10 research outputs found
Visual symptom identification of grapevine leafroll-associated virus 3 in red berry cultivars supports virus management by roguing
Grapevine leafroll-associated virus 3 (GLRaV-3) is the
most serious virus in New Zealand and South African
vineyards. Its negative influence on berry development is
reflected on wine quality, thus making GLRaV-3 control
a priority. In red berry cultivars, changes in leaf colour
could be useful for the visual identification of GLRaV-3-infected
vines with a view to roguing (removing) such vines.
We tested the efficacy of visual diagnosis as a potentially
cost-effective alternative option to the enzyme-linked immunosorbent
assay (ELISA) that is usually used for this
purpose. All the vines, or a subsection of vines, in multiple
vineyards in New Zealand or South Africa where annual
roguing was being performed, were evaluated with the two
methods. Of the 114,782 vines assessed visually for symptoms
and tested by ELISA, the two methods were in agreement
for 114,701 (99.9%) vines, with only 81 vines showing
differing results. In 11 of the 44 annual vineyard analyses,
visual detection of symptoms was perfectly correlated with
ELISA results (sensitivity 100%). The specificity of visual
symptom identification compared with ELISA was higher
than 99.7% in 43 of the 44 annual vineyard analyses.
Symptoms as a predictor of negative ELISA proved to be
above 97.5% in all 44 annual vineyard analyses but as a
positive predictor, was 100% in 10 of 19 annual vineyard analyses where this could be determined. We conclude
that for the red-berried cultivars in this study, visual assessment
of foliar symptoms should be adopted as a costeffective
alternative to ELISA during implementation of
roguing for GLRaV-3 control.This work formed part of the New Zealand Grape
and Wine Research programme.New Zealand Winegrowers, the New Zealand Institute
for Plant & Food Research Strategic Science Investment
Fund and also Winetech and Vergelegen
Wine Estate (South Africa).http://www.sipav.org/main/jpp/index.php/jpp2018-06-30am2017Forestry and Agricultural Biotechnology Institute (FABI)Microbiology and Plant Patholog
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Can information affect sensory perceptions? Evidence from a survey on Italian organic food consumers
This paper aims to investigate the influence of information on consumers’ preferences and sensory perceptions of organic food using a sample of 301 Italian organic food consumers. Consumers stated their preferences for “core organic” attributes, labels and information on food products and performed blind and informed tests on strawberry yoghurts and cookies. Data were analysed using descriptive analysis, Mann-Whitney U tests and Wilcoxon signed-rank test. Results revealed that consumers appreciate “core organic” attributes, like artisanal production and variability of sensory attributes. Comparing blind and informed tests, results showed that information affects the overall liking of products and consumers’ perception of product-specific sensory attributes. However, the influence of information on sensory perceptions depends on the product category, sensory attributes and the type of information provided
Lipid-Based Natural Food Extracts for Effective Control of Botrytis Bunch Rot and Powdery Mildew on Field-Grown Winegrapes in New Zealand
Synthetic controls of crop pathogens are increasingly associated with harm to the environment and human health, and pathogen resistance. Pesticide residues in crops can also act as non-tariff trade barriers. There is therefore a strong imperative to develop biologically based and natural product (NP) biofungicides as more sustainable alternatives for crop pathogen control. We demonstrate the field efficacy, over multiple seasons, of NP biofungicides, NP1 (based on anhydrous milk fat) and NP2 (based on soybean oil), on two major diseases of winegrapes—Botrytis bunch rot (Botrytis) and powdery mildew (PM). The NPs were integrated into a season-long integrated disease management programme that has produced chemical-residue-free wines. Efficacies for Botrytis control on three different varieties were: 63–97% on Chardonnay, 0–96% for Sauvignon Blanc and 46–58% on Riesling; with 65–98% PM control on Chardonnay and Riesling. NP2 exhibited the significant control of Botrytis latent infections, making it a viable alternative to mid-season synthetic fungicides. Disease control was significantly better than the untreated control and usually as efficacious as the synthetic fungicide treatment(s). Yields and wine quality in NP-treated crops were normally equivalent to those in the synthetic fungicide treatments. The results indicate that NP-mediated disease control of Botrytis and powdery mildew can be obtained in the vineyard, without synthetic fungicide input
Characterization of intestinal inflammation and identification of related gene expression changes in mdr1a−/− mice
Multidrug resistance targeted mutation (mdr1a−/−) mice spontaneously develop intestinal inflammation. The aim of this study was to further characterize the intestinal inflammation in mdr1a−/− mice. Intestinal samples were collected to measure inflammation and gene expression changes over time. The first signs of inflammation occurred around 16 weeks of age and most mdr1a−/− mice developed inflammation between 16 and 27 weeks of age. The total histological injury score was the highest in the colon. The inflammatory lesions were transmural and discontinuous, revealing similarities to human inflammatory bowel diseases (IBD). Genes involved in inflammatory response pathways were up-regulated whereas genes involved in biotransformation and transport were down-regulated in colonic epithelial cell scrapings of inflamed mdra1−/− mice at 25 weeks of age compared to non-inflamed FVB mice. These results show overlap to human IBD and strengthen the use of this in vivo model to study human IBD. The anti-inflammatory regenerating islet-derived genes were expressed at a lower level during inflammation initiation in non-inflamed colonic epithelial cell scrapings of mdr1a−/− mice at 12 weeks of age. This result suggests that an insufficiently suppressed immune response could be crucial to the initiation and development of intestinal inflammation in mdr1a−/− mice