Do these pepper plants seem to have pepper mottle virus? They’re in pots, are growing well and fruiting well (7 inches or so high, 5 peppers growing and the fruit looks healthy and smooth). However, the leaves are growing out mottled yellow and green, and some are developing dark brown spots.
Thank you for your question about Pepper Mottle Virus and congratulations both on catching it early and for doing some research .
You have the plant in front of you and are probably right, but I don’t want to jump to conclusions from what I see in the photo .
Pepper Mottle Virus produces puckered and mottled or mosaic patterned yellow leaves but from the photo , your leaves seem to be yellowing along the margins rather than all over and neither mottling or puckering is obvious . Your fruit is healthy ,not stunted , distorted or lumpy .
You might want to consider images of symptomatic plants at this link: https://www.cabi.org/isc/datasheet/43826 offered by CABI , a respected scientific encyclopedia .
By the way , I assume that you are fertilizing and that nutrient deficiency is not the issue?
Since you mention ( though I cannot see ) brown leaf spots which can suggest a bacterial infection rather than a virus, could we consider other possibilities ? In the meantime , please isolate any affected plants and monitor others nearby.
Plant disease experts at Cornell University offer a comprehensive photo gallery of brown spots, mottled leaves and associated problems at this link: http://vegetablemdonline.ppath.cornell.edu/PhotoPages/PhotoGallery.htm#Pepper.
Comparing visual symptoms in their photos with yours suggests to me some other possibilities including bacterial leaf spot (dark brown spots on upper leaves are depressed with brown border and beige centre , underleaf spots are slightly raised ), anthracnose, Alternaria , cucumber mosaic on peppers or even tomato spotted wilt virus on peppers that has yellow leaves similar to yours. Much of the information on control is geared toward commercial growers but at least we can get the diagnosis right .
If you decide it is bacterial leaf spot , Cornell University’s helpful “Vegetable MD Online is easy to read at this link: http://vegetablemdonline.ppath.cornell.edu/NewsArticles/PepperLeafSpot.htm .
If you decide it is in fact Pepper Mottle Virus , there are no chemical or biological controls available to consumers so, as you suspect , the affected plants should be destroyed ( no composting for this one). The virus is spread by physical contact ( think hands, gloves, clothing , tools , pets ) and gets onto skin ,clothing ,tools , the pot so disinfect /sanitize well , handle as little as possible , do not reuse the soil and if you have any in the ground , plant something else there next time .
Please feel free to circle back to us again if you either confirm your suspicions or find another answer and want to discuss. It is always interesting to puzzle through these issues . Thanks for thinking of us and good luck .