Distribution of propiconazole-resistant in peach orchards with or without cull fruit amendments.

Resistance to propiconazole in G. candidum was reported previously in isolates collected from peaches after cold storage, but the origin of resistance was unclear. If resistance had been generated and selected in the packinghouse with postharvest propiconazole drenches, we would expect to find resistance in the sour rot pathogen only in orchards that had received cull fruit returned to the orchard floor from the packinghouse.

Propiconazole resistance phenotypes in from South Carolina peaches are linked to point mutations in gene.

Geotrichum candidum Link (1809) is a yeast-like fungus that causes sour rot of peach (Prunus persica). Outbreaks of the disease have occurred since 2021 in peach fruit kept in cold storage despite post-harvest treatments with propiconazole at a commercial farm in South Carolina (SC). A total of 58 isolates, 40 from symptomatic fruit from cold storage in Saluda County (SC packing house isolates), 11 from three SC orchards in Saluda County, Spartanburg County, and Pickens County (SC non-packing house isolates), and 7 California (CA) isolates (at least 3 from packing houses) were evaluated for propiconazole sensitivity.

Fludioxonil does not antagonize propiconazole activity against .

Fludioxonil and propiconazole are frequently used fungicides for managing fungal diseases in specialty crops. They are often used in mixture to manage brown rot caused by Monilinia fructicola and sour rot caused by the yeast-like fungus Geotrichum candidum,respectively, on stone fruits. Research indicated, however, that fludioxonil can increase the expression of the ATP-binding cassette transporters CDR1 and CDR2 in the yeast Candida albicans, leading to increased resistance to DMI fungicides.

In vitro co-culture system for investigating Armillaria root rot in Prunus spp. using a fiber-supported liquid approach.

In vitro co-culture techniques that allow the growth of plants and pathogens under controlled environmental conditions are being used to re-create host plant infection. These approaches reduce infection times, promote reproducibility, and enable a rapid evaluation of plant-pathogen interactions. As a result, these systems have become essential in breeding programs aimed at developing plant resistance to diseases.

Characterization and Fungicide Sensitivity of Causing Gnomonia Leaf Blotch of Strawberry in the Carolinas.

Emerging fungal pathogens have always been an issue of concern in southeastern U.S. strawberry production.

Identification of Fungicide Combinations for Overcoming and Fungicide Resistance.

Fungal diseases, including downy mildew (caused by ) and gray mold (caused by ), significantly impact the marketable yield of grapes produced worldwide. Cytochrome b of the mitochondrial respiratory chain of these two fungi is a key target for Quinone outside inhibitor (QoI)-based fungicide development. Since the mode of action (MOA) of QoI fungicides is restricted to a single site, the extensive usage of these fungicides has resulted in fungicide resistance.

Low frequency of resistance to thiophanate-methyl in Monilinia fructicola populations from southeastern United States peach orchards.

Methyl benzimidazole carbamate (MBC) fungicides were once widely used for brown rot (Monilinia fructicola) control of peach (Prunus persica (L.) Batsch) in the southeastern US, but their use was substantially reduced and often eliminated due to widespread resistance. In this study, 233 M.

Reevaluation of Sensitivity of Isolates to the DMI Fungicide Propiconazole in the Southeastern United States and Investigation of the Genetic Element Mona.

Sterol demethylation inhibitor (DMI) fungicides continue to be essential components for the control of brown rot of peach caused by in the United States and worldwide. In the southeastern United States, resistance to DMIs had been associated with overexpression of the cytochrome P450 14α-demethylase gene Mf as well as the genetic element Mona, a 65 bp in length nucleotide sequence located upstream of Mf in resistant isolates. About 20 years after the first survey, we reevaluated sensitivity of from South Carolina and Georgia to propiconazole and also evaluated isolates from Alabama for the first time.

Efficacy of calcium propionate against fungicide-resistant fungal plant pathogens and suppression of botrytis blight of ornamental flowers.

Conventional fungicides are used in IPM programs to manage fungal plant pathogens, but there are concerns about resistance development in target organisms, environmental contamination, and human health risks. This study explored the potential of calcium propionate (CaP), a common food preservative generally recognized as safe (GRAS) to control fungicide-resistant plant pathogens, mainly Botrytis cinerea, and botrytis blight in ornamentals. In-vitro experiments using mycelium growth inhibition indicated a mean EC value for CaP (pH 6.

Development of a Molecular Tool for Identification of a New sp. Associated with Disease Outbreaks on Strawberry.

A new sp. was recently reported causing outbreaks of leaf spot and fruit rot on strawberry in Florida, Georgia, and South Carolina. In contrast to other pathogens, the new species appears more aggressive and destructive on strawberry.

Identification and Fungicide Sensitivity of spp. from Apple Flowers and Fruitlets in Brazil.

Glomerella leaf spot (GLS) and bitter rot (BR), caused by spp., are major diseases on apple in southern Brazil. Among integrated pest management tools for disease management in commercial orchards, fungicides remain an important component.

Occurrence of causing Downy Mildew on in Brazil.

Impatiens walleriana (Balsaminaceae), popularly known as Impatiens, is an African succulent and a popular ornamental plant worldwide (GBIF, 2019). In Brazil it is broadly grown indoors and outdoors, including in public parks of Curitiba, State of Paraná (Viezzer et al. 2018).

Characterization of High Fludioxonil Resistance in Isolates from Calibrachoa Flowers.

The fungicide fludioxonil is one of the most effective single-site fungicides available for managing flower blight caused by on fruit and ornamental crops. Although low and moderate levels of resistance to fludioxonil have been reported in the pathogen across the United States and Europe, high resistance has been reported only from greenhouses in China. In this study, two isolates with high resistance (half maximal effective concentration >100 µg/ml) to fludioxonil were detected on ornamental calibrachoa flowers grown in a greenhouse.