Project Number: 13C-3361-4795 TITLE: Epidemiology and control of apple powdery mildew Principal Investigator: G. G. Grove, Plant Pathology, WSU-IAREC, Prosser, WA Objectives • Develop a forecasting model to improve management of apple powdery mildew, caused by Podosphaera leucotricha. • Develop biorational disease and fungicide-resistance management programs • Lower disease pressure through cha...

Pycnidial fungi of the genus Ampelomyces are widespread intracellular mycoparasites of powdery mildew fungi worldwide. Their pycnidia are produced in hyphae, conidiophores and immature ascomata of their mycohosts. Thus, they suppress both the asexual and the sexual reproduction of the invaded powdery mildew mycelia, and then destroy them completely. Conidia of Ampelomyces are released from the ...

Prior studies have shown that applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab. Here field and glasshouse trials suggest that 2,4-D foliar treatments may also reduce the biologically distinct tuber disease, powdery scab. Significant correlations between suppression of common and powdery scab from the field trials s...

members of erysiphales cause powdery mildew diseases on wide host rang and produce whitish primary mycelium on surface of infected parts. based on microscopic study of one specimen on jasminum sp., structures of fungus including conidiophores and conidia were observed. foot cells of conidiophores were cylindrical or curved in basal part, followed by 1-2 shorter cells. conidia were ellipsoid to ...

Powdery mildew (Sphaerotheca mors-uvae) severely infects young shoots and leaves of black currants (Ribes nigrum) and red currants (R. rubrum) in the Pacific northwestern U.S. Environmentally sound control measures are being sought as alternatives to sulfur or demethylation-inhibiting fungicides. This study examined the effect of mineral oil spray on powdery mildew infection in susceptible blac...

We had previously isolated and characterized syringolin A, one of the molecular determinants secreted by Pseudomonas syringae pv syringae that is perceived by nonhost plant species such as rice. Here, we show that syringolin A is recognized by wheat and that it induces the accumulation of gene transcripts and increases protection against powdery mildew when applied before inoculation. Moreover,...

Loss of function mutations of particular plant MILDEW RESISTANCE LOCUS O (MLO) genes confer durable and broad-spectrum penetration resistance against powdery mildew fungi. Here, we combined genetic, transcriptomic and metabolomic analyses to explore the defense mechanisms in the fully resistant Arabidopsis thaliana mlo2 mlo6 mlo12 triple mutant. We found that this genotype unexpectedly overcome...

Additional Index Words. Cucumis sativus L., greenhouse, protected culture, beit alpha cucumber Abstract. The Beit Alpha (BA) cucumber is a new commodity for the Florida greenhouse industry. In past trials, BA cultivar production and quality were compared to traditional ‘Dutch’ or European cucumber cultivars. The cv. Sarig, a BA-type, produced three times more yield than the Dutch-type cv. Kalun...

Wheat is one of the most widely grown cereal crops in the world and is an important food grain source for humans. However, wheat yields can be reduced by many abiotic and biotic stress factors, including powdery mildew disease caused by Blumeria graminis f.sp. tritici (Bgt). Generating resistant varieties is thus a major effort in plant breeding. Here, we took advantage of the non-transgenic Ta...