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2021-2022 Pear IPM Study Circles

green anjou pear with droplets of water on the side

Join us for pear study circles this winter – they’re free!  It’s a great learning opportunity for growers, consultants, researchers, and industry professionals.  Our goal is to improve pear profitability and sustainability. Each study circle will include a 30 minute presentation and 2 hours of facilitated discussion.

Topics include:

  • Oct 19, 2021 – Choosing products that work: A discussion of pesticide efficacy
    2019-2021 research results from Louis Nottingham, WSU Entomology. Grower experience from the field.
  • Nov 23, 2021 – Honeydew Washing Systems – Adding a Cultural Control to your Toolbox
    2020 research results from Tianna DuPont, WSU Extension. Grower presented case studies.
  • Dec 14, 2021 – Using pear psylla phenology to better time applications
    Outline of the new psylla phenology model from Louis Nottingham, WSU Entomology. Examples of scouting information showing when the model has worked and when it has not. Brief intro to potential scouting app. Discussion of getting weather stations to improve accuracy. Discussion of how growers/consultants want to best access data.
  • Jan 11, 2022 – Assembling IPM programs that work
    Discussion of IPM and bio-based IPM programs step by step through the season and new research on natural enemy impacts of current products, Louis Nottingham, WSU Entomology.
  • Feb 8, 2022 – How can we integrate thresholds and scouting?
    Current research on thresholds for psylla and natural enemies. Input on phone application/website for data access.

Download a flyer here, or visit the WSU Tree Fruit web site events page for more information.  Hope to see you there!

Plant Defense Elicitors

November 18, 2021

Test of plant defense elicitors for arthropod pest suppression and PR-1 gene induction in pear orchards

Plant defense elicitors (PDEs) are chemicals that stimulate plant defenses against pathogens and herbivores. Previous work shows that PDEs acibenzolar-S-methyl (ASM) and harpinab protein (harpin) can induce the pathogenesis-related gene PR-1 in plants and suppress herbivorous arthropods. In this study, we tested the potential for these PDEs to induce PR-1 in pear, Pyrus communis L. (Rosaceae) orchards and suppress pear psylla, Cacopsylla pyricola (F€orster) (Hemiptera: Psyllidae), and spider mites, Tetranychus spp. (Acari: Tetranychidae). In 2017, we compared densities of each pest on mature pear trees following a single application of either an ASM product (Actigard; Syngenta), a harpin product (Employ; Plant Health Care), or no PDE treatment in four commercial and two research center orchards. In 2018, we sampled pear psylla and used qPCR to assess PR-1 induction in pear leaf samples before and after PDE treatments at one commercial orchard. Neither PDE treatment showed evidence of pest suppression in either year, and no differences in PR-1 expression were detected. Potted greenhouse trees treated with ASM in 2019 showed higher PR-1 expression relative to untreated trees, verifying that our procedures can detect induction and suggesting that a single PDE application was sufficient to induce PR-1 in potted but not mature pear trees. We conclude that plant defense elicitors may contribute to pear pest suppression in some contexts, but effects are unlikely to be strong or consistent. Our results highlight the need for field experiments to advance plant defense elicitor knowledge towards effective field applications.

Reflective Mulch Field Trials at Parker Pears

green circle with a light green pear tree graphic and the words parker pears

March 23, 2021

Sam Parker, pear grower and social media extraordinaire, shares his experience being a cooperator on the Nottingham lab reflective mulch trials currently taking place in his organic pear orchard.

Clicking the pic will take you to the video on Sam’s Instagram account.  You don’t need an Instagram account to watch it, but you should probably have one so you can follow Sam.

winter pear orchard with leafless trees. white reflective mulch is seen between the rows of trees and a mane is in the foreground talking to the camera


Sustainable Control of Pear Psylla

mostly white slide with drawing of tree fruits in the lower left corner, a small video feed of the speaker in the upper right corner and the title be brave pear psylla management

February 22, 2021

Be BRAVE: Pear Psylla Management

On Thursday, February 18, 2021 as part of an OSU/WSU webinar, Stijn van Laer gave a talk on pear psylla management in northern European pear orchards.  Stijn is a crop consultant that works for company called FruitConsult based in Belgium.  They are a private consulting firm that does not sell products (i.e., chemicals), just management recommendations. Stijn discussed management of pear psylla in European orchards with conservation biological control (i.e., only using soft insecticides and at economic thresholds) and by augmentation of earwigs.  He also discussed the importance of proper sprayer calibration and how this can make or break effective management.

Prebloom Management of Pear Psylla with Particle Film

February 8, 2021

Psylla will soon be on the move!

Louis Nottingham and Robert Orpet wrote an article in the February 2021 edition of ‘Tree Fruit News’ reminding growers to start preparing dormant sprays of kaolin clay (Surround) to deter pear psylla colonization in the orchard. A dormant Surround spray will provide the first line of defense to keep psylla from entering your orchard. The optimal time to make this first Surround application depends on weather, but here is a good rule of thumb: if it is warm and dry enough for you to safely spray, go for it – psylla are probably colonizing your orchard!

Click the pic to learn more.

closeup of two pear buds in the orchard
Picture taken on 3/24/20 of a pear bud just before burst, sprayed at dormant (3/16/20) with Surround CF at 50 pounds/acre. This bud remains protected against oviposition until fresh green tissue ‘bursts’ from within the hard exterior scales.


Reflective mulch for pear psylla

two people working in a pear orchard with reflective mulch

November 19, 2020

New Publication!

Pear psylla, Cacopsylla pyricola (Förster), has remained the most challenging pest of commercial pears in Washington and Oregon, the top producers of pears in the United States. The lack of effective integrated pest management tactics for this pest has been a major barrier to effective management. In this study, we examined the potential for reflective plastic mulch affixed beneath pear trees to suppress pear psylla. In 2017 and 2018, single pear tree (cv. Bartlett) plots of reflective plastic mulch, black plastic mulch, and no mulch (check) were established in a research orchard to compare their effects on pear psylla.

Nottingham, L. B. and E. H. Beers 2020. Management of pear psylla (Hemiptera: Psyllidae), using reflective plastic mulch. J. Econ. Entomol. 113:2840-2849.

screenshot of publication in the journal of economic entomology