Frustrated and disappointed - help would be appreciated

[Siberian]

Hi all,

I know this is a long post, but I'm having some disease or disease-like symptoms on my plants and would really appreciate some help. I am growing: tomatoes, cucumbers, summer squash, and hot and sweet peppers, and eggplants, all showing similar symptoms.

Symptoms are: yellowing of the bottom leaves, working its way up the plant, with the affected leaves either falling off or browning and wilting completely. Plants are also wilting in hot, direct sun. Here are some photos, all labeled, ranging from symptoms at youngest age (plants wilting) to now the yellowing of leaves. http://s1239.photobucket.com/albums/...Garden%202012/

I know they are generally rarely seen in home gardens but it looks a lot like what I understand to be either fusarium or verticilium wilt. Is it possible that they came infected from my seed supplier? I have used the same supplier the past 2 years and had almost identical problems (they were separate seeds of different varieties purchased each year). Anyone else having problems with Sustainableseedco.com seeds?

I even used the biotamax/actinovate/mycogrow dip solution at plant out and have continued with foliar spraying of Exel LG, seacom pgr, and actinovate.

Any thoughts on identification, control, etc. are welcome.