I had about 3 small green tomatoes that were roting on the bottom when they were just about the size of golf balls.
any Ideas of the cause?
It is called BER - blossom end rot. I linked the FAQ on it here for you and there are lots of discussions about it too.
Here is a link that might be useful: What is BER FAQ
It's called BER ( Blossom End Rot) and is quite common. If you go to the FAQ link at the top of this page you'll find an article about it that I've linked to below.
And I'm cutting and pasting an explanation that I wrote which goes into a bit more detail, Betsy has had posted it recently and I was glad to be able to save it for myself;
(With BER there is NO problem with absorption of Ca++ though the roots. The problem is maldistribution within the plant that can be induced by a number of stresses which include uneven delivery of water, too much N, growing in too rich soil, too hot, too cold, too wet, too dry you name it.
As the plants mature they can better handle the streses that can induce BER so usually it goes away.
The two exceptions are first, if the soil has NO Ca++ as confirmed with a soil test, and that's a rare condition, and second, if the soil is too acidic in which Case Ca++ is bound in the soil.
Again, adding lime, egg shells and on and on can not and will not prevent BER b'c absorption of Ca++ thru the roots is OK.
Paste tomatoes are especially susceptible to BER and I think someone in a post above mentioned that.
If you go to the top of this first page and click on the FAQ link and scroll down you'll also find an article about BER in case some of you have never looked at the FAQ's And there's some darn good articles there as well, but I wouldn't pay any attention to the variety list b'c it's way out of date.
The old information about BER being caused solely by lack of soil Ca++ has been shown to be wrong with research that's been done in the last 20 years or so, but it's going to take another generation before the real story gets into books, websites, magazines, etc. Most of the better websites already have the correct information.
BER affects not only tomatoes, but peppers, squash, cabbage, cauliflower, etc., and it's a huge multimillion dollar problem for the industry, which is WHY all that reasearch was done. For instance, when tissues were taken from a plant that has BER fruits and was assayed for Ca++, the normal level of Ca++ was found, it just wasn't getting to the blossom end of fruits. And there's also a condition called internal BER where the fruits look fine, no evidence of BER externally, but when you cut open the fruit the inside is black
Hope that helps
Betsy had written the following after my article and I'm leaving it here as well since so many folks talk of adding eggshells, or lime or spraying the foliage with milk, which just does not work.
So, what it comes down too is: Tums do not work, nor do egg shells, milk, and other "home remedy" treatments. Foliar spray only works in some cases. Time and good management practices work best.
Carolyn, who notes that since no one can control the weather that, along with too much N, etc. as explained above, there will always be stresses on the plants that can lead to BER.
Here is a link that might be useful: Blossom End Rot
Dave, your post wasn't there when I started mine so we posted almost at the same time.
It took me a while to go fetch the article I cut and pasted and then I stared out of the window here from time to time at a gift someone gave me. It's a solar powered artificial bird perched on a short pole that turns colors of green, blue and red, and the blue one lights up the whole back yard.
I've been wondering what the reponse would be if one of the local critters came by when the backyard was blue. LOL
Good thing it's in the backyard b'c if it were out front by the road I suppose someone might call 911 and report that an alien ship had landed. LOL