New bacterial rot found in Argentine pears and apples

Researchers at INTA Alto Valle have identified Rahnella aceris as the bacterium behind a previously unrecognised storage rot affecting pears and apples in Argentina’s main pome-fruit region.

Cases were found in packing and storage facilities during the 2024 and 2025 postharvest seasons. Damage appeared after fruit had spent between two and eight months in cold storage.

D’Anjou pears showed the highest incidence, followed by Packham’s, while cases were also recorded in Red Delicious apples. Laboratory tests later confirmed that Williams and Abate Fetel pears are susceptible as well.

Affected fruit develops soft, sunken brown rot, sometimes with translucent margins. INTA researchers believe the infection may begin in the orchard and remain latent until storage.

Epidemiological work is continuing to determine how the disease spreads and how it can be controlled.

source and photo: argentina.gob.ar