European Union officials reportedly ordered trees and plants killed near the site of an almond grove that tested positive for an invasive bacteria.
Newsweek reports that the discovery of Xylella fastidiosa was the first on the Spanish mainland.
The pathogen, which is native to the Americas, can dry out tree leaves by preventing the flow of water and nutrients. It has no known cure and is often deadly.
The bacteria was discovered in Europe for the first time in 2013 in Italy, where officials subsequently criticized the response of Italian authorities. It spread to the island of Corsica by 2015 and last year was discovered on the Spanish island of Mallorca.
This year, officials in eastern Spain tested a group of almond trees after their production appeared to slow down; 12 of the 17 trees tested positive for X. fastidiosa.
Although no olive trees appeared to be affected, officials worry that the spread of the bacteria could wreak havoc on one of Spain's most important crops. The country is home to some 340 million olive trees and accounts for about half the world's supply of olive oil.
Newsweek also noted that a subtype of the bacteria can kill grapevines — another key Spanish crop — and was also recently discovered in Mallorca.