Cause Several viruses can infect rhubarb including Arabis mosaic virus, Cherry leafroll virus, Cucumber mosaic virus, Strawberry latent ringspot virus, and Turnip mosaic virus. It is unclear from scant reports, which ones are prevalent in the Pacific Northwest. Turnip mosaic virus is reportedly the most common in British Columbia. Mosaic symptoms as described below have been observed. Many of these viruses can be found on weed hosts, and some are transmitted by nematodes.
Symptoms Pale-yellowish or dead spots or rings on leaves, usually with pale green mottle. Young leaves show well-defined to severe light and dark green mosaic mottle. Leaves often are crinkled and distorted. Symptoms may disappear in hot weather.
- Assay soil for nematode vectors before planting.
- Plant stock that has been tested and found free of all known problematic viruses in fields not planted to rhubarb the previous 3 years.
- Dig up and destroy symptomatic plants.
- Remove and destroy adjacent weeds.
Reference Tomlinson, J.A., and Walkey, D.G.A. 1976. The isolation and identification of rhubarb viruses occurring in Britain. Annals of Applied Biology 59:415-427.