Most Attractive To Bumblebees?

[joseph]

Yes, I am looking to enhance cross pollination rates of tomatoes. Using an existing pollinator and selecting for plants that are more attractive to that pollinator seems like the most straight forward approach.

I already have a decent population of bumblebees. I counted at least 5 species on two tomato plants this summer. The other varieties were ignored. I'd like to do more to cultivate bumblebees.

Some years ago I switched from growing barren potatoes to growing abundantly fruiting potatoes. The bumblebees used to ignore the barren potatoes, but they are all over the abundantly fruiting potatoes. On close examination, the non-fruiting potatoes have clumpy pollen. It doesn't come out of the the flower, and when dissected to pollen looks like jelly. If I jostle the fruitful potato flowers a stream of pollen pours out. The bumblebees like collecting pollen so they visit the flowers. I noticed the "jelly pollen" trait on one of the few tomato flowers I dissected this summer.

I think that I am looking for something similar with tomatoes. There might be several different traits to seek out: non-clumpy pollen, more open anther cones, etc... I figure that the bees will tell me without going to the trouble of dissection.

[joseph]

The other thing that I think is important to mention, is that the two plants that were highly attractive to bumblebees set fruit abundantly. (I called them the two best tomatoes in my garden this year.) I am speculating that they got pollinated more completely.

If increased attention from pollinators could lead to better fruiting then I'd gladly accept the uncertainty of not knowing who's the daddy.

[bower]

There's quite a buzz about using bumblebees as pollinators for greenhouse tomatoes - the trick is though that nectar (or substitute) has to be provided because tomatoes have none, and the bumblebees need both. Typical design has a sugar syrup provided in the artificlal bbee-nest.

I found this document by British beekeepers that lists plants rich in pollen, nectar, or both. I'd say it would be handy to have a nectar-rich (not pollen) plant handy to the tomato crop (pansies, for example), so the bumblebees have a source of energy to gather your tomato pollen without going further afield.

http://www.bbka.org.uk/files/library...1310045511.pdf

[Heirloom gard]

attracting bumblebees is great so long as you don't use any sprays on things.


wild bumblebes are dying out and to help the local bees out i may have to kill all the wild native plants I've planted in our yard because the staff spray raid, because the bees sting people.

[Fusion_power]

Tomatoes are attractive to honeybees, but only if there is no better source of pollen around.

Joseph, the trait you are looking for is more abundant pollen. Tomato flowers produce a range of pollen from none to enough to coat your fingers in yellow from one flower. I have not looked at the genetics involved, but the bees will find the most abundant source of pollen and work it assiduously. Best option would be to plant several varieties and watch to see who the bees like to play with.

[joseph]

I don't use -cides on my farm.

I'm getting mostly new fields this year because the landlady of one field died, and the other field got sold. The field where I was contemplating planting tomatoes next year hosts a 30 colony honey bee apiary. I think that I might want to find someplace else to do the bumblebee pollination testing. One of my remaining fields from this year is unsuitable because some animal picked all the green tomatoes when they were about marble size.

Is there much chance of finding tomato blossoms that are highly attractive to honey bees?

[Fusion_power]

I have not seen a tomato flower that produces nectar though they can produce a lot of pollen.

honeybees visit flowers in order of:
1. most nectar
2. most nectar plus pollen
3. some nectar plus pollen
4. most pollen.

They deviate from this in some conditions where they have a lot of brood to feed which means increased protein demand. That is when they will visit any and all pollen sources.

Honeybees specialize with some collecting only nectar, some both nectar and pollen, and some only pollen. Bumblebees on the other hand tend to be voracious pollen collectors.

[Doug9345]

I still suspect that the timing of the when the tomatoes flower relative to other species near by will influence if the bumble bees collect the pollen. Have you explored working with one of the wild tomato species?

[carolyn137]

I'm not so sure about all the comments about X pollination with bumble and honey bees when the article written by Dr. Jeff McCormack, former owner of SESE, clearly stated that most X pollination is done by sweat bees, aka Halictid bees, which areso tiny they are difficult tosee..

http://www.southernexposure.com/isol...es-ezp-35.html

Jeff's comments about isolation distances are quite conservative since at the time he was producing seed for SESE.

Just adding that it used to be thought that all true currant, S.pimpinellifolium, varieties have exherted stigma's but it's turned out that only about half of them do.

Carolyn

[NathanP]

http://www.youtube.com/watch?v=dY7iATJVCso
I have no idea who Marla Spivek is or what research she bases her comments on, but she claims in this video that most tomato pollination is done by bumblebees.

[carolyn137]

Originally Posted by NathanP

http://www.youtube.com/watch?v=dY7iATJVCso
I have no idea who Maria Spivek is or what research she bases her comments on, but she claims in this video that most tomato pollination is done by bumblebees.

Her name is Marla,not Maria and here's who she is:

http://beelab.umn.edu/

I read through quite a few of the links on that page and she described many genera and species of bees and what crops they are most important for, but not once did I see her refer to Sweat Bees,aka Halictids as far as I read.

Yes, she referred to bumble and honey bees but I saw nothing that said tomato blossoms are always, or similar, pollinated by bumble bees/

It makes sense to me that different kinds of bees in differfent parts of the US, and in different seasons, would pollinate tomato blossoms, but I also know Jeff McCormack well and his background, so still feel that overall it's sweat bees we can't see so well, that do most of it most of the time.

Carolyn, who,in past years spent far too much time in her tomato field and never saw any kind of insect working the blossoms although it's also good to rememebr that most tomato blossoms are self pollenized before the blossom is even open.

[Worth1]

I have never seen anything buzzing around my tomato blooms ever.


Worth

[joseph]

I guarantee that I have perfect eyesight, and am extremely observant, and I have paid attention to wild bees since I was a child, and that I could readily notice if any sort of sweat bee was visiting my tomato flowers regardless of how small they are. I spent days last summer watching the pollinators on tomato flowers. Sweat bees routinely visit my sunflowers, and squash, and onions, and carrots, but I have never seen one visit a tomato flower. I even know about the little worms that are around 2mm long that live inside my tomato flower's anther cones... I doubt that they are contributing to cross pollination though.

That says nothing about the rest of the world. It only means that in my garden with my varieties of tomatoes and other competing flowers, and with my species of bees, that my sweat bees are not the slightest bit interested in my tomato flowers, while at least 5 species of bumblebees were highly interested in the flowers of only two varieties of tomatoes.

I grow naturally, and never apply any type of -cide to my garden, and I actively cultivate a wide range of pollinators including sweat bees, parasitic wasps, and bumblebees.

Jeff said; "These crops are frequently visited by wild bees (halictid bees, such as sweat bees) and bumblebees in search of pollen. This situation may contribute to a high frequency of [natural cross pollination] in bee-rich areas in crops that are primarily self-pollinated." He also said; "For example, in parts of Virginia I have observed and photographed bumblebees (Fig. 3) and halictid bees (Fig. 4) such as sweat bees collecting pollen from tomato flowers."

[Fusion_power]

Marla Spivak is a relatively well known researcher who has done quite a bit with honeybees. I've read several articles of hers over the years.

Sweat bees may be important elsewhere, but here in Alabama, the only bees I've seen on tomato flowers are mason bees and honeybees. The mason bees are particularly interesting to watch. They hang underneath the blossom, press their thorax against the pistil, then vibrate their wings with a "BUZZ" sound. Pollen showers out if it is present in the flower.

[joseph]

Thanks for your contributions to my understanding of tomatoes and pollinators. It helped me write my most recent blog for Mother Earth News. Here is a copy of the blog.

Landrace Gardening Promiscuously Pollinated Tomatoes
Creating a landrace of promiscuously pollinated tomatoes. Details about my major plant breeding project for the next few seasons and a plea for help.


By Joseph Lofthouse
Tags: landrace gardening, tomatoes

In previous blogs I have written about landrace development projects that I have been working on for years. Today I am describing a project that is just beginning. I would like to convert my tomato population into a promiscuously pollinated landrace. A freely cross-pollinating population of tomatoes would greatly simplify the process of survival-of-the-fittest selection for families of tomatoes that thrive in my garden.

Background

In their natural non-domesticated state, tomatoes are a promiscuously pollinated crop. During domestication they were converted into a highly inbreeding crop. I believe this is due partially to not taking the tomatoes natural pollinators with the plant when it left its native land, and partly due to the intense focus in the last century on preventing cross-pollination. Naturally cross-pollinated tomatoes are typically considered a liability in modern times both in mega-ag and among home growers so heavy selection pressure has been put on the species to eliminate traits that lead to higher cross-pollination rates. I intend to reverse that trend in my garden and to create a landrace of tomatoes that is promiscuously cross-pollinating.

What Triggered This Project?

During the 2013 growing season I conducted a cold/frost tolerance trial on tomatoes. That got me into the tomato patch regularly to take measurements and photos. While there I noticed that just about every time I was in the tomato patch that there were two plants, out of 50 varieties, which were highly attractive to bumblebees. At least 5 different species of bumblebees visited the plants while I was watching. They spent around 10 seconds per flower. If the bees even visited other tomato plants they stayed for less than a second on any particular flower. Those two plants also happened to be the most productive plants in my garden. The varieties are named Jagodka and Nevskiy Red. I attribute the high productivity in part to the bumblebees doing a highly effective job of pollinating the flowers on those plants. I believe that more flowers got better pollinated leading to higher fruit set and larger tomatoes. That got me to thinking about what I really want out of my tomatoes. Do I want to continue trialing highly inbred varieties from far away that perform marginally? I decided that doesn't work for me any more. I want a locally-adapting population of tomatoes that is constantly generating lots of natural hybrids so that they can get more and more acclimated to growing in my garden with its unique pests, soil, climate, and farmer.



Where Do I Go From Here?

I have identified two varieties that are highly attractive to bumblebees, and that were very productive in my garden. They will form the basis of my new population. For the next few years the primary selection criteria for my tomatoes will be 'Highly attractive to pollinators'. Secondary selection criteria will include 'children of natural cross-pollination', productivity, and 'traits that might lead to higher cross pollination rates'.
Some of the older heirloom-type tomato varieties have retained traits that make cross-pollination more likely. I intend to gather some of those varieties together and allow them to cross-pollinate if they will, and select among the offspring for plants that are highly attractive to pollinators.

Possibly Useful Traits

Last summer I used a 20 X magnifying glass to carefully examine tomato flowers. I noticed a number of traits that might be useful in this project, especially if all of the traits could be combined into a single family. If a couple of years of natural pollination and observant selection don't lead to the combining of these traits I may attempt manual pollinations later on.

Simple Flowers: Some varieties of tomatoes have so many layers of petals that they prevent pollinators from reaching the interior of the flower. I will be selecting for simple flowers that allow easy access by insects.

Non-Fused Anther Cones: There was wide variation in how tightly the anthers were fused together. In some varieties they were loosely connected if at all, and in others the anthers were tightly fused together. I believe that a non-connected or marginally fused anther cone might lead to higher cross-pollination rates.

Loose Anther Cones: Some anther cones were tight against the style. This tight fit might prevent pollen from reaching the stigma or from leaving the anther cone, thus leading to lack of interest by pollinators and low cross pollination rates. Other anther cones fit very loosely around the style. I will be selecting for loose anther cones.

Extended Stigmas: Some varieties had stigmas that were totally inside the anther cone, others had stigmas that were outside the anther cone, and everywhere in between. I expect to be selecting for long styles that are outside of the anther cone so that they can rub up against a bees belly and collect some foreign pollen. That requires that pollinators are attracted to the flower in the first place.

Abundant Pollen: I attempted to extract pollen from many varieties of tomatoes this summer. The two varieties that were attractive to bumblebees were the only two varieties in my garden that released clouds of pollen for me when vibrated. Bees are not dummies. If a plant isn't feeding them then they are not going to hang around. The trait of attracting bumblebees might be a sufficient selection criteria to use for developing a locally-adapted survival-of-the-fittest promiscuously-pollinating tomato landrace in my garden.

Collaboration

I'd love feedback on this project. Have you noticed specific varieties of tomatoes in your garden that are highly attractive to bumblebees or other pollinators? Do you know of any varieties that readily release clouds of pollen or that are unusually susceptible to natural cross pollination? If you notice a variety during the coming growing season that the bees just won't leave alone, please tell me about it. I have a small amount of seed from Jagodka and Nevskiy Red which the bumblebees really liked this summer. If you'd like to collaborate on a grow out or in making manual crosses with something like Hillbilly let's correspond.

Conclusion

I believe that there is plenty of diversity available among commonly available tomato varieties to allow a group of observant plant breeders to return a population of tomatoes to their natural state of being promiscuously pollinating. I believe that it is easily possible to combine modern traits like large fruits with ancestral traits like being highly attractive to pollinators and very susceptible to cross pollination. A tomato landrace that combined the best of both worlds would constantly be regenerating lots of new hybrid vigor. This is part of the reason why I believe that landrace gardening is a path towards food security through common sense and traditional methods.