Search results for "Mildew"
showing 10 items of 37 documents
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…
Natural products against the powdery mildew of rose plants
2005
Control of powdery mildew in cut roses using natural products in the greenhouse.
2009
Roses grown under greenhouse cultivation are commonly affected by diseases and regular fungicide applications are commonly used. The aim of this research was to identify natural products that can substitute and reduce the health and environmental impacts of typical chemical treatments in the control of powdery mildew [(Podosphaera pannosa (Wallr. Fr.) de Bary] and grey mould (Botrytis cinerea Pers.). Treatments were applied in the greenhouse on the cut rose cultivars Sunluck (Gold Strike®) and Nirpbredy (New Fashion®) growing in a soilless system. Oregano and clove essential oil at 0.5 ml/l (an emulsifier was added) and sodium bicarbonate (NaHCO3) at 4 g/l were sprayed on rose plants to run…
Antimicrobial Activity of Resveratrol Analogues
2014
Stilbenes, especially resveratrol and its derivatives, have become famous for their positive effects on a wide range of medical disorders, as indicated by a huge number of published studies. A less investigated area of research is their antimicrobial properties. A series of 13 trans-resveratrol analogues was synthesized via Wittig or Heck reactions, and their antimicrobial activity assessed on two different grapevine pathogens responsible for severe diseases in the vineyard. The entire series, together with resveratrol, was first evaluated on the zoospore mobility and sporulation level of Plasmopara viticola (the oomycete responsible for downy mildew). Stilbenes displayed a spectrum of acti…
Toward the Identification of Two Glycoproteins Involved in the Stomatal Deregulation of Downy Mildew–Infected Grapevine Leaves
2015
SPE Pôle IPM UB; International audience; Stomata remain abnormally opened and unresponsive to abscisic acid in grapevine leaves infected by downy mildew. This deregulation occurs from 3 days post inoculation and increases concomitantly with leaf colonization by the pathogen. Using epidermal peels, we demonstrated that the active compound involved in this deregulation is located in the apoplast. Biochemical assays showed that the active compound present in the apoplastic fluids isolated from Plasmopara viticola infected grapevine leaves (IAF) is a CysCys bridge-independent, thermostable and glycosylated protein. Fractionation guided assays based on chromatography / stomatal response and prot…
An endophytic bacillus subtilis strain protects grapevine against downy mildew by direct effect and defense stimulation
2018
National audience; Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen. Phytochemicals are generally used to control infections, but the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. Biological control has received a great deal of attention as an alternative and promising measure to control different plant diseases. Many antagonistic microorganisms, including Bacillus spp., have been exploited against different pathogens. Bacillus spp. activity results from multiple modes of action including antibiosis, competition, a…
Volatile organic compounds: a role in elicitor-induced resistance of grapevine against pathogens?
2014
International audience; As Vitis vinifera varieties are susceptible to fungal diseases, numerous chemical treatments are generally required to ensure the quantity and quality of the harvest. However, in the context of sustainable viticulture, there are increasing societal request, political incitation, and winegrowers’ awareness to reduce the use of pesticides. Among possible solutions the use of elicitors that could be included in integrated pest management or biocontrol strategies might be very promising. These bioactive compounds are able to trigger plant defences, leading to induced resistance (IR) against pathogens. Despite IR can be elicited very successfully in controlled environment…
Impact of biostimulants on the resistance induction level of grapevine to downy mildew by elicitors
2018
The protection of vineyards against cryptogamic diseases such as downy mildew is mainly ensured by synthetic fungicides, which cause serious environmental and health problems. The induction of resistance by elicitors could allow to reduce their use. However, even if their efficacy is demonstrated in greenhouse conditions, it remains quite variable in field conditions. Indeed, the efficacy of an elicitor depends on the plant’s ability to respond, or more generally, on the latter’s physiological status. In this context, part of the FUI project IRIS+, the aim of this present work is to evaluate whether biostimulants, through their effect on the plant’s physiology, would be able to increase the…
Does leaf position influence induced resistance to grape downy mildew?
2013
National audience; We observed that protection against grape downy mildew achieved by resistance inducers was higher in the adult leaf than in the younger, not fully expanded leaf. Using sulfated laminarin as inducer, this difference of efficacy could be correlated to stronger defense reactions (i. e. H2O2, defense gene expression) in adult leaf as compared to the younger one. These findings should be taken into account in disease control strategies involving induced resistance.