The Almond Board’s 14th annual Environmental Stewardship Tour in May showcased the lifecycle of an almond orchard — from the importance of state-of-the-art breeding techniques all the way to the care of a mature orchard. Duarte Nursey in Hughson hosted the tour, which was attended by more than 50 attendees from local, state and federal regulatory agencies, along with media, elected officials and various almond industry members.
Gabriele Ludwig, the Almond Board’s Director of Sustainability and Environmental Affairs, John Duarte of Duarte Nursery and Almond Board’s President & CEO Richard Waycott explain the lifecycle of an almond orchard at the 14th annual Environmental Stewardship Tour.
Almond Board Environmental Committee Chair Rob Kiss greeted the attendees and noted this was the first time the annual tour had featured a nursery. “Our goal is to show the lifecycle of an orchard in order to give you, as regulators, a better understanding of all of the factors that go into producing almonds.” The rootstock selected, the almond variety chosen by the grower, the irrigation system, soil pest management and insect management are all important factors in managing the production of almonds, explained Kiss.
Host John Duarte and Duarte Nursery’s Director of Research Dr. Javier Castillon led a tour through Dry Creek Labs, noting the clean rooms offer the perfect environment for clonally propagating rootstock from tissue culture. “With clonal rootstocks you will see increased uniformity, higher disease resistance, larger more vigorous trees and increased yields,” said Castillon.
By using the USDA-run Plant Material Center, Duarte nursery tries to start off with virus-free trees, which improves the long-term health of the orchard, noted Duarte.
To highlight how genetics can play a role in managing soil borne diseases, the tour next visited orchards managed by Scott Long from Pacific Coat Producers. These soils contain Armillaria (oak root fungus) which is a devastating disease that persists in the soil for many years and for which there is no cure, though soil fumigation may help. The tour visited a rootstock trial to assess whether any have resistance to Armillaria. UCCE farm advisor David Doll said the trial was monitoring root infection and tree mortality and noted it took seven years before symptoms of Armillaria showed up. Doll also highlighted the partnership in research between growers, UC extension and grower organizations, such as the Almond Board of California, to conduct research on how to better grow almonds.
Ron Nydam of Waterford Irrigation Company discussed the preparation for a new almond orchard going in next to Duarte’s home and the importance of irrigation design and installation based on the soil type, availability of water (frequency and how delivered), frost risks and other factors. While a drip system may be more water-use efficient, for many soils, microsprinklers are a better choice for water penetration.
To ensure optimal irrigation, soil moisture monitors gauge the amount of water needed to accelerate growth. This method keeps the trees hydrated and reduces stress. “The younger trees don’t take nearly the amount of water that a mature orchard needs," pointed out Nydam.
Gabriele Ludwig, the Almond Board’s Director, Sustainability and Environmental Affairs, told guests the Board has been funding almond breeding program research for over 40 years. “The varieties and rootstocks relied upon by almond growers are largely influenced by long-term breeding research by University of California, USDA’s Agricultural Research Service,” she said, “and then the efforts by UC Cooperative Extension to monitor how the rootstocks and varieties do in the real world of the orchard. Traits of the rootstocks and the varieties can help deal with some important environmental issues.” Unfortunately, as UC Davis almond breeder Dr. Tom Gradziel, noted, it takes at least 10 years of testing in the field before a variety may be deemed acceptable for use by growers.
