Western Laboratories provides plant disease testing using traditional and DNA testing with the polymerase chain reaction (PCR). We have been conducting traditional diagnoses since 1999, based on visual examination of plant parts and culture on semi-selective media. For several years now, Western Laboratories has successfully utilized DNA technology into its plant pathology program using PCR protocols in which species-specific DNA markers are amplified and detecting using a real-time system. 

DNA analysis allows detection of plant pathogens at much lower levels than are possible with traditional methods.  DNA can be extracted from both soil and plant tissue. In the fall of 2011, we took DNA testing to a new level with the addition of DNA probes that will improve specificity, lower detection level and the ability to multiplex up to 3 diseases in a single analysis. These probes are the cutting edge of DNA diagnostic technology. 

Testing for diseases: The general list of diseases that can be tested for is growing rapidly; therefore, the list of diseases is never complete, please contact the lab if the disease your interested in is not on the list. For those customers that want to test for several diseases, we offer disease testing packages for hops, potatoes, mint, onions, ornamental crops and gardeners at discounted prices. 

Variable Rate Fumigation for Potatoes and Onions: Western Laboratories has integrated grid sampling for diseases testing with variable rate technology to provide customers with maps of pathogen distribution that are in turn; used to create chemical treatment maps.  In potatoes this has been done with Verticillium wilt and Black Dot. In onions, this approach has been used for management of Pink Root. This approach has been highly successful, especially when combined with Grid sampling for Nematodes and Nutrients since interactions exist between disease severity and Root Lesion nematode counts and soil nutrient status. 

Grid sampling for Wireworms is also offered under the Soil Pro programs. We have a crew that can be requested to collect Grid samples. We process the samples and identify the Nematodes at a reduced cost. We also can make the fumigation maps (GPS files) for your VRT controller. All the work is done in house and that gives the grower the most value for their money spent. 

Our Nematologist/pathologist Harry Kreeft has been with Western Laboratories since 1998. He graduated from the University of Wageningen (Netherlands). To contact him please call or email him via the Contact page. For submission forms for this testing, click HERE.

For our ongoing list of diseases, please look under the Downloads " WL Disease List". To see the prices of each test, please click HERE. For your convenience an example report is available to you under the Downloads section. 

For any further questions please contact us



WL Disease List (pdf)


Example Plant Disease Report (pdf)