Correct identification of disease?

[Paradajz]

hi,

@holyhotpeppers,

looks quite like a leaf miner.
anyway more chances for an insect than Powdery mildew, but keep observing- if leaf margins start being necrotic chances might turn the other way.
you might also want to check one of those leafs with a lens and towards the light, it could show something sleeping inside

@tlintx,

it also looks quite like insects damage as primary, but i don't like the spots and shape of the leafs, suggests that there could be a secondary, possibly a viral or bacterial disease.
observe the plants carefully, any changes in appearance- discolorations, leafs leaning upwards or downwards, weaker growth, wrinkled young leafs, unusual stems, shrub- like appearance, etc.?

p.s.

Powdery mildew actually does visit tomatoes although it's not that often and that serious at open fields, it's more of an issue with in- door places.
it also doesn't make serious damages at open fields- the disease usually stops with weather changes and unfavorable weather conditions, but if the plants are low on strength and immunity it can still make quite some trouble.
please also note, it's a systemic disease and copper cant do any good once it has found a host, only systemic fungicides can.
but i also agree that tlintx may try with copper- for a purpose of preventing the spread if there is a secondary disease in her plants, although it will narrow down her choices of other fungicides and insecticides she could use for quite a bit

[ginger2778]

Powdery mildew systemic? I think you may be mistaken. Also many fungicides can take care of it. Here's a few links:http://gardening.about.com/od/garden...deryMildew.htm
http://www.hort.uconn.edu/ipm/veg/htms/pmildtom.html
TL- I used mildew as just a general name for fungus and didnt intend to imply that it was powdery mildew. The black spots in your picture are something I have never seen in my own plants when they got powdery mildew. I don't necessarily think it is that, but I do think it is some kind of fungus. I respectfully wish to disagree that only a systemic fungicide will do. These links don't mention that.
Marsha

[Paradajz]

hi, Marsha.

ok, to be precise with my choice of words :

Powdery mildew is a common name for a disease caused by quite a number of fungus strains. there are 2 basic families of those- Leveillula taurica and Oidiums.
statisticaly, larger number of epidemics are caused by Leveillula strains, and those are generally more troublesome- because this pathogen is endoghenus ( this is a term in our language, i believe in English the correct word is endophytic ), which in a simple language means that it develops inside the plant tissue. that's why i used the term systemic. Oidiums on the other side are egzogenus ( sorry, i really don't know the correct term for this ) and generally easier to manage because of it.

so, finally, once inside the host, Leveillula taurica cannot be controled by a contact fungicide ( again, a term from our language, i believe you use the term preventive ) and if the outbreak is agressive and significant in range systemic fungicides are a definite choice ( in- door it's a must ).
by the way, copper isn't the first choice there, but sulfur. generally, if there is a history of Powdery mildew at a specific spot, sulfur fungicides are to be used in the prevention phase ( depending on weather conditions but with vigillance for high temperatures ), and if the disease still appears systemics like difenoconazole ( ideal for it's broad spectrum ) or more narrow penconazole should be used. usually 1 or 2 treatments do it out- doors.

although i still believe that both of the posters here don't have a mildew issue, but i do enjoy the conversation with you.

br,
ivan

[ginger2778]

Originally Posted by Paradajz

hi, Marsha.

ok, to be precise with my choice of words :

Powdery mildew is a common name for a disease caused by quite a number of fungus strains. there are 2 basic families of those- Leveillula taurica and Oidiums.
statisticaly, larger number of epidemics are caused by Leveillula strains, and those are generally more troublesome- because this pathogen is endoghenus ( this is a term in our language, i believe in English the correct word is endophytic ), which in a simple language means that it develops inside the plant tissue. that's why i used the term systemic. Oidiums on the other side are egzogenus ( sorry, i really don't know the correct term for this ) and generally easier to manage because of it.

so, finally, once inside the host, Leveillula taurica cannot be controled by a contact fungicide ( again, a term from our language, i believe you use the term preventive ) and if the outbreak is agressive and significant in range systemic fungicides are a definite choice ( in- door it's a must ).
by the way, copper isn't the first choice there, but sulfur. generally, if there is a history of Powdery mildew at a specific spot, sulfur fungicides are to be used in the prevention phase ( depending on weather conditions but with vigillance for high temperatures ), and if the disease still appears systemics like difenoconazole ( ideal for it's broad spectrum ) or more narrow penconazole should be used. usually 1 or 2 treatments do it out- doors.

although i still believe that both of the posters here don't have a mildew issue, but i do enjoy the conversation with you.

br,
ivan

Ok, now I understand and agree that once a fungus becomes endogenous it is impervious to external fungicide.
Marsha

[tlintx]

I can't get to the Depot until Monday, but everything seems tentatively to be all right. Or at least not worse. In the last two weeks we've gone from cool and rainy to warm and rainy to HOT HOT HOT and muggy.

I greatly appreciate the help -- I kind of expected to have a lot of issues over the summer here, with an eye to learning how to deal with them by fall and for next spring!


Tl