Search results for "powdery mildew"

Climate vs grapevine pests and diseases worldwide: The first results of a global survey

2016

<p class="Abstract"><strong>Aim:</strong> This paper aimed to address the relationship between grapevine disease, pest occurrences and climate. The extremely large extension of viticulture worldwide offers the possibility to evaluate the impacts of climate variability on many aspects of the grape growing system. For this, we initiated a global survey to retrieve the most important diseases and pests in many grape growing regions worldwide and to identify the risk of exposure to pests and diseases of viticulture as a function of climate.</p><p class="Abstract"><strong>Methods and results:</strong> Based on the answer of respondent about the main repo…

Breeding For Organic Farming : Obtaining And Evaluation Of Flax Somaclonal Families

2015

Plant calli culture could be used as a source of genetic changes (somaclonal variation). There are known several flax varieties, bred on the basis of somaclonal variation, with improved resistance to biotic and abiotic stresses, plant height, seed yield and other traits. This method is useful for obtaining the new initial material for flax breeding, including for intensification of breeding for organic farming. Goal of the study was to obtain plants-regenerants from the calli culture of the fibre flax variety ‘Vega 2’ and to evaluate their agronomical traits and resistance to powdery mildew. For obtaining plants-regenerants was used early elaborated protocol of somatic calli cultivation. Ag…

USE OF ALGINATES OLIGOMERS TO IMPROVE PLANT PROTECTION AGAINST PATHOGENS

2021

The invention concerns the use of alginate oligomers in sequence α(1-4)Guluronane and/or ß(1-4)Mannuronane having a DP greater than 30, as an active ingredient of biocontrol products in plants, and that may be combined with another molecules such as phytohormones, against cryptogamic diseases of plants, in particular of vine (Vitis vinifera), or to protect other species against aggressors such as pathogenic microbes or insects.

Climate change impacts on phytosanitary risk evolution in north-eastern France vineyards : observations and modeling : The case of powdery mildew

2021

From now on, agriculture must adapt and anticipate climate change, whose impact has already been observed on the biology of crops and their production. Beyond plants, this climate change also impacts pathogen development and therefore host/pathogen interactions. Thus, building adaptation strategies requires considering not only the crops but also the organisms with which they interact.The objective of this thesis is to characterize the impact of climate change on the phytosanitary risk related to grapevine powdery mildew (Erysiphe necator) in the wine regions of Burgundy and Champagne. More particularly, it questions two central aspects related to the epidemic risk: the grapevine sensitive …

Arbuscular mycorrhizal fungi influence host infection during epidemics in a wild plant pathosystem

2022

SummaryWhile pathogenic and mutualistic microbes are ubiquitous across ecosystems and often co-occur within hosts, how they interact to determine patterns of disease in genetically diverse wild populations is unknown.To test whether microbial mutualists provide protection against pathogens, and whether this varies among host genotypes, we conducted a field experiment in three naturally-occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected epidemiological data on experimental plants from six allopatric populations that had been inoculated with a mixture of mutualistic arb…

DISEASES DIVERSITY FOR FLAX GENETIC RESOURCES IN LATVIA

2017

Flax ( Linum usitatissimum L) yield of stem and seeds and them quality is influenced by a number of harmful diseases but investigation about pathogens in recent years have not been done in Latvia.  Each stage of development of disease is important in the pathogen life cycle and requires certain condition. Goal of this study have identify possibilities of the pathogens and were assess disease severity depending on the genotypes on flax in variable environmental conditions. The resistance to the diseases for 24 flax genotypes and standard variety ‘Vega 2’ were evaluated. The field trials have been carried out over the period from 2015 to 2016 at the Research Centre of Priekuli, part of Vilani…

Powdery mildew on Rhododendron caused by Erysiphe azaleae in Latvia.

2013

In 2002 a fungus causing powdery mildew on Rhododendron in Latvia was discovered and identified as Erysiphe azaleae. The powdery mildew has since then been observed on leaves and seed pods of deciduous azaleas as well as evergreen rhododendrons, although the disease is more common on taxa of deciduous azaleas. Development of mature chasmothecia has been noticed at every location where the disease was detected. The distribution area of E. azaleae is expanding gradually from the south-west and central regions to the north and east parts of Latvia. It has been suggested, that climate change and large-scale plant import favour this process. To our knowledge, Latvia is so far the farthest north-…

Exploring the factors affecting spatio-temporal variation in grapevine powdery mildew

2019

Chitin Deacetylase, a Novel Target for the Design of Agricultural Fungicides

2021

Fungicide resistance is a serious problem for agriculture. This is particularly apparent in the case of powdery mildew fungi. Therefore, there is an urgent need to develop new agrochemicals. Chitin is a well-known elicitor of plant immunity, and fungal pathogens have evolved strategies to overcome its detection. Among these strategies, chitin deacetylase (CDA) is responsible for modifying immunogenic chitooligomers and hydrolysing the acetamido group in the N-acetylglucosamine units to avoid recognition. In this work, we tested the hypothesis that CDA can be an appropriate target for antifungals using the cucurbit powdery mildew pathogen Podosphaera xanthii. According to our hypothesis, RNA…

USE OF NATURAL PRODUCTS FOR THE CONTROL OF POWDERY MILDEW OF ROSE PLANTS

2007

PowDery mildew caused by Podosphaera pannosa (Wallr. Fr.) De Bary on roses in greenhouse cultivation is usually controlled by chemical products. Aiming to lower the use of chemical treatments, in vitro and in planta assays were carried out using some natural products. The inhibitory effect of essential oils extracted from oregano inflorescences (Origanum heracleoticum L.) and cloves (Syzygium aromaticum L. Merril et L.M. Perry), was evaluated by in vitro tests. Essential oil at 0.5, and 0.125 ml/L concentration was added to conidia suspension (8 x 105 conidia/ml). After 2, 4, 8, 12, 24 and 48 hours, 400 conidia for each treatment and control were evaluated and the germination percentage cal…