No, I'll go so far as to say that very few bag their blossoms. Since tomato blooms are self-fertile, cross pollinating is a relatively small percentage - +or-5% of the crop. Open-pollinated tomatoes are very stable without bagging. If you are saving seed for yourself it isn't needed. If you are into hybridization or commercial sale of seeds then it may be. Otherwise it is purely optional.

Those of us that trade seed usually label them as OP just so the recipient knows they were not bagged blooms. Haven't had anyone object yet. ;)

If you want to review them there are several prior discussions here on bagging bloom and cross-pollination that the search will pull up for you.

Dave

Those of us that trade seed usually label them as OP just so the recipient knows they were not bagged blooms. Haven't had anyone object yet. ;)

If you want to review them there are several prior discussions here on bagging bloom and cross-pollination that the search will pull up for you.

****

Dave, I think you meant to say not OP as you did, but perhaps OP unbagged as opposed to OP bagged. ( smile)

And there's an excellent FAQ here about cross pollination and bagging blossoms spacetomato. Just go to the top of this first page and click on the FAQ link and scroll down until you find that article.

I don't bag blossoms either,never have, and of maybe 3-400 varities I've listed in the SSE Yearbooks I know of maybe less than 10 that were crossed.

But each person really needs to know roughly what their cross pollination rate is re the pollinators in their own area b'c it varies considerably, or can do so.

There's a good discussion of the many variables written by Dr. Jeff McCormack when he owned Southern Exposure Seed Exchange and it's still there. So if you go to that site and look around you'll find that valuable article.

Carolyn

Dave, I think you meant to say not OP as you did, but perhaps OP unbagged as opposed to OP bagged.

You're right, Carolyn. I did. Senior moment. ;) Thanks.

Of the 36 plants I grew this year, all from saved seed, 3 were not true to type. That's 8%. And of the 3 crosses one was a really nice Brandywine x something (probably CP) that was a nice surprise, so I really only had 2 of 36 I wasn't happy with. That's 5.5% and supports the experts from a small sampling.

It's also possible to have extremely high rates of crossing from unbagged blossoms, especially if you only save seeds from one fruit.

One year I grew four plants from seed I got in a trade, and three of them were crossed. One plant was true to type and the other three produced horrible-tasting seedy things that went into the compost heap.

After that experience, I try to always grow at least 3-4 plants of a new variety, especially if the seeds are known to be from unbagged blossoms.

And never save seeds from just one fruit. If that one fruit happens to be from a blossom that was pollinated by a bee, the rate of crossed seed can be very high. Saving seeds from several fruits raises the odds of getting good seed from blossoms that self-pollenized before a bee found them.

Would the close proximity of other plants,..... close enough for the movement of two blossoms to brush against exerted stigmas... and then have pollination occur... or cross to ocurr?
Could it be possible that this type of contact.. pollinate even a blossom with closed anther cones?
Or are the odds just so astronomical as to not concern ones self?
I am thinking in a cramped garden space... with other varietys even intertwining ... that this could lead to bagging as a means of assuring the purity of the lineage?

Tom

I need an answer to windclimber's question also. I have a teeny space, and I expect my tomatoes haven't exactly kept to themselves...

Would the close proximity of other plants,..... close enough for the movement of two blossoms to brush against exerted stigmas... and then have pollination occur... or cross to ocurr?
Could it be possible that this type of contact.. pollinate even a blossom with closed anther cones?
Or are the odds just so astronomical as to not concern ones self?

******

Very few heirloom varieties have exerted stigma' so I don't see direct contact leading to X pollination as a strong possibility. The stigma ends up exerted at the end of normal pollenization and that shouldn't be confused with a real exerted stigma.

Only if the adjacent plants were identical would you end up with perpetuation of the variety. Otherwise, it would probably be a X pollination event.

(I am thinking in a cramped garden space... with other varietys even intertwining ... that this could lead to bagging as a means of assuring the purity of the lineage?)

Yes, bagging would help but it all depends on what you mean by cramped and how far apart the plants are.

Self pollenization occurs most of the time and almost all cross pollinations occur via insects.

How pure you want your seeds depends on what you're going to do with them. If for home use I don't think it makes much difference but if you're listing them in the SSE YEarbook or using them for trades, that's a different story entirely in terms of seed purity.

Carolyn

We plant to start saving tomato seed next year for home use and also seed sharing (gardenweb trades and SSE yearbook). I assume that good bagging practices would be a must with these growing conditions and seed sharing plans, right?

Here's our tomato area from last year. 92 plants, at least a dozen types:

{{gwi:344354}}

Lynda

Lynda, I it's not a MUST for listing varieties in the SSE YEarbook, but if it's convenient for you do and/or you feel strongly about it, by all means go ahead and do it.

I'm a long time LifeTime SSE member and have listed 100's of varieties and have had less than maybe 10 that I knew were X pollinated after offering them. But there are lots of variables that also come into play for X pollination rates depending on many variables. When data for the Yearbook is due in early Nov there's no way to check seed for new ones except looking at PL ones and if you see RL ones then you know there's a problem. And I don't do that either.

When I list I say whether or not the seeds are bagged or not, just generally, not by variety, but that's only in the past few years b'c someone else now does that for me since I fell in Dec of 2004 and can no longer do what I used to do.

I still save, with help, some unbagged seeds and offer them in my online seed offers as well as offering some of them in the YEarbook.

Before 2004 I was growing up to 500-700 plants a year and maybe 250 varieties and there was absolutely no way that I could even attempt to bag blossoms.

And it isn't often said, but bagged blossoms can also rot so unbagged blossoms and the fruits they produce are a plus.

Most folks who list in the Yearbook say nada about bagged or unbagged blossoms in their blurb at the front of the YEarbook. Both in the Yearbook and for my seed offers I plainly say that seed purity is not guaranteed.

And I do think it's very important to save seed never from one fruit, save seeds from several fruits on one plant, even better is several fruits for two plants and even better, well, you get the picture.

That way if there is any X pollination the number of X pollinated seeds is diluted out if blossoms aren't bagged.

Carolyn

Thanks for the info, Carolyn. That's useful to have a feel for how low the chance of cross pollination is. From a tomato sandwich standpoint it could be a lot better for us to grow lots of tomato fruits and save seed off of a large number of fruits and plants if bagging might interfere with the amount of tomatoes we can harvest.

Wow, 500- 700 tomato plants must have been amazing - and delicious. We have broiled tomato sandwiches for lunch almost every day in the summer and have felt so wealthy picking through the harvest bowl with all sorts of colors and flavors. Picking through 250 kinds - wow. All I can say is "yum".

Thanks again for the information.

Lynda

I tried bagging blossoms for the first time this last summer. I had major problems with the blossoms that were bagged dropping. I tried shaking the plants and "tickling" the blossoms in the bags, but I still had really low rates of polination. I ended up saving seeds from about half bagged and half unbagged. This year I'm not going to bother.

Ask yourself ... how did over 4,000 tomato varieties get listed in the SSE Yearbook?

Answer ... unbagged blossoms!

Okay, well in some cases ... ungagged imagination.

the outcrossing rate for most Brandywines is probably higher, in fact one study put it around 20% (which likely explains parts of the mess Carolyn mentioned - that 20% may also be tied to timing and insect populations)

************************************
I pasted the above from a thread "Brandywine Brand"
which was written by "mule" for what it's worth.

I have heard 5% form most and not 20%????

John

Why don't you try this:

Plant two pure Brandywine Sudduth plants.

Plant nothing else but regular leaf tomato plants the same year and in the same garden all spaced out as you regularly would space your plants.

Collect all the fruit produced by the Brandywine plants and extract all the seeds out of all the fruit. Mix all the dried seeds thoroughly together in one container.

Take about a hundred seeds randomly scooped out of the batch of saved Brandywine seeds.

Germinate all 100 seeds and check the cross pollination rate by counting the regular leaf seedlings ratio to the potato leaf seedlings.

Let's say you get 15 regular leaf and 75 potato leaf seedlings and the rest didn't germinate. That would be 20% cross pollination random average.

Whatever ratio you got from a random sample would indicate a general idea of what kind of cross pollination rate you can expect in YOUR garden for Brandywine.

Do it and you won't have to wonder about it or question someone else's notions about it.

Last year, I had several bumble bees (the big black and yellow fuzzy ones, at least that's what I grew up calling them) in the garden, and every time I went out there, they were busily going from one plant to the next. Am I safe not bagging blossoms in this situation? I bagged and saved some, but it was such a pain that I only did a couple. I will try again this year, but if they return, can I pretty safely not bag blossoms? Thanks!

is Carolyn137 DR Carolyn Male

is Carolyn137 DR Carolyn Male

*****

She was until she retired but has been reading and posting online about gardening since 1989 and has always signed off as Carolyn, and that's what she prefers.(smile)

Carolyn, who notes that if you click on her page aka (My Page) where her user name is she has outlined, in a too long blurb that needs to be rewritten, about her past activities.

Great - I have owned 100 heirloom tomatoes for the american gardener for about 8 years - is their going to be a new book the next 100 or maybe a supplement? my relatives are from Missouri and PA where several heirlooms came - have lived in So Calif for all of my 60 yrs and I am going to move to Montana in the next few years so I have been planting cooler weather plants hoping to find those that handle cooler temps better - and last month we had an artic storm come through and ice/frost was on the grass several days - some plants died others did not and have set fruit and didn't drop remaining blossoms yet - do you have a site where people can write or is this an appropriate way? - how many plants - which do you grow now

The 5% number has been floating around for a while and is probably what one person found by eyeballing his/her growouts, and not from a series of controlled studies. If it is from a controlled study was it carried out in several locations over several years?

There are several factors involved, the most important of which is the number of halictid bees you have in your area. These are tiny sweat bees, often iridescent green incolor. They are about as long as the anther cone of the tomato flower and easily missed if you are looking for larger bumble bees, and they only stay at a flower for a second or two before moving on. They pack pollen into a nursery burrow and then lay an egg and seal the chamber and start all over again collecting pollen for food for the next egg. When they find a good source of pollen, such as your tomato patch, they repeatedly come back to it. Flying several hundred yards is not a problem for them, but they are going to stick around areas with highest source of pollen closest to their brood sites. Each flowers may be visited as many as 50 times in 2-3 days (depending on how many bees are around), mostly in the late morning, but little after mid afternoon. So if you are not in your garden during this time you may miss the activity. An individual bee usually has enough foreign pollen on its body to fertilize every single seed in a tomato with just one visit, but tomato flowers contact their own pollen as they are opening so the question is what is the ballpark percentage of unfertilized seeds/ova at the time the bees get at the flower. This would depend on weather and temperature as it relates to the flower releasing pollen as it is opening, as well as flower development/structure. Flower development and structure depends on the variety as well as the form of the flower, some varieties have a lower percentage of malfomed blossoms than others. The bees' posture while collecting pollen from a tomato flower is such that cross pollination is favored on a perfectly formed flower, but the stigmas of malfomed flowers may be less likely to contact their own pollen, so some hard data is needed to know just what the effect of flower deformation is on cross pollination rate.

With a very small sample size, In fruits off of the first truss of the year, I have cross fertilization rates as high as 12.5% per fruit, but with 7 out of 10 fruits showing no cross pollination. This is before heavy bee activity later in the season, and on plants whose cages were whacked with a stick daily to aid self pollination.

So you may hear people say 5%, but it is a ball park figure and we don't all play at the same ball park. If your ball park was sprayed with sevin or there are no adequate sites for halictid bee nests you may have a very low cross pollination rate.

do you have a site where people can write or is this an appropriate way? - how many plants - which do you grow now

*****

No, I don't have my own website. And I gave up answering e-mail questions about 8 years ago, with very few exceptions concerning some complex issues, b/c the volume was too high and b'c I strongly feel that all questions and all answers should be posted publicaly. That way anyone who wants to answer can and no one is dependent on the answer of a single person.

I read and post at 5 different message sites and no I can't post them here b'c GW would ban me.

I'll make this short, but I had to retire in 1999 b/c of two bad hips and in Dec of 2004 I fell b'c of that and severed all four quads in my right leg. And subsequently I had two new hips put in, but one of the quads didn't return to function after surgery so I've been in a walker since then and will continue to be so.

The last season when I grew hundreds of plants and varieties was the summer of 2004. Since then I grow stuff here at home, and someone else does all the gardening, and I try to grow only varieties new to all or most for my SSE listings as well as seed offers that I make online. A friend in VA grows my plants for me and a friend here in NYS does most of the seed production by bagging blossoms, but with help I still do some seed saving here at home where this past season I had 30 plants.

Many have asked if there will be another book or a supplement but I think you can see that the answer is no b/c of my current physical condition.

My friend Craig LeHoullier and I have been talking about doing something that might lead to a small book vis a vis updating and commenting on issues of Off the Vine (OTV), which was a newsletter about heirloom tomatoes that we published until the mid-90's, so we'll see where that might or might not go as time passes.

Carolyn

So you may hear people say 5%, but it is a ball park figure and we don't all play at the same ball park. If your ball park was sprayed with sevin or there are no adequate sites for halictid bee nests you may have a very low cross pollination rate.

*****

Spiced, in one of the first posts in this thread I referred to the article written by Dr. Jeff McCormack on NCP ( natural cross pollination) which can be found at SESE ( Southern Exposure Seed Exchange).

And as I recall Jeff cited several controlled studies where NCP was studied and as expected, the range was from 0 up to about 30-40%. And there were, at least a few years ago, several of those controlled studies still on the net and accessible. I had several in my faves at one time.

The point is, and I think it was made in posts above, that no two situations/gardens/areas/pollinators are the same when it comes to NCP and there are many many variables, which Jeff also spoke to in that article in detail, which I think is a good read for anyone interested in NCP.

When I say I usually get about a 5% NCP it's not a ball park figure, it's the result of growing thousands upon thousands of plants and varieties over the years and seeing the results.

For sure others in different areas and different situations get different results in different years, or should just based on the averages.

Low rates of NCP often don't show up in a seed batch for many years b'c it takes hundreds of those seeds grown out before even one off plant might be seen that was the result of maybe just a few X pllinated seeds in a seed batch where many fruits were processed for seed.

So yes, the information on controlled studies is out there and yes, rates can vary from year to year b'c of so many variables including kinds of pollinators, how many, weather, when those pollinators are active , and on and on. I don't think most folks realize that weather can cause a stigma that would normally be retracted to exert, and that's a problem as well.

Carolyn

Original question:

Does everyone practice blossom bagging when saving tomato seed? To what extent are Heirlooms stable without bagging?

Answer is: No, most do not bag blooms and stability of heirlooms is exceptionally high without bagging for all the reasons detailed above.

Are there exceptions to the +/- 5% guide? Of course. Should that figure be ignored? Of course not. Could it be higher in your individual garden? Perhaps. If so, will you know it? Unlikely for most. Could it be lower? Very likely.

MPE - In over 40 years of growing hundreds of different heirloom variety tomatoes and saving my own seeds and trading those seeds with others I have personally experienced 2 or perhaps 3 crossed plants and had no reports of any crossed seed from any traders. And that is with steady winds the length of the rows, 70-80% humidity, and with halcid bees and bumble bees and honey bees (until recently) in abundance.

Bottom line - bagging is your choice but it most definitely is not required unless 99% seed purity is your goal for some reason. 100% isn't possible even with bagging - just ask the professional hybridizers. ;)

Dave

Carolyn,

As you say 0-47% cross pollination rate has been reported, but if you check many posts on forums you will often run into 5% given as gospel, often with some statement along the lines of "don't worry about bagging". This is not a good practice for people trying to preserve the integrity of heirloom varieties if their garden happens to be someplace where 30-40% occurs. Sure, if you need to save a large quantity of seeds for sale/trading bagging is problematic, but for most of us a couple of tomatoes will provide plenty of seeds for our own use and a little trading. It's not a big hassel to slip a bag over a flower truss, and sachet bags can be found at Walmart, Target, etc. stores $4/dozen.

There is something I don't understand here (I am quite a novice when it comes to seed saving) : how can one call a seed "open pollinated" if the blossoms producing it has been bagged?

I'm trying to find an answer to this since a few days on the internet but to no avail.