As many of us know, BER does not seem to have one cause alone, since it relates to complex processes involving the transport of calcium to tomato tissues. In the meantime, science is searching for ways to lessen its occurrence, and I found these statements on the internet:

=====
Many genetic and genomic resources are becoming available for tomato. Ultimately, these will allow genes affecting the occurrence of BER to be identified. Such knowledge will inform breeding strategies to eliminate BER. In the meanwhile, increasing the apoplastic Ca concentration in susceptible fruit tissue should provide a simple and reliable, practical solution for the prevention of BER in tomatoes. It is suggested that current horticultural practices, such as the manipulation of the mineral composition of the feed or the growth environment, are not completely effective in reducing BER because they affect apoplastic Ca concentration in fruit tissue indirectly. Therefore, spraying Ca directly onto young fruits is recommended for the prevention of BER.
=====

Well, I tried to find definitive information about the permeability of tomato skins if you want to spray calcium on young tomato fruits, and there isn't much on the internet. On another forum which we cannot refer to here, I did find this statement (but not its source):

=====
Studies show that tomato skin is permeable when the fruit is very young and the light green skin is still tacky feeling.
=====

And I don't know if this is relevant or not:

=====
The stem scar is more permeable to ethylene gas than the tomato skin.

http://www.plantphysiol.org/cgi/reprint/102/3/911.pdf
=====

So based on this flimsy and possibly incomplete or even wrong evidence, I'm going to take the plunge this spring. I'm going to spray my VERY young tomato fruits with a calcium solution of some kind. I suppose this means when they are first visible and as long as they are growing, though they may not absorb any more calcium through the skin after a while.

What kind of calcium solution is likely to be best absorbed by young tomato fruits?

:-)

Anyway, I found a couple of sites that also advise spraying the PLANT LEAVES with calcium to guard against BER, but the people at the link claim spraying the very young fruits is more effective. I've never done either one before now.

=====
Spray calcium -- The plants may be sprayed with a calcium solution at the rate of 4 lb of calcium nitrate or calcium chloride per 100 gal of water (or 4 level Tbs per gal of water). This spray should be applied 2 to 3 times a week, beginning at the time the second fruit clusters bloom. These materials can be mixed with the spray that is used for control of foliar diseases. Chelated calcium solutions also provide an excellent source of calcium. When using these chelates, follow label directions. Several foliar spray materials containing calcium are available and all work well for tomatoes.
=====

If you lived in the Chicago area, I would advise you that calcium chloride is widely available, right now, as sidewalk deicer.

We've have this discussion every year. Mostly the replies will be that cultural practices rather than sprays are more effective at controlling BER. But I will be one of the members who will agree with your information that calcium based sprays have been proven effective WHEN THE FRUIT IS VERY YOUNG and their skins are still permeable.

However, wouldn't it be more practical, less expensive, and possibly more cautious to just go ahead and institute the recognized cultural practices ... like heavy mulching, regulated irrigation, avoidance of root pruning or root damage, prevention of root overheating, etc.?

Since tomatoes are known lovers of soil pH on the slightly acid side of the scale, I'd be hesitant to apply calcium in any amounts/frequencies such as recommended to prevent BER for fear of inadvertingly raising the pH of my tomato beds.

Also, your results will be skewed by the fact that most plants simply outgrow their propensity to BER and some varieties are just resistant. Yet you may be wholesale spraying all the plants, some may benefit and others not so much, meanwhile broadcasting calcium all over the place.

Bill

- Steve

For the first time this year I'll be growing some tomatoes that are noted for BER, pastes. So I thought they'd be my experiments. I hadn't planned on spraying the plants, but rather the tomatoes themselves when they're small. I agree that it would be risky to drench the entire plants time and time again. But I won't do that.

Furthermore, I'll be careful about the environmental-cultural practices since I'll be going to all this trouble for the pastes. Soil analysis, deep mulching later in the spring (I have 25 bales of hay!) and consistent watering, fertilization, and calcium in the planting hole, though I'm sure there's enough from last year to satisfy them. I won't be able to do anything about the weather but we all take our chances there.

Actually, I haven't had severe problems with BER except with one variety, and that was a Park's beefsteak tomato that had at least 75% BER on all the tomatoes for two years in a row.

But this is the first time I'll be growing paste tomatoes, so I want to be armed for what other people have experienced with pastes.

TVG

Yes, I'll report back during the fall on whether or not MY pastes had any BER. They may anyway, despite my trouble, but I won't know unless I do it.

Since I am the only person who posted something regarding potential negative effects from spraying calcium, I have to assume you're referring to me.

No need to get all snarky about it, Steve. Maybe you better read my post again. Because I never said it's unnecessary to apply calcium to a potting mix. Quite the contrary, my homemade potting mix contains agricultural lime and I'm fully aware of the tomato's need for calcium whether in the native soil or in a manmade mix or growing medium.

Fortunately, most sedimentary soils have plenty of calcium and in most areas of the U.S., adding calcium to garden soil isn't necessary. But what is absolutely necessary to avoid or minimize BER is facilitating or maximizing the plant's ability to take up and deliver calcium to the developing fruit walls in a regular and sufficient manner.

And yes, absolutely, when growing in soilless media, the addition of calcium is required, whether in the mix or via fertigation. I've covered that issue many times in many posts here and at other tomato discussion boards.

"After loosing 100+ almost full-sized San Marzano's last year to BER, I beg to differ with them and am looking for a calcium deficiency solution." [Steve]

Questions would be did you grow your San Marzano (a cultivar known to be BER susceptible) in containers or in native soil? If in containers, did your growing medium contain supplemental calcium? And if in containers, did you follow a regular irrigation schedule with no incidents of dried out grow mix or overheated containers? If in native soil, have you had your soil tested for calcium content?

My intent was earlier and continues to be suggesting ways to avoid or minimize BER and I continue to believe the most effective and efficient way to do that is to plant BER-resistant/tolerant varieties and to employ proven cultural practices rather than spray substances that might throw the pH or garden soil off kilter or unnecessarily add salts to the soil.

With regard to paste tomato varieties, I have to assume they generally are determinate and yield in concentrated sets of dozens of fruit that cover each plant.
I'd also assume that someone growing paste tomatoes generally grows multiple plants to get sufficient harvest to can sauces, etc.

With that in mind, I wonder at the practicality of dabbing each and every little green tomato with a calcium solution rather than applying it wholesale to the plant in the course of "spraying Ca directly onto young fruits is recommended for the prevention of BER" as is said in your original post.

That was the source of my initial concern about applying quantities that might alter your garden pH. Are you gonna take a Windex type spray bottle and squirt each little tomato individually? Just curious. Seriously, I am :::smile:::

(Ha!) Well, yes. But I don't think I'll use a spray bottle; maybe a small brush so as not to inadvertently spray any surrounding unpollinated blossoms with calcium. And I may not keep it up the entire season unless BER shows up on newly-forming tomatoes when I stop.

Four plants out of twelve will need treatment, I believe, and two of them will be Opalkas, which are indeterminates -- maybe there won't be a kazillion of them all at once to worry about! The other two are Monomakh's Hats, a heart-type indeterminate, which may or may not be susceptible to BER. Haven't seen reports on it yet.

This year I'm just checking out whether growing paste tomatoes is worth it, since I've frozen my left-over eating maters for sauces in past years. They make delicious sauces, but they sure take up a lot of freezer space and are watery until you cook them down.

If it works to prevent BER and I want to grow a bunch of pastes in the following years, then I'd have my work cut out for me!

Variety A grown one year with BER may not have BER grown the next year.

The problem isn't uptake of Ca++ from the soil, the problem is maldistribution of Ca++ within the plants which no doubt is genetically controlled.

I know of only one situation where addition of Ca++ to the soil is suggested and that's when the soil has NO Ca++ and Hoosier also mentioned that and that'a very rare situation. The other situation is when soil pH is too acid and Ca++ is complexed in the soil and can't be absorbed via the roots and that's corrected by altering the soil pH.

And I know that several tomato geneticists have been searching and searching for genes that might be involved with Ca++ transport within the plant.

How many of you have ever seen BER with cherry tomatoes? Probably none of you, I know I haven't with all the different varieties I've grown.

And contrast that with most paste varieties which are exceedingly susceptible to it.

It never says on the bottle of Stop ROt to NOT spray it on more ripe fruits and we know that the tomato epidermis doesn't allow molecules through that membrane; if it did the fruits would blow up after any rain.

My own feeling is that if I wanted to control BER I'd make sure I could do something about all the variables that I had control over such as not using too much N for tomato growth either by addition of fertilizers or by growing in too rich soil, You can't control rain that falls and mulching is suggested but really, with a deluge mulching isn't all that great.

And what happens to the Ca++ sprayed on immature fruits. How long does it stay inside the fruits? I'm sure most of you have had green immature fruits with BER, I know I have.As long as a fruit is attached to the vine stuff is being transported to the inside of the fruit and stuff is going out as well.

I suppose the only way to test spraying immature fruits is to do it with several plants of the same variety and then with several plants of the same variety don't spray the fruits. The latter is the control and is necessary before any conclusions can be reached.

And even doing that how does one control for all the variables that can'[t be controlled that are known to impact BER induction, such as variable temps and humidity and rain ( from the sky which obtains where L live, LOL).

Carolyn

I don't recall any previous conversations about applying Ca to the tomato skins. I don't even remember any talk about tomato skin permeability. Please, refresh my memory.

I may not have to go so far as to set up a control unless all the tomatoes I treat end up with no BER.

As struwwelpeter suggests, if the calcium treatment doesn't prevent BER (the first time around), there is no point in doing more tests. If it isn't gonna' work, I think that would be obvious from the get-go.

Now, it would be more complicated if it seemed to work! That's when controls would be needed for more than the few plants I'd grow.

But first things first... This is really a test of those researchers' claim that spraying young fruit with a calcium solution is the best treatment for BER, and maybe secondarily, the unsourced claim that very young tomato fruits have permeable skins.

Do you take the fact that you don't blow up in the rain as evidence that your skin doesn't allow molecules through that membrane? In fact, anything will diffuse through anything to some degree greater than zero. Consider the nicotine patch.

"Questions would be did you grow your San Marzano (a cultivar known to be BER susceptible) in containers or in native soil? If in containers, did your growing medium contain supplemental calcium? And if in containers, did you follow a regular irrigation schedule with no incidents of dried out grow mix or overheated containers? If in native soil, have you had your soil tested for calcium content?"

To answer your questions, all of my tomatoes were grown in containers last year & will also be this year. The potting medium was a mixture of MG Moisture Control & a few other items. It did not contain supplemental calcium. I'm kind of gathering data on how to make a better container mix this year (Al's posts in Container Gardening, etc.) before I go out and buy everything to mix it.

I did follow a regular irrigation schedule & all of my veggies (other tomatoes, peppers, etc.) did fine except the SM's. I didn't have any incidents of dried out mix or overheated containers. In fact some people thought my "Monster Cherry Tomatoes" of last year weren't getting enough sunlight, but that's a whole nother story...lol. I do plan on purchasing some type of soil tester this year to more closely monitor the mineral levels in my potting medium.

Anyway, I figured i'd chime back in, as I didn't mean for my post to be taken negatively.

- Steve

Do you take the fact that you don't blow up in the rain as evidence that your skin doesn't allow molecules through that membrane? In fact, anything will diffuse through anything to some degree greater than zero. Consider the nicotine patch.

******

No, I don't blow up in the rain b/c my epidermis is not the same as the tomato epidermis; different structures. ( smile)

The information about the mature tomato epidermis and cell wall not allowing molecules through is from articles I've read online speaking to the inability of Stop Rot sprayed on mature fruits to not prevent BER.

And no, I don't have any links to give you b'c they were all on a previous hard drive and I'm not going to start Googling again.

I'm up close with the nicotine patch and know of many drugs that are now administered in the same way, but the human epidermis is not the same as the tomato epidermis.

Carolyn

Again, with regard to blossom end rot (BER), I think cultural practices are preferred and more effective than spraying (or otherwise topical applications of) calcium.

Keep the soil pH at 5.8 or 6.5 which is a bit on the acid side of 7.0 neutral pH.

Perform a soil test to determine the pH of your tomato bed. If a base material is needed to raise the alkalinity of soil up to 5.8 to 6.5, apply the recommended rate of lime using dolomitic or high-calcium natural limestone. Be sure to apply lime two to four months before planting tomatoes to give the calcium time to marry into the soil.

Also apply the required (recommended for tomatoes) amount of fertilizer, when necessary, based on soil test results. Healthy tomato plants depend on the correct balance of nutrients and ample supply of micronutrients. But applying too much fertilizer at one time can induce BER, especially too much nitrogen.

By following soil test recommendations you ensure proper soil fertility.

Mulch heavy with high organic content mulch to conserve moisture and help bind nutrients for root health. Good mulching practices will dramatically reduce incidences of BER.

Some varieties of tomato tend to be more sensitive to conditions that cause BER. Some varieties are known to be susceptible to BER while some varieties are known to be resistant. If you are growing heirlooms or paste tomatoes, try growing several varieties and keep notes regarding incidents of BER, etc.

Depending on "mono-culture" (growing one variety for one purpose) with tomatoes is a sure route to disappointment for the hobby gardener or home canner. Mix it up a bit.

Keep plants adequately irrigated. Tomato plants need the equivelent of 1.5 inches rainfall weekly during the fruiting cycle. Too dry soil can exacerbate BER and chronic wetness can drown roots, shut them down and cause BER. Also, radical fluctuations in soil moisture can result in a greater incidence of BER ... like letting your containers or beds go dry and then soaking them down. Even watering is the key.

Be very careful not to roto-till, hoe or otherwise cultivate the soil within the major root zone of a tomato plant. Root pruning during fruit development will cause BER! Again, mulch heavy and maybe lay down walking path boards to protect against soil compaction or root damage especially when your rows are close together and the root zone extends into the space between the plant rows.

If you still intend to experiment with or apply calcium directly to the plants (topical applications whether foliar or to the fruit itself), spray them with a calcium solution at the rate of 4 tablespoons (level, not heaping) calcium chloride or calcium nitrate per one gallon of water.

Always be careful with calcium chloride because at daytime temperatures above 85* F, calcium chloride can burn tomato plants. If you have to spray calcium during high temp. conditions, calcium nitrate is a better choice.

Problem, again, with spraying calcium is that you need to spray two or three times a week beginning when the second flower blossoms begin blooming, assuming you're getting fruit set, to do any good delivering the calcium to its target destination inside the developing young fruit walls. And I think that may risk altering soil pH. But you can test for that at the end of the season and, if needed, add sulfur to rebalance your soil toward acidity.

Remember, spraying calcium will not substitute for proper cultural practices such as cultivar selection, soil fertility management, mulching, or proper irrigation.
Also, if you get BER, immediately remove and discard the damaged fruit because the rot will continue to degrade the tomato and provide bacteria and fungi a route into the plant.

Silicone surfactants are reputed to help fertilizer salts penetrate leaf cuticles so it might be a good choice to use here.

Not necessarily. It only proves that calcium chloride is capable of damaging tomato skin whether in a permeable stage or not.

"Then the goal should be to find the maximum concentration that doesn't cause damage."

Why? Horticulturalists already have determined the usable rate of application. Why go to the "maximum concentration that doesn't cause damage?" Seems wasteful of the unneeded/unusable excess and risks damage in the event of elevated temperatures AFTER application (as noted in the preceeding post).

"A saturated solution of calcium chloride on stems and leaves will definitely damage them. That is why you should PAINT the tomato, not spray it."

Yes, a concentrated solution will damage the plants, especially during elevated temps., as already noted. But can anyone imagine the labor intensive and actually silly practice of hand painting hundreds of little green tomatoes? OMG. What's up with that?

"Silicone surfactants are reputed to help fertilizer salts penetrate leaf cuticles so it might be a good choice to use here."

But I thought your suggestion was to paint the fruit and not spray the leaves. Or are you saying the fruit will have the same cuticle structure as leaves? Help me understand here.

"If you paint half of the tomatoes on one plant, you can use the other half as controls."

Not necessarily. I mean unless you paint-skip the fruit in a specific pattern acknowledging the fact that the fruit at the tip of the truss are more distant within the internal calcium delivery system than the fruit on the pedicles closer to the stem. Oh, and the fact that the farther up the plant, the less likely BER anyway. This exercise would seem nearly uncontrollable for an amateur to control.

"Then I suggest that you put a pound of Milorganite in the planting hole. That should be enough to give every one of your controls BER."

Explain, please.

It only proves that calcium chloride is capable of damaging tomato skin whether in a permeable stage or not.

To damage the skin without penetrating it, it would have to react with the surface, either a chemical reaction or dissolution. What is the surface material? Cellulose, wax, whatever. I doubt these react with calcium chloride. Otherwise, it doesn't change the course of the experiment, in that the concentration should be reduced.

Why? Horticulturalists already have determined the usable rate of application.

Name one for tomato skins and especially tell it to carolyn137.

Why go to the "maximum concentration that doesn't cause damage?" Seems wasteful of the unneeded/unusable excess and risks damage in the event of elevated temperatures AFTER application (as noted in the preceeding post).

The possibility of higher temperatures is already accounted for in "maximum concentration that doesn't cause damage."

Wasteful? Calcium chloride is cheap. People literally spread it on the streets where it eventually goes down the sewers.

But I thought your suggestion was to paint the fruit and not spray the leaves. Or are you saying the fruit will have the same cuticle structure as leaves? Help me understand here.

No. In either case, a surfactant is necessary to prevent beading and, on average, an educated guess is better than a random choice.

But can anyone imagine the labor intensive and actually silly practice of hand painting hundreds of little green tomatoes? OMG. What's up with that?

Yes, I can imagine that it is slightly more work than picking the fruit.

In applied research, it is better to first prove technical feasibility and second prove economic feasibility. It is done this way because economic feasibility is more likely to change with time than technical feasibility.

And, OMG, some of the people here control mites by spraying with dish soap followed by washing it off almost every day. To whom do you think you are talking?

I mean unless you paint-skip the fruit in a specific pattern acknowledging the fact that the fruit at the tip of the truss are more distant within the internal calcium delivery system than the fruit on the pedicles closer to the stem. Oh, and the fact that the farther up the plant, the less likely BER anyway. This exercise would seem nearly uncontrollable for an amateur to control.

Unless you have evidence that BER has a preference, separate the plant into W and E halves. Who said anney is an amateur? Not that I care.

Explain, please.

Excess nitrogen contributes to BER. I bet it is because fast growing shoots use nearly all Ca that the roots can deliver, thus leading to a Ca deficiency in fruit. One pound of Milorganite contains 23 g. of nirogen, the equivalent of 10 tbs of Miracle Grow 15-30-15. I seem to remember having a bad case of BER with much less N on a plant that wasn't particularly susceptible. I recommended Michiganite because I bet it doesn't burn at that concentration.

Since you pontificate on ways to prevent BER, surely, you must know the best way to cause it. So, what's your recommended way to cause BER?

Severe root pruning during early fruit development. You would've known that if you'd read my pontifications more closely and been able to retain simple concepts.

There are no "concepts" in pontification because there are no rationales or references. Also, it pains me to read affectations.

Meanwhile, I thought of a better method. Grow a potted plant in a mixture of peat moss and perlite without lime and fertilize with a hydroponic fertilizer with little calcium. This is convenient because hydroponic fertilizer without calcium is sold with the intent that calcium nitrate and magnesium sulfate be added to the solution later.

Here is a retail source for 5 lbs. of each:

Hydroponic Tomato Fertilizer, 5 lbs for $26.95

You can substitute Miracle Gro for the above.

Calcium Nitrate, 5 lbs for $7.95

But, you may as well kill two birds with one stone by substituting Calcium Chloride:

Calcium Chloride, 50 lbs for $21.00

Don't forget to add Epsom salts (magnesium sulfate), available at any drug store.

"But can anyone imagine the labor intensive and actually silly practice of hand painting hundreds of little green tomatoes? OMG. What's up with that? "

What about the labor-intensive and disappointing practice of yanking off hundreds of small/medium tomatoes as they show the black tip beginnings of BER. I had a roma last year. ****ALL***** of the tomatoes had BER. in a self-watering container. Probably wasn't planted right, but still...

I way prefer the taste of Roma style tomatoes chopped in salads than the silly beefsteaks or cherries. At least all the grocery store ones are watery with little flavor.