Is this little thing really what's destroyed my gardens?

[Paradajz]

ok, now i would really like to be there.

i still need to make an explanation for the wormcasting you'll be using there, and it's effects, and a summary for the finals, but at this point your Ph details need some fast reaction.

ok, we need to make a clear disctintcion for starters:
the test- procedure you will be doing is designed for a simple cause- to show if you can fully control the disease issue there. the fundamental result that interests you is disease related.
on the other hand, it's very clear that a full ''optimal growing approach'' at this particular moment, aiming to make the best of your plants altogether, cannot be fully respected now. there is either no sufficient time to make the soil preparements needed to improve your garden, or it would be unneccessarily complexed for the cause of test results.
therefore, there are quite some significant overal steps that need to be taken for your next growing season there, and we shall have full Autumn/Winter period to elaborate it, but at this specific moment we'll be doing stuff simply to conduct this specific test to the optimal possible result.

some additional info:
generally, soil Ph status ( if correctly given and i would estimate it was ) there is creating a very significant additional complexity. slightly alcaline means that the pathogens are at unfavorable soil at one side, but it also means that plant roots over there are disturbed a bit- there will generally be quite some more additional activity in the root area in such conditions, and consequently more agressive activity from the pathogens may be expected. there are some very open issues regarding it, such as phosphorus ( solubale ) levels in the soil, salinity of your water, etc., which you will need to pay some attention for the next season, but not for the test.

also, some additional sulfur related explanations:
please note, it's clear to me why anyone would think it could be used for increasing the Ph levels, especially when elemental sulfur labels Ph at 9.0 approx. range.
but it is actually quite the opposite- sulfur is one of the best and most effective possible choices for a general and controled Ph decreasement approach. simply, soil bacteria + water + sulfur + normal conditions will result in sulfuric acid and consequent convenient Ph dropp down. it's a completely organic process, and it would be just perfect for your next season ( if you do the ''cooking'' this Autumn/Winter and still determine high Ph values next Spring, it would be just perfect to add some 0.6- 0.7 pounds of elemental sulfur to each 100 square feet of the soil there; hope i converted the values correctly ). the other way is lower Ph peat moss, but it's far more expensive solution when we are talking the whole garden and not a small test area. also, the basic ''minus'' of a sulfur solution at this point is that it takes time- lowering Ph with sulfur is a constant but slow process, which is just perfect for a regular growing season and soil preparements for it, but will not work for your experiment, no time there.

some additional explanations:
the Ph you found there seems appropriate to me, it's a natural result of the combination of your water and soil amendments you made- quite some sands and a bit of lime there, helped by dolomite quite much.
also, calcium being the tricky one there, you need to know that plants will have troubles with it in alkaline soils too, although it should generally be a real problem at thigher Ph levels than yours is.
finally, a tomato plant is quite tollerant to the Ph levels you have there, but for the purpose of both disease control and optimal growing conditions it should be lowered as close to 6.8 as possible.
finally, please note that the plant will make best use of soil nutrients when there is some water in the soil, which basicaly means that the fundamental Ph ( the one which interests you the most ) will be higher due to the water Ph level, which again brings some additional complexity to the issue.


so, what i recommend there:
soil amendments ( 72h after the mixture drench with your current temps ):

* 1- 2 inches of peat moss, thoroughly incorporated in the soil
* 5- 6 lbts of gypsum per 100 square feet ratio, incorporated with the peat moss
* 1.5- 2 lbts of wormacastings per 10 square feet, incorporated with the previous ones
* any organic high potassium fert ( NPK 4 - 4 - 8, 5 - 3 - 9, etc. ) at medium rate, if possible incorporated with the others, if not this one can be done later

this should do, but please note: it's modeled only for the test- use, it's not neccessarilly a procedure you or anyone else should do in such conditions as some kind of a standard. regarding your next season you should absolutely do a soil analysis, and we can talk about the amendments then.

about the recommended amendments:
* peat moss is the fastest, almost ''mechanical'' way to lower the initial Ph. btw, when you get started for the amendments ( 72h after the mixture ), check the Ph again.
* with those factors ( water especially ) gypsum will provide a consistent and long lasting influence towards the preffered Ph level, leave woodashes for the next season
* all the other steps which will come later, in the phase of plants tending, will move in the same direction

nothing to worry, i'm under impression that you are making quite a progress , talk later.