ABOVE: ©iSTOCK, GOMEZDAVID
Standing in the orchard, Jennifer Randall could see something was seriously wrong. A plant pathologist and molecular biologist at New Mexico State University, Randall had traveled in late 2013 to Arizona to take a look at some of the state’s pistachio tree nurseries at the request of growers in the region. “I wanted them to send samples to me to test,” Randall tells The Scientist. “They said, ‘No, no, you really need to come see these trees.’”
When she arrived, “trees were actually falling down in the wind,” says Randall. “In Arizona, we have really high winds, but we’re talking three-year-old trees. That is unusual, for them to be falling down. Their root system just had not taken hold.” The trees were stunted, with peculiarly bushy tops and swollen tissue, or galls, on the stems. Growers explained that the rootstocks weren’t accepting scions—tree shoots grafted onto the ...
