First Report of pv. causing Bacterial Canker in Sweet Cherry Orchards in Washington State.

In 2023, an outbreak of bacterial canker disease (BCD) in sweet cherry orchards caused significant economic losses to growers and nurseries in the Pacific Northwest, USA (Fig. S1). The cherry industry in Washington State alone is valued at over $800 million (USDA NASS, 2022).

First European Lytic Bacteriophage Cocktails Effective in the Host: Characterization and Prospects for Fire Blight Biocontrol.

Fire blight, caused by the plant-pathogenic bacterium , is a highly contagious and difficult-to-control disease due to its efficient dissemination and survival and the scarcity of effective control methods. Copper and antibiotics are the most used treatments but pose environmental and human health risks. Bacteriophages (phages) constitute an ecological, safe, and sustainable fire blight control alternative.

Improved Canker Processing and Viability Droplet Digital PCR Allow Detection of Viable Nonculturable Cells in Apple Bark.

The bacterium causes fire blight and continues to threaten global commercial apple and pear production. Conventional microbiology techniques cannot accurately determine the presence of live pathogen cells in fire blight cankers. Several factors may prevent from growing on solid culture media, including competing microbiota and the release of bacterial-growth-inhibitory compounds by plant material during sample processing.

Selective Quantification of Erwinia amylovora Live Cells in Pome Fruit Tree Cankers by Viability Digital PCR.

The accurate assessment of Erwinia amylovora live cell populations in fire blight cankers by classic microbiology methods has major limitations. Some of them are the presence of competitive microbiota in samples that inhibit E. amylovora's growth and the release of toxic compounds by plant material during sample processing, which may hamper the pathogen's ability to form colonies on solid media.

Proof of Concept for Shoot Blight and Fire Blight Canker Management with Postinfection Spray Applications of Prohexadione-Calcium and Acibenzolar--Methyl in Apple.

To reduce the severity of shoot blight and prevent the resulting development of cankers on perennial apple wood, we evaluated eight fire blight postinfection spray programs of prohexadione-calcium (PCA) alone or with acibenzolar--methyl (ASM) over 2 years. On mature trees of cultivar Royal Court, a single application of the high PCA rate (247 mg/liter) at 2 to 3 days after inoculation resulted in 89.5 and 69.