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-   -   ID help: dirty-looking leaves (http://www.tomatoville.com/showthread.php?t=45429)

soozbz June 25, 2017 01:18 PM

ID help: dirty-looking leaves
 
3 Attachment(s)
Hi all,

Can someone help me identify this disease? I've got four plants- one sweet 100, one sungold, one celebrity and one Cherokee purple, planted in two Earthboxes. Something is killing the leaves on all four of them, but I'm not sure what it is. The leaves start looking kind of dirty or dusty with very small spots - see attached photos. Then they turn yellow/brown starting around the edges, develop a papery texture, and die.

I've been pruning off the most affected leaves and accompanying stems in hopes of preventing further spread, but it hasn't worked - by now pretty much every single leaf is infected. Somehow the plants are still growing fruit, but not at the same rate as before, since I've had to cut off a lot of the stems. But I'm not sure how much longer the plants will last without leaves!

Any pointers as to what this is and what I can do about it? I wonder if it might be septoria, but I haven't seen any photos of that that match up precisely to what I'm seeing here.

Thanks!

Susan

Spartanburg123 June 25, 2017 01:25 PM

Ugh, sorry to hear this! It looks to be the opposite of TSWV, which has black speckles and spots. I hope these great folks can help you identify it and hopefully cure it- they sure saved me just yesterday!!! Good luck!

Darin

ginger2778 June 25, 2017 01:40 PM

Speckled stippled leaves =spider mites. Nothing else looks like that. In your second photo you can see one crawling along the smaller stem at the 11 o'clock position. Your first photo shows some webbing too, in first photo, look between the leaflets, you can see them.

oakley June 25, 2017 01:47 PM

Could be very advanced powdery mildew but an expert will be along shortly.

Many plant/leaf problems mock others.

I keep a small arsenal of products on hand and try to identify the problem asap, with
help, before applying anything.

Has it been damp and hot?
I always, every year, get powdery mildew on my summer squash so i treat in advance as a preventative.

Thanks Ginger...(posting at the same time). Makes sense Inspector Ginger. :)

soozbz June 25, 2017 01:54 PM

oakley: It's been plenty hot (I live in Texas!), but not damp. But, until I started pruning off the sad leaves these plants were enormous and there wasn't much space for the leaves to breathe - I imagine that could make them more susceptible to mold?

ginger2778: I think you may be right that spider mites are the culprit. I've actually seen small webs all over my swiss chard and basil recently, and couldn't figure out where they were coming from. Good eye - I couldn't even see the webs and mites in person, let alone in my not-so-high-quality photos!

Does anyone have suggestions for dealing with a very, very bad spider mite infestation? I see a few options here, but I'm not sure where to start: [url]https://www.planetnatural.com/pest-problem-solver/houseplant-pests/spider-mite-control/[/url]

Worth1 June 25, 2017 02:01 PM

I was going to say spider mites too but held back for the experts.
I think I even see them.
Another thing is if it is a disease at least in my case I can keep in in check by pinching.
when you have the whole plant pinched off it is a sign in my case of infestation of some sort you cant get a handle on.

As far as I know I have never had a spider mite here.


One odd thing that happened the other day was the top of one of my plants over night was black and dried up dead.
I cut it off and it didn't come back.
I have never seen this before.
No it wasn't nitrogen burn.

Worth

ginger2778 June 25, 2017 02:07 PM

[QUOTE=soozbz;649829]oakley: It's been plenty hot (I live in Texas!), but not damp. But, until I started pruning off the sad leaves these plants were enormous and there wasn't much space for the leaves to breathe - I imagine that could make them more susceptible to mold?

ginger2778: I think you may be right that spider mites are the culprit. I've actually seen small webs all over my swiss chard and basil recently, and couldn't figure out where they were coming from. Good eye - I couldn't even see the webs and mites in person, let alone in my not-so-high-quality photos!

Does anyone have suggestions for dealing with a very, very bad spider mite infestation? I see a few options here, but I'm not sure where to start: [url]https://www.planetnatural.com/pest-problem-solver/houseplant-pests/spider-mite-control/[/url][/QUOTE]

Pyrethrin and permethrin sprays will kill them, but more hatch daily. You have to go to war, not an easy war to win. Thoroughly spray above and below leaves and entire stem and drench at soil line. Repeat every 4 days for 3 times, then keep it up every 7 days for control, management. The hotter the weather, the faster they multiply.

Spartanburg123 June 25, 2017 02:10 PM

What she said ^^^^^^^.

:)

zipcode June 25, 2017 02:49 PM

It's quite advanced :(. Tomatoes, especially some varieties are really sensitive to spider mites and simply yellow and die even at a mild infestation.
Last year I have used stuff containing acequinocyl (chemical obviously) and it is truly effective, kills very well and has about 2 weeks effects, so offsprings are killed too. I didn't do it so late in the season, fruits were just tiny back then, I used it to slow their advance. They will reappear after a while of course, so after this mass decimation, you could switch to neem spray or smth to not let them come back.

soozbz June 25, 2017 02:53 PM

Ooh boy, sounds like I'm in for an interesting summer. I will get some pyrethrin spray and try giving frequent, intensive treatments as ginger2778 suggested. And I guess I'll also stop hacking all the leaves off!

Thanks so much for your help, everyone! I'm sad to hear that these are tough to get rid of, but it's still a relief to know what the problem is.

soozbz June 25, 2017 02:57 PM

[QUOTE=zipcode;649841]It's quite advanced :(. Tomatoes, especially some varieties are really sensitive to spider mites and simply yellow and die even at a mild infestation.
Last year I have used stuff containing acequinocyl (chemical obviously) and it is truly effective, kills very well and has about 2 weeks effects, so offsprings are killed too. I didn't do it so late in the season, fruits were just tiny back then, I used it to slow their advance. They will reappear after a while of course, so after this mass decimation, you could switch to neem spray or smth to not let them come back.[/QUOTE]

Hmm, duly noted! I wonder if I can try acequinocyl and pyrethrin at the same time?

zipcode June 25, 2017 03:30 PM

At the same time would be a bit of a waste.
The problem with mites is that they develop resistance real fast. What the acequinocyl for example doesn't kill, they will make babies which will be more or less resistant. So repeating again after 1 month let's say, will have a much lesser effect and so on. They even say on the bottle max 2 times per year.
So best way is to alternate, at a certain interval (1-2 months?).
You have to note that both of these are chemicals, one shouldn't use more than it has to.
There's also the predatory mites, but they are so very expensive here in Germany, but people say they work quite well if introduced when bad mite population is low.

oakley June 25, 2017 03:42 PM

I'm finding with a few of my early issues with fungus gnats and aphids, caught early, but
non the less aggressive, is using a combination of organic treatments that deal with all
the 'life stages' of the ugly predators.
Not one product solved the problem.

The Cannabis growers have so much of that figured out being 'high value' crops.

b54red June 25, 2017 04:21 PM

I agree with using Permethrin or pyrethrin but if you use just that you will be spraying for the rest of the summer. For each gallon of spray make sure to use the maximum amount of the poison and add 1 Tablespoon of Dawn dish washing liquid. And most important of all before adding the Dawn or poison put 2/3 cup of food grade diatomaceous earth in a jug with part of your water and shake it well then strain it through a fine mesh strainer into your sprayer then add the remaining water, the Dawn and the poison. Shake your sprayer and pump it up as high a pressure as you can and spray all parts of the plant especially the undersides of the leaves, the stems and the ground or mulch under the plant. Wait three days and remove any dead or dying leaves then repeat this spray again. The poison gets the adults it hits and the soap helps coverage and in penetrating the webbing. The DE will remain on the plant killing juveniles that hatch out from the multitude of eggs that mites lay. Adding the food grade DE really cuts down on the number of times you will have to spray your plants. It is best to use this concoction late in the day near or at sundown for the benefit of any bees you may have.

This is the only thing I have found that is effective in stopping a big infestation of spider mites. You still might lose a few plants that have become infected in the new growth but most will recover with time. Once you use this method be ready in the future to use it again but just as soon as you see that stippling of the leaves indicating that mites are present even if you don't see them. Once you see webbing it indicates a fairly bad infestation already even before leaves start to brown and die. Every day you wait to treat them is increasing the problem and the damage that they are doing to your plants.

Good luck. I went through the worst mite problem I have seen in over 40 years of growing tomatoes. I usually see them at least once each year but last year was off the charts.

Bill

soozbz June 25, 2017 05:59 PM

Thanks for the great info, everyone! The pyrethrin, dish soap and diatomaceous earth combo sounds worth a try. I suspect this might be too big a job for my tiny spray bottle - maybe it's time I invested in an actual garden sprayer!


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