Lots of discussions here the search will pull up for you on BER if you want to read through them and I linked the FAQ here about it below.

In reading I think you'll find that research shows that consistent soil moisture levels is the key to preventing BER, not any "lack of soil calcium" as was claimed for so many years. And most find that the BER sprays are of little value.

If your plants are in containers then adding lime to the potting mix may be of benefit according to some.

But spraying with limed water could be problematic. Not only would it result in increased fungal disease risks because of the wet foliage but alkaline burn of the leaves would be a really possibility IMO too depending on the concentration. Lime is a strong base and can interact quite actively with any acidic surface it comes into contact with.

JMO

Dave

Here is a link that might be useful: BER FAQ