Subtropical Fruit Crops Research & Education
University of California
Subtropical Fruit Crops Research & Education

Posts Tagged: tylenchulus

Nemas and What YOU Need to Know

Plant-parasitic nematodes are microscopic, unsegmented roundworms that live in soil and plant tissues and feed on plant roots. The predominant species parasitic on citrus in California is the citrus nematode. This nematode is reported to be present in most citrus orchards and in all soil types. It also parasitizes grape, lilac, olive, and persimmon. Citrus nematode attacks roots by burrowing its anterior end deep inside the root cortex while the posterior end remains outside in the soil.

The sheath nematode is less widespread than the citrus nematode; it has been found on citrus in the Coachella Valley and on some native desert plants. However, it has a broad host range and thrives well at high temperatures and at low moisture levels

 From UC IPM Pest Management Guideline:

Citrus nematodes, Tylenchulus semipenetrans, parasitizing a citrus root. The second-stage larvae initially feed on root hairs. The larvae then penetrate into the feeder roots, molt three times, and establish a permanent feeding site (nurse cells) inside the root cortex. The swollen rear end of the mature female remains outside the root

Find out more about these underground animals from UC AG Expert, Ole Becker.


Management of plant-parasitic nematodes in citrus orchards - Thursday, February 21, 2019, from 3-4 pm

Dr. Ole Becker, cooperative extension specialist & nematologist at UC Riverside, will discuss plant-parasitic nematodes in citrus, their biology, symptoms, and management, including soil & root sampling, interpretation of analysis results, and rootstock selection. One DPR CE hour (other) and one CCA CE hour (IPM) were approved.


And there's more to hear, coming up:

Laurel wilt - Wednesday, March 20, 2019, from 3-4 pm

Dr. Monique J. Rivera will present current knowledge of the laurel wilt, its biology, and spreading. More information to come.

Management of Glyphosate-Resistant Weeds in Orchard Crops - Wednesday, April 24, 2019, from 3-4pm

Dr. Brad Hanson, cooperative extension specialist, will discuss what is herbicide resistance, current state of resistant weeds in CA permanent crops, identification and lifecycle of key glyphosate-resistant weeds, selection pressure for resistant biotypes and species, herbicide modes of action, and examples of herbicide programs for orchard crops. One DPR CE hour (other) and one CCA CE hour (IPM) are pending.

To register for any of the above webinars, please visit and click on the relevant link on the top of the page.

Recordings of the past webinars are available on UC IPM YouTube channel at

CE hours are NOT available for recorded webinars.


Please note that webinars are targeted to growers and pest control professionals (PCA, QAL, CCA). Master Gardeners may benefit from participation, however, presented pest management methods, especially chemical control, may not be relevant for them.



Check those roots to see if they are healthy


citrus nema damage
citrus nema damage

Posted on Wednesday, February 6, 2019 at 7:59 AM
Tags: citrus (310), nematode (1), tylenchulus (1)
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