UC Nursery and Floriculture Alliance
University of California
UC Nursery and Floriculture Alliance

CDFA nursery advisory board report Spring 2016

By Loren Oki


by Loren Oki

The CDFA Nursery Advisory Board (NAB) met in Sacramento on March 10, 2016. The agenda, as usual was packed, but here are some highlights:

There was a discussion of nursery inspections and the action that is taken when there is a detection of a regulated invasive organism. California is unique in that there is a county-based agricultural regulatory system, which other states do not have. The county commissioner’s office conducts annual and other nursery inspections and may detect regulated pests. When there is a find during a county inspection, the relationship with CDFA is activated and the regulatory process is initiated. Unfortunately, most transport of illegal plant materials is by those that know better and are trying to avoid issues with declarations at point of entries associated with overseas travel.

The NAB meeting includes reports from representatives from different programs within CDFA. Following are summaries from a few of those reports:

New Pests – Jason Leathers, Primary Entomologist, CDFA

  • Scirtothrips dorsalis, chilli thrips, is a B-rated pest, native to Southeast Asia and Australia. Polyphagous, it feeds on more than 200 plant species, causing leaf curling and vectoring viruses.
  • Zaprionus indianus, striped vinegar fly, is a B-rated pest, native to Africa, the Middle East and southern Eurasia. It was discovered by a resident in Downey (Los Angeles County) last July and there have been unconfirmed reports at LAX and in San Diego. It has been in Florida since 2005 and is abundant in eastern U.S. vineyards. It feeds on undamaged figs, but is mostly a generalist on undamaged fruit. Since California is the primary fig producer in the United States, growing 96% of the nation’s product, there is concern that if the pest were to establish it potentially could reduce fig yields by 40 to 80%.
  • Macrohomotoma gladiata, curtain fig psyllid, is native to Taiwan, China and Japan. It was first found in an Orange County nursery last August and has since established in several residential and commercial landscapes in Anaheim. It has two main hosts, Ficus microcarpa and F. retusa. This insect produces copious wooly secretions and has overlapping generations.

Noxious weeds – Dean Keltch, Primary Botanist, CDFA

  • Sesbania punica (S. tripetii), red sesbania, is native to South America. It was introduced in California through horticulture and has become a noxious wetland weed.
  • Arctotheca calendula, capeweed, is an annual with dark purple disc flowers that distinguish it from A. prostrata, a related species that is often confused with A. calendula. This noxious weed is currently in Marin, Humboldt, San Mateo, Merced and Stanislaus counties.
  • Butomous umbellatus, flowering rush, is a cold-tolerant noxious weed that is highly invasive in cool climates in wetland edges.
  • Calicotome spinosa, spiny broom, is native to the Western Mediterranean region and has been newly discovered in an area north of Pasadena. It looks similar to other brooms, but is very thorny. It is likely fire promoting.

Marijuana cultivation

Amber Morris is the Branch Chief of the Medical Cannabis Cultivation Program and is working on establishing license and certification programs. Among the issues related to this crop, there is concern of the potential environmental impacts of its cultivation. Substantial coordination will be needed with the California Department of Pesticide Regulation (DPR), California Department of Fish and Wildlife (CDWF), State Water Resources Control Board (SWRCB) and other agencies.

The next NAB meeting will occur in August or September.

Coverage of the CDFA NAB is now a regular feature of the UCNFA Newsletter.

Loren Oki is UC Cooperative Extension Landscape Horticulture Specialist, Department of Plant Sciences, UC Davis.

Webmaster Email: jtillman@ucdavis.edu