ISSUE 10   July 6, 2006

PLANT DIAGNOSTIC LAB SUMMARY

Below is a summary of samples diagnosed in the past week (research samples and seed health testing results are not included):

Host

Diagnosis

Taxonomic name

County

Amaranthus

Poor Or Insufficient Sample

 

Cass

Apple

Botryosphaeria Canker

Botryosphaeria sp.

Cass

Ash

Lecanium Scales

Lecanium sp.

Traill

Bean; Dry

Herbicide Injury; Exposure

Abiotic pathology

Traill

Corn

Herbicide Injury; Exposure

Abiotic pathology

Ransom

Corn

Nutritional Deficiency

Abiotic pathology

Otter Tail

Crambe

Poor Or Insufficient Sample

 

Cass

Cucumber

Fusarium Crown Rot

Fusarium sp.

Hettinger

Lawn

Leafspot Crown and Root Rot;

Bipolaris sorokiniana

Stark

Linden

Iron Deficiency

Abiotic pathology

Dickey

Purple coneflower

Environmental Stress; Problem

Abiotic pathology

Cass

Rape

Poor Or Insufficient Sample

 

Cass

Soybean

Growth Regulator Effect

Abiotic pathology

Cass

Spruce

Rhizosphaera Needle Cast

Rhizosphaera

Burleigh

Spruce

Spruce Mite

Oligonychus ununguis

Burleigh

Spruce

Yellowheaded Spruce Sawfly

Pikonema alaskensis

Mchenry

Sugarbeet

Herbicide Injury; Exposure

Abiotic pathology

Clay

Sunflower

Herbicide Injury; Exposure

Abiotic pathology

Bottineau

Sunflower

Poor Or Insufficient Sample

 

Unknown

Tomato

Growth Regulator Effect

Abiotic pathology

Cass

Wheat

Fusarium Root Rot

Fusarium sp.

Bottineau

Wheat

Herbicide Injury; Exposure

Abiotic pathology

Hettinger

Wheat

Leafspot Crown and Root Rot;

Bipolaris sorokiniana

Bottineau

Wheat

Wheat Stem Maggot probable

Meromyza americana

Norman

 

The most common diagnostic request in the last week has been to visually evaluate samples for possible herbicide injury. The NDSU Plant Diagnostic Lab can only visually assess possible herbicide injury. Before assessing visual symptoms as possible herbicide injury, we make every effort to rule out other possibilities. The visual analysis is dependent on the information given to the lab. As a result, accurate information on the pattern of injury, timing of symptom appearance, crop history, dates and rates of chemicals applied (for at least the past 2 years), method of chemical application, tillage practices, and soil information (type, pH, organic matter), is critical. If drift is suspected, we need to know what the surrounding crops are, what was suspected to have drifted, timing of suspected application, and timing of symptom appearance. Samples submitted for visual analysis should include entire plants, showing a range of symptoms, along with healthy, unaffected plants (if available). We are not equipped to routinely perform chemical analyses of herbicide residue. For a partial list of labs that can perform quantitative/qualitative chemical analyses for herbicide residue, along with contact information, please visit the NDSU Plant Diagnostic Lab website: http://www.ag.nodak.ndsu.edu/diaglab

If you know of a lab that can perform such services that is not listed on the site, feel free to contact me with that information and I will add it to the site.

Kasia Kinzer
NDSU Plant Diagnostic Lab
e-mail: diaglab@ndsuext.nodak.edu
Telephone: 701-231-7854
206 Waldron Hall, PO Box 5012
Fargo, North Dakota 58105


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