So when we talk about tomato acidification in canning, this information can give an idea what we are talking about.

Federle 6.5 4.59
Pete's Italian Plum 4.7 4.56
Zapotec Pink Pleated 6.3 4.56
Jersey Devil 5.2 4.55
New Jersey 5.3 4.55
Spitze Russia 7.3 4.54
Large Polish Paste 8.2 4.53
Bisignano #2 7.3 4.52
Opalka 5.9 4.51

UNDER 4.50
Rutgers 6.8 4.51
Burbank Red Slicing 4.2 4.49
Tondo Fario 5.7 4.49
Black Krim 9.4 4.48
Grandma Mary's Paste 3.4 4.47
Marglobe 5.8 4.47
Rio Grande 3.0 4.47
Super Sioux 5.0 4.47
Le Case di Puligia 1.0 4.46
Soldacky 13.5 4.46
Ten Fingers of Naples 1.9 4.46
Brandywine, Pink 14.1 4.45
Rio de Fuego 2.5 4.45
Hungarian Heart 14.1 4.44
Kavalarovo Plum 1.1 4.44
Antique Roman 6.9 4.43
Homestead 8.9 4.43
Amana Orange 15.4 4.42
Amish Paste 7.4 4.41
Joe's Plum 10.2 4.41
Juane Peach 1.6 4.41
Goliath 16.1 4.40
Howard German 4.1 4.40
Polish Linguisa 6.0 4.40

UNDER 4.40

Rose de Berne 5.4 4.40
Delicious 6.2 4.39
Italian Plum Canning Type 3.0 4.39
Moskvich 6.2 4.39
Brandywine, OTV 10.7 4.38
Cherokee Purple 8.6 4.38
Martino Roma 1.9 4.38
Napoli 1.7 4.38
Popovich 3.1 4.38
Santiam 3.2 4.38
Arkansas Traveler 4.8 4.37
Brandywine, Yellow 13.2 4.37
Di Santos 7.7 4.37
Costoluto Genovese 4.9 4.36
Saucy 1.8 4.36
Anna Banana 5.9 4.35
Black From Tula 9.9 4.35
Ellis Island 14.7 4.35
Stupice 2.2 4.35
Ernie's Plump 6.9 4.34
San Marzano 2.1 4.34
Watermelon 14.2 4.34
Super Italian Paste 5.4 4.33
Bloody Butcher 2.6 4.31
Jubilee 6.9 4.31
Striped Stuffer 3.9 4.31

UNDER 4.30

Giant Syrian 10.6 4.29
Landino di Panocchia 3.5 4.29
Laurano 2.5 4.28
Mortgage Lifter 12.8 4.28
Pantano Romanesco 7.8 4.28
Caspian Pink 12.4 4.27
Persimmons 9.0 4.27
Bull's Heart 9.3 4.26
Ropreco Plum 1.8 4.24
New Hampshire Surecrop 1.0 4.23
Pomodoro Grosso 5.4 4.22
Oscar 6.3 4.21
Silvery Fir Tree 3.8 4.21
Abe Lincoln 4.9 4.20

UNDER 4.2O

Bianco Great White 9.2 4.16
Prairie Fire 2.3 4.10
Purple Calabash 4.0 4.07
Platillo 4.1 4.02

For instance, when North Dakota State University tested Opalka, their test resulted in a pH of 5.08. Quite a difference from the University of Illinois's test result of 4.51.

The point that you are obviously missing is that pH is wildly variable. So just acidify everything and be safe.

Is there a particular reason you keep bringing this up? As I recall, you don't even can tomatoes. Actually, I don't think you can anything, correct?

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REASON ?
For your information this is a "forum" (not a governmental advisory board) if you understand its meaning.

I do can tomatoes although not a whole lot. So far this season I have canned just 10 quarts.

The list that I put up is just to get an some idea about tomatoes acidity and what is required for safe canning.

In the absence of a pH meter I add about 1/2 TB spoon per quart, just to be sure. And that should bring pH of any tomato under 4.

If you object to the taste of lemon juice, there's always citric acid.