It is growing next to an Early Girl and Brandywine, in the same raised bed but they have the following differences:

-- Only BK has very dark green foliage foliage.
-- Only BK has always shown some degree of leaf rolls. Sometime it seems that to be more pronounced at nights. Also the leaves are leathery tough too.

I have been fertilizing and watering all those 3 the same way (as they are in the same bed).

I did a research about this and have found out that this is very common with BK and even other BLACK tomato plants. But have not found a common consensus about the cause of it.
---Some stated that it is due to high temperatures.
--- Some have said it is due to TOO much watering/rain
--- Some mentioned it is due to cool temperatures.
--- AND somebody mentioned that the plant's root system , realizing that it cannot fully support the growth, tries to cut back the amount of water to the leaves and thus the leaves curl.

IN MY CASE:
-- There has not been high temperatures. Our highs rarely go over 83F.
--- We have not had rain(Other than some light thunder storm with less than a 1/4" precipitation) for weeks.

---As with low temps, Our nightly lows are around 60F(+/-2)

So if ther is anybody out there who has been or is growing BK, and has experienced similar problem, please let me hear your side of the story.
Thank you all in advance.

Just to add to your list of possible causes, this site ( below) attributes leaf roll to periods of extended dryness as well as periods of excessive wetness. Also mentioned are severe pruning, close cultivation, and, as I recall from elsewhere on the web, there is an insect that can cause leaf roll too, but I don't remember what it is. It appears to me that leaf roll is basically some kind of general stress response due to any number of causes, and, just as with people, some individual plants are more apt to be stressed than others.

The plant pathologist , in the given link. also has no clear clue and just proposed several possibilities and mad general obvious suggestions.

Appears to me that genetic trait is the most probable cause.
I have seen younger leave/growth on BK to wilt at the peak of sunshine a relatively normal day. This, perhaps, tell me that the plant's root is very conservative in sending water up to the top And as if they are suffering from lack of water, curling, reducing light exposure and getting leathery.

So far as my internet search has pointed up , there exists some strong co-relation between some BLACK tomatoes and LEAF ROLL?CURL. This is similar to, eg, the co-relation between BER and Roma, SanMarzano, ....
So far, IMO , there is a direct co-relation here with no clear explanation , beyond some generalization of almost all the growing/physiological conditions( wind, cold temps, hot temps, dryness, wetness, root stress, pruning, ...)These are no better than fortune telling found inside the fortune cookies, TO ME. No where, nobody had a doubt about the plant's genetics, nutrients and soil chemistry.

But the good news is that (smile), as it appears, all the EXPERTS agree that this symptom has no ill effect on plants life and its fruits production.

Lets see what has your personal experience been or what is your take on it.

Leaf Roll usually occurs only when plants are young and there's an imbalance in root mass and above ground vegetative mass. When both are in balance as the plants mature, no more leaf roll. But If the leaves roll into a tight roll then one has to also think about aphids being inside.

Leaf Curl can occur if it's too wet, too dry, too hot too cold,etc., in other words stress, and most hybrids show leaf curl normally and it can also occur on any plant that has a heavy fruit burden.

I've seen both leaf roll and leaf curl on varieties of ALL colors, not just the so called blacks, and more specifically never just with Black Krim.

Carolyn, with yes, over 3K plus varieties grown to date,grew up on a farm where we had acres and acres of tomatoes, is a retired senior citizen now, but has been up close and personal with tomatoes since she was 5 and just turned 74 this past June. And is still growing some tomatoes at home, but someone else does it for her b'c she's been using a walker since Dec of 2004 when she severed all four quads in her right leg. But finds the seeds for her annual seed offer elsewhere,most new to all folks, and others do the growing and seed production for her. No more growing several hundreds of plants and varieties each year at the old family farm with rows 250 ft long.

It might be leaf rolling because you are pruning it. Are you pruning the Early Girl and Brandywine too?

"Lets see what has your personal experience been or what is your take on it."

As I stated in the other thread, I've grown many blacks, and never seen leaf rolling on Black Krim except when my watering has been outstripped by increased temperatures and therefore greater evaporation and transpiration, and when this happened, tomato plants of all colors also exhibited leaf rolling.

My personal take on it, is that your apparent "...suffering from lack of water, curling, reducing light exposure and getting leathery." is due to your pruning the plant and it has gone into conservation mode.

Stating that Black Krim is prone to leaf rolling is perhaps faulty Post hoc, ergo propter hoc thinking.

Betsy

To Betsy

I have been pruning ALL my tomato plants systematically after planting, not all at once, at one stage .Yes I have also pruned BW and EG, same method. Also, I prune the branches at a very early stage(much smaller than pencil size)

As I have mentioned, in my case there has been NO; high temps, No low temp, No rain, No high winds.
Your opinion is that PRUNING is responsible ?
It may just well be the cause. But I have done the same thing on all my plants not just this one.

Perhaps because Black Krim is usually such a vigorous plant, it does not tolerate pruning as well as the other two plants. Or perhaps a mini-micro-clime difference? Like a really big rock 2-3 feet down under BK inhibiting root spread and nutrient uptake? Maybe because it is gregarious and you have a single BK, it is pining for company of its own kind? Who knows?

Betsy

In my quest to find out more, I came up with a page called :"Pacific Northwest Gardener" with a nice write up about his plants and several pictures of them. His plants are:
Black Prince, Black Krim, Cherokee purple, and Sun Gold.

All three show leaf roll to some degree , especially Black Prince and Black Krim. Sun Gold looks fine.
This had been in late July, 2011.

Here is a picture of his black Krim.
look at the leave at the lower left quarter. That is how my plant's lower leaves looks like.

I think what I have, is more like this one than the BK shown before, whwn I compare fruits shape.

Betsy