tomatoes & oyster shells

[tonymalone]

i have had in the past a problem w/ my tomatoes rotting from the bottom about the time they get ripe.

i have been told the stuff ya spray on em to prevent this is calcium, and that if ya will put some oyster shells (like for chickens) in the ground around your tomatoe plants, that it will prevent the rotting from the bottom.

anybody know anything about this?

thanks

[robin303]

Not really but I do put a good handful of crushed egg shells in the hole before I plant. At least it breaks down after time.

[dice]

The disease that you describe is called Blossom End Rot (BER).

A calcium deficiency in the soil is one cause. Crushed oyster
shell is one source of calcium. Others are lime, gypsum, egg
shells, rock phosphate, bone meal, fish bone meal, probably
crab and shrimp meals, azomite, etc. Some of these raise the
soil pH while adding calcium (lime in particular, oyster shell,
probably azomite). Gypsum (calcium sulfate) has neglible effect
on soil pH. I do not know about the effect on soil pH of the
others.

There are other things that can cause calcium deficiency in
the plants besides a simple lack of it in the soil: high nitrogen
fertilizers and rapid plant growth, wide fluctuations in soil
moisture caused by drought or heavy rains, root pruning during
cultivation, etc.

Some people assert that the soluble calcium sprays cannot
solve BER in tomatoes, because there is no way for the calcium
to get from the foliage (where the spray is absorbed) into the fruit,
and it cannot be absorbed by the fruit directly. Others say
"It works for me," (without necessarily knowing why; might
have something to do with saturating the leaves and new
growth with calcium, leaving more of what is absorbed through
the roots for the fruit).

[tonymalone]

thanks dice, very informative.

[carolyn137]

Dice, I'm laughing a bit b'c I was doing a search to be able to put a link here about BER when ASAP there were two replies instead of one.

But I didn't find a good general one about BER.

Tony, lack of Ca++ is one cause of BER but isn't even the most common cause so I can't see putting eggshells or oyster shells or Tums or that kind of stuff in the planting hole.

Anything that's a stress to plants can cause BER and the most common causes are uneven delivery of water and too rapid growth caused usually by growing in too rich soils or using too much fertilizer.

There are very few soils that don't have enough Ca++ with two exceptions. One is if the soil is too acidic and then Ca++ remains bound up but that can be reversed with proper treatment of soils to make them less acidic. And the other reason is soils that lack Ca++ and that's exceedlingly rare.

As Dice mentioned above, the product Stop Rot isn't a good way to go b'c it's true that small molecuoles can't penetrate the fruit epidermis, and if they did the fruits would blow up when it rained, and experiments show that application to the foliage of Stop Rot doesn't work well either.

When stems and foliage are removed from plants with BER fruits it's been found that they have sufficient Ca++ so the problem is not one of uptake of Ca++.

Rather, it's the maldistribution of Ca++ in plants that are stressed that doesn't allow it to get to the bottom of the fruits.

Not all varieties are equally susceptible and paste tomatoes seem to be the most susceptible.

So basically any stress can result in fruits with BER.

[tonymalone]

hhhhmmmmm, w/ stress being a major factor in BER, will i be 1 step ahead in the deal, by planting boxcar willie, and mule team tomatoes, since they both are resistant to several different stress's?

[carolyn137]

Originally Posted by tonymalone

hhhhmmmmm, w/ stress being a major factor in BER, will i be 1 step ahead in the deal, by planting boxcar willie, and mule team tomatoes, since they both are resistant to several different stress's?

They are?

I introduced both of those varieties, they are quite similar as bred by Joe Bratka's father and I never noticed any particular tolerance to stresses.

And the stresses that I mentioned above are really quite different.

[Ross]

My understanding on the BER issue is dominated by two issues. The plant lacking available Ca (in the soil) and a soil moisture content that experiences extremes of high and low.

I also save kitchen eggshells all year long, crush them up within a large container, and then apply heaping handfuls of shell pieces into my soils as I break it open after frost is gone and begin to prep my beds (with other organic supplements too) where both tomatoes and peppers will be planted. I also add more eggshells in back fill when plants go in the ground in late May.

My soil also will have granular humate and ample compost added in so that there is the "uptake" (of Ca) influence from the additional humic acids present as the eggshell pieces are breaking down. They will, and do, break down quicker than many think.....if the soil has good microbial and earthworm activity ! Plenty of compost and active earthworms will do more wonders to modify and regulate a supportive pH than most will ever know. If the pH is nearer to 7 that Ca will become available and the BER problem will be minimized.

The water content issue is equally critical and requires a solid understanding of one's soil quality at thr depth of majority of roots. Damp or moist...good. Saturated, soggy...bad. Dry, parched...bad.

[dice]

Containers are another place where actual calcium deficiencies
are common. Many fertilizers have some, but not necessarily
enough for a big, productive, indeterminate tomato plant.

I have seen BER increase in fairly cold summer weather even
in moist soils with plenty of calcium (whole bed limed in late
fall and a handful of gypsum in the bottom of each planting
hole with compost and horse manure). I guessed that it was
because the plant was simply not transpiring enough water
at the low temperatures we were having to pull enough of the
calcium in the soil up into the plant to meet the needs of both
foliage and fruit.

Crushed oyster shells are more expensive than lime, but not
exceptionally expensive when purchased in bulk at feed stores
(sold for grit for chicken feed, etc). They are fairly big, hard
chunks compared to the finely powdered lime that you can get
in bags, and they would probably slowly release their calcium
into the soil over several years. It is a way to add a slow, steady
supply of calcium without having any radical effect on soil pH.
Hard rock phosphate would work this way, too, while slowly
dribbling a modest supply of phosphorus in there as well (costs
quite a bit more, though).

[carolyn137]

My understanding on the BER issue is dominated by two issues. The plant lacking available Ca (in the soil) and a soil moisture content that experiences extremes of high and low.

****

Ross, I don't necessarily agree that those are THE two main issues, but whatever.

Another point I should have made above is that folks will use eggshells and other sources of Ca++ and then say that they don't see BER. Fine, but unless at least two plants of the same variety are grown in the same season and only one has received supplemental Ca++ as a control no conclusion can be made.

The other point I didn't make was that BER is almost always found on the first fruits of the season, and that's b/c as the plants mature and get larger they're better able to handle the multiple stresses that do come their way.

Ross, I don't know where in CO you grow your tomatoes but I spent many years in Denver teaching at the med school and also raised tomatoes when I was there.

The soils in CO are alkaline and have plenty of Ca++ in them already.

Actually it's extremely rare anywhere to find that soils are absolutely lacking in Ca++.

Do I miss Co? Yes, sometimes, but not when the winds blew from the north and the Montfort feedlot smells made it all the way down to Denver.