Hi Bill,

I don't know. I think it all depends on several different factors.

First of all, the Daconil sprayed on the leaves coats them and keeps disease spores from "attaching" to the leaves, and I know you know that. The thing is, not all spores are splashed around by water....they can be carried by the wind. So, even if you are not having moisture falling from the skies, or splashing up from your irrigation system, air-borne disease spores still could be an issue.

Secondly, how disease-free are your plants? If they are fairly disease-free at this point, I probably would be comfortable discontinuing the spraying of Daconil. If I felt like the diseases were lurking all around (for example, if all my gardening friends in the neighborhood were having disease issues on unsprayed plants), I'd be less likely to stop spraying.

Third, if your humidity levels are low in the mornings and there is no dew on the plants in the early morning, I'd be more comfortable discontinuing the spraying.

Fourth, if your plants have set all the fruits they're likely to set because temperatures have gotten above those crucial levels, then I'd be more comfortable discontinuing the spraying.

Fifth--on the other hand....if you hope to carry your plants through the heat of the summer and it is your hope that they will bloom and put out a new set of fruit in the fall, that would be an argument to keep spraying.

Sixth, if you are growing tomatoes in order to sell to a local restaurant or at the Farmer's Market, I'd keep spraying if I had tomatoes on the plants that will be ripening throughout July. From a financial standpoint, it would "pay off" to keep the plants going a few more weeks if it would give you several more weeks of sales.

Seventh, I say all this with the thought in my head that you and I grow in very different conditions. Where I live, we are still having very high humidity in the mornings (96% around 7 a.m. today) although it drops to the upper 20s by mid-afternoon. We also have dew most mornings, and this morning it was a very heavy dew. You are in an area that is normally much, much drier. So, if I sprayed with Daconil (and I don't) and I felt I had a lot of production capacity left, I'd keep on spraying.

Since you're in a very dry area and your moisture has dried up, you might not find it necessary to keep spraying.

Eighth, the wind plays a role. If you have good wind virtually every day, it probably is safer to stop spraying now that it is so dry because any moisture that might occur would be dried up quickly by the wind.

Finally, in this instance, I'd go with whatever Jay recommends. Jay's growing conditions are very similar to your conditions there in Anadarko and I feel like he's more qualified than I am to comment on whether Daconil is useful in the climate conditions that y'all have. So, I hope Jay sees this thread and responds, and I think he will.

Dawn

Bill,
I agree with what Dawn said. And now I'll add my 2 cents also.I will apologize in advance as this will be lengthy. About 3 years ago I made the statement i never had disease problems. As always that came back to haunt me. And in 07 and 08 I was swamped with them. Some soil borne and some insect borne. Why? I will never know all the reasons. It started when I started getting so many seeds from different sources saved so many different ways. I also made the mistake of planting onions next to my tomatoes. 08 especially was a bad year and plants were stressed. Plants are like humans when stressed more apt to get sick. Also several new diseases moved in for the first time. 07 was the first season I ever used Daconil and got started late. Then started early last year as I could see it was going to be bad. In 07 I think I quit spraying around Sept 1st and last year around Aug. 20th. I did go over the 2 week period up to a week and a few times more. With no noticeable increase in disease trouble. No doubt in my mind it helps. Especially if you have problems and no doubt it helps to start before they show up. I removed diseased leaves on some and sprayed them and they recovered and did well especially in 07. But also lost some. This year I haven't started yet. And haven't decided yet to spray them all or if I will spray at all. There are a few reasons I haven't. One is after the last two years I researched and got information from extension services and horticulturists and growers who I trusted who have had experience with diseases. One thing a few suggested for soil borne diseases was to move to a new spot and soak every seed before planting in a Clorox solution. I did that this year and most of the plants look very healthy. There are the exceptions. And I've pulled a couple I didn't like the look of. A few of the late planted ones were in the cups too long and stressed and may of got something. I believe avoiding as much stress as possible really helps. We have enough stress built in with our climate conditions. For the insect borne diseases I'm using Garlic Barrier and overall pleased. It has worked on everything but the worms on the Tomatillos. In closing I will say the 7-10 days schedule is what I call the fail safe recommendation. If you follow that you should limit the diseases. As you go over you increase your chances of getting something. I just use common sense and spray when I feel the conditions call for it. If you receive a big rain then probably wise to spray. I would never tell anyone it was safe to go longer as they would then lose their plants and I would feel bad. When gambling with mine I feel ok taking a few chances. And then I might spray a portion so I can have enough for myself and take a chance on the others. With over 80 plants I have some room to lose a few.

I tried Seranade on a few last year and Daconil on the others and in two weeks I went back and spray those sprayed with Seranade with Daconil. I know many claim to have had great result with it. Here in my conditions last year I feel I would of been just as good to of sprayed with straight water and saved my money. I don't plan on trying it again. In my opinion yes Daconil works. In the end it comes down to the extent of disease problem in your garden and are you willing to lose a few or do you need every plant you put in the ground. This year with as healthy as the plants look I may decide to take my chances and not spray and be willing to lose a few. I may spray a couple I really want seeds from and gamble with the rest. Jay

Dawn & Jay,
Thank you both for prompt and good information.
I was at odds with myself over it, but now will continue. Yes, there is humidity in am's and I do have some (I think) residual damage already, but not near like it was last year when it just ate my lunch. I have some yellowing of the leaves and some spots, (some breeds worse than others), but will just tough it out - along with the WAR I've declared lately. I've already found some red spider mites, had the tomato worm, seen some squash bugs, some cucumber beetles, trapped 3 gophers that poison wouldnt kill, (it's a sad feeling when you stand there and watch one of the monsters pulling a tomato plant under), 100 degree days, hot nights, no rain, but I still just love it. And tnx agn for your info.
Bill

Bill,

You are welcome. I hope that, at the end of the season, you'll report back on your results with the spraying of Daconil and whether or not you think it made a big difference (or a medium or small one).

It does seem like the pests are showing up kind of all at once. I have everything you have, but no gophers because the cats keep them completely under control. Spider mites just are not an issue for me at all even though we have them here, so I can only assume that I have some beneficial insects gobbling them up.

When I was a kid, spider mites drove my dad and his gardening pal who lived two blocks away just absolutely stark raving mad. Those mites killed their plants every year.

I love gardening too, but this heat is making it difficult for me to stay outside long enough to do everything I need to do.

Dawn

What's this Daconil stuff and why are you spraying your plants with it? What does it do?

(I'm not going to rush out and get some and go crazy with it, but if it's something people routinely use down here in OK to combat some problem I'm not yet aware of, I'd like to know. My tomatoes all look fine right now except for one that has slightly curly leaves all the time. It's a volunteer growing with some zinnias and marigolds and otherwise seems fine - good color, growing well, no pests - so I'm leaving it be.)

Gamebird,
Daconil is a fungicide. It's active ingredient is chlorothalnil. Basically the same as Ortho Garden Disease Control. You can do a search and read about it. It is effective preventing many diseases especially the blights. Which I had the last two years along with some other things. I try not to use anything. But if it comes to using something or not having a crop I will use the safest product that gets results that is approved. And in my case the last two years after trying several of the other products available the chlorothalnil products were the only ones that got good results. Each of us has to make up our own mind what we will use in our garden. If you have ever bought veggies at the store chances are your have ate something sprayed with it. Many commercial growers use it. I don't know it is routinely used. But know those of us that used it around here last summer were about the only ones with plants left to get a crop out of at the end of the season. Jay

Jay,

I tried Serenade the first year it was commercially available and it seemed to work very well. However, the next two years, it just wasn't effective, so I quit using it. That first year must have been "beginner's luck" with the Serenade, and it was a drier year in which disease might not have been an issue any way.

Game bird,

To add to what Jay said about chlorothalonil, it is most effective if used as a preventive spraying treatment literally from day one that the plants go into the ground. It essentially coats the leaves and protects them from infection by certain diseases. It also is most effective if used on a regular 7-10 day spray schedule. It doesn't totally prevent disease, but it keeps the disease pressure very low. And it is most effective when used as part of an overall disease prevention program that includes sterilizing seeds the way Jay does, mulching heavily to reduce soil splash, watering with drip irrigation or soaker hoses, and avoiding overfertilization and overwatering.

Some people alternate the use of products containing Daconil with fungicides containing copper or other active ingredients. They do this to avoid the development of resistance to the chlorothalonil.

In many parts of the country that routinely have high humidity and regular rainfall, many tomato gardeners say they could not/would not get a crop of tomatoes at all without Daconil. In drier, less humid areas, it is easier (although not necessarily easy) to garden without it.

Early blight (Alternaria solari) is the most common fungal disease many people see on their tomato (and related) plants, and it often shows up just when your tomato plants look absolutely "the best" they've ever looked and are carrying a heavy load of ripening fruit.

I've never routinely used Daconil because I prefer to garden as naturally as possible, but I certainly would use it if I felt like it was the only way I could get a crop. Generally, the climate here in Love County helps me out with that because, in recent years, we've tended to get most of our rain earlier in the season (March, April, May) and not so much in June, July and August when EB is more active.

I suspect that almost all of the tomatoes raised commercially in this country (except those that are raised organically) are routinely sprayed with chlorathalonil.

For home gardeners, the chlorothalonil product I see on store shelves most often is Ortho Garden Disease Control.

Dawn

Here is a link that might be useful: Image of Early Blight on Tomato Foliage

Jay,

What ratio do you mix on the Clorox solution?

Bruce

Bruce,
Two of the sources I consulted that use this method use different ratios. I have used both and haven't noticed any difference in results. One uses 3 parts water to one part Clorox and the other 4 parts water to one part Clorox. I had 85-100% germination on the seeds I treated. Did have lower on seeds from one source. I then planted 20 seeds of that variety. Soaked 10 and didn't soak ten. And got one out of ten up each way. I soak for two minutes. The time was the same with most of the sources I've received information from.
I know of another grower who didn't dip this year and lost two trays of seeds and the disease started on plants from the same source in both trays. The trays he had only his seeds in he didn't lose a one. Everything was the same. He says he will dip outside seeds next year. I don't know if one year is enough to make a fair judgement and the season isn't over yet but so far my plants are looking healthier and have had less trouble than the previous two years. Knock on wood. Jay