Bacterial Spot in Almonds

Sabrina General, Specialty Crops, Tree, nut & vine crops

There’s a new problem causing damage to almonds in the San Joaquin Valley this year, and almond growers have the opportunity to learn more about it at a field day this week. Sabrina Hill reports.
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Bacterial spot is often found in Australia, where is has caused so much damage to two almond varieties that growers have stopped using them. It was recently discovered in an orchard in California and is causing concern for growers here.

Signs of bacterial spot start out as large balls of amber-colored sap on the hulls, which then turn into depressed lesions. Later, the damaged almonds shrivel and fall from the tree.

Bacterial spot can be misdiagnoses as leaffooted bug feeding injury, but an important difference is the color of the “gum” or “sap” on the hulls. In leaffooted bug damage, it is clear. With bacterial spot, it is amber-colored.

The University of California Cooperative Extension is having an almond field day this week, that will focus on bacterial spot.

Growers will learn more ways to differentiate between bacterial spot and leaffooted bug damage, how the bacterial spot pathogen is isolated and identified, and management strategies.

The bacterial spot on almonds field day is scheduled for this Friday, July 12, from 9:00 a.m. 11:00 a.m. at Travaille and Phippen, Inc. located at 12700 East Graves Road in Manteca.

For more information on bacterial spot, visit the Almond Doctor website.