What causes cucumber mosaic virus outbreaks?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Acknowledging the causes of cucumber mosaic virus is helpful to protect your expansion plans. I have been monitoring infections across farming systems for a decade. Aphids, infected seeds, and our own gardening practices are the primary contributors to the perfect storm that enables the virus to spread so rapidly. If you are aware of the causes, this aids in breaking this dangerous cycle.
Aphids are the primary vectors of this virus. They become infected in just a few seconds while feeding on infected plants and then shortly thereafter deposit the pathogen on healthy crops. I have seen green peach aphids move infection from one plant to the next across an entire greenhouse in just a matter of hours. Their rapid feeding allows them to be very effective vectors of this pathogen.
Aphid Transmission
- Over 80 aphid species carry the virus
- Transmission occurs within 10-60 seconds of feeding
- Winged aphids spread virus up to 1 mile daily
Human Activities
- Contaminated tools spread virus to multiple plants
- Clothes transfer pathogens between garden zones
- Improper disposal of infected plants spreads virus
Environmental Factors
- Weed reservoirs near cultivation areas
- Pollen transfer between infected and healthy plants
- Warm temperatures above 75°F accelerate spread
Unbeknownst to the farmer, seeds from one planting could be passed to another, creating a silent outbreak. You will likely find that the seeds of one weed in particular have the highest rates of infection. In my confidence as a plant pathologist, I was able to trace the source of an enormous outbreak to contaminated seeds that were mixed in a bag labeled "wildflower mix." The grower was horrified, of course. The truth is, the best prevention begins before you plant anything. Always purchase seeds certified as disease-free from reputable sources.
Often, we unknowingly spread the virus through our own actions, and similarly, pruning shears transfer pathogens each time we cut. Clothing transports infected plant debris to new locations, especially if you have a garden on your property. I infected my entire herb garden by wearing the same gloves everywhere without even thinking. I now sanitize my tools between plants, and I have separate outfits for separate sections of the garden.
Break the cycle of outbreaks with targeted strategies. Plant aphid-repelling barriers such as reflective mulch early. Create sanitation stations at garden entrances. Work with neighbors to control weed reservoirs. On farms utilizing these tactics, I've reduced outbreaks by more than 90%. Your garden deserves this proactive protection.
Read the full article: Cucumber Mosaic Virus: Complete Control Guide
