Apple Trees Are Mysteriously Dying All Across America

— Written By
en Español / em Português

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

Bryan Nelson | 3/28/2019 | Mother Nature Network

Apple trees are an iconic national symbol in America, but the future of this beloved fruit could be in doubt, reports Science magazine.

Something is killing apple trees across the American countryside, and the epidemic is reaching plague-like levels. Worst yet, scientists are completely clueless as to what is causing the mysterious pestilence.

Apple Orchard
The puzzling affliction is being called RAD, or rapid apple decline, and it typically begins on a single tree limb. As the leaves begin to grow, they curl up and turn yellowish-red while they are still small. This then spreads to other limbs until the entire apple tree dies. Sometimes the disease seems to spread from tree to tree like a contagion, other times it manifests randomly across an orchard.

“Rows of trees collapse for what seems like no reason,” said Kari Peter, plant pathologist from Pennsylvania State University.

This isn’t the first time something like this has happened to apple trees. A similar unexplained phenomenon seemed to crop up back in the 1980s, but it pales in comparison to the latest epidemic, which began in 2013. Without being able to identify the underlying cause, scientists can’t be sure if the two outbreaks are related.

What’s causing this?

When it comes to plant pathology, there are the usual suspects: viruses, fungi, bacteria, parasites and insect infestations, etc. But so far, the problem doesn’t seem linked to any of these. Scientists have tried a wide range of chemicals to combat each of these potential suspects, to no avail. It’s possible that there is no pathogen, and the trees are withering due to a range of environmental stressors, but it’s unclear what those might be.

While the disease is widespread, some areas are being hit particularly hard. Up to 80 percent of orchards in North Carolina may show symptoms of the deadly illness, for instance. Apples are one of the continent’s most valuable fruit crops, worth some $4 billion last year in the United States alone, so the mystery illness threatens entire agricultural sectors.

Continue reading.