How a potato plant grows!

[Durgan]

http://www.durgan.org/URL/?QHBIN 21 August 2009 How a Potato Plant Grows
There is a great deal of information on the Internet about growing potatoes in tires, boxes and indicating that large quantities of new tubers can be produced with high vertical hilling. The view propagated is that potatoes grow from branches all along the main stalk. This is utter nonsense, as the pictures indicate. New tubers are formed around the seed potato and always slightly above it.

My potato growing test box was opened today. The pictures speak for themselves. Clearly there is no advantage in carrying out excessive hilling when growing potatoes. The purpose of hilling is to insure the tubers are covered, since light affects potatoes producing a green appearance, which is an indication of solanine, which is harmful if ingested in large quantities. For comparison one Pontiac Red was dug in the same row, which was almost identical to the test box potato in appearance. Some annotations are at the bottom of the photographs.

 

[ninnymary]

Burgan, thank you for such informative information. I learned so much from those pictures. Because of my tiny yard, I planted potatoes in a 15 gal. It was so successful that I plan to plant 4 containers this year. But I did hate the fact of adding so much soil to hill them. Next spring, I will definitely add less, maybe just 15 inches? What do you think?

Mary

 

[Durgan]

Burgan, thank you for such informative information. I learned so much from those pictures. Because of my tiny yard, I planted potatoes in a 15 gal. It was so successful that I plan to plant 4 containers this year. But I did hate the fact of adding so much soil to hill them. Next spring, I will definitely add less, maybe just 15 inches? What do you think?

Mary

Nothing wrong with using containers as you can see from my test box pictures. But those phony pictures (Seattle Times) are just that- phony. Talking about 100 pounds of potatoes in a small space-unbelievable. I knew it was nonsense from observation, so decided to test. Potato tubers do not grow along the stems like tomatoes. Mind you I tend not to read gardening books, but observe what I grow and change conditions as required by trial and experiment.

Also, anybody can grow potatoes but there is a big difference in the new tubers if not grown properly. A plant should produce a variety of sizes with a total weight of from 3 to 8 pounds with four being a good average, depending upon the cultivar. The new tubers should be free of blemishes with no knobs, and not too deep eyes. When cut open there should be no hollow in the centre, and the flesh nice in appearance. One year due to lousy weather, I wouldn't even eat my own potatoes. They were so inferior.

 

[ninnymary]

Durgan, sorry I misspelled your name the first time. This year I bought 5 potatoes from the nursery. Since I didn't want to cut them up to plant, I selected the smallest I could find. I was afraid that if I cut them to several eyes each, that the cut part would not heal and rot. How do you do yours? It would be a lot cheaper if I would cut them up. :/

Mary

 

[Durgan]

Durgan, sorry I misspelled your name the first time. This year I bought 5 potatoes from the nursery. Since I didn't want to cut them up to plant, I selected the smallest I could find. I was afraid that if I cut them to several eyes each, that the cut part would not heal and rot. How do you do yours? It would be a lot cheaper if I would cut them up. :/
Mary

The large potatoes are cut into pieces insuring at least two eyes in each piece. The whole potato is utilized. After cutting, the pieces are set aside until the wounds harden and seal over. If there are sufficient quantity about the size of a golf ball or slightly smaller are planted. Almost any piece with an eye will grow.

I like to chit (Chitting)my potatoes before planting. This is simply placing the seed potato in an open egg carton with the eyes up and placing in bright sunlight until they produce coloured sprouts (color dependant upon the cultivar). This takes about 4 to 6 weeks and to inhibit shrinkage, they are sprayed periodically with water. The sprouts will be about one inch or less in length.This gives the seed tuber a good start when planting.This sprouting is not the same white sprouts when the potatoes are in storage. Storage sprouts should be broken off when planting. They are usually broken off when handling anyway.

 

[digitS']

Nothing wrong with planting a whole potato, Mary.

The concern isn't so much the size as how many eyes are on it. If there are 12 eyes on a potato, large or small, you are kind of in trouble. That is, unless you are happy to have tiny potatoes to harvest. With each eye having the potential to grow into 1 plant, the crowding of plants limits production. Or, it just limits the size of the many tubers produced.

I am inclined to agree with Durgan about the miraculous amount of potatoes that some are claiming with certain techniques. I may not have used as strong as words as "phony" and "utter nonsense" is all . I have had an idea of essentially growing potatoes in vertical space - very much like a strawberry pot. Room vertically could be utilized by a number of plants. That ONE plant is capable of some miraculous poundage doesn't even seem logical. The starches are coming from photosynthesis and dependent on leaves, after all.

I have never tested ANY of these theories and have just grown potatoes in the open garden. That works well enuf for me.

Your good production in containers, Mary, is probably a result of good soil and, perhaps, good location - lifted a little above neighboring plants and competition for sunlight. I think that you should probably plan on "hilling" with additional soil at only a little more than would be a maximum in open ground. Maybe 15" would be excessive but if it is loose soil, there would be settling.

The lower leaves may not have great potential for photosynthesis as they age but the plant shouldn't struggle to grow leaves only to have those leaves buried again and again.

Steve

 

[ninnymary]

Steve, you are right. They did have new potting soil and were on my deck where they received full sun. I planted 5 small potatoes in 1 container and harvested 15 small ones and 15 medium size ones like the ones at the stores. They were Yukons that I bought for $1.50 at the nursery. My son loved them.

Mary

 

[thistlebloom]

The concern isn't so much the size as how many eyes are on it. If there are 12 eyes on a potato, large or small, you are kind of in trouble. That is, unless you are happy to have tiny potatoes to harvest. With each eye having the potential to grow into 1 plant, the crowding of plants limits production. Or, it just limits the size of the many tubers produced.
Steve

I believe that may well be the answer to something I've been wondering about! My total poundage harvested hasn't been too miserable, but the size of the majority of the potatoes is piddly small.

I'll be counting eyes next season. Thanks for the light bulb moment Steve!

 

[Durgan]

The concern isn't so much the size as how many eyes are on it. If there are 12 eyes on a potato, large or small, you are kind of in trouble. That is, unless you are happy to have tiny potatoes to harvest. With each eye having the potential to grow into 1 plant, the crowding of plants limits production. Or, it just limits the size of the many tubers produced.
Steve

I believe that may well be the answer to something I've been wondering about! My total poundage harvested hasn't been too miserable, but the size of the majority of the potatoes is piddly small.

I'll be counting eyes next season. Thanks for the light bulb moment Steve!

I dispute this conclusion. The number of stems growing has almost nothing to do with the size of the potatoes. One eye will produce many above ground stems. All the vegetation contributes to all the new tuber growth. Twelve eyes are seldom encountered. I have carefully measured the weight and compared quality of the potatoes over several years, and see no correlation between the number of eyes and number of tubers. One small piece of seed potato with a couple of eyes will produce as many potatoes as one seed potato with many eyes. Moisture at the correct time of growth is as big variable.
This is a sample of great potato production. I even had better in other years, which I will look up if push comes to shove.

http://www.durgan.org/URL/?ZLDZE 15 September 2010 Viking Potatoes Harvested
http://www.durgan.org/URL/?RUDKB 15 September 2010 Chieftain Potatoes Harvested.
http://www.durgan.org/URL/?MNCMQ 15 September 2010 Alaska Sweetheart Potatoes
http://www.durgan.org/URL/?ATRDM 15 September 2010 Agria Potatoes Harvested
http://www.durgan.org/URL/?FBQWE 11 September 2010 Russian Blue Potatoes.
http://www.durgan.org/URL/?BKWAI 11 September 2010 Yukon Gold Test Box

 

[digitS']

I dispute this conclusion. The number of stems growing has almost nothing to do with the size of the potatoes. One eye will produce many above ground stems. All the vegetation contributes to all the new tuber growth. Twelve eyes are seldom encountered. I have carefully measured the weight and compared quality of the potatoes over several years, and see no correlation between the number of eyes and number of tubers. One small piece of seed potato with a couple of eyes will produce as many potatoes as one seed potato with many eyes. Moisture at the correct time of growth is as big variable.
This is a sample of great potato production. I even had better in other years, which I will look up if push comes to shove. . .

Not wishing to push or shove, Durgan.

I'll provide some emphasis but the University of Idaho provided the text:

"The number of stems produced by a potato plant is directly related to the number of tubers that plant will set. Because each stem tends to produce a certain number of tubers, the higher the number of stems, the more tubers that will be produced by each plant. Having more tubers per plant can be advantageous for cultivars like Shepody that set few tubers with many of them oversized. However, the opposite is more often the case for cultivars such as Russet Burbank, which tends to produce a high number of undersized tubers. Both seed piece size and physiological age influence the number of stems produced by each plant. Every eye on a seed piece has the potential to produce at least one stem. Consequently, the more eyes per seed piece, the more potential stems. Additionally, as seed ages, the number of stems produced by each eye increases. The key to producing a more uniform tuber set is getting a consistent number of stems among plants by reducing variability due to wide ranges in seed piece size or physiological age." Presented at the Idaho Potato Conference on January 17, 2007 (link).

"Seed potatoes with more eyes will grow to produce a larger quantity of potatoes but the potatoes will generally be smaller. Seed potatoes with fewer eyes will produce fewer potatoes, but those potatoes will tend to be larger." University of Nebraska, Lincoln (link)

"Tuber set (number) is directly related to stem number . . ." Manitoba Agriculture, Food and Rural Initiatives (link)

Steve