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: http://ipm.ucanr.edu/PMG/r107200111.html

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.

Register: https://ucanr.edu/sites/ucexpertstalk/

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 https://ucanr.edu/sites/ucexpertstalk/ 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 https://www.youtube.com/playlist?list=PLo3rG4iqv4gHBV3YA6w4wkBufwh7GBjrX

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

"Trees should be firmly staked at planting"

        MYTH!!!!!!!!!!!!!!! Read on:

Chalker-Scott, L. , Extension Specialist And Associate Professor, Washington State University
Downer, A.J., Farm Advisor, University of California

Nursery-grown shade trees are often rigidly staked to prevent blowdown and damage during cultivation. In some cases, trees are pruned to a long, untapered standard with a bushy top that requires a tight stake to hold it up. Nurseries often remove side branches from the young trunk and while this creates the illusion of a small tree, the practice actually inhibits the development of taper in the trunk (Harris, 1984; Neel and Harris, 1971). Trees without taper will not stand without staking. Poor culture of ornamental trees in nurseries necessitates staking once trees are planted into landscapes because they do not have the structural development in their trunks to stand on their own. Due to these cultivation errors, landscape installers frequently keep the nursery stake and add more stakes to firmly secure the tree in place and further prevent its movement in the landscape.

Staking takes three basic forms: rigid staking, guying, and anchoring. All methods of staking reduce development of taper, increase height growth, and decrease caliper of the developing tree relative to unstaked trees (Figure 7). Moreover, improper staking can result in increased tree breakage either during the staking period or after staking is removed (Figure 8a-b) (Thacker et al., 2018).

Decades ago, researchers discovered that movement of the trunk and branches is necessary for the development of trunk taper (Neel and Harris, 1971). Trees grown in a growth chamber without movement did not develop taper and instead grew taller, while trees in an identical chamber that were hand shaken each day developed significant taper and remained shorter.

Until trees are established in landscapes they may require some staking. In areas of high wind, guying (which involves cables staked to the ground) gives the greatest protection against main stem breakage or blowover (Alvey et al., 2009). Whatever system is used, any such hardware should be removed as soon as the tree can stand on its own:

• The traditional two stakes and ties system is the least harmful to trees staked in landscapes.
• Staking should be low and loose to allow trunk taper to develop naturally.
• Remove all staking material as soon as possible.

If a tree is not established after a year of staking, it is unlikely to ever establish

Read on:

https://www.nacaa.com/journal/index.php?jid=885&fbclid=IwAR3fS2iKo8ibifQEDPUrG6UlcB8n-yUgOe6xx1y56MeAcLhP6ZoUkQbUQNg

News from the Ventura County ACP-HLB Task Force

Winter 2019 area-wide treatment cycle has begun

This is a reminder that the Winter 2019 area-wide management (AWM) treatment window opened Jan.7. You are encouraged to file pesticide use reports (PURs) electronically through CalAgPermits, Agrian, or another system that allows treatments reports to be rapidly filed and recognized. Treatment reminders will be emailed (mailed for those without an email record) about 2-3 weeks prior to the treatment window. In some instances, our contact list may only have contact information for your farm manager, pest control advisor, or pest control operators. If you are not receiving emails, please contact one of your grower liaisons (see contact information below) to receive information about ACP, HLB and your citrus.

Website redesigned

The Citrus Pest & Disease Program (CPDPP) launched a redesign of its website to provide members of California's citrus industry easier access to the key maps, regulatory updates and events they need to stay informed on the fight against HLB in California. The website is at www.citrusinsider.org.

HLB confirmations continue to increase

At least 1,024 residential trees had been confirmed as infected with HLB as of January 2019. No HLB-positive trees have been found in commercial groves. The HLB quarantine boundaries and the latest tally of HLB confirmations, updated weekly, is available online at https://citrusinsider.org/maps-and-quarantines/.

Report neglected and abandoned citrus

Help prevent neglected and abandoned citrus from serving as a breeding ground for ACP and the spread of HLB by reporting its location County Agricultural Commissioner's office at (805) 388-4222. If your citrus is not worth the resources required to protect it from ACP and HLB, it may be a good time to consider removing the trees. Tree-removal assistance is offered to small growers through the California Citrus Mutual and Bayer's ACT NOW program. For more information contact Joel Reyes at  jreyes@cacitrusmutual.com or (559) 592-3790.

Calendar

UCR Citrus Day (Jan. 29)

This year's UC Riverside Citrus Day will be on Tuesday, Jan. 29. Agenda and registration information can be found by clicking here.

International Research Conference on HLB/Citrus Virologist Conference (March 10-15)

The joint International HLB and Citrus Virologist conference will be at the Riverside Convention Center in Riverside, CA. Registration and more information can be found here.

Citrus Pest and Disease Prevention Committee meeting (March 12)

The CPDPC is charged with advising the state on management of the Citrus Pest and Disease Prevention Program. The CPDPC and subcommittee meetings are open to the public, and options for participation include in person or by webinar and conference call. Click here to view and register for upcoming committee and subcommittee meetings. Attendance is free. 

esources

University of California ACP area-wide materials list and ACP monitoring protocols

Movement of bulk citrus materials list

Ventura County AWM maps and schedule

Citrus Pest and Disease Prevention Program

Ventura County ACP-HLB Task Force mailing list signup

Contact your grower liaisons if you have additional questions: 

Sandra Zwaal

szwaal2@gmail.com

(949) 636-7089

Cressida Silvers

cressidasb@gmail.com

(805) 284-3310