Use of ammonium calcium nitrate

[tankertoad]

In the prevention of blossom-end rot in tomatoes, would use of ammonium calcium nitrate as a foliar spray periodically, in addition to using it as "the snack" through the water fill tube, be helpful, unnecessary, or counterproductive?

Thanks.

[gardendoc]

Calcium uptake occurs through the root system, foliar calcium is ineffective.  One tsp calcium nitrate is better than the ammonium form,

[tankertoad]

Thanks for the response.

[kitty grandma]

Is there a source for non-ammonia calcium nitrate? Thanks

[gardendoc]

Yes, plain old calcium nitrate, get at your local independent garden center of feed store

[tankertoad]

In my experience, there is no such thing on the market as "plain old calcium nitrate."  Labels may say "Calcium Nitrate", but all calcium nitrate out there for gardening, again as far as my research on the issue is concerned, has ammonium as a constituent in the form "1% Ammoniacal Nitrogen".  The brand I use, Greenway Biotech", says its label of "Ammonium Calcium Nitrate" is because California requires the use of ammoniacal nitrogen to be noted in its name.  Greenway's (which is used in hydroponic gardening and is readily water-soluble) and all other brands I have checked, which is quite a few, include 1% ammoniacal nitrogen in the constituent label, regardless of whether or not the name on the item says it is "ammonium calcium nitrate" or just "calcium nitrate".  That should make your search for what you need much easier.

Of course, if someone can give me a brand that does not include 1% ammoniacal nitrogen and is easily completely soluble in water (hygroscopic), I will gladly be receptive to that information.

Thanks

[gardendoc]

Point taken, 14.5 % nitrate, 1% ammonium. Why is this an issue with the ammonium content? I don't think you'll find any farm or ag grade w/o the NH4, maybe try Fisher Scientific. I don't I understand the insane California labeling.

[tankertoad]

I imagine the issue arises from a response from you (unless "gardendoc" isn't a specific individual) to a question I asked which started this thread.  I asked if foliar feeding of ammonium calcium nitrate had any impact on blossom end rot.  Part of the answer was "One tsp calcium nitrate is better than the ammonium form."  That threw me a curve, as I think it did "kitty grandma", but since I couldn't find calcium nitrate that didn't have 1% ammoniacal nitrogen, I did some research and finally decided to use the Greenway Biotech product since it was used in hydroponic gardening.

I don't understand a lot of things that come out of California.

Thanks again.