Can root rot spread through Cannabis plants?

Explore the key methods that drive the spread of root rot and threaten the health of your cannabis crops.

Understanding the gravity of Pythium's impact on cannabis crops is crucial, especially considering that Fusarium and Pythium species are among the most destructive root pathogens. Particularly harmful when infections occur during the vegetative growth stage. In some cases, these pathogens can potentially lead to 30% of the total yield(1).

Fusarium and Pythium species have the potential to cause irreparable damage to the root system, compromising nutrient uptake and water absorption. The vulnerability of cannabis plants during the vegetative growth stage makes it imperative to implement disease control methods within the first 2–4 weeks of the production cycle for effective management(1).

Download our Pythium Fact Sheet for more information.

Pythium species transmission methods

Mechanical transmission

Contaminated equipment and tools, such as pruning shears, trays, or containers, can serve as vectors for Pythium spores. Without regular sanitation practices, these tools become conduits for the transfer of the pathogen from infected plants to healthy ones.

We recommend that tools be soaked in a 10% bleach solution to prevent or remove viroid contamination. This equals 1 part bleach mixed with 9 parts water for 60 seconds in between each plant. Be sure to select a bleach brand whose main ingredient (sodium hypochlorite) is 6% or greater. Alternating between several pairs of scissors in a bleach solution can make disinfection efficient during trimming.

For more information, download our review of common sterilizaiton methods, Tool Sterilization to Prevent Viroid Transmission.

Water transmission

Pythium spp, being a water mold, has an affinity for spreading through water sources used for irrigation. Contaminated water carrying Pythium spores can swiftly introduce the pathogen to the root system, initiating an infection that could prove devastating to the entire crop.

Consider testing your water sources with TUMI Genomics Water System Test.

Soil and Growing Medium

The soil and growing media act as potential reservoirs for Pythium spores. Failure to properly sanitize these materials can significantly contribute to the ongoing spread of the disease, posing a continuous threat to the health of your cannabis plants.

If you’re using coco medium for your plants, consider sterilizing the coco using this operating procedure.

Airborne transmission

In certain scenarios, Pythium spores can become airborne, settling on healthy plants and further exacerbating the risk of infection. Two species, P. dissotocum Drechsler and P. myriotylum Drechsler are able to produce zoospores at 24–27 °C, and were shown to cause root damage in Cannabis, resulting in browning and stunting(2). Therefore, maintaining optimal ventilation and air circulation is essential to mitigate this potentially airborne transmission.

Armed with an understanding of the mechanisms through which Pythium spp. can spread and by implementing stringent phytosanitary measures early in the production cycle, cultivators can be their own regulatory body, ensuring the sanitation of their grow facilities. By staying informed and taking decisive action, cultivators can protect their investment and guarantee a robust, healthy cannabis crop.

For more information on Pythium infections, download Pythium Fact Sheet .

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References and Resources:

1. Punja Z.K. Emerging diseases of Cannabis sativa and sustainable management. Pest Manag. Sci. 2021;77:3857–3870. doi: 10.1002/ps.6307.

2. Punja Z.K., Rodriguez G. Fusarium and Pythium species infecting roots of hydroponically grown marijuana (Cannabis sativa L.) plants. Can. J. Plant Pathol. 2018;40:498–513. doi: 10.1080/07060661.2018.1535466.

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About TUMI Genomics

TUMI Genomics is advancing cannabis cultivation by bringing biological insights to help commercial growers thrive. Through comprehensive preventative solutions, superior pathogen diagnostics, and AI-driven insights, TUMI Genomics is helping cultivators start clean and stay clean. The unrivaled diagnostics, transparent validation and industry-leading pathogen detection innovations provided by TUMI Genomics are raising the standards of commercial cannabis cultivation. The team at TUMI Genomics is composed of deeply experienced Ph.D. molecular biologists, bioinformaticians, business strategists, and accomplished serial entrepreneurs.

Media Contact: Hailey Spencer, Marketing Director

hailey@tumigenomics.com

Research Inquiries: Tassa Saldi, Ph.D., Co-Founder and CSO

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