Entomologist Walt Bentley found some spider mites on leaves at the base of an almond tree.
Dozens of almond growers, pest control advisers and others gathered in a Fresno almond orchard for an up-close look at insect pests and to hear about ways to manage a California crop that is worth more than $3 billion and is forecast to hit more than 2 billion pounds and approach near record levels this year.
What they learned at that field day could help them achieve what was being forecast on the same day in Modesto, a federal estimate of 2.07 billion pounds for this year’s California almond crop, which would be about 300,000 pounds shy of the previous record in 2011.
Some growers brought samples of insect pests or the damage they caused as field day participants gathered for the event sponsored by the San Joaquin Sustainable Farming Project. It was hosted by Gina Rushing, a principal in LPGL Ranch.
Entomologist Walt Bentley opened the meeting with tips on finding spider mites and pinpointing the presence of pests that included the leaf footed plant bug, navel orange worm and stink bugs.
David Doll, who has been nicknamed the “almond doctor” and who is a Merced County University of California pomology farm advisor, closed the meeting with a discussion of hull rot and nutrient management.
Inside the orchard, participants saw eggs from a leaf footed plant bug, thanks to the sharp vision of Lacey Mount, an agronomist with Dellavalle Laboratory Inc. in Fresno.
And they saw Bentley, a retired UC Statewide Integrated Pest Management entomologist, worm his way into the branches of an almond tree and find evidence of some spider mites.
Bentley showed how to distinguish damage of almonds from weather conditions — spiking cold and warm temperatures — from insect damage caused by the leaf footed plant bug or stink bug. In both cases, there was some gumming on the nut.
But, he said, “The key is to walk the orchard, cut into the nut and see if there is a darkened, discolored area.” That, he said, is an indicator that the pests have injected saliva.
Almond varieties with softer shells such as Fritz, Sonora, Aldrich, Livingston, Monterey, and Peerless are more susceptible to leaf footed bug damage for a longer period during the season.
Butte and Padre trees comprise the orchard in Fresno. They, along with the Monterey, are hard-shelled varieties that mature late, making them particularly susceptible to damage from the navel orangeworm because they are all harvested during or after the third flight of that pest, Bentley said.
“With Nonpareil nuts, they are down and off before that third generation comes on,” Bentley said.