I am sure it does not rain for ever, every single day. Find a window of time ( couple of days or more) and do it. Check the weather forecasts. Again, wait for another opportunity. after the rain stops. Here in PNW we get rain often and that is how I do it myself.

Just an example:
My spraying schedule is near. But It will rain on this coming Friday. So on Saturday I'll do it.. The poit is not to give the spores a chance to grow, as much as possible. I read Somewhere that there is a product that you add to the mix. so it sticks . I don't know how effective it is in rain.

Sey

A surfactant / wetting agent could be Spray-N-Grow COCO8 Coco Wet Organic Wetting Agent. It works very well, but I don't know how effective it is in rain.

Nitsua wrote:

> Sey, sometimes it really can rain "every single day" for a lengthy period of time.

Nitsua, that picture is the FORECAST; it does not HAVE TO HAPPEN as they say in the forecast.

See the picture bellow: forecast 8 days in a row of rain.

Only... ONE day it rained - Friday.

Tropical storm Bill is moving through with a bulls eye on this area. In this case, there's an excellent probability of forecast accuracy. 5 to 7 inches expected over the next couple of days according to some sources. It's quite unlikely there will be NO rain.

Daniel - Ah, but you are looking back at what happened. You don't know what the weather will actually be until after the day passes. So how do you know when to spray if the forecast can't be relied upon. That is exactly what I faced this past spring. Rain forecast almost every day and it did rain almost every day. So as Nitsua asks, what to do if it does rain for several consecutive days.

I wouldn't spray. I think the rain will wash the fungicide. The surfactant / wetting agent will not help, imo. I would wait until the rain stops. If it's not COLD I don't think it's a big problem. Well, if it rains 2 weeks everyday...

Nitsua, Bill might or might not "visit" you. You will have rain for the next few days, but I don't know about 7''. They say that "southern and eastern Missouri" will be affected. Are you in those areas?

I'm not a 'sprayer', and my experience in that regard is almost nil, but as daniel said, I don't think a wetting agent would help. In fact, a wetting agent would make things worse, wouldn't it? Soaps, for example, make things 'wetter' than water. Thus the substance would be even more susceptible to being washed away. I don't know the chemistry behind fungicides, but if my thinking and chemistry is correct, you would need the exact opposite of a 'wetting agent'. You need an oil, or better yet, a wax. But, as I said, I have some experience with chemicals, but I don't really know how fungicides work.

Yes, Daniel, I'm right in that area. I agree that 7 inches does sound extreme but then that's close to what we got with the remnants of Hurricane Ike in 2008. TS Bill is looking very similar so far according to the anticipated storm path and behavior. These types of events are quite effective in pulling up a lot of moisture from the gulf.

So far this week, 1.7" Sunday, .5" yesterday, and about .3" (so far) today. I went out and harvested all the garlic this morning rather than risk keeping it out there with more rain.

Spraying doesn't make much sense under the circumstances, so I'll wait until more typical (and dryer) weather returns and hope for the best. I do mulch well, so hopefully all will be okay with the tomatoes.

In the case of Daconil, as long as it dries on the plant then it should be good for several days. The more rain you get obviously the shorter the time period between treatments. Don't get too hung up on schedules. High humidity, or cloudy, no wind type weather, shorten the time between treatments. Low humidity, windy and sunny, stretch it out.

Tropical Bill is also headed my way but reading all the comments, I think I will try to spray tomorrow if it doesn't rain. The forecast does indicate more rain. I lost most of my tomatoes last year and I was never sure if the roots just rotted or they got a fungus. It had rained lots around the middle of June and then topped it off June 24 & 25 that left puddles in the garden and our pond flooded over with carp swimming around!

Nitsua, according to the forecast there will be 7 days of rain.

imho in 2-3 days the rain will stop in your area.

By Friday it will be sunny.

I so much hope you're right, but at this time, predictions are for over an inch on Friday. NOAA says ...

Still thinking we will see a swath of rainfall averaging 5-7 inches over the next 5 days centered near a Rolla-Waterloo-Salem axis, with the highest rainfall period centered in the Thursday night-Friday time frame. Local rainfall totals could be quite a bit higher.

Its been raining nonstop for several hours now and everything is quite soggy outside with water starting to pool up outside of the raised beds.

Despite the frequent rain, there have been short periods where the sun has come out creating a very steamy tropical-like atmosphere. Its quite unusual.

Daconil washes off easily. It is only a preventative and does not have direct fungicidal/bactericidal effect. What is does is connects to receptors on the leaves preventing microbes from attaching to the leaf. Copper is better as it does not wash off easily and has some antimicrobial properties.

Helen, if you are building a boat, I am joining LOL. It has been raining daily for over a week. Hot and humid and cold and humid... Not unsual for Chicago June weather. Soil drenches will help more in this situation specially if you have no drainage problems. I use Exel LG and actinovate, as well as compost teas. Drenches with aspirin water are said to be beneficial. Keeping plants pruned if they happen to be overgrown but in zone 6 it is probably not an issue yet.

Daconil under normal circumstances is not absolutely necessary. To me it is like insurance policy, for just in case, mostly as preventive measure..
So you can wait until it clears up and then go ahead and spray.

Sey

Personally, rather than trying to spray to counter the plants being perpetualy wet, which would be very difficult, I'd try to figure out a way to keep the plants dry so spraying is less necessary. I'm not sure how many plants and how feasible that is for you, but creating a shelter would be my starting point.

Nitsua, later today the rain will stop and plants will dry, so you can / should spray. If necessary, prune a little before spraying.

Currently Bill is going NORTH.

Probably tonight he will head NORTH-EAST and visit you.

Meantime it might lose some power.

A shelter could help, but the high humidity is also bad.

Especially if it's COLD, which - fortunately - is NOT your case.

Helen, the rain will stop later, plants will dry and you will be able to spray.
It might rain tonight / tomorrow, but maybe not.

Bill might visit you these days.

Right now, your rain is heading East, toward New York.

I will not panic just yet and I am going to keep a better eye on them this summer. I have around 65 plants so I can't cover them. It was raining this morning so I haven't gone out to the garden today but it looks as if the rain has stopped but no sun, just clouds overhead.

daniel_nyc(7a) wrote "Nitsua, later today the rain will stop and plants will dry, so you can / should spray. If necessary, prune a little before spraying."

Unfortunately, there was nothing dry here today. It rained continuously until about 8:30pm, although today it was a very light rain and drizzle. Humidity has now dropped down to 99%.

Bill will move through on Friday and it looks like the sun will finally return on Saturday.

But when I went out to grab some lettuce, I did see an almost ripe Sungold!

Nitsua, Bill is there. Not the bulls eye, but still plenty of rain.
Worse, an ugly cloud is coming from North-West...
Please check the interactive map.

"Bill" goes N -NE.

The "ugly" cloud goes SE.
I'm wondering who will win when they will collide...

This is an interesting thread, to see the wide range of opinions. I think the original question has an easy answer, and I'm not convinced that the opinions are scientific as much as negotiated attempts to comply with label instructions along with perceptions on the rain resistance of Daconil.

"Should I spray fungicide between the rains? I know it will rain again in the evening."

Depends specifically if you can get an interval long enough between the rains to get the leaves dry. This is a simple yes/no which you must guess. You know the leaves are dry after spraying if you can get a dry white evaporate smudge on the leaves. If you can, then spray. A heavy rain will remove much of the residue but some will probably remain. Just double your spray frequency during rainy weeks.

Daconil is less toxic than heavy metal synthetic copper fungicides used in organic gardening, both for humans and for the terrestrial environment. Copper persists and accumulates and upsets the organic ecosystem in soils, Daconil doesn't accumulate when used as directed. However, it is highly recommended you do not rely on a single fungicide, and mix it up. Not varying will encourage selection for baddies and even if not selection, some mold/fungi are more vulnerable to one over the other anyway.

The long answer would be ... depends on what you are spraying for. If it is late blight which has taken a foothold, you are up the creek with a toothpick for a paddle with either. That is what these are usually called "preventatives". This post refers to prevention. I am mostly concerned about mold, which is a battle I have a prayer to overcome, which makes a big difference, but usually depends on other environmental factors.

Hope that helps.
PC.

PC wrote:

> Daconil is less toxic than heavy metal synthetic copper
fungicides used in organic gardening…

Daconil is “potential human carcinogen” while copper is not, so how
Daconil is less toxic than copper?

"Daconil is “potential human carcinogen” while copper is not"

A casual read of the above declaration would seem to logically imply that copper is not a carcinogen. Copper is a known acute toxin which has conflicting results regarding carcinogenicity, especially long term. Part of the problem is that since it is toxic acutely, long term studies at high concentration are not possible. Daconil is not acutely toxic, though it can be an irritant.

Copper is known to damage Human DNA, whereas Daconil has not been shown to damage DNA.

Copper enjoys its own "Category D", which corresponds to the Daconil's classification, the category you mention, currently classified in "Category B2" for Daconil.

Group B2 is used for Agents for which there is "sufficient: evidence
from animal studies and for which there is "inadequate evidence" or "no
data" from epidemiologic studies.

Group D - Not classifiable as to human carcinogenicity. This
group is generally used for agents with inadequate human and animal
evidence of carcinogenicity or for which no data are available.

Modern copper fungicides have been in use for over a century. Daconil is a relatively recent innovation and had specific hurdles to meet with regulators, to a greater degree than copper, since Daconil was an unknown. Daconil was fed to lab animals chronically at ridiculously high rates which resulted in stomach tumors. Reproducing some of the similar studies (but not all) with copper would likely have killed the test animals by destroying their livers or kidneys with acute copper toxicity before any long term ingestion could be related to tumors.

Unfortunately toxicological studies usually don't mesh with practical uses and are sometimes intended for other purposes. Public regulators are not breathing down your nor my neck to compare what we and how we are applying these.

Toxicology is all about persistence, accumulation, dosage and method of entry. When certain animals are fed diets of copper, it becomes fatal. In trace amounts it is a mineral. If you drink a quart of Daconil concentrate I think you would get a lot more than a stomach ache and medical people would be very interested to see if it resulted in cancer of some sort 20 years later (if you survived)

Daconil is more easily washed off and degrades quickly in real situations. Copper accumulates to the point that soils in some places (and I bet they include NY, CA and France) are polluted and for cleanup we are talking Superfund. You know, like the Superfund cleanup of copper in Plainview, Long Island, or all the copper contamination in Long Island Sound? Have you ever heard of that? There are many other opportunities for exposure to copper in our life, including pipes and pots and pans. These are low, though, because they are not in soluble ionic form as some of the fungicides have the copper. That means available quickly to kill pests. When a toxicologist looks at that, they don't automatically say ... there is a very low level exposure due to these things so it must be safe. It is the other way around. Copper is an industrial byproduct and many are getting more than healthy doses. Now you just added another source with the fungicide.

Is Daconil absorbed through the skin? Ans: NO
Is copper absorbed through the skin: Ans: YES

Are they both damaging to the lungs: Yes, but Daconil breaks down quickly while copper persists. Ammonia fumes or bleach in cleaning solutions would be similar to Daconil as far as I can tell. Don't breath them in...

Just something to keep in mind if you spray like I do and it settles back on your hands and rest of skin. Most of the Daconil studies are from injection of 99% pure Daconil into the unfortunate subjects. If I remember correctly the concentration of Daconil sprayed on leaves is about 1200 ppm ( 0.12 %), but the RTU crap formula is like half that.

Finally, there are no guidelines as to how much Daconil can be in your soil by the same regulators, however soils with over I don't know, is it 100 ppm copper? They are considered contaminated. These are simply artifacts of levels of measurement. The bottom line is the level of exposure to Daconil the way we use it, is orders of magnitude below what happens with any accidental ingestion. Furthermore, Daconil does not persist, so after a few days you can forget about having used it. I wouldn't want to earn a daily living spraying either Copper or Daconil, though. And I recommend you use both if you go the spraying route.
PC

Nitsua, Bill is coming.

It is raining now as I read your posts which I appreciate very much. We had a few hours reprieve today but it is at it again. High winds and rain coming down in buckets. Daconil or no Daconil, I couldn't apply it if I wanted.

Helen, we're just gonna have to ride the storm out and pick up where we left off when things get back to normal. Bill should work its way into Missouri, then take a right turn and head east toward southern Ohio.

I can't think of much that can be done for the plants right now under the circumstances. So far, all of my plants look okay with the exception of my Marketmore 76 cucumbers that have some pretty unhealthy looking lower leaves.

My preferences would be for copper because I CAN choose low strength from range of 0.5 to 2 fluid oz and I know exactly what amount of copper my soil contains from soil test. I would use Daconil only in the beginning of season at planting out or if I know to have long stretch of hot dry weather and my plants are overcrowded as usual LOL. But yeah, discussing one over another is like discussing which chemotherapy drug you like best...

Nitsua, 3 days ago – Tuesday to be exact – I wrote:

> By Friday it will be sunny.

It’s Friday.

It’s sunny.

So far today, I have 3.3 inches of "sunny" in my rain gauge. Total for the week is now 7.5 inches.

The worst of it is over and now its overcast with some occasional light mist. I should see the sun tomorrow. Let the drying out begin!!

Now, that was a good rain.

No need to water for 2 weeks.

Any heavy winds ? Damages ?

Everything is rather "squooshy" out there and probably will stay that way for a few days. After a high today of 72, the heat will return tomorrow and we'll hit the mid 90s by Monday.

Fortunately, no wind problems here and there was very little thunder and lightning all week ... just a rather boring rain.

Plants seem fine and some even seemed to thrive through the almost consistent rain - zucchini and beans in particular.

Natsua, I am still optimistic that the tomatoes will survive, peppers are looking a little pale green. It rained all day yesterday and started up again this morning. The forecast is for rain each day thru this coming Friday. At least I am not in Southern Ohio, I am just above Columbus. Southern Ohio seems to get most of the snow and rain coming through.

I am still trying to get all the tomatoes staked and tied. I do the Florida Weave but when they grow too fast before I can get to them, they seem to turn crooked and it is hard to get them going straight.

Well Nitsua, good that Bill left your area.
Currently Bill is...(see picture bellow.)
Actually looks like Bill might be heading toward... New York City area.
Hope not.

Bill deposited 3.5 inches here in the last 24 hours. That makes 5 inches for the week with several more chances in the coming week. Yikes. It has been a little on the dry side so far this spring but overall pretty good tomato growing weather. One thing for sure it will be very humid next week with highs in the 90's and heat indexes approaching or exceeding 100.