Is this mosaic virus on peppers and tomatoes and if so, how to manage going forward. - Ask Extension
I noticed changes in pepper (Lesya, Padron and Pizza Pepper) fruit and leaves, and some tomato leaves (Orange Paruche, Gold Spark and Striped Roman),...
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Is this mosaic virus on peppers and tomatoes and if so, how to manage going forward. #840498
Asked July 13, 2023, 2:06 PM EDT
I noticed changes in pepper (Lesya, Padron and Pizza Pepper) fruit and leaves, and some tomato leaves (Orange Paruche, Gold Spark and Striped Roman), within the past 1-2 weeks. Reading and questions to my seed source (Territorial) suggest mosaic virus. The plants have been robust and fruiting well up until now, and I would like to cut my losses and allow the existing fruit to ripen before pulling all plants out. We have not observed aphids (in fact, the hops which grow 10-15 feet away have had no aphids this year, though they have been troubled in the past three, requiring neem +insecticidal soap). I have sterilized tools with quaternary ammonium but realize I often touch plants without washing my hands in between, so I may be the vector. A neighbor suggested the foliage changes also could be due to herbicide drift. We use no herbicides but live in a suburban neighborhood with extensively landscaped homes where this is possible. If this is indeed a mosaic virus, what steps can I take with the soil to return it to viability. I have read various gardening sources that suggest replacing the soil, but this is impractical as we have four 4 x 8 and two 4 x 6 raised beds approximately 2.5 feet high filled with soil. The peppers and tomatoes are in four of them, which leaves us limited options for gardening in the next years. Thanks in advance for your time and consideration.
Washington County Oregon
Expert Response
Hello Colleen: those symptoms on your pepper are dramatic. My first thought was herbicide injury. Your photograph of the deformed shoot tip (that appears to be tomato) gave me a pause, concern that your plants are infected with Tomato brown rugose fruit virus, but if this was the case, the pepper fruit should be much more severely deformed.
The interveinal chlorosis apparent in your photograph of the leaves in the second photograph is not typically seen with this virus either, but interveinal chlorosis can occur when pepper or tomato is infected with Tomato chlorosis virus, but again, the pepper fruit should show more symptoms if the plant is infected with this virus.
The symptoms in the photographs that you uploaded are not typical of either alfalfa mosaic virus not cucumber mosaic virus either, so I don't think it's a mosaic virus problem.
I'm leaning towards that your plants may have had an exposure to some type of herbicide. It is notable that these different cultivars started showing symptoms in the past 1-2 weeks.
Drift of triazine herbicides can cause interveinal chlorosis while 2,4-D damage can cause deformities similar to what is seen with the tomato shoot tip in your photo.
Do you have other vegetable dicot-types growing in your gardens, such as cucumbers or beans? If so, do you see any symptoms in other types of vegetables?
The interveinal chlorosis apparent in your photograph of the leaves in the second photograph is not typically seen with this virus either, but interveinal chlorosis can occur when pepper or tomato is infected with Tomato chlorosis virus, but again, the pepper fruit should show more symptoms if the plant is infected with this virus.
The symptoms in the photographs that you uploaded are not typical of either alfalfa mosaic virus not cucumber mosaic virus either, so I don't think it's a mosaic virus problem.
I'm leaning towards that your plants may have had an exposure to some type of herbicide. It is notable that these different cultivars started showing symptoms in the past 1-2 weeks.
Drift of triazine herbicides can cause interveinal chlorosis while 2,4-D damage can cause deformities similar to what is seen with the tomato shoot tip in your photo.
Do you have other vegetable dicot-types growing in your gardens, such as cucumbers or beans? If so, do you see any symptoms in other types of vegetables?
Thank you for your prompt response! I have cucumbers but so far they are healthy, although a little behind the tomatoes, peppers and summer squash. The squash (pattypan and bush marrow) have been robust though the bush marrow has a little white residue at leaf ends that looks like the mildew that plagued them late in the season last year. There are a few leaves that have some yellow spots but not extensive, I recall similar spots last year and they did not affect yield and the mildew was kept in check with neem oil.
Your explanation is giving me some hope, because the description of mosaic virus and its outcome seemed catastrophic.
Kind regards,
Colleen Colley
The spots on the cucurbits could be herbicide injury. I'm going to try and reassign your question to someone with a specialization in weed science/herbicides and see what they think of your issues in your garden. Good luck.
Many thanks
On Thursday, July 13, 2023, Ask Extension <<personal data hidden>> wrote:
On Thursday, July 13, 2023, Ask Extension <<personal data hidden>> wrote:
Dear Colleen, here's the response to your question:
The spots on the cucurbits could be herbicide injury. I'm going to try and reassign your question to someone with a specialization in weed science/herbicides and see what they think of your issues in your garden. Good luck.
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Thanks for your patience as we researched your question. I agree with the previous expert that accidental herbicide exposure could be at play here. It will be hard to track down what exactly happened at this point.
One question: did you add any new soil or compost to your garden this year?
One question: did you add any new soil or compost to your garden this year?
Hello Brooke:
I did add some compost to the existing soil (G&B Organics Harvest Supreme) at the beginning of the season, with some G+B Raised Bed Soil conditioner.
At this point, the plants are still growing but the damage to the pepper and tomato foliage is present. They continue to fruit, but some peppers are abnormal (i.e., about 2/3 of the current Padron peppers are globe-shaped and mostly seeds, not the usual elongated shape with folds). There have been a few leaves at the base of the peppers/tomatoes with patterned chlorosis but not an overwhelming number at this time; could also be the heat as they have been in locations with prolonged sun. I have tried searching the web to determine how long it would take for MV to declare itself but have not found any clear guidance. I continue to hope it is herbicide damage, as this bodes more favorably for next and subsequent year's plantings in addition to this season.
If I observe further damage to leaves/fruiting do you recommend sending any material off for diagnostics? I would like to know if MV is present (because this would be in as many as 4 of our 6 raised beds) going forward. If so, where would I look for a lab which offers such testing?
thanks for your follow up,
kind regards,
Colleen Colley
It's so hard to predict what is going to happen with these plants. It's a complex interaction of the plant's genetics, any environmental stresses (like more hot weather), how the plants are treated (watering, etc.), and then whatever caused this problem. I'm leaning more toward herbicide damage since different genera of plants are involved.
The OSU Plant Clinic offers virus testing. There is a fee for this service and it can be quite expensive (~$100). Please contact them for information on collecting the best sample, shipping/delivery, and the specific charges.
Fingers crossed that your plants can grow out of this! If not, now is a great time to plant for a fall/winter garden. So maybe there is a silver lining?
