Graduate studies in plant pathology with a focus on almond diseases

Just about everyone says almonds are good for human health, but what’s good for the health of almonds?

UC Davis graduate student Leslie Holland wants to know. In pursuit of her Ph.D. in plant pathology, Holland studies canker diseases in almond. Canker diseases invade the woody tissue of the almond tree, typically the result of a fungus entering through a pruning wound.

“California is crop central, and almonds are one of the biggest and most economically important crops in the state,” said Holland, who came to UC Davis in 2015. “California grows more than 80 percent of the global supply of almonds.”

Summer internship led to interest in plant pathology

Holland studied general biology as an undergraduate at New Mexico State University and became interested in plant pathology during a summer agricultural internship. After helping plant a vineyard, she learned the vines had to be pulled out when it was discovered the new plants were diseased. She wondered, “How can I help prevent that kind of problem?”

Holland completed a master’s degree in plant pathology at Washington State University and then came to UC Davis to do doctoral research on almond diseases. She studies with Cooperative Extension specialist Florent Trouillas, a stone fruit and nut expert stationed at the Kearney Agricultural Research and Extension Center in the heart of almond country — California’s Central Valley. Over the summer, Holland will help Trouillas answer calls from growers and farm advisors who seek advice on sick trees.

Cue the cavalry

In the field, the plant pathologist toolkit includes an array of shears, pruning saws, hatchets, and machetes. “We’re like the cavalry arriving to collect samples, which we bring back to the lab for analysis,” said Holland. “I like working with growers and trying to provide answers.”

Holland has learned that it takes a holistic approach to keep almonds healthy. “We stress the integrated approach to orchard management, looking at planting, pruning, water, fertilizer, and pest management,” she said. “There is no silver bullet.”