Techniques to induce potato flowering

[DarJones]

I'm trying to work out methods that would induce flowering in potatoes. There are obvious differences between varieties and species that can be exploited and there are environmental influences that could also be useful. Here are the methods to trigger flowering that I am currently aware of.

1. Graft onto another solanum such as tomato. The plant does not have potatoes to mature so it makes flowers instead.

2. Modify the soil by increasing potassium and possibly phosphorus. This is moderately effective as shown in my garden this year.

3. Reduce the load of potatoes on the plant by artificially removing them. By planting at the surface of the soil and letting the plant grow downward, it tends to produce feeder roots but not stolons. Any potatoes that are formed can be removed by hand.

4. Use chemical sprays that induce flowering. I haven't tried this, but from a couple of articles published recently, most flowering plants are triggered to produce flowers by a series of plant auxins. It should be possible to use similar chemicals to induce flowering.

Does anyone have any other possibilities for getting potatoes to flower and produce berries?

DarJones

[graybell]

Darrel, I have not done any scientific controls on growing. So this is just observation and hunch from the way I have amended soil in the past.

This year was the first year I did not use either bonemeal or rock phosphate directly in my holes for planting potatoes. This year I amended heavily with turkey manure. Aged about 2 years.

My flowering was significantly less on some varieties that typically flowered in the past. Some didnt flower at all. Last year I had several varieties to flower, this year only banana Mtn. flowered, and made berries. I did however get some record yields for me on tubers. I wonder if giberrillic acid would cause a potato plant to flower and set berries. Gray

[Tom Wagner]

www.springerlink.com/content/m762226n4120l673/ may give a few of you a hint to the hows and whys of potato flowering induction.

Dr. Joe Pavek sometimes would place a tuber on a brick cover with vermiculite or perlite mix and remove that mix once the plant was growing well enough to initiate stolons for tubers....he would then remove the stolons, allowing the energy to go to flowering. That was done in the greenhouse, however, I have not done enough of that procedure to make a blanket statement.

I rely on super flowering varieties to make crosses.....often leaving poor flowering lines to chance. I run out of time to baby sit my potatoes well enough to trick them into flowering. I do use a good mineral/nutrition sprinking in the furrow when planting the potatoes and that seems to work for me. I try to keep the NPK ratio to an optimum level for flowering abilities.

[DarJones]

I am updating this thread with some observations I found by accident this season. I had thrown some Azul Toro potatoes away into my trash pile. The soil had a heavy ash layer from burning wood and plant materials. It was virtually free of weed seed. I happened to throw the heavily sprouted spuds into a small area between some boards that were waiting to be burned. We had abundant rainfall with the result that plants were able to grow and establish quickly and easily. These plants were on the surface of the soil, they were not buried at all. The plants grew rather rampantly and were supported by the boards. No tubers were formed because no part of the stem was below ground. They bloomed abundantly and formed fruits from several flowers. I collected seed from the berries that matured.

Here is how I think this could be repeated in the garden under controlled conditions.

Start by preparing the soil, then lay a row of spuds down and put two boards about a foot wide down with about an inch between them. The boards should be propped up so that they form an inverted V on top of the soil and such that the potatoes are about 6 inches below the opening. Put two more boards but stand these up vertical to the ground and so that they are at the edges of the other two boards. They would form a figure like a W if you look at it from the end. Prop the boards into place with a few stakes. The potatoes should grow up and out from the center of the W and be supported to some extend by the vertical boards.

The disadvantages I can see are that the potatoes would be susceptible to mice, rats, etc. They would also have to be weeded regularly by hand.

The result should be an abundance of seed produced by varieties that do not normally produce fruit.

Darjones

[wingnut]

I have found healthy plants properly fed will bloom, and with enough different pollen donors most will set berries. All but a handful of my well fertilized/irrigated 300 or so varieties bloomed and set berries.

[DarJones]

wingnut, potatoes bloom more abundantly at roughly 45 degrees latitude than I normally see here at 36 degrees. My observation is relevant to varieties that are difficult to get to bloom and/or rarely set fruit when they do bloom. This was the first actual fruit with seed that I have had from Azul Toro in the 6 years that I have grown them. Climate is also a factor with serious droughts a typical part of my growing season.

DarJones

[graybell]

Darrel that is very interesting. So heavy wood ash or phosphorous and not enough depth to allow the potato to produce tubers causes the plant to put all its energy into flowering and fruiting.

BTW I got great yields on the azul toro you sent at Joesphs behest and thank you once again.

I will try this as I didnt get any fruit but got lots of flowers on azul toro.