Brown Thumbs
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Summer watering...does it cause blight?

Below picture shows a pepper plant wilting. It all of a sudden did this since I watered with a sprinkler two days ago. There's another pepper plant, and some leaves on a neighboring tomato doing this, all of a sudden. Weather is hot, humid, and it's been fairly dry lately. Is it blight and did my watering cause it?

I ask because this has happened in the past. All looks good, it gets real hot humid weather, I water, then "zap" a few peppers and tomatoes wilt and never recover. It's like let them be too dry or water and cause something to kill them.

I dug a little near this one and the soil is moist below surface. What should I do...pull them up or see what happens?
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imafan26
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If it looks really good and suddenly within a week it withers and dies for me that is usually phythoptora blight.
I get it more in summer after the ground has been soaked by rain. In the hot humid days that follow the plants suddenly wilt and die. Phythoptora in the soil can persist for 20 years or more. I just avoid the spots where it is bad and plant annual shallow rooted crops. Crops with roots that don't normally go past 10 inches usually do o.k. I plant the most susceptible plants in pots. Most of my peppers and tomatoes are in pots because of nematodes and phythoptora.
https://vegetablemdonline.ppath.cornell. ... hytoph.htm

Asica
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My dad always tells me to water veggies with the water from the barrel sitting there in sun all day.

Brown Thumbs
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I've used water that sat outside in buckets around plant bases, but we didn't have any and I decided to use a sprinkler. I wonder if it matters either way with wilt/blight. I know getting leaves wet can cause mildew too.

I'm almost scared to water now but gosh, in 90+ temps and no rain I feel I should. Leaves, especially bottom ones on all peppers wilt down but seem come back up over night.

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Lindsaylew82
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Is anything burrowed into the stem?

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Gary350
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There is probably nothing wrong with your plants. I never water my plants in the hot sun it will very often kill them. Yesterday my pepper leaves were hanging down like wet toilet paper they looked dead for sure, it was 3 pm the hottest part of the day 96 degrees. I returned at 7:30 pm the leaves were looking good, nothing wrong with these plants. We had a flash flood the day before plants were setting in mud I knew my plants were not wilted for lack of water. Tomatoes and other plants often wilt in the not sun. If you must water your plants do it about 1 hour before dark when the sun is low on the horizon.

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Lindsaylew82
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I don't agree with that part about never watering...

I would absolutely lose some plants if that were the case. We haven't had rain here since June 4. That's s long time for plants who were used to getting fairly stead spring rains.

I say water deep and regularly. Especially with tomatoes and peppers.

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kayjay
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Well, blights are infectious diseases, so water alone isn't going to cause it. But I wouldn't water with a sprinkler. That's for lawns. I water veggies gently with a hose and try to keep water off the leaves - soil only. Optimally, I'd water with sun-warmed water out of a container. That might be a future project for me - find something to use as a rain barrel.

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Lindsaylew82
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I agree, top watering can encourage fungal diseases, especially if there isn't anything (like mulch, which you seem to have!) preventing splash up.

This doesn't look like any type of disease related issue. There may be something in the stem of the plant, or something munch on roots down below, but it looks like they are just dry. Regular deep watering a are fine when it's hot and dry for long periods of time. Drop hoses are a great way to water, and they're pretty cheap!

n8young
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I think if you have to top water, do it early in the morning before it gets hot out. I cant imagine sprinkling cold ground water on a plant in 90 degree sun is good for it.....no scientific basis on these thoughts

imafan26
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I don't think it is specifically a watering problem. If it was not enough watering then the other plants would be looking droopier. The plants look well mulched to help conserve moisture
If it is in a low spot, water could be collecting more in that spot and that could cause the drooping and yellowing.
But, as Lindsaylew said, it might be an issure with insects. Insects will usually attack the weakest plant first. I have been having problems with broad mites and white flies on the peppers and spider mites on eggplant. Weevils will also be out now. It would narrow things down to check under the leaves and the stem for signs of insects.

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jal_ut
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"Summer watering...does it cause blight?"

I am going to say NO!

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jal_ut
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This board software needs some help!

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Lindsaylew82
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I think the rest of the plants ARE Looking dry, and the bottom leaves are consistently droopy, and slightly curled.

Brown Thumbs
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Yes, bottom leaves were droopy on each one but it had only been two days since watered real good. I usually water during late afternoons. I just recall the blight getting peppers and tomatoes years ago and always seemed to hit during mid summer and after watering good, or maybe heavy rain.

Good news is there's a good chance of rain tomorrow...finally. Thanks for all the comments!

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Gary350
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Blight usually runs in 5 to 6 year cycles. If other people have blight in their garden you will likely have it too. I have not seen or heard of blight yet this year. There was no blight last summer. About 7 or 8 years ago everyone was having a blight problem. I learned copper and lime will often prevent blight but this is a prevention it will not stop blight once you get blight. Put about 50 copper pennies in the soil around your plants, also put 2 tablespoon of pellet lime in the soil around your plants. Once you get blight it is not easy to stop. Copper sulfate works just as well as pennies but it is hard to find in small amounts and expensive. You can always wash the dirt from the pennies and spend them after frost kills the garden. Several years ago blight was so bad tomatoes were dead by mid July every year. Not knowing how much copper and lime was needed I had to experiment. The third year I had my blight under control enough to keep my plants alive until the end of August. 2 tablespoon of pellet lime, 1 teaspoon of copper sulfate in the soil at the time of planting tomatoes PLUS I mixed a gallon of wood ash in a 5 gallon bucket of water then pour the water through cloth to filter out all the partials so I can spray the water on my tomato plants, I also put 1 tablespoon of copper sulfate per gallon in the spray water. I sprayed my tomatoes every day for 2 months when the weather here started to get cooler in the fall tomatoes slowly got blight and were all finally dead by Halloween. My plants are usually dead by Halloween anyway that is usually our first frost. I think your geographic location has a lot to do with blight it is very humid in TN I think we have blight worse than most places. I used a 2 gallon hand pump sprayer in the garden to spray plants add 1 teaspoon of dish soap to the spray water it helps the water stick to the plants.

Peter1142
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I don't see how pennies in the ground is going to prevent blight. I think this is an old wives tale. First of all modern pennies aren't even made with copper anymore, second I really doubt any copper on pennies will wind up taken up by the plant, third excessive copper is very bad for the soil.

The common recommendation by the blight authorities is to spray your plants with copper or a non organic fungicide regularly as a preventative... not add anything to the soil. But even this is far from foolproof.

Also blight does not run in cycles. Late blight can not overwinter at all and early blight is highly unlikely to overwinter, at least in temperate gardens with a significant winter. It comes up every year from down South on transplants and by wind. There is no cycle to it.

I highly recommend anyone worried about blight to go read up about it at usablight.org ... there is so much misinformation out there on this subject. Don't take my word for it, go read what the experts say yourself.

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jal_ut
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In high dry Utah, we either irrigate or burn up. My irrigation water comes from a reservoir down a canal then into a pipeline. I have gravity fed pressurized irrigation on my lot. I use 4 inch aluminum sprinkler pipes with rainbirds every 40 feet. I run a line for 12 hours once a week. It puts down a little over an inch of rain over the whole area. Odd that I don't seem to have a picture available. Will have to work on that.

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Gary350
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If you read what is in the $15 pint bottle of blight spray it has copper sulfate, lime, calcium carbonate, baking soda. Calcium carbonate is TUMs. If you don't have copper sulfate the next best thing is, copper, copper tubing, copper wire, copper shavings, copper pennies, any type copper. I don't believe metal copper will work very well, very little copper will actually get into the plant.

I bought 10 lbs of copper sulfate several years ago. I still have 9 3/4 lbs.

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Lindsaylew82
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Gary350 wrote:If you read what is in the $15 pint bottle of blight spray it has copper sulfate, lime, calcium carbonate, baking soda. Calcium carbonate is TUMs. If you don't have copper sulfate the next best thing is, copper, copper tubing, copper wire, copper shavings, copper pennies, any type copper.

I bought 10 lbs of copper sulfate several years ago. I still have 9 3/4 lbs.

If there were any truth to that, every single grower would have copper tomato stakes! ;)

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Gary350
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Lindsaylew82 wrote:
Gary350 wrote:If you read what is in the $15 pint bottle of blight spray it has copper sulfate, lime, calcium carbonate, baking soda. Calcium carbonate is TUMs. If you don't have copper sulfate the next best thing is, copper, copper tubing, copper wire, copper shavings, copper pennies, any type copper.

I bought 10 lbs of copper sulfate several years ago. I still have 9 3/4 lbs.

If there were any truth to that, every single grower would have copper tomato stakes! ;)
Several companies make, blight control, blight prevention, blight stopper, fungicides, etc. They are not all the same. Some contain long 30 letter chemical names I can not pronounce, I would never put that on my garden it might cause cancer. Some are common every day things it makes a person wonder if it is a fake. They are too expensive to try very many, I tried 2 and my tomatoes died anyway. We had blight in TN for about 6 years I learned once my tomatoes have blight there is no stopping it. I did a lot of online research finally learned copper sulfate and lime are the key items to prevent blight, put it in the soil before you plant tomatoes. Urine and wood ash both contain a large percentage of lime. I buy pellet lime at Farm Supply. I bought copper sulfate at Tractor Supply = TSC.

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Lindsaylew82
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Yes Sir, but copper sulfate and copper pennies, piping, etcetera are two very different beast on the bioavailability chart...

They are not interchangeable. Copper pennies does not equal copper sulfate.

The worms don't like it anyway...

Back to the OP....


I think if you just remove the affected yucky looking leaves, use a mild fungicide, like neem oil, baking soda, peroxide, or milk, and use bottom watering from drip lines, you'll be surprised how manageable it is.

We get blight EVERY year.... It's just a practice of keeping it at bay long enough to get a good crop.

Susan W
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There are many theories and wives tales on watering, as we can see/read here. I try to deep water with the hose every few days, and some plants need more daily. Weather is the deciding factor! Duh! We had 2 weeks of hot and mostly dry which meant stressed plants. As I set up a sprinkler for some azaleas and other shrubs that were getting cleaned, mulched etc, moved over to cover another area including plants starts and some large containers. What a difference an hour of light spray made! The water washed off dust etc from the leaves, and the leaves absorb water as well as the roots. It doesn't take much water going through the hose to have a sprinkler cover a decent size area. Since that a few days ago we have had rain and slightly cooler temps. Plants look much better!



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