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Tuesday, June 4, 2013

Leaves Turning White and Papery - Peppers and Tomatoes - Answered

Today after work, I ambled out to the garden for my daily check-in.  To my dismay, my sweet peppers and tomatoes are exhibiting a problem that's totally new to me.  Portions of the leaves are turning white and going all flimsy.  When viewed from underneath, it's clear that something has sucked out all the green part of the plant and left just a paper-thin white remnant in the shape of the leave but with no internal supports.  The white part is like a soft gauze.

I don't know how else to describe it.  Here are some pictures:


On the picture above, you can see that the tips of my pepper plant are complete turned to gauze and the affected area extends around the entire perimeter of the leave.  On the left hand side, that portion that is hanging down along the center of the leave is a part that tore off when I tried to handle it.

Here are a couple of other plants.  In the picture immediately below, you can see the papering on the right hand leaf, but on the left hand side, that's not a flash glare on the leave but rather whiteness from the same problem.  





All of the above pictures are of my pepper plants, but there is at least one tomato suffering from the same ailment.  The tomatoes and peppers are planted adjacent to each other. In the below picture, again, while it looks like sunlight is reflecting off the right-hand leaf, it's not.  I took this at dusk.  That is whiteness of the leave all around the edges. 



This is freaking me out.  If this much damage can happen in a 24 hour period, I fear what I'll come home to tomorrow.  Decimation of my peppers?

All of these plants have been hardened off and have been outside weathering heat and cold for some time now.  So it's not sunburn. 

I looked diligently for pests and could find none on the leaves.  Perhaps it's a disease??

Amy - help!


ANSWER

I haven't ever encountered this before, but I'm afraid it might be a kind of virus. There are several mosaic viruses that are vectored by aphids. You can't kill the aphids before they infect your plant, and both peppers and tomatoes can "catch" them. There is the cucumber mosaic virus, the tobacco mosaic virus, the alfalfa mosaic virus and a few others. If I had to make a guess, it would be cucumber mosaic virus, as it affects the most plants. Unfortunately, there isn't any treatment. There is only eradication and prevention.

Once an aphid has contracted the virus, it can only infect a plant within a few hours. But flying aphids actually move around quite a bit, so the viruses can spread very quickly. They like to probe a lot of different plants until they find the right one. It's nearly impossible to control for the aphid population if the virus is spreading around your area.

The tomato plants look more like the typical mosaic virus, in that there are separate spots around the leaves that turn white. But the symptoms are pretty varied.

I've gotten to this a little late, so can you give an update? Sometimes plants can overcome the virus, but the general consensus involves sacrificing the plants. Otherwise it can spread. Unfortunately, the other recommended action is to get rid of all weeds in the area. I understand how difficult that can be, if you don't control an entire field. Can you check for symptoms in some of the weeds in the area?

Now for my disclaimer: it's entirely possible that there is some insect that causes these symptoms and I just haven't encountered it yet. Before sacrificing all of the plants, it would be worth it to pull one and check it's roots, under the leaves and all over it. It could possibly be a powdery mildew, but you should be able to rub that off.

I wish I had a better answer, but this type of damage makes me nervous too. Especially the damage I see on the tomato plant.

UPDATE

I think you might be right.  I did some further internet reading on mosaic viruses.

- http://www.extension.umn.edu/distribution/horticulture/dg1168.html
- http://www.extento.hawaii.edu/kbase/crop/type/cucvir.htm
- http://www.ipm.ucdavis.edu/PMG/r783102811.html

This really really really sucks.  I do remember finding some clusters of aphids on my peppers during the hardening off process, back when I had two flats into which I crammed all of the peppers and tomatoes together.  The aphids may have come from my yard or they may have come from the ONE tomato plant that I bought (at the Tilth sale) and set in with all my home-grown seedlings.

But I fear I might be the vector.  I tend to touch my plants when examining for insects, turning over the leaves and such.  I have certainly not been washing my hands with hot soapy water in between touching each separate plant, or disinfecting my garden tools by boiling them for 5 minutes, as recommended by the UMN website. 

In the time since I last posted, things haven't changed much, although the problem does seem to be getting worse with respect to the peppers.  Here are some additional photos:




All of the above pictures are on my peppers, which are planted in front of the tomatoes. 

This picture below is one of my tomatoes that I planted separately in a pot against the house.  It has a lot of white spotting, and something has also been eating the leaves.  The fact that this tomato exhibits the white spotting tells me that the spread of virus occurred back when I had all of the seedlings in flats together with the peppers, rather than spreading in the garden bed (because this one is in a different part of my yard far away from the garden bed).  


My plan:

1.  Pull out the peppers and the worst-infected tomatoes in order to try to save the tomatoes that so far look uninfected.  This makes me very sad, by the way.

2.  STOP touching the plants with my hands and will boil my hand tools today and wash with soapy water.

3.  Throw away my pink gardening gloves that I used when doing most of the planting and tending of these plants.  I have some new ones that I haven't used yet this season, and I'll switch to those for handling soil and any other plants. 

4.  Cross my fingers and toes.

I'll post updates along the way.

3 comments:

  1. I can't help, but I can commiserate. My tomatoes exhibit the same symptom. I'm in Indiana. I haven't seen this problem before. Best wishes to you in finding an answer. I'll come back here and post again if I learn anything useful.

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  2. Jane - thanks. I now have a working theory about the problem, supplied by my sister Amy (see updated post above). Mosaic virus. But keep me posted if you learn otherwise, or if you have any further thoughts on how to respond.

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  3. Hi i know im really late but this looks like a sunburn. i just googled around and thats what i found. my serrano plant was getting that too, and my temp out here in texas are hitting 100F in the mid afternoons. so one of my newly plants got sunburned

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