Force potatoes to make seeds by grafting on tomatoes

[reed]

Has anyone ever tried or heard of this? I read it somewhere (I was at work) and didn't save the link. Any way the premise is that grafting pretty much any potato on to a tomato root will cause the potato to bloom and fruit abundantly. I might try it anyway but especially if some of you folks think it might work. Could be a good way to stock up on TPS. 

[billw]

I've never tried it, as I live in a climate that is much friendlier to potatoes than tomatoes, but as I understand it, this is technique better suited for getting particularly challenging potatoes to set seed, rather than an all-purpose tool for increasing seed set. Unless you are after some uncommon genetics, it seems like it would be better simply to grow potato varieties that set seed reasonably well in your climate and work from those.

You may also be able to achieve a similar result by growing plants in loose soil and periodically removing the tubers.

(Not that I would discourage you from trying it; I'm sure it would be fun!)

[Joseph Lofthouse]

Speaking from total ignorance in the use of this technique... I think that it mostly will not work for most varieties of potatoes... For example, this technique will not restore fertility for any potato that is a triploid. There are other traits like clumpy pollen, and defective fruit stems that I think would not benefit from this technique. Those are genetic traits that are unlikely to be much influenced by the rootstock. Perhaps this technique would be of value for use with potato varieties that occasionally set fruit depending on stress, or environmental conditions, or mechanical damage to the plants, etc. Perhaps some of those varieties could benefit by not expending energy on making tubers. A variation on this theme would be to graft onto potato varieties that are known to bear seeds prolifically.

When I have examined this sort of thinking for other crops -- such as not allowing garlic to flower -- the differences in yield have been so small that it would take measuring with a scale and using statistical analysis to detect a few percentage points difference in yield. I typically don't chase a few percentage improvements here or there especially if it takes materials or labor.

[DarJones]

Grafting is effective Joseph. It works best on varieties with Chile cytoplasm which tend to be pollen infertile for various reasons including the S gene for self incompatibility. For example, grafted Kennebec will flower profusely and if pollinated with compatible pollen will set viable fruit with seed. It is nearly impossible to get Kennebec to set fruit otherwise.

Grafting is not really needed, you can achieve similar results on potato roots. Wait 4 weeks past normal potato planting time for your area and plant several small tubers about 1 inch diameter by just barely pressing them into the surface of the soil. The resulting plants will produce very few tubers all of which should be removed. With no tubers to mature, the plant will flower and set fruit. Compatible pollen is required so you would need several varieties done this way.

I got viable seed from Azul Toro by accidently dumping a tray of leftover potatoes into my garbage pile. A few of them sprouted right on the surface of the soil and proceeded to bloom and set fruit. Since then, I've been able to regularly get seed from Azul Toro using shallow late planting.

[reed]

I'm pretty much ignorant about potato varieties and the issues of infertility and the like. Thinking back to when I was little and hearing about how my parents and grandparents lived during the depression I imagine that the loss for what ever reason of their seed potatoes would have been a real problem. Even when I was little the left over potatoes in the cellar each spring were pretty precious things.



Actual potato seeds, if I can learn to produce them, sounds like a very worthwhile endeavor.
 DarJones, might, in the absence of small tubers to plant like you described would a larger one planted in a similar way work? Or maybe cutting some up and planting small sections each with just one or two good eyes? 

[DarJones]

Cut chunks with a single eye and plant them with the eye facing up. Push the piece into the soil deep enough to just barely cover the piece of potato. Note for the record that I do not advise this method for the average person trying to produce potato seed. It is far easier and IMO a better option to get a variety that tends to be highly fertile, i.e. that produces large amounts of seed with little effort. I have one purple skinned line from Tom Wagner that is an abundant seed producer. I can get several other varieties to produce seed with a little manipulation. Kennebec is a variety that I would love to have mature seed from, however, it is in the difficult to very difficult group in terms of setting fruit.

Drop in on Tom's website if you have specific questions about producing potato seed. tatermater.proboards.com/

[reed]

Thanks, I think I will try Kennebec and Russet, may not work but those are the ones I know I like. I don't like most of the purple and yellow kinds I'v eaten or even red ones so much. Already have several others from the store but don't know what they are. I am pretty sure that deer and rabbits don't bother potatoes so I can just make a spot for them in the yard. Since I don't want them to make tubers it shouldn't matter too much that I use a previously unworked area of my hard packed clay. I also like your suggestion better than the grafting thing.

Along with the seeds Joseph sent it will be fun to see how this works.

On the off chance I have success with the Kennebecs I will let you know and share some if you want. Do they easily cross pollinate? If so I'll keep them separated.