Our virus and pathogen testing lab features an experienced, well-credentialed staff, overseen by senior virologist and plant pathologist Dr. Tefera Mekuria, Ph.D. This lab is the only ISO Certified lab of its type in North America, testing for all known grape viruses, fungal and bacterial pathogens. Utilizing Quantitative Polymerase Chain Reaction (qPCR), the most precise commercial plant testing technology, this laboratory follows protocols established by researchers at Foundation Plant Services, University of California Davis. We have built the facility with adequate space for process separation, where every testing step is performed in a different room to minimize risk of cross contamination.


Testing soil, water and plant tissues for crop nutrients and fertility, this multi-purpose lab features a variety of efficiency testing programs through American Lab Proficiency (ALP). Located in a separate building but in the same complex as Wonderful’s virus and pathogen lab, this state-of-the-art facility uses some of the industry’s most advanced equipment. Our credentialed staff employs best practices for soil preparation and utilizes a custom-built leaf washing machine that removes contaminants to ensure product cleanliness before testing.


Red Blotch - Year Round (cane or green tissue preferred)
Leafroll (All) - Fall/Winter (cane samples preferred)
Vitiviruses & Fleck - Fall/Winter (cane samples preferred)
Fanleaf - Early Spring (green tissue preferred)
Pierce's Disease - Spring/Fall - (symptomatic leaves/petioles & adjacent stems)
Grown Gall - Year Round (woody tissue & gall)
Powdery Mildew - Spring/Summer (spore collections rods)

Fertility – Based on Crop* (Leaf & Petiole)
Soil – Anytime
Water – Anytime
*Call for sampling protocols.


449 N. Zerker Road, 
Shafter, CA. 93263