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Post by gilbert on Mar 22, 2016 7:56:29 GMT -5
Two more ideas: I think I will coil a soaker hose through at least some of the towers.
And for the layered towers, I think I will start the seed potatoes in the bottom of large biodegradable containers, and hill them up till they reach the top. Then I can place the containers sideways within the various levels of the tower with the tops sticking out the side. This will allow me to have the roots near the center of the tower, where the moisture and temperature will be stable, without worrying about the shoots finding the light at the edge.
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Post by oldmobie on Mar 22, 2016 19:14:49 GMT -5
Planted two of last year's mini-tuber plants in cat litter buckets to experiment with towering. One was planted unaltered, the other with two cuts in it's stem, wedged open with toothpicks below the soil level. Hopefully these cuts will encourage rooting and stolon formation. Basically it's air- layering, but underground. Dirt-layering? With the others I'll probably experiment with cutting back, and with starting new plants from the cuttings. I hope to also try the pull-start idea. Since all of that falls outside the scope of your thread, I'll track those experiments elsewhere.
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Post by gilbert on Mar 23, 2016 9:28:10 GMT -5
Hello oldmobie,
That is a really interesting idea, cutting the stem to encourage rooting. I wonder if even a commercial, modern variety could be made to root up the stem that way. If it could, that would be wonderful; we could let the plant develop six inches of leaves to store up energy for the next push, and then nick and bury it. Repeat ten times up the tower height.
What variety are you using?
I looked into pull starts, but I'm assuming that would be counterproductive if I want to keep the stem from ever greening up.
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Post by gilbert on Mar 23, 2016 10:05:31 GMT -5
This post is a summary of the "state of the art." Please suggest corrections or additions.Potato and sweet potato towers with improved yields compared to in ground plantings are possible, but are a difficult goal to achieve. The following factors influence yield: Variety: This may be the most important factor. Most potato varieties currently available in the USA are bred to have one clump of short, un-branched tuber bearing stolons, just above the seed potato. They tend to die down as opposed to growing continuously through the season. Thus the increased hilling of potatoes in a tower is not advantageous. However, there are a few varieties that do grow more stolons along the stem. They tend to be "unimproved" or older varieties. Most come from genetic groups other then S. tuberosum Tuberosum, to which most commercial varieties belong, such as S. tuberosum groups Andigenum, Phureja, or Stenotonum. (Example, the Papa Chonca potato.)The Kenosha potato project has some good information on varieties with high tuber set. Breeding new varieties from TPS may be a good way to develop this trait further, but this would likely be a long, hard road. However, even these varieties, which set tubers high in the ground, may fail to set tubers high in a tower. This is possibly because for a potato to do well in a tower it would have to have other traits then setting tubers high; for instance, heat resistance. In a layered tower (with multiple levels of individual plants) these traits of commercial varieties are less of a problem. However, the varieties chosen still have to be more heat tolerant and adapted in other ways to the conditions in a tower. Even in a layered tower, potatoes that keep growing all season and set tubers in multiple locations would improve the yield. (As a side note, there are people who say that even commercial varieties can be induced to grow tubers all along the stem. More on that later.) As far as sweet potato varieties, I have less information. Tower construction: The basic distinction is between a layered tower and an unlayered tower, touched upon above. However, there are many types of both. Wooden stacking bins, barrels (with holes in the sides for the layered types) stacks of buckets in pyramids or on shelves, stacks of tires, straw lined wire mesh bins, plastic lined bins, and many other styles. Tower construction affects yield insofar as it affects other variables. And of course, it shouldn't fall down! Tower filling materials: There is a distinction between two materials: what is under the tuber, and what is above the tuber. The material under the tuber should be soil like, whether the amended ground the tower stands on, or a potting mix of some type. This is for the roots of the potato plan. For layered towers, this should fill the whole tower. The material above the tuber in an unlayered tower (and, for that matter, the soil below the tuber as well) must meet the following criteria to enable tuber production: it should not be too heavy (this presses on the root system;) it must retain water well (if the tower dries out no tubers will be set;) it must not contain too much air (this will retard tuber set.) Sawdust, sand, finely mulched straw, compost, and rotted wood chips in some combination have potential. Straw or plain wood chips will not work. Water: this is very important. The tower must not dry out. With sweet potatoes, this may be less of an issue. Water can be ensured by installing soaker lines, and possibly ollas or wicking bed features in a tower. PVC pipes with holes in them inserted in a tower can make watering easier. Towers with solid walls will be easier to keep watered, as will wider towers. Potato plants should be kept away from the drying edge of an unlined tower. Soil Temperature: Temperature fluctuations and too warm of a soil inhibit tuber production in Irish potatoes. Soil temperatures that are too cool will slow the development of sweet potatoes. Tower construction and color play a role here, as does variety selection. Temperature fluctuations can possibly be damped down by using light colored or reflective material, or including an insulating " sacrifice zone" in a tower. Fertilization: If a plant either in a layered tower, or in a classic tower, is expected to produce a lot of tubers, it has to have plenty of minerals in the soil. As a fan of Steve Solomon, I would also add that the minerals should be balanced with one another insofar as is possible. There should be plenty of organic matter to feed beneficial microorganisms. Foliar feeding with nitrogen and trace elements may boost yield. Less tested ideas include compost and herbal teas sprayed on the plants. Cultural practices: This includes a bunch of things. Individual, small seed potatoes are better then cut pieces of larger ones. In a classic hilled tower, the stem must not be allowed to green up between hillings. (Some think this is the single most important factor. ) There is an untried idea that nicking or slicing the stem may promote underground stolon production, and another that nipping out the growing point may produce more branches. Trellising or spreading out tall plants may allow them to access more sun. Time of planting for a given climate is important. There is another untried idea that starting seed potatoes in small containers and then transplanting them to a layered tower would be more effective then starting them directly in a tower. Uncontrolled factors. The ultimate limiting factor is the amount of sunlight in a given location and the efficiency of photosynthesis. Air temperature/ degree days, humidity, and length of growing season are largely uncontrolled, but could be controlled with a tower in a greenhouse. Minor/ unknown factors. There are a number of unknown factors at play; symbiotic relationships with other organisms, electromagnetic effects, biodynamic type effects, trace elements that are too minor to test for, etc. Tower height: The ultimate variable! With a skyscraper size layered tower containing 1600 layers of potato plants, I'm sure I can get that elusive 100 pounds!
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Post by gilbert on Mar 23, 2016 10:30:41 GMT -5
I've started work on the potato towers. Yesterday, I dug 4 holes on the farm, each 4 feet cross and 18 inches deep. I back filled them with the topsoil from the hole, mixed with peat moss. The amount of peat moss varied, but we used two and a quarter bales (compressed, 3 cubic feet each) on the 4 holes. The holes contained about 75 cubic feet of soil, so that will give you an idea of the ratio. Also take into account that some subsoil was removed from the holes. The holes were fertilized with my special, super secret blend. Actually, the mix contained soy bean meal, kelp meal, soft rock phosphate, ag gypsum, zinc sulfate, and borax. This was tailored to bring my particular soil into balance as per the recommendations of Steve Solomon. ( The Intelligent Gardener.) In the end , each hole got about .7 pound of soy meal and .2 pounds of kelp. The other exact amounts don't matter since they were contingent on my soil. I did not add the copper that my soil needs, since copper sulfate is dangerous; I opted to add soluble chelated copper (biomin copper) as a foliar later in the season. Each hole ended up mounded above the surface level. Before I plant potatoes in then, I will also add some compost. My soil is roughly neutral, clayey, with good water holding abilities; classification, Nunn loam, 1 to 3 percent slopes. It has high calcium and very high potassium. The area I chose has not been used in any way for years; it was currently wild grass. These four holes will eventually be two classic, hilled towers, and two layered towers, both with wire mesh / plastic sheet surrounds. The hilled towers will contain multiple varieties, each in its own bucket mini tower, as discussed above, and hilled with rotted wood chips/ compost. The layered tower will be filled with potting mix of some type. For both, the potatoes will be planted a few inches below the surface of the mounds. (In the layered tower, subsequent layers of potatoes will be added every foot or so.) Before they are planted, some compost and more soy meal will be mixed into the surface of the mound.
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Post by oldmobie on Mar 23, 2016 12:01:19 GMT -5
What variety are you using? Probably Joseph Lofthouse 's Bountiful. Last year I planted his TPS seeds along with the seeds from one berry I found here. They were all planted together. The Bountiful outnumbered my seed. I don't know if mine were viable. These are the resulting mini-tubers.
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Post by gilbert on Mar 23, 2016 12:50:34 GMT -5
I just posted this on the Tater Mater forum. If anyone here has any thoughts, I would be glad to hear them!
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Post by reed on Mar 24, 2016 5:31:58 GMT -5
Not to be discouraging but any plant has to have leaves exposed to sun in order to grow so no matter how prone to setting tubers along a vertical stem it probably won't start setting any at all until leaves find the sun. I have no idea of the actual correlation is but say it take 5 sq inches of leaf to feed the production of 1 cubic inch of potato.
Once leaves find sun and it starts to grow that correlation between (leaf surface / potato) is unlikely to change. Even if the plant sets tubers up and down the vertical stem rather than just at the bottom how will that change the volume of potato produced? Won't you just end up with a stack of little potatoes instead of a pile of big ones?
I'm just guessing but I suspect a relationship between leaf surface and production volume is a real thing. I wonder that if a tower is going to work it will have to be one where different seed potatoes are planted at intervals above each other with the stems coming out the sides rather than the top or in a series of containers stacked up on some kind of rack kinda like toomanyirons suggested.
Otherwise you need a seed potato or a TPS capable of growing for a long time without sun. Then, once it finds sun, it has to grow a lot of large leaves very quickly in order to make potatoes in whatever time is left in the season.
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Post by gilbert on Mar 24, 2016 9:07:19 GMT -5
Hello Reed,
Yes, you have a point. I'm hoping that I can find or breed varieties which will take just a few weeks to climb the tower, setting "Tubers to be" along the way. Then it would grow a lot of leaves to bulk them up.
Maybe that is not realistic and I should try to use oldmobie's idea of nicking a green stem to try and make it produce potatoes.
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Post by nathanp on Mar 24, 2016 12:45:44 GMT -5
What I have seen is that there is a race for the stem to reach the top of the tower, buried along the way, before the seed tuber exhausts itself. Some varieties cannot do that. You have to bury nearly all the stem along the way, otherwise you risk the stem not sending out stolons at multiple levels. If too much stem foliage is present, it may not set stolons high along the buried stem. If you bury too much foliage, you risk the plant only receiving energy from the tuber, and not from the sun.
I have also seen stems rot when buried, which is another problem entirely, and I am not sure what the cause of that is, unless it is just from the tuber being buried too deeply.
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Post by Joseph Lofthouse on Mar 24, 2016 16:54:14 GMT -5
It's common in my family to have potatoes sprout in the root cellar, in complete darkness, to have stems 18" long before we finally discover them. I suppose that those stems could be planted 17" deep, and retain the ability to send out roots and/or stolons all along the stem, if it's the type of potato that does that sort of thing...
Those same potatoes stored in a location with a bit of light only grow stems 0.5 to 2 inches long...
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Post by nathanp on Mar 25, 2016 18:31:16 GMT -5
I suppose that those stems could be planted 17" deep, and retain the ability to send out roots and/or stolons all along the stem, if it's the type of potato that does that sort of thing... Ha - I can't believe no one has thought of this sooner. I think that's a great idea to try.
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Post by gilbert on Mar 26, 2016 9:59:40 GMT -5
Yes, sounds like a good idea to try. I was thinking of starting all my potatoes in pots in the greenhouse to get a jump on the season (it is still snowing outside) and so that I could make sure the roots ended up in the moist, inner layer of the tower. Now I think I will start them all in pots in the basement, hill up the sprouts as they grow, and then transfer them to the greenhouse before the tuber runs out of energy.
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Post by gilbert on Mar 26, 2016 10:30:34 GMT -5
So, a progress update. No more work on the outdoor towers, since we got a foot of snow on Wednesday, and I haven't even made it out to the field again. But I got a bunch of the Survive and Thrive TPS seeds from Marianna's Tomatoes (from Chris Homanics) planted inside. Since I was not sure how best to plant them, and there was conflicting info online, I tried a bunch of different ways. I planted about 40 seeds in soil (Miracle grow organic potting mix) and about 20 on the surface of a cornstarch gel. I'm heating half of each with a heat mat during the day, and not heating the other half. They are in a dim room, so as soon as any sprout, I will have to move them to my heated or my unheated frames, depending on the weather outside. All the pots are covered with plastic wrap. I will be misting the surface of both media types every two days with a hydrogen peroxide solution ( 1 and 1/2 teaspoons of 3 % peroxide to a cup of water) to prevent mold growth and possibly stimulate germination.
I will probably do some more work on the project today and update here.
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Post by Joseph Lofthouse on Mar 26, 2016 12:17:08 GMT -5
My experience is that potato seeds germinate better at cooler temperatures: Like 50 F to 60 F. Looking forward to learning about the results of the heat mat experiment.
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