Research and Extension Center System
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Research and Extension Center System

Posts Tagged: pistachio

Kearney hosted a workshop on leaffooted bug monitoring, damage to tree nut crops, and management strategies.

On May 10, 2016, Kearney researchers, Kris Tollerup, UC ANR cooperative extension advisor at Kearney Agricultural Research and Extension Center, specializing in Integrated Pest Management (IPM) for almond, pistachio, tree fruit and grape crops; and Themis Michailides, UC ANR plant pathologist and lecturer in Plant Pathology at UC Davis and Kearney Agricultural Research & Extension Center, conducted a workshop to help attendees learn more about leaffooted bug monitoring, damage, management, and its involvement in spreading Bot of pistachio and other diseases on pistachio and almond.

Tollerup discussed the different Hemipteran pests (leaffooted bugs and stink bugs). A PowerPoint handout was provided. The handout covered what the bugs look like; the stages of the bugs' growth; diagnostics for identification; the host crops; overwintering, what the damage to almonds and pistachios looks like; when the damage occurs; what we know, and what we need to know.

In the field, Michailides showed how the insect damage can lead to an increased incidence of pathogenic infections. Field research by Michailides and Dave Morgan has shown that there is an “association of Botryosphaeria panicle and shoot blight of pistachio with injuries of fruit caused by Hemiptera insects and birds.”

Michailides concluded that the disease in almonds caused by insect damage “is a new disease of almond and it is very similar to the stigmatomycosis reported on pistachio.” Early insect damage can result in the nuts dropping from the tree and later damage can render part of the crop unmarketable due to decay and black spots on the kernels.

The photograph shows: Infection of pistachio fruit by Neofusicoccum mediterraneum (initially identified as Botryosphaeria dothidea, thus the name Bot of pistachio disease) initiated from insect-punctured fruit and spread into the main rachis of the cluster [A and B; note a leaffooted bug (Leptoglossus clypealis) on the rachis of pistachio cluster in B]; C, fruit infected by the pathogen and covered with pycnidia surrounding the sap exuded from the insect's injury; D, fruit infections initiated from injuries caused by birds and spread into the main rachis of clusters.

Infection of pistachio fruit by Neofusicoccum mediterraneum (initially identified as Botryosphaeria dothidea, thus the name Bot of pistachio disease) initiated from insect and bird damage.
Posted on Thursday, May 12, 2016 at 10:01 AM

Implications of foliar phosphite applications on pistachio rootstock

Pistachio leaf morphology

California nut growers have benefited from the use of phosphite products, marketed and sold both as fertilizers and EPA-labeled fungicides.  These products offer plant protection from root and crown diseases caused by a group of pathogens known as...

Posted on Monday, May 4, 2015 at 7:14 AM

Meeting at Kearney helps stakeholders understand and detect Pistachio Bushy Top Syndrome.

Jennifer Randall, Research Associate Professor in the Department of Entomology, Plant Pathology and Weed Science at New Mexico State University provided a presentation on “Pistachio Bushy Top Syndrome: Disease etiology and diagnosis procedures" on April 7, 2015 at Kearney Agricultural Research and Extension Center (KARE).

The presentation was followed by a Q&A session conducted by Randall; Florent Trouillas, Assistant Cooperative Extension Specialist at KARE and in the Department of Plant Pathology at UC Davis specializing in fruit and nut crops; Craig Kallsen, UC Cooperative Extension advisor in Kern County, specializing in citrus, subtropical horticulture and pistachios; Robert Beede, UC Cooperative Extension advisor, emeritus, in Kings County, specializing in horticulture: tree fruit, nuts and grapes; and Elizabeth Fichtner, UC Cooperative Extension advisor in Tulare County, specializing in orchard systems.

Background: In the last few years, a new disease affecting UCB1 rootstocks emerged in CA, AZ, and NM. This disease was named Pistachio Bushy Top Syndrome (PBTS). Scientific evidence in 2014 demonstrated that PBTS is caused by the bacterium, Rhodococcus fascians (Rf). The percentage of rootstock exhibiting symptoms varies widely among plantings. At least 20,000 acres in CA have been affected to some extent. Two strains of Rf have been identified. Each is pathogenic, and they act synergistically to cause more severe disease symptoms. Pistachio growers in CA need to test for the pathogen in their newly planted orchards. This workshop attempted to bring academic, private and governmental diagnosis labs up to date on this new disease. Dr. Jennifer Randall from NMSU presented her group's latest research on the disease biology and detection methodologies.

Posted on Tuesday, April 7, 2015 at 4:54 PM
Tags: pistachio (4), plant pathology (2), rootstock (1)

UC President Janet Napolitano and the President's Advisory Commission tour Kearney in April 2014.

UC President Janet Napolitano and the President's Advisory Commission visited KARE on April 14, 2014. The stated purpose of the visit was to meet with the PAC to discuss issues facing agriculture and to visit KARE and learn more about what we do and the importance of our research and outreach. The President learned about the work we are doing to control mosquitos (Anton Cornel), our work to support small farmers and the blueberry industry (Manuel Jimenez), the use of AF36 to control aflatoxin in pistachios (Themis Michailides), and the importance of rootstocks (Louise Ferguson). The President and her PAC were engaged and enthusiastic about their visit to the Center. We also shared information on what we are doing to conserve energy and provided a general field tour. The Fresno Bee wrote an article on the visit.

Posted on Tuesday, April 22, 2014 at 1:36 PM
  • Author: Jeffery Dahlberg
Tags: blueberry (1), mosquito (1), pistachio (4), rootsock (1)
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