Screen Plants for Botrytis, Russet Mites with youPCR®

We expanded our youPCR® Plant Screening Platform to include two new youPCR® detection assays for common cannabis plant pathogens: botrytis and russet mites. These early detection assays, along with our powdery mildew test, can help cannabis cultivators identify infected plants before they show visual signs.

Cultivators can use these tests as a preventative measure to reduce the risk of a costly pathogen outbreak. Common uses include screening incoming clones before they are added to a grow room and testing mother plants before creating new clones. Cultivators can also use youPCR® Plant Screening tests to diagnose an infected plant and determine the proper treatment.


Botrytis cinerea is a systemic mold infection in Cannabis. This mold is often called “Bud Rot” or “grey mold”. It can remain cryptic or dormant for long periods of time before it sporulates. The infection starts within the bud, making it difficult to detect in the early stages of infection. Peer-reviewed papers have also demonstrated that Botrytis is a systemic infection that can be passed to future generations via seeds.

DNA-based techniques, like youPCR®, are very sensitive and can detect the infection long before it is visible, so cultivators can take measures to minimize its damage.

Russet Mites

The microscopic Hemp Russet mite infects cannabis and can result in significant crop loss and chronic infestations. Russet mites are 200um x 45um and are thus invisible to the eye until late infection when their numbers begin to discolor the plant.

Russet mites are resistant to most pest treatments and thus care must be taken to screen incoming material to a grow. Visual detection of mature mites is possible with 14X objective loupe but eggs and nymphs likely escape convenient optical detection. They are believed to be hosts for other plant viruses.

Early detection with youPCR® could assist in screening clones or soils to prevent infections of larger grows.

Start Testing with youPCR®

Whether you are a testing lab that wants to offer additional testing services to customers or a cultivator looking to test plants on-site, we can help get you started with youPCR®. Using the youPCR® platform, you can detect pathogen DNA from a hole punch from a cannabis leaf before visual signs are present. Read more about our technology on the youPCR® webpage 

All youPCR® tests can be run on either a 8-well miniPCR thermocycler or a standard 96-well thermocycler. Download our youPCR® Protocol for a full list of equipment and consumables.

Sign up for youPCR® webinar

Learn all about screening plants for pathogens (powdery mildew, russet mites, botrytis) and genetic traits (CBD synthase, THC synthase, Gender) at our May 23 Webinar. Medicinal Genomics Chief Science Officer Kevin McKernan will explain how The youPCR® Plant Screening Platform can be used to protect grows from costly pathogens, accelerate breeding programs, and reduce operational costs.