Anthracnose Ouestion

[DennisinPa]

Hi all, I have trouble with Anthracnose and hate throwing tomatoes away
This year I want to try using Daconil and was wondering if I should start using it at the first sign of trouble or start applying it sooner


Thanks for the help
Dennis

[Suze]

Dennis, I have limited experience with anthracnose here, but time and time again, I've heard cooler zone growers (including Carolyn) say that it tends to be more of a late season disease that doesn't really express itself until towards the end of the season when night temps drop and morning dew increases.

It might not be necessary for you to start spraying right this second, but if you choose to spray, you would want to start spraying before you'd normally see symptoms -- just like with most fungal diseases.

FWIW, I've also heard some state that it is more likely to affect tomatoes that are left unpicked to the dead ripe or overripe stage. So if you're having problems with anthracnose, it might be a good idea to pick fruits before they reach that stage.

[DennisinPa]

Suze, Thank you for the information

Dennis

[feldon30]

Every one of my tomatoes and even one of my bell peppers are ripening and exhibiting anthracnose.



Do I need to throw these fruit away?

If I spray with Daconil right now, will it systemically treat the anthracnose, or are all the green fruit hanging off my plants doomed?

I ask because it's mid-June, and in Houston, most people pull up their tomato plants anywhere between late June through July. It's not really worth trying to nurse unproductive plants through 95 degree, humid weather for 3 months when the fruit they produce if they survive is apparently not as good in the fall.

So if these plants are all diseased and there isn't much I can do to save the fruit that's on them now, then I guess I will just pull them. I guess I can look on the bright side. I'll have more time to spend dividing my 6' wide garden into two 3' wide gardens as well as building my new 3' wide gardens.

Also, is this a soilborne disease? Do I need to do anything to treat the soil for this? Or since I have had this problem, do I now need to preventatively spray anything I plant there this fall (I intend to do a lot of beans which I know are vulnerable to anthracnose) every other week since this fungus is established?

I'm pretty sure this all happened because of the 4 days of torrential rains we had two weeks ago plus I recently overwatered when I didn't use a watering timer.

[feldon30]

P.S. I have a Brandywine pink and Cherokee Purple that each have fruit. Should I try to save these and spray with Daconil?

[feldon30]

Just read some articles and it looks like I need to pull the plants. The fruit also needs to be discarded. Nothing goes in the compost pile since anthracnose is soilborne. So the question is, do I need to spray the soil and mix the soil up? Or just go on the basis that anything I plant in that soil is going to be infected with anthracnose so I need to start systemically treating the plants with Daconil?

[Suze]

Feldon,
Daconil doesn't work systemically -- it works by 'sealing' attachment sites for fungal spores. Pretty much the same w/copper sprays. So, no, Daconil is not going to reverse any symptoms you currently see on your fruits and plants. It is also not going to help when sprayed on the soil or used as a soil drench.

I'd recommend that when you pull plants, as much refuse as possible needs to be disposed of away from the growing area (I don't compost any of that stuff either, some do... I'll just say I don't recommend it and leave it at that). You may also want to either turn under your beds before planting in them again and/or solarize them for a reasonable time period (fyi-clear plastic is better than dark).

And frankly, this late in the game in Texas, I wouldn't waste the $$$ and time spraying with anything (except maybe your peppers depending on how they look).

If you're going to spray here at all, it's best done early, often, and regularly -- way before any spring rains start. I don't even bother any more in June.

[Suze]

A couple more points--

Mulching heavily helps to limit or even prevent splashback of fungal spores. If your peppers and any tomatoes you might decide to leave in aren't mulched, then you might want to do so now. And I would also recommend that you mulch your beds thickly next year.

Yes, the fungal spores for anthracnose are in your soil now. However, those spores have to actually contact the surfaces of your plants to infect them (which is why heavily mulching is such a good idea - to limit splashback). Plants won't take the anthracnose up into their roots and become infected in a systemic fashion.

[feldon30]

I've kinda been figuring I should just pull the tomatoes and peppers and dispose of the plants and unripe fruit away from the compost pile.

I hate to toss my Brandywine and Cherokee Purple that finally decided to get some fruitset (but which are realistically about 2-3 weeks away from being ready).

What mulch would you recommend? Hay? Straw? Not sure where to get leaves at this time of year.

Do you preventatively spray Daconil? Or only after it rains? I am seriously going to use a tarp next time we get rain like we did.

[Suze]

Mulch -- I like straw; light color, has great insulative properties, i.e., straw bale homes, etc. Don't get hay, there are too many seeds.

I start spraying the very day I bring the plants outside to harden off (late Feb-early March). Then I spray every 7-10 days until about early/mid-May or so. I used to just use Daconil, but have come to greatly prefer a rotation of Daconil and Mancozeb.

My goal is to prevent buildup of fungal spores (early blight and septoria) as well as possible buildup of bacterial speck to the greatest extent possible before those inevitable late spring/2-4 day long downpours move in.

By doing so, I can usually get about 70-90 days of spring harvest out of my plants as opposed to the 30-50 I'd get if I didn't spray.

Keeping your plants dry if you can is a very good thing here, so if you don't mind tarping them during any downpours, I'd say to go for it.

[feldon30]

I pulled all but 2 plants today. Very upset about it but based on the information I had it seemed the right choice.

The plants were actually in excellent health considering the heat, except for the spider mites I discovered on my Matt's Wild Cherry. I had a grand total of over 100 tomatoes hanging off the plants in various stages of ripeness. Realize that these are Celebrity and Roma tomato plants. Not very excited about them, but when oven roasted, they had a good flavor in spaghetti sauce and I was looking forward to harvesting more of them.

The problem is, nearly all the fruit I've pulled from the plants in the last week have shown Anthracnose, which is a fungal infection of the fruit. I am fairly certain that this came about because of the copious amounts of rain we had 2 weeks ago which splashed soil up onto the plants and fruit. All I know is I was pulling very good looking fruit and then all of a sudden all the tomatoes had sunken spots that started rotting.

For all intents and purposes, the plants *looked* great. Much healthier than all the doom and gloom I'd been hearing. But it didn't make sense to try to keep ever-sickening plants alive that would produce worse and worse tomatoes as time went on. Folks normally pull plants in July, so basically I've lost a month of harvest.

Based on the advice of forum members here, I pulled all the plants because once anthracnose takes hold in the green fruit, Daconil and other copper-based fungicides will not fix the problem, and you can't tell it's infected until it ripens. So basically what I had to look forward to was another month or so of harvesting fruit, most of which would probably be infected with anthracnose.

I am trying to avoid chemicals and just use things like Neem Oil, insecticidal soap, and mostly organic fertilizer and compost.

But with Houston's torrential downpours, and warm muggy days, I am thinking that funguses absolutely will take hold. And because anthracnose is now in the soil, I intend to spray with Daconil every 2 weeks from now on. I wouldn't do it if Carolyn and other tomato folks didn't do it.

My intuition was to put tarps over my entire garden when we had that torrential rain, but I didn't act on it. I know it sounds unconventional, and most people just let it rain and then gripe about how soggy and rotten and fungusey the soil and plants become. I have huge tarps that I can easily cover the entire garden beds with and intend to use them the next time the sky opens up and I'm at home.

I saved cuttings off the MWC and my Brandywine so maybe I'll get a jump on those this fall.

This may not be the thread for it, but is there a thread or guide that covers just what pitfalls there are to fall Tomato growing in Houston? I keep hearing it's more difficult but the details never come.

[feldon30]

Out with the old:




in with the new:

[Little_Rhody]

Suze,

"I used to just use Daconil, but have come to greatly prefer a rotation of Daconil and Mancozeb"

I had never heard of mancozeb before and did a google search on it after seeing your post. I was wondering why you prefer to use both. Also, has anyone tried Champion WP, a fungicide, said to be organic, offered by Johnny's Selected seed?

[JBinKC]

After Suze mentioned Mancozeb, I picked some up, I really liked it and it really did help.

I don't have the Daconil Label at the moment but "Mancozeb helps controls cercospora, leaf spot, rust, gummy stem blight, downy mildew, early and late blight, Black spot"
When you look for the directions for Tomatoes it states under diseases "Anthracnose, Early blight, Gray leaf spot, late blight, leaf mold, septoria leaf spot.

I'm sure alternating the two help keeps the plant from (Dang it I was doing so good and then my memory just went kaput) building up a resistance to one or the other so they don't work as well.

EDIT: I was just having some mildew or some sort of problem not anthracnose.

Ok I'm going back to my coloring book now

[Suze]

Originally Posted by Little_Rhody

Suze,

"I used to just use Daconil, but have come to greatly prefer a rotation of Daconil and Mancozeb"

I had never heard of mancozeb before and did a google search on it after seeing your post. I was wondering why you prefer to use both.

Carolyn,

First reason--Daconil is an anti-fungal, and thus isn't helpful in protecting against bacterial spot and/or bacterial speck, and those can be occasional problems for me.

Secondly, while I've found that copper really doesn't help a whole lot with early blight, it can have a fairly decent preventative effect on septoria leaf spot, which tends to be more of a problem in my garden than EB. I get much better results 'sealing' the plants with both than I do just using the Daconil. The mancozeb gets used every third spray (I spray once a week to ten days).

My approach is to spray early and often, then let off once the plants reach a decent size and have started to set some good fruit.