The leaf loss you describe could be any of dozens of diseases -- or even natural aging of the leaves. It would help if you could post photos (both leaf close-ups and photos of the whole plants).

Did your part of Canada have unusual weather this year? Wetter than usual?

In the meantime, you can compare your problem with the photos and info at these sites:
Cornell's Tomato Disease Identification Key: Leaf Symptoms
Texas A&M's Tomato Problem Solver: Disorders of Tomato Leaves

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F-M's giant veggies collection

No, there doesn't seem to be any info on that variety other than Ferry-Morse's blurb. I was being very cynical about their not saying if it was hybrid or OP -- but then I looked at the rest of their veggies and noticed that they do use the word "hybrid" on the front of their seed packets (and sometimes in the variety name). So I'll guess that your tomato is OP -- and most likely a re-named older variety that F-M is resurrecting for their "giant" collection.

Then again, it might be that they've got a new variety and want everyone to keep buying their seeds.

I'm rather boggled that F-M expects anyone to impress their neighbors with 17 oz. monster tomatoes [quoting their advertising]. Since when is 17 oz. a monster?

I'm glad you like that variety, whatever it is. The most important thing is that you're happy.

The second question concerns heirloom tomtoes. I have grown several such varieties over many years, but this year decided to grow Uncle Joe and Early Girl to get a good crop before the frost.

Early Girl is a hybrid and is very unlikely to come true to the parent plant if you save seed from it. (If it has been dehybridized, I am not aware of it, or how true to type it might be.)

If you have the space, you might grow out some saved seeds from the "Garden Leader Monster" to see if it grows true to type.

Since when is 17 oz. a monster? On that, I agree with missingtheobvious, and ultimately it is what you like in your garden that is important.

As for the yellowing of the leaves, mto is correct on that too. We need more info, especially pictures.

Betsy

Yes, Early Girl is an F1 hybrid, first bred in France, but I won't go into the details here.

There is an OP version of Early Girl F1 called PSR-37 which was stabilized by Tim Peters, formerly of Peters Seed and Research.

I distributed seeds for it the past several years in my annual seed offer that I do elsewhere.

Some were getting PL plants from it but not all that surpirising since there may have well been a PL parent somewhere in the breeding of this variety. And actually some folks are getting some PL plants from the F1 Hybrid called Early Girl Improved F1, but I don't think anyone knows what the "improvement" is. LOL

Also, I doubt if it's a virus infection where you live b'c almost all of the more common viral diseases are spread by insects that aren't that far north.

What you describe does sound like one of the normal foliage pathogens and some links were given to you in a post above to try and ID. Sometimes it's difficult to ID a disease from pictures b'c those are static while disease is progressive. You say that the bottom leaves are affected first which suggests splashback infection which occurs when spores amd bacteria of those foliar pathogens fall to the ground in a previous year and then get splashed back on the plant via rain or irrigation.

The fungal foliage pathogen problems can be prevented by a vigorour spray schedule with a known effective ant-fungal.

The four most common foliage pathogens are:

Early Blight ( A. solani), fungal
Septoria Leaf Spot, fungal
Bacterial Speck
Bacterial Spot

And there are very very few hybrids that have tolerance to any of them, except for Early Blight and that tolerance is so low level that it's really only of use to Commercial farmers. A new cherry tomato, Mountain Magic F1 does have some decent Early Blight tolerance.

So no, OP heaurlooms are NOT more susceptible to the most common tomato diseases, the ones that affect foliage and the same is true for hybrids.

Hope that helps.

Carolyn

The most common foliage pathogens

I forgot to mention that Cucumber Mosaic Virus (CMV) is a viral disease that can be found in our area, I'm not that far from you in upstate NY, but the symptoms you described are not those of CMV which results in distorted leaves and stems.

Carolyn

Thank you for all your posts. First OT: although I ticked off the option to have replies directed to my in-box, the only one I received was from Carolyn. I was rather surprised when I came on to the forum and found the other posts here. This is about the thrid time this has happened to me so perhaps I will send a message to the site administrator.

Second OT: I goofed. The tomato I grew was Earliana, not Early Girl, so I apologize for misleading you. I thought it so strange that Carolyn was talking about Early Girl, then I re-read my post.

I also thought it a little daft of me not to post pictures, which I had and I will do so now. These pics show the progression of the leaf damage.

Carolyn you provided some very valuable information, and perhaps the conditions were just right for one or other pathogen to take hold. I was careful with 'splash' and I apply shreded paper around the roots of all my tomato plants. I am relieved to know that it is not perhaps something that will ruin my entire garden, ornamentals, fruit trees, and all. Just for my personal satisfacton, I will check out the five pathogens you have listed.

I will save seed from all of these varieties, making sure to use the fermenttion method which, I am told, is best for getting rid of any free loading pathogens. I do like the fruit from the Tomato Monster, although they are the size of a regular supermarket tomato. They slice well, and are a good size for burgers. We have been having them daily in salads as well. Incidentally, this was a tomato my husband chose, and only discovered it among the seeds at check-out.

You have been very generous with your information and it is very much appreciated.

That looks like septoria leaf spot, which is a fungal disease.

Here is a link that might be useful: Septoria Leaf Spot

Use a fungicide with chlorothalonil in it, like Daconil, to prevent fungal infections of tomato plants.

Here is a link that might be useful: Septoria Reference

How did Garden Leader Monster do for you? I'm thinking about growing it, this year.

I just sent the company a message to find out if the Garden Leader Monster tomato and pepper are F1 hybrids. So, we should know soon. I had already asked them in the past about the Garden Leader Monster watermelon (they said that the watermelon is open-pollinated).

Okay, Plantation Products kindly got back to me. The Garden Leader Monster tomato, pepper, and watermelon are all open-pollinated. So, they should breed true.