Please help in identification

[mashermike]

Built a partial hoop house over the tomatoes on the advice of a local commercial grower. The plants still get wet from blowing rain and dew however.

Am I correct to think this is either early blight or some form of mold/mildew? I've sprayed bleach after rains, daconil once, then recently, Mancozeb and Copper Fungicide.

Thanks,
Mike

[Paradajz]

hi, Mike.

with 95% probability it's Cladosporium fulvum, a.k.a. Fulvia fulva, or simplier, Leaf Mold.
the 5% i leave to Botrytis Cinerea ( Gray Mold ).
not sufficient material to be conclusive on it, but some of the photos suggest a slight touch of a secondary disease there.

funny you asked about it, i made quite a fuss with it here http://www.tomatoville.com/showpost.php?p=355992&postcount=137

it's a totally rare issue when growing outdoors, the case with my plants i referred to with above stated link is actually the first one i witnessed in 19+ years . compliments to abnormal weather conditions that have fallen upon us this season.

as for disease, you unfortunately need to be prepared for some heavy defoliation there, there is no curable treatment after the initial symptoms appear.
the disease is not a particularly heavy one, but it's a headache- when the pathogen enters the host it takes 10-12 days for the first symptoms to appear. this means that the sections which were infected then can not be saved ( spraying some cool systemics in 48h after the infection at latest could ).
all 3 of those ( chlorothalonil, mancozeb and copper ) are effective for the disease, but only when we talk about the further spread. in other words, you should be prepared that up to 10-12 days after the last spray you could be seeing further spread.
if a substance like boscalid is available to you i would use it for an increased protection.
you also need to be vigilant for secondaries there, therefore another treatment with copper/mancozeb mixture would be handy if boscalid is unavailable or unwanted.

but, above all, try to find a way to air- condition those plants, this bugger can't go on when relative humidity gets under 85% and temps rise constantly above 25C.

br from ''a companion in pain''

[efisakov]

I am guilty, as many tomato growers, in not keeping plants less bushy, more ventilated. I have somewhat similar look on my tomatoes. Had to go and chop lots of leafs (including healthy once). We are heaving too many rains here. Spraying may not help if you can not get it all covered with what ever you using. I spray not just leafs but a stems as well.

[mashermike]

but, above all, try to find a way to air- condition those plants, this bugger can't go on when relative humidity gets under 85% and temps rise constantly above 25C.

Maybe now would a good time to finish closing in the hoophouse? I think I can keep them dry but I'm a little worried about keeping them cool. I'm not familiar with any fungicide by the name boscalid.

Thanks,
Mike

[Paradajz]

hmmm, what's your weather prognosis for next week, and when did you do the last spray?

boscalid is a substance, not a commercial product name, e.g. in our market you could find it as a product named ''Endura'' from BASF, and a plenty of others.
i for example didn't use it on first symptoms appearance with my plants, but cyprodinil + fludioxonil ( a product named ''Switch'' from Syngenta ). the reason i recommended boscalid to you is 'cause it's a bit stronger with Botrytis ( which i couldn't exclude as a ''companion'' hiding behind F.F. there ), and it also has some secondary effects on Blights and Spots, which could easily be present there and significantly threatening to endanger those highly stressed plants.
fenhexamid is also an adequate substance for this bugger.

a pair of advices:

* it's not a terrible disease, but it will highly depend on weather conditions- if it continues to be that bad, i would definitely recommend the use of a systemic there since you simply cannot spray enough copper/mancozeb under such conditions. chlorothalonil ( Daconil ) has been shown some resistance with this.

* your plants generally look a bit high on nitrogen side. when you add setting fruits ( stress factor, and a strong one ), weather ( stress again ), and the disease ( more stress ), it makes your plants highly sustainable to any diseases right now, and that's actually what you need to be vigilant for there.

* to cover for defoliation ( present and future one ), leave some suckers not- pinched ( higher ones ), it could be useful once you see the final result of defoliation.

* i guess the fruits there won't get sun scald- ed, but a possible result of the defoliation can be a significant reduce of photosynthetic capacity of your plants. therefore, in addition to leaving some suckers as a ''reserve army'', do a ''strength/anty- stress'' treatment:
3 consecutive foliars at 4 days intervals with kelp+ beneficial bacteria product+ adequate pottasium foliar fert, all mixed at 30% of the recommended rate.
BTW, this procedure helps with just about any high- stress situation with a plant, heat- shocks especially. it even makes stuff like leaf roll easier

it would be nice if you could post updates too.

br

[mashermike]

Thanks much Paradajz

Rain is forecast for next 7 days 30%-60% .... raining now.

For better or worse here is what I have done:
6/1 - Daconil
6/5 - Feed 1 tbs 10-10-10 w/micro & calcium nitrate
6/6 - Mancozeb
6/14 - Copper

I found Pristine but it is $475 .... maybe a bit expensive. Ok on foliar spray.

Mike

[efisakov]

Epsom salt helps with plant grows.

[mashermike]

Here are the follow-up pics after three foliar sprays. Not too much rain in the last week.

I have not trimmed any leaves in a week so one picture is showing some dead foliage .... I hope.

Plants are looking better. I've pulled about a dozen hornworms however.

Thanks for the help!
Mike

[mashermike]

I last sprayed on 7/1 - mixture of Mancozeb and Copper. The relative humidity has been in high 90's. Its raining now but all the plants but one are doing pretty well.

Pictures 1-3 and 5 show problem plant. Picture 4 and 6 picture show general plant health.

Is this mold or septoria? Should I pull this plant or give it some time?

Thanks,
Mike

[RayR]

Looks like Leaf Mold to me, I don't see any evidence of Septoria.
The general health looks good.