Mixing Fungicide and Insecticide

[RonnyWil]

Does anyone mix their chemicals to spray their tomatoes. I wanted to mix my Daconil, pyrethrin and maybe even fish emulsion in one sprayer to cut down on the number of times I have to wet the foliage and cut down on time spent spraying.

[Suze]

Originally Posted by RonnyWil

Does anyone mix their chemicals to spray their tomatoes. I wanted to mix my Daconil, pyrethrin and maybe even fish emulsion in one sprayer to cut down on the number of times I have to wet the foliage and cut down on time spent spraying.

In general, I do not recommend mixing Daconil with anything else. Chlorothalonil works by sealing attachment sites for fungal spores on the leaf surface -- and diluting the mix further (or possibly affecting PH balance) by adding something else can limit effectiveness.

Definitely NO on adding a fish or seaweed emulsion. Do that separately. My advice if you want to foliar feed is to do that the day before you spray Daconil, or put it on first, let it dry/absorb, then apply Daconil. Or alternate weeks with foliar feed and Daconil.

On other substances: Depends. In general, probably not. Usually, what I'll do in the case of pesticides (pyrethrins, bt) is to lay down my coating of Daconil, let it dry, then come back and apply the other on top, later that day or the next day. Bt and pyrethrins don't have to be applied to the point of runoff/dripping/rinsing the coat of Daconil off in order to be effective.

Having said all that, I have been known to occasionally mix PyGanic (5% pyrethrin) with a Daconil spray with good results. Wouldn't do it with bt though (PH concerns).

[feldon30]

Suze and I had this discussion the other day.

And I see she got her response in already.

Pyrethrin and Neem are oil-based, so I don't know how well they mix with water-based products like Daconil and Fish Emulsion. Also there is the fear that they will burn the plants if applied under sunny skies.

Suze suggested that I spray the plants thoroughly with Daconil in the morning, let it dry, and then 20-30 minutes or so later go back with a smaller amount of B.T. spray for the hornworms and fruitworms. Not to soak the leaves but just get some on all the leaves so when the caterpillars eat it, they stop.

If you are in a particularly humid climate, then foliar feed may be impractical. I know Earl recommends just pouring diluted fish emulsion directly at the soil line. I suppose if you wanted, you could do fish emulsion one day and daconil the next. This is only my first year trying Earl's method, but it really seems to make sense to me to distribute the nutrients in a cubic foot area around the roots which encourages them to reach out to get them. The even distribution throughout the area should result in an even supply. A side dressing with TomatoTone a few inches from the stem and then watering it in might be good as a boost during heavy fruitset.

[honu]

Originally Posted by feldon30

If you are in a particularly humid climate, then foliar feed may be impractical.

I'm curious why would it be impractical? I am in a humid climate, but have very good results with foliar feeding, and not just on the tomato plants.

[feldon30]

Because you want the leaves to be covered with Daconil at all times, and a foliar feed of fish emulsion or seaweed would wash it off. I know every morning lately, we are waking up with dew on the leaves. That can encourage fungus, so even applying foliar feed on Tuesday and reapplying Daconil on Wednesday would mean you have 1 day that the plants were uncovered.

It's hoped, although scientifically untested, that spraying with Daconil, and then coming back and adding a lower quantity of B.T. will cause a layering effect, protecting the plants from chewing AND fungus, rather than the B.T. application washing off the Daconil.

I have to say I am impressed at how well my Kimberly has bounced back.

Here's how it looked on April 9th after I stripped off 2/3rds of the leaves:




It has set another 15 fruit and put on a lot more leaves, none of which show the disease.

I have also cleaned up the bottom 8-12" of each of my plants since most of those leaves get Early Blight anyway. People often ask me if I prune tomatoes. My initial answer is No, since I do not actively seek out suckers and pinch them off, but I do pick off 10-20% of the foliage of each plant just to clean the plants up and remove foliage with EB, Septoria, or caterpillar chewing.

[amideutch]

Honu, What type of regimen do you use for disease prevention on your tomatoes. Ami

[carolyn137]

All I can add here is that many years ago I called ortho to ask about adding other substances to Daconil and I was told at that time that to do that would decrease the effective ability of the Daconil molecules to attach to the leaf attachment sites where the pathogenic fungal spores must attach in order to germinate and infect.

And I've been giving out that advice online now for at least 10 years now as many here already know.

I don't know the reason and rationale re other substances interferring and I'd say that the only prrof you['d have would be by trying this or that.

But you've got to know that what you're dealing with is a FUNGAL foliage infection, and Morgan, a quick look at that leaf of yours sure doesn't look fungal to me; it looks much more like Bacterial Spot to me. But I can go back up and take another look if you wish. I'm just running late here this AM and haven't taken my AM pills, so in about 2 min I dissolve into a wee puddle of protoplasm and flow out the front door.

[honu]

Originally Posted by amideutch

What type of regimen do you use for disease prevention on your tomatoes.

Ami, last year, I used Daconil once in awhile, before some anticipated heavy rains. In between, I had to treat for spidermites, mealy bugs, etc. and on alternate weeks, foliar fed. In previous years, I sprayed with compost or worm tea, EM, cornmeal, or seaweed solution.

[barkeater]

And I completely disagree that mixing causes effectiveness to noticeably decrease. In fact, NOT adding a spreader/sticker to the mix will decrease the coverage and protectiveness of Daconil or any other fungicide.

Think about it. You add x ounces of Daconil to x gallons of water. When sprayed there is still the same ratio of Daconil : water. The addition of another liqiud chemical reduces the ratio insignificantly. If you wanted to, you could add a little more Daconil to keep the ratio the same.

This thing about receptor sites makes no sense to me either. Every epidermal leaf cell is receptive under the right conditions. That is why completeness of coverage with a spreader/sticker is most important.

[dcarch]

It is kind of a pain to have to spray so many different kinds of chemicals.
Mixing, pumping, storing leftover liquids, washing cleaning the sprayer, etc. Disaster is when you make a mistake and spray "Roundup" on your plants.

So I have four separate sprayers, one of them is cordless electric. Life is much simpler now.

dcarch

[amideutch]

dcarch, I hear you. I have one sprayer whose whole purpose in life is "Roundup".
Honu, Thanks for the info. What are you using for foliar feed now? Ami

[carolyn137]

Originally Posted by barkeater

And I completely disagree that mixing causes effectiveness to noticeably decrease. In fact, NOT adding a spreader/sticker to the mix will decrease the coverage and protectiveness of Daconil or any other fungicide.

*****

Since no one knows the specific experiemnts that Ortho has done I'm willing to believe that mixing certain things with Daconil will decrease its effectiveness. Not spreader sticker b'c they make Daconil with and without spreader sticker. And I don't see that spraying without spreader/sticker will decrease coverage but as with almost all products with added spreader/sticker it does make the primary product stay on the foliage longer.

*******

Think about it. You add x ounces of Daconil to x gallons of water. When sprayed there is still the same ratio of Daconil : water. The addition of another liqiud chemical reduces the ratio insignificantly. If you wanted to, you could add a little more Daconil to keep the ratio the same.

******

I don't think that's the issue. I think that Ortho has no doubt done experiments with added fertilizers, insecticdes and more and found that there was binding between certaion of those preps and Daconil molecules, thus effectively decreasing covereage.

******
This thing about receptor sites makes no sense to me either. Every epidermal leaf cell is receptive under the right conditions. That is why completeness of coverage with a spreader/sticker is most important.

And I do believe the thing about receptor sites b'c so many viruses and bacteria and more have to have certain specific receptor sites before the microorganisms can bind and then infect.

Take N fixing bacteria as one example. There are specific sites on the roots to which they must attach before they can send an infection thread into the root.

And the world of human infectious disease is full of examples about specific attachment sites either being available or not available in order for certain pathogens to be able to infect the person.

So I, for one, cannot discount that foliage has specific attachment sites for fungal foliage pathogens, and none of us are privy to the research that ortho has done b'c those kinds of data are proprietary and not divulged for obvious reasons, I think.



Carolyn

[barkeater]

Unfortunately, I still have to disagree. I do know a lot about all the different types of fungul diseases, but admittedly little about Carolyn's field of expertise concerning bacteria and viruses.

When it comes to Early Blight, Septoria Leaf Spot, Grey Mold, Rusts, and the such, there are very definitive "receptor sights". Some are through the stomata, most thread their way between the cell walls, and some pierce right through the epidermis into the plant cells.

There is no proprietary knowledge Ortho has or had. Fungi do what fungi have done since creation. The metallic based fungicides that destroy fungal spores in plants are the same metals used in humans when we develop fungal infections.

[honu]

Originally Posted by amideutch

Honu, Thanks for the info. What are you using for foliar feed now?

Ami, I use a variety, including fish, seaweed, and other organic solutions, such as Neptune's Harvest, Dr. Earth, Earth Juice, Maxicrop, Organic Gem...had good results w/ all of them.

[feldon30]

Originally Posted by barkeater

The metallic based fungicides that destroy fungal spores in plants are the same metals used in humans when we develop fungal infections.

Which is why they cause liver damage.