and scintigraphic studies. These results indicate that in normal dogs there are differences in both the rate and the pattern of solid-phase gastric emptying of a radiolabeled meal as assessed by scintigraphy and the gastric emptying of small BIPS.     

Myeloperoxidase activity of the large intestine in an equine model of acute colitis.

OBJECTIVE: To determine whether quantification of myeloperoxidase (MPO) activity could be a useful laboratory technique to detect granulocyte infiltration in equine intestinal tissues. SAMPLE POPULATION: Intestinal tissue (inflamed or healthy) collected from 16 age- and sex-matched Shetland Ponies. PROCEDURE: Intestinal tissue MPO activity was determined, and histologic assessment of adjacent specimens from healthy and inflamed intestine was done. RESULTS: Intestinal tissue MPO activity and histopathologic score increased with time after castor oil challenge and peaked at 16 hours in an equine diarrhea model in which individual ponies provided their own control tissues. CONCLUSIONS: Intestinal tissue inflammation scores correlated positively with tissue MPO activity in adjacent specimens. CLINICAL RELEVANCE: Tissue MPO assay may be a useful laboratory tool to quantify intestinal mucosal inflammation in ponies.     

Effects of codend circumference and twine diameter on selection in south-eastern Australian fish trawls

Two experiments, done in a south-eastern Australian trawl fishery targeting school whiting (Sillago flindersi: Sillaginidae), examined the relative efficiencies and selectivities of five codends and extension sections made from double-twine, 90-mm (inside stretched length) mesh netting. All extension sections were made from 3-mm diameter twine and were 100 meshes long and 100 meshes in circumference, while the codends were 25 meshes in length. The first experiment tested three codends made from 4-mm diameter twine: one with a circumference of 100 meshes and two of 200-mesh circumference, with one of the latter incorporating two cross-sectional joins in its extension piece. The second experiment compared two 200-mesh circumference codends, one constructed from 3-mm diameter twine and the other from 5-mm diameter twine. The codends were alternately fished with a small-meshed control. The results showed a general trend of reduced selection by the 200-mesh circumference and thicker twined codends, and especially by the industry-preferred 200-mesh circumference codend constructed from 5-mm diameter twine. Experiment 1 found that the 100-mesh codend caught significantly fewer school whiting, retained catch and total catch than did the two 200-mesh codends, and the 200-mesh codend with the modified extension section caught significantly fewer school whiting and retained catch than did the 200-mesh codend with the straight extension. In the second experiment, the 200-mesh 5-mm twine codend caught significantly more total and retained catch, school whiting, and longspine flathead (Platycephalus longispinis: Platycephalidae) than did the 200-mesh 3-mm twine codend. Across all codends, the smallest lengths at 50% probability of retention (L₅₀) were estimated for longspine flathead, redfish (Centroberyx affinis: Berycidae) and longfin gurnard (Lepidotrigla argus: Triglidae) in the 5-mm 200-mesh codend. The limited size range of school whiting resulted in unreliable estimation of selectivity in the 200-mesh 5-mm twine codend, but this design was the only one that retained a substantial proportion of individuals below the minimum marketable length (15 cm fork length). While the 200-mesh 5-mm twine codend retained commercial quantities of school whiting, it seems far from optimal. It is suggested that a more efficient design comprising possibly smaller, square-shaped meshes should be developed and used in conjunction with temporal, spatial and catch restrictions.     

Biotic affinities of rocky reef fishes,invertebrates and macroalgae in different zones of the Port Davey marine protected area,south‐western Tasmania

• 1. Assemblages of fishes, invertebrates, and macroalgae showed strong and predictable distributional patterns within the newly declared Port Davey marine protected area (MPA) in south‐western Tasmania. Biotic assemblages in the eastern estuarine section of the MPA within Bathurst Channel were extremely anomalous, both in relation to biota elsewhere in the Port Davey region and also to those present along the wider Tasmanian and Australian coasts. Much of this variation was due to the phenomenon of deepwater emergence, with species in 5 m water depth in eastern Bathurst Channel possessing a mean maximum recorded depth of 200 m, compared with<80 m for the same metric when calculated for sites studied elsewhere around Australia. Deepwater emergence in Bathurst Channel was particularly notable for sessile organisms, although also evident among fishes and mobile macro‐invertebrates.
• 2. Quantitative baseline surveys of reef‐associated species were undertaken at sites interspersed among MPA management zone types and biotic community types, thereby providing an appropriate benchmark for assessing ecological changes in different management zones within the Port Davey region through the long term. Distinctive biota present in eastern and western Bathurst Channel, and eastern Port Davey, are well protected within ‘no‐take’ sanctuary zones; however, a bias in location of sanctuary zones towards areas with little fishery resources resulted in less protection for the western Port Davey biota, which also extends along the open coast. Although the lack of high level protection for sites with fishery resources detracts from conservation goals, the Port Davey MPA nevertheless represents a major advance in environmental protection because the ecologically unique, fully protected locations are a necessary inclusion within any comprehensive Australian MPA network. Copyright © 2009 John Wiley & Sons, Ltd.

     

Lower soil nitrous oxide emissions by a high lipid genetically modified perennial ryegrass line compared to its wild type

We describe an experiment where cattle urine was applied at a rate of 420 kg N ha⁻¹, equivalent to 10 L m⁻², to mesocosm swards of a high lipid genetically modified perennial ryegrass line (HME) and its wild type (WT). We measured N pools and fluxes in the plant and soil, soil microbial populations and N₂O production. HME plants produced 21% greater biomass than WT (p = .02), resulting in greater N uptake (27% higher in HME, p = .05). Urine N recovery in total plant biomass during the experiment in HME and WT swards were 54.7% and 33.9% respectively. The nitrification potential of soil was significantly lower (p = .01) in HME than WT. Partial least square-discriminant analysis using microbial gene abundance data indicated that HME and WT plant growth induced distinct microbial populations in the soil. These differences in plant soil microbial interactions between HME and WT swards resulted in significantly lower N₂O emissions from the HME sward. Total N₂O emissions over the 4 weeks after urine application was 38% lower (p < .03) in HME swards than in WT swards. The next step in this work is to identify the specific changes in HME traits that drive the reduction in N₂O.