Both yellowing and dropping lower leaves are normal, IMO.

The black dots are not the cause but are the after effect.

I would trim all those before they become host for diseases. The serve no role other than that and being a burden on the plant.

BTW: a picture of the whole plant can be helpful to make a better judgement.

JMO

Okay so I won't worry about lower leaves - but what if the yellow leaves occur up in the middle of the plant? And there appears to be black specks/droppings on the branches and other leaves? The black specks come off, and look like coffee grounds almost.

(It's a Sweet 100 planted in amended native soil, 18" high bed SFG style, with Dr. Earth Tom/Veg organic fertilizer every 6 weeks. It gets 6 hours of sun a day and consistent watering by hand but never on the leaves)

Here is a picture of the whole plant - there aren't very many of these leaves in the middle - but the coffee grounds seem to be all over....

The yellow leaves in the first picture are showing both a nutrient deficiency as well as the symptoms of over-watering so those issues need to be addressed. The leaves show classic signs of nitrogen and potassium deficiency as well as soil salts damage either from your water or from the fertilizer being used.

I can't tell from the photos if the black spots are eggs or some sort of pest droppings but if they rub off easily then it isn't likely any disease processes. Check the plants very closely for pests.

While it is fairly common for the plant's leaves to begin to die from the ground up as the plant gets older (toward season's end) it isn't normal assuming proper nutrient levels are supplied. In those cases the leaf appearance is not like in your photo. It is a gradual tanning, drying, and shriveling of the leaf tissues.

Dave

Thanks Dave. I fed them a week ago with a liquid fertilizer made (according to directions on box) with Dr. Earth's tomato/veggie fertilzer, so hopefully that will help if there are nutrient deficiencies.

The black specks come off when rubbed, and don't smush - I am thinking they are caterpillar droppings? I searched for pests but only found some of the tiny ants that are ever-present in our yard. They may be following up on someone else's munching....I did see a small amount of webbing with droppings stuck in it - maybe mites....

There aren't a ton of these yellow leaves - and they seem to happen randomly around the plant - often on branches where I pinched a sucker (related? stress?) I've stopped pruning pretty much....

Looking at your last picture, showing the entire plant, I don't see a problem with it. So if the focused yellow leave picture belongs to the same plant, it reaffirms my previous thinking that the yellowing is part of the normal process of aging in that climate. This is especially often the case in hot dry windy air in southern California. Even with moist soil the plant cannot get enough moisture to replenish what is lost due to low humidity and hours of direct sun. So the plant prioritizes its resources and aborts the older leaves. We see a lot such plants that I call them "Naked" right around the time that fruits are ripening. Compacted soil and small root space can also be a factor. This situation is often associated with container growing.
In contrast in our PNW cool and no wind, good humidity you will not see such things. Plants stay green all summer.

Judging from the color of the foliage, maybe your plant can benefit from some more nitrogen but TO ME it doe not seems to be deficient in that respect.

JMO

okay thanks! i will just keep an eye out for critters and see if the yellowing develops in a systemic way as we progress.

Thanks again!!!

Hmmm....well the symptoms continue. Does this still look like nutrient deficiency? The leaves are in the middle of the plant mostly - and also on the plant next to it, though the two plants in a separate bed don't show any signs of it. Looks like some images of blight I've seen....

Yes, it still looks like the primary issue is nutrient deficiency - the inconsistent coloring of the leaves, all the leaves that show interveinal chlorosis (green veins but pale leaf tissue).

You have some secondary issues (plant leaf chews/holes, and perhaps a touch of Early Blight) but the main issue is nutrients (see causes in link below).

Dave

Here is a link that might be useful: Causes of chlorosis in plants

Okay thanks again, Dave. I removed all the leaves that looked like that which also opened up the bottom part of the plant for air circulation. The growth on the top 2/3 of the plant looks good so I will just hope that the fertilizer regimen is working, and spray neem oil as well for the possible blight.