Well, it finally happened -- "Got BER"?

When I initially planted my tomatoes, I mixed in pulverized eggshells with the soil to provide a nice solid foundation of calcium to feed the plants for their growth into maturity. I figured I might have to supplement a little towards the end of the growing season, but it wasn't foremost in my mind.

Well, the other day I noticed some black spots on the lower sides of a couple tomatoes. It looked like BER (blossom end rot), but it wasn't directly at the bottom. BER has always looked to me like it doesn't compromise the shape of the tomato much, just turns it brown as if soaked in dirty oil. But it can cause a significant depression in the skin, which is what I was seeing.

BER is usually caused by a calcium deficiency, but not necessarily due to a lack of calcium in the potting medium. The common cause is dramatic swings in potting medium moisture, going from dry to soaking wet and back, that impedes the ability for the plant to uptake calcium from the soil. This did happen to my BK... when I'd let it go about 3 days between watering. There appears to be little margin of error with container growing. If your water supply runs dry, the plant starts suffering very shortly thereafter.

Instead of allowing the fruit to continue growing, I picked it since I didn't want any precious nutrients devoted to a failing prospect. Thankfully the two others that have small BER like depressions in their sides have not shown any BER progression.  Hopefully they'll avert that fate.

UPDATE: Unfortunately, the tally went higher. I've had a total of 8 tomatoes that were struck by BER...

Here are some other examples... one looks like BER but the other seems to be more like a lesion (hopefully minor and won't spread):

Peculiar lesion on the side, with segmented pattern

Front one is likely stake rubbing, but tomato behind it has a classic BER side dimple

BTW. today I noticed the BK parent plant has been increasing water intake. We had a major rainfall just two days ago and when I checked the plants yesterday they had decent reservoir water levels. But when I checked this morning, the BK was nearly dry. Several leaf clusters near the top had softened and started drooping and the tallest production stem was bending over. I promptly filled the reservoir in addition to a little watering from the top and within about 15 minutes, the plant showed a significant response. Another 15 mins after that, I noticed the reservoir was down about a quarter! This plant was really thirsty. First time I'd ever seen this.

Meanwhile, I picked another lemon boy and it was interesting to see the stark contrast between freshly picked and counter-top ripened, essentially lemon vs. cadmium yellow.