Pepper Mild Mottle

Pepper mild mottle virus (PMMoV) is not the same as pepper mottle (PepMoV or PeMV). This member of the tobacco mosaic virus family has been linked to tomato mosaic virus. Unlike pepper mottle, pepper mild mottle does not affect eggplant or tomatoes. This is a peppers-only disease (we hope).

Bell peppers infected with pepper mild mottle (UF/IFAS Pest Alert Website/Pamela Roberts) CC BY 2.5

Pepper mild mottle symptoms

Like many other diseases, pepper mild mottle causes stunting and chlorosis, or yellowing of the leaves. It also causes distorted and lumpy fruit, leaf curling, and streaking (not the 70’s kind). These symptoms will vary depending on the species and cultivar.

Pepper leaves infected with pepper mild mottle on the left (Yubing Jiao, et al) CC BY 4.0

Pepper mild mottle management

The virus that causes pepper mild mottle occurs around the world. It is the most abundant RNA virus found, I beg your pardon, in human feces. It ends up that we are the Number One carriers of this disease. Just as livestock manure can carry many pathogens, such as E. coli, our own waste can, too. This virus also moves around on our clothing, tools, and skin. There is some suspicion that this virus can also cause disease in people, but more research is needed. Whether it hurts us or not, it can be devastating to your pepper plants.


This pathogen thrives in heat and humidity. This makes it a common problem in greenhouse environments. Once in an area, these viruses can enter plants through wounds and other damaged areas. This disease is very contagious in the pepper world and the virus is very stable. This means it remains viable on tools, containers, structures, and plant debris for a long time.


Once a plant is infected with pepper mild mottle, it must be destroyed. Pull it out and throw it in the trash. Do not add it to the compost pile and do not burn it. These viruses are so tough that they can travel on smoke! And wash your hands.


Commercial growers used to apply methyl bromide as a pre-plant treatment. That nasty chemical has been banned in most countries. One Japanese study has found soil rich in humus is less likely to harbor the pepper mottle virus, so keep mulching and composting. Crop rotation is a good idea, too.


The best way to prevent this disease is to only use certified disease-free seeds and seedlings.