Tomato Spotted Wilt Virus (w/ Pix)

[gill_s]

Has anyone had TSWV as far North as South of UK. I have got it! We did not realise what it was. We thought mineral deficiency, then Septoria Leaf Spot, not even thinking of TSWV. I am now sure that is the problem. It has spread so rapidly it is too late to stop. We have, however removed all nearly ripe fruit and will remove more in the hope they will not be too badly affected. Interestingly it seems(fingers crossed) that my one Kumato plant is ok. This has dark green leaves. I should be interested to know if anyone else in N Europe is affected.
Gill

[b54red]

Gill why did you remove the nearly ripe fruit? I just had a hamburger at noon with a tomato off my Cowlick's Brandywine that has had TSWV since early June.

[gill_s]

Originally Posted by b54red

Gill why did you remove the nearly ripe fruit? I just had a hamburger at noon with a tomato off my Cowlick's Brandywine that has had TSWV since early June.

Hi, thanks for your reply. The reason for harvesting the 'nearly ripe' toms was because at the time we thought it may be Septoria Leaf Spot. We planned to spray the plants and as the only effective fungicide we have available in the UK is Dithane we cannot harvest fruit till at least 5 days after spraying.
I thought it may help, once we realised it was TSWV, to remove more fruit to stop them being affected by the virus. It seems that you have found this not to be necessary? After the initial rapid spread of the condition it does seem to have slowed down somewhat. I am hoping that I shall get some more decent fruit.
My debate is what to do next year. I have to admit that a few days ago I felt like giving up completely. I have never had such a bad year for my tomatoes. We had a bad fungal problem in our two small hydroponic systems and had to remove 3 plants.
Gill

[Structure]

I've been compiling a list of resistant varieties, and I have to admit that at this point I'm actually looking forward to growing some out. There are also some control methods that I haven't tried (reflective mulch), but will next season. My current list of varieties reads:

1. Top Gun (currently not available...but next season is a ways away yet)
2. Plum Regal (ditto)
3. Bolseno
4. Talladega
5. Sophya (looks pretty at least)
6. Super Cromo F1, Mountain Glory, Amelia, Bella Rosa, several others.

I plan to try the top 3-4 next year.

Between using resistant varieties and trying to protect some favored OPs, I'm optimistic for next year despite some real bummer moments this one.

[gill_s]

If it really is TSWV which has infected my plants( I Hope to get confirmation with a test kit). That isn't right! I don't want it confirmed but I do want to know what the problem is.
If it is TSWV then Plum Regal is affected. I have no others listed as resistant
The most tolerant plant I have is Kumato. Most of my others seem to be affected to some degree. The worst are Principe Borghese and Mini Rose which were both paler leafed plants from seedling stage. Kumato is a dark green leafed plant.
My dilemma is where it has come from as it is not abundant in the UK although now reputedly occuring worldwide.
Gill

[b54red]

Two days ago I had to pull my Wes and my Cowlicks after both survived and produced numerous good tomatoes after falling ill to TSWV the first week in June. Hard to believe any plants could survive and almost thrive for that long after being infected. I think they might have made it all the way into the fall if we hadn't had 3 weeks of temps hovering around 100 with humidity to match and no rain. That weather killed some of my very healthy plants. I just couldn't keep them all watered adequately. Of the approximately 15 to 20 plants I lost to TSWV this year only those two survived over one month after showing clear symptoms.

[linuxman51]

Apparently my 'spare' tomato plants got wiped out by this (or so my dad tells me. He called the local extension office asking about it and found out that that's what was whacking his plants. I think they're all wiped out now).

This is a bit disappointing, and of course has me on edge now

the question I have is regarding these new varieties.. b602 I think is one, that is TSWV resistant.. how resistant is resistant? Is it just going to prolong the inevitable or will it actually fight it off?

and... do containers and/or raised beds lessen the impact of thrips?

[b54red]

I have noticed far more thrips on the plants this year than last and have already lost one to it for sure this year. I'm just hoping most won't get infected. The unusual winds we are having this year seem to have blown in more thrips than usual; I just hope most of them aren't carrying the virus. I am only growing one plant that is supposed to be tolerant for the simple reason that every tomato from a tolerant variety that I have tasted has left a lot to be desired. I just keep a lot of seedlings ready to replace any that die or get really sick. Since I have fusarium which is a far bigger problem for me I am constantly replanting. It is a little frustrating at times but seems to be the only solution that works. I have already replanted 20 plants and the season has just begun. It will get much worse soon if past history is any indication.

[linuxman51]

gosh darnoodley. <what? hahahaha that's great. I'll get some more plants que'd up then. so.. containers, yay or nay as defense against some of this stuff?

[semi_lucid]

I've been reading, and I thought these fact-iods were interesting:

TSWV has been reported to be transmitted in the seed of Petunia x hybrida and Lycopersicon esculentum (Tomato). It is believed TSWV is carried on the seed coat, rather than in the embryo.

Tomato spotted wilt, first described in Australia in 1919, was later identified as a virus disease.

Previously, these viruses had been a problem in subtropical areas. It was not until the late 1980s that they began to affect the U.S. greenhouse industry. Because of the way plant material is transported, the viruses spread quickly across the United States and now are found everywhere.

To manage these diseases, it is important to know the thrips life cycle and feeding habits, because thrips spend a large part of their lives off the plant. Both virus and vector need to be targeted in control programs.
A thrips completes its life cycle in about 10 days. Eggs are laid in the leaf. Larvae hatch in about three days and immediately begin to feed, thereby picking up the virus. After four days, they pupate in the soil, and in a little over three days, the pupae become adults. Adults feed and transmit the virus.
Only larvae pick up the virus and only adults transmit it. Adults can transmit the virus within 30 minutes of feeding. If larval stages can be controlled, virus transmission can be prevented, even if adult thrips are present

Perhaps the tin foil might interfere with the pupae dropping down to the soil? Perhaps not?

Maybe sticky paper on the ground could catch the larvae? Really it seems like the only real hope is to prevent the thrips from getting to the plants in the first place.

We are having a bad drought here this year, maybe that will keep the thrips down.

http://www.ext.colostate.edu/pubs/garden/02947.html
http://vegetablemdonline.ppath.corne...pottedWilt.htm

[Big Hutch]

I received the following information from a co-worker who is a horticulturalist with the LSU AgCenter with 30 years experience.

Thrips are attracted to yellow. That is why the come to the tomato blossoms. He recommends using any yellow container like a yellow bucket and smearing vasoline in the container and around the rim on the outside. This is a cheap but effective thrip contol.

Also, simple cultural practices can be helpful. Thrips spent time on some of the various thistles and other yellow flowers. Mowing these other attractant plants seems to help.

Just some thoughts.
Robbie

[b54red]

I don't know where the thrips are coming from but they just keep showing up on my plants. I just had to pull my only Earl's Faux because of TSWV. Two down and about 100 more to go. So far the virus is way behind the destruction caused by fusarium wilt and I hope it stays that way. I fear from the number of thrips I have seen this year that my loses could be even worse than last year which was the worst for TSWV I have experienced. I check the plants daily for thrips and for most of the last month they have been in abundance.

[semi_lucid]

Originally Posted by b54red

I don't know where the thrips are coming from but they just keep showing up on my plants.

Around here, when the winter wheat dries up in spring, the thrips can take to the air by the millions.

[semi_lucid]

b54red

If the pupae/larvae get infected in the first few days of their life, and then drop to the ground for a few says before emerging as infected adults, maybe you should kill the soil under the infected plant you pulled. Pour some bleach on it or something.

If you read in the post above:

Only larvae pick up the virus and only adults transmit it. Adults can transmit the virus within 30 minutes of feeding. If larval stages can be controlled, virus transmission can be prevented, even if adult thrips are present

In other words, the pupae emerging from under infected plants are guaranteed to be infected. Kill em while they are in the ground.

It may be a good idea to try to kill them in the ground under any infected plant, even before you pull the plant.

Any suggestions as to what might be the best treatment to do that? Bleach? Maybe some bleach covered with plastic sheet so the chlorine gas will get them.

John

[b54red]

John, although the best suggestions for handling TSWV call for immediate removal of the plants from the garden, I have not noticed any spread from infected plants. I had a few plants stay in the garden after getting it last year and none of the adjacent plants ever got TSWV. I always pull small plants immediately because they don't have a chance to ever produce once infected; but a few of the large healthy mature plants seem to be able to keep on producing in a limited fashion despite the TSWV.

I have now had three plants killed by TSWV and none were near each other and so far none of the nearby plants show any symptoms. The varieties lost so far are Mule Team, Earls Faux and Cherokee Green.