ISSUE 1   May 15, 2008

UPDATE FROM THE NDSU PLANT DIAGNOSTIC LAB

Another season has begun at the NDSU Plant Diagnostic Lab. Familiar faces include Kasia Kinzer (plant diagnostician), Montgomary ‘Monty’ Botschner (lab technician), and Aimee Thapa (summer office assistant).

From January 1 to May 13, 2008, the NDSU Plant Diagnostic Lab has received 483 samples. The table below summarizes the types of samples processed during this period:

Sample Category

Number

Seed Health/Phytosanitary

379

Other

50

Woody ornamental (evergreen)

18

Field Crop

13

Soil - Aphanomyces bioassay

6

Vegetable

3

Mold ID

3

Annual ornamental

2

Turf

2

Woody ornamental (deciduous)

2

Insect ID

1

Plant ID

1

Food substrate

1

Perennial ornamental

1

Fruit

1

Total

483

Among the woody ornamental evergreens, winter injury or other environmental stress was the most common diagnosis, followed by possible root or lower trunk injury (root girdling, mechanical injury, or improper cultural practice). No needle cast diseases have been diagnosed yet this season.

Cytospora canker was suspected on one spruce samples this year, based on symptoms alone (dead limbs, excessive sap production, no obvious mechanical wounds). A diagnosis for Cytospora canker is much more reliable if the fungal fruiting bodies are detected, but this usually requires submission of the entire limb (all the way back to the trunk of the tree).

 

SUBMITTING SAMPLES TO THE NDSU PLANT DIAGNOSTIC LAB

The NDSU Plant Diagnostic Lab generally examines samples on a ‘first-come-first-serve’ basis, but certain samples (such as suspected high risk pests or pathogens, and samples where a timely diagnosis is required for appropriate treatment) must take priority. A good sample usually includes different stages of symptoms, but completely dead plants or twigs seldom yield any useful information. In general, wrap a sample in dry paper towels before placing in a plastic bag and sealing the bag. Place the bag in a sturdy shipping box to avoid damage to the sample. When tree samples are submitted, include several images (photographs or digital images) showing the entire tree, the lower trunk, the ground area around the lower trunk, and close-up images of symptoms of interest.

For more information on how to submit samples to the NDSU Plant Diagnostic Lab, please see the following website, http://www.ag.ndsu.nodak.edu/diaglab/, where you can obtain a lab form and tips on submitting good quality samples.

Before submitting a sample to the NDSU Plant Diagnostic Lab, please first consider using your local county extension agent or other local expertise. A nominal fee of $15 for North Dakota residents ($25 for non-residents) helps offset the cost of running the lab.

Kasia Kinzer
NDSU Plant Diagnostic Lab
701-231-7854


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