2022 Diagnostic Summary Report

The 2022 Diagnostic Summary Report is now available! This document is a summary of the samples received and services rendered by the University of Connecticut Plant Diagnostic Laboratory in 2022. Available data includes host, pathogen, and submission information. Confidential information of clients is withheld.

The report may be accessed for viewing and download here, or by navigating to the diagnostic reports tab above.

Warm regards for a prosperous 2023,

Dr. Nick Goltz

UConn PDL director

UConn PDL to Temporarily Suspend Service During Move

The UConn Plant Diagnostic Laboratory will be moving to a new location on campus (YNG 011) in December. To accommodate this move, we will suspend our services temporarily. The last day to submit physical samples for 2022 will be November 30. We anticipate reopening January 17th, 2023.

From all of us at the PDL and Home & Garden Education Center, we wish you and your loved ones peace and prosperity this holiday season.

– Dr. Nick Goltz, UConn PDL Director


Lab closed 8/15

The lab will be closed to visitors Monday, August 15 as our building finishes asbestos abatement. Please drop-off your sample later in the week or leave it in the cooler at the entrance of the hallway for us to collect. Thank you!

Welcome to the Team, Lou!

We are excited to announce the hiring of our new undergraduate Extension assistant: Chenghao “Lou” Lou.

Lou will help us produce elevated extension materials including videos and podcast episodes. Stay tuned for these resources!

Welcome to the team, Lou!

Hiring Undergraduate Laboratory & Extension Assistant

The UConn Plant Diagnostic Laboratory (PDL) is seeking applicants for part-time student assistants (2). One position will support the PDL with media preparation, sample receipt, client data entry, sample plating/incubation, and PDL email account management. The other assistant will support the PDL and UConn Home & Garden Education Center with occasional outreach events and extension publications, such as blog posts, newspaper articles, and fact sheets (reviewed and edited by supervisor prior to publication).

These positions will help prepare a student for work in more advanced laboratory settings, entry-level extension positions, and positions in the nursery and horticulture industry. Useful skills will be developed and extension-style publications are possible to enhance one’s CV/resume.

– Salary is $15.50 – $18.00/hr, depending on experience and qualifications (see below)
– Flexible schedule and number of hours (min 10 hrs/week; max 30hrs/week)
– Grant-funded through Aug.31st
o May be renewed on 8/31/22 depending on applicant interest and availability of grant funding
o If continuing beyond 8/31/22, positive performance may lead to raise in salary as well as opportunities to support research and attend/present at professional meetings (APS, ESA, NPDN, etc.)
– Work computer and other necessary equipment will be provided for the duration of employment

Required Qualifications:
• Basic knowledge of laboratory equipment and safety protocols
• Must have passed, with a grade of “B” or higher, Fundamentals of Plant Pathology
o Will consider any of the following as substitutions with justification from applicant: Herbaceous Ornamental Plants, Introduction to the Horticulture of Cannabis, Introduction to Plant Science, Nursery Production, Plant Pest Control, Plant Propagation, Small Fruit Production, Turfgrass Management, or Vegetable Production
• Proficient with Microsoft Office (Word, Excel, PowerPoint)
• Must be comfortable handling live plants, insects, soil, and fungi on a routine basis
• Must comply with current University masking and vaccination policy, as well as lab safety protocols

Preferred Qualifications:
• Good with technology, in the sense of being able to transfer video, photo, audio files etc. responsibly over OneDrive
• Proficient with video editing applications Adobe Premiere Pro and/or Final Cut Pro (ability to insert opening/closing titles, lower-thirds, Ken Burns effect scroll over photos and videos, background music, etc.)
• Experience with creating closed captioning, preferably in Adobe Premiere Pro
• Knowledge of how to use smartphone and standard cameras and advise on best settings to use

To Apply:

Email PDL Director, Dr. Goltz (nick.goltz@uconn.edu), with any questions and:
– a copy of your CV/resume
– brief statement describing qualifications and interest
– interview availability, and
– contact information for at least 1 professional reference (may be previous employer or instructor)

Interviews will occur on a first-come, first-serve basis until the position is filled. Thank you for your interest!

No Sample Processing April 25th-29th

The UConn Plant Diagnostic Lab will not be able to process samples between April 25th and April 29th. We encourage you to wait to submit samples until Monday, May 2nd. Any samples received between April 25th to April 29th will be logged into our system and kept in cold storage until Dr. Goltz’s return from the NPDN meeting. Anticipate a delayed response if submitting a sample during that window. Any questions regarding plant health or management should be directed to the UConn Home & Garden Education Center (ladybug@uconn.edu). The friendly and helpful staff at the center will support you.

1/4/22 – Lab Accepting Samples, Closed To Visitors

Following updated UConn COVID-19 guidelines, the UConn Plant Diagnostic Lab will be closed to visitors until, at earliest, February 1, 2022. We will be accepting samples as usual during this time, however. If you wish to submit a sample, please either leave the sample in one of the coolers at the wheelchair-accessible entrance of the Ratcliffe Hicks Building (by the Home & Garden Education Center sign), or mail the sample to us, following our sample submission guidelines.

We hope you and your loved ones stay safe, healthy, and warm!


Is your pachysandra suffering? Might be Volutella blight.

Volutella blight lesions on pachysandra

During these times of quarantine I’ve become very familiar with my neighborhood sidewalks, using them as new hiking trails. These neighborhood hikes have afforded me a new way to observe a city street landscape, and as a plant pathologist I’ve used this time not only as exercise but to also track common plant disease issues by just keeping my eyes open. You’d be surprised to know how many sick plants are out there to see!

While azaleas, rhododendrons, and Japanese maples are in most neighbors’ yards (and they sure are pretty right now!), I see pachysandra patches nearly everywhere. It is certainly a beloved plant, and very successful as a groundcover. Pachysandra prefers part to full shade and is typically quite low maintenance. The plant naturally grows into a dense carpet, and while this growth pattern usually doesn’t provide any reason for concern, if environmental conditions are right and a particular pathogen is present, disease in a pachysandra patch can spread fairly readily. And that’s exactly what I’ve been seeing this spring.

Volutella blight, caused by the fungus Volutella pachysandricola, is a common destructive disease to pachysandra. The disease presents as brown lesions on the leaves, often with a concentric circle pattern. The lesions expand in size until the whole leaf turns brown-black and dies. Lesions also occur on the stems, causing plants to wither and die back. Orange-pink masses of spores can be seen within lesions during wet and humid conditions. Plants die in patches, and disease spread usually appears in a circular pattern in a bed.

Salmon-orange sporulation of the fungus, emitted under humid conditions

The classic dense planting culture of pachysandra increases the humidity in the bed, providing ideal conditions for Volutella blight to develop and spread. Further, because the pathogen thrives in cool, wet weather, all the rain we’ve had this spring in the Northeast has contributed to disease development as well. Because pachysandra plantings are usually so low maintenance, they can be easy to forget about. As such, stressed plants are more susceptible to Volutella blight. Stress from drought, winter injury, pruning injury, or insect infestations can also contribute to the spread of the disease.

To manage Volutella blight, only work in plants when they are dry, because the fungus moves through water splash. Remove infected plants and destroy them; do not compost as home composting systems typically do not reach high enough temperatures to kill spores. Thin the planting to increase airflow, which also will encourage plants to dry out more quickly. When thinning, sanitize tools with a 10% bleach or 70% rubbing alcohol solution to not accidentally infect new plants. There are fungicide options to help manage Volutella blight, but will only be useful if these other measures are taken. They will not cure infected plants.

So, head outside today and check on your pachysandra patch. Might be time to give it a little love!

Allium leafminer in Connecticut

The allium leaf miner (Phytomyza gymnostoma) was first reported in the northeast in 2015, but was not found in Connecticut until January 2020. Learn more about this pest and how to prepare for it this season.

The allium leafminer is an Agromizyid, or leafmining fly, native to Poland and Germany. While leek and onion may be the most heavily damaged crops, many crops in the Allium genus are susceptible, including shallot, chives, garlic, and green onion. Some species of wild onion and ornamental alliums may be hosts as well, but the full host range is currently unknown.

Adults (Fig 1a-c) lay eggs in the top of leek leaves between late March and May, by making repeated punctures with their ovipositor in the distal end of leaves (Fig. 2). These holes are the first signs of an infestation. The larva mine the leaves, creating tunnels of damage as they eat tissue (Fig 3). Larva will move down to bulb and leaf sheaths, where they pupate either in the plant or drop into the soil. The tunnels the larva create and leaf puncture holes provide good entry point for secondary fungal and bacterial infections, which can cause further damage to the crop. The second generation will emerge in September to October, laying eggs in the leaves again, and the pupa will overwinter.

Avoidance of the adult flies is one of the best prevention strategies. Covering all alliums prior to the emergence of adults (late March-May), may help exclude the pest. Alternatively, delaying planting until after the adults have emerged and their oviposition period is over, around mid-May, may be an effective strategy. If an infestation occurs, rotate out of leeks and other alliums in that area. Utilize yellow sticky cards and/or yellow bowls containing soapy water in infested fields. Contact PlantDiagnosticLab@UConn.edu to send a sample for identification.

There are insecticides that may be effective for allium leaf miner control, including both organic and conventional options. Always check the pesticide label to confirm the crop is listed, the rates, and the days to harvest intervals. This information can be found in the references section below.


  1. Fleischer, S. and Elkner, T. 2016. Pest alert: Allium leaf miner. Penn State University Extension. https://ento.psu.edu/extension/vegetables/pest-alert-allium-leafminer
  2. Gilrein, D. 2016. Insecticides for leafminers in onions and related crops that may be effective against allium leafminer (Phytomyza gymnostoma). Cornell Cooperative Extension of Suffolk County. https://www.agriculture.pa.gov/Plants_Land_Water/PlantIndustry/Documents/Insecticides%20for%20leafminers%20in%20onions%20and%20related%20crops.pdf
  3. Hutchinson, M. Allium leaf miner. Pennsylvania Department of Agriculture. https://www.agriculture.pa.gov/Plants_Land_Water/PlantIndustry/Entomology/Pages/ALLIUM-LEAFMINER.aspx

Author’s Note

This article appeared in the April 2020 edition of Crop Talk, UConn Extension and Plant Science & Landscape Architecture's Quarterly Newsletter for commercial fruit and vegetable growers. You can find the rest of the publication here: http://ipm.uconn.edu/documents/view.php?id=1663.  To sign up to receive the digital newsletter, contact: mackenzie.white@uconn.edu.