hi again.
you are welcome, Naysen, but no need to thank me, i enjoy conversation with people who have a tendency of knowing what they are talking about, like you and Steve, and plenty of others here, of course
thanks, Steve, but very far from an expert i am. ages and ages ago i have studied with one though, and i would so much wish that you could hear the speech he would have given on those photos... 10sec after it Naysen would go ''all in'' for verticillium, i guarantee it
about the subject:
Naysen, i have noticed that you use raised beds with various soil compositions.
but please note, verticillium is one of the hardest villains to recognize, treat, predict or prevent. the nature of it is to unstable and hard to understand, e.g. much different than fusarium. as a matter of facts it's been almost a decade since i've seen a case where so many reliable symptoms appeared as with your plants.
as simply as i can:
* it's not determined how many strains, V.albo- atrum and V.dahliae are just general division for plenty of happy families.
* albo- atrum is commonly heavier but somehow more predictable, can survive in soil in various forms ( mycelium and mycosclerotias ), dahliae on the other hand prefers leafs and weeds for it's mycosclerotia, both can easily survive up to 50cm deep in soil, bla bla bla... anyway, mostly dahliae ( but a.a. not excluded ) can produce such splash- back infections starting from a simple tiny piece of weed that you wouldn't believe it. also your hands and tools and other equipment can- the bugger can survive on a piece of metal up to 6 months, in just about any organic environment 2 years minimum.
as for L.T. this isn't it. believe me you would know an explosive outbreak of L.T. if you had one- i have often witnessed plants which were hardly recognizable no more than 8-10 hours after the initial symptoms appeared in favorable conditions for the disease.
again, just as it was the case on the photos of L.T. you posted- the chlorosis is definite and clearly borders the infected spots. further more, it's a disease ''of a specific spot'' and not systemic, which results in another definite sign- the necrosis won't appear the same on both sides of an infected leaf ( at initial disease stages especially ), while with V. it will.
further more, leaf margin's necrosis is much wider/variable with L.T. than with V., meaning that you will most often meet it at leaf tops just the same as at leafs sides.
more, it will start as small whitish/grayish spots on leafs front side which you can easily distinct.
and the easiest of all, i believe that you are experienced enough to detect a living fungus appearance at leaf surface, with or without a lens, which with a V. you won't be able to do.
finally, if it was a nutrient thing, it would be on the excess side and not a deficiency, and it would go for potassium ( or boron, which is almost impossible ), but it would have appeared much earlier, also on fruits ( pre- maturation ) and flowers ( dropping/burning ), and it would also stop after some time and not develop extensively further.
vau, time to sleep, good night all,
ivan