In situ potato storage

[Tom Wagner]

Amphigories and Gobbledygook

Prefacing the illogical is the only way I can introduce this topic.

The phenomenon of leaving something exactly in place where it occurs and not moving it to some special medium is a biological definition of in situ!

Often, I leave potatoes in the ground where they were grown and this is an "On Site" conservation term and is significant when one leaves the potatoes to suffer the winter's ravages such as freeze damage. Many varieties fail simply because the tubers are set too close to the surface and freeze quickly when the frost level goes down to 3 to 4 inches. This past winter with no snow cover and temperatures in December down around 10 degrees F. shot the freezing line down to about 10 inches.

You are probably asking at this point why I would leave potatoes in the ground un-harvested all winter. Simple…I plant too many potato varieties in too many places with too little time to travel and harvest in time and a lack of storage facilities to place the potatoes. But then again, I stress the need for sustainability practices and the need for survival crops and the breeding therein.

In-situ conservation, protecting a plant species (Solanum) in its agricultural habitat; for the conservation of genetic resources applied to conservation of agricultural biodiversity in agro-ecosystems by this farmer; is especially an unconventional farming practice.
One benefit to in-situ conservation (wintering over) is that it maintains surviving and recovering populations in the surrounding where they have developed their distinctive properties (freezing resistance). Another is that this strategy helps ensure the ongoing processes of evolution and adaptation within their environments. As a accidental or planned event, ex-situ conservation may be used on some or all of the population, forcing a screening of tuber lines that set deep enough to escape freeze damage.
The population size must be sufficient to enable the necessary genetic diversity to survive within the population, so that it has a good chance of continuing to adapt and evolve over time. Such methodologies link the positive output of scientific research with this farmer’s experience and field work. The accessions of a variety stored at a germplasm bank and those of the same varieties in multiple crosses and multiplied by this farmer are jointly tested in the field. I get knowledge about the production characteristics of the surviving varieties and the best tested accessions are crossed / mixed and multiplied under replicable situations. Thus, this farmer’s efforts are enabled to grow improved selections of his own varieties. This technique of conservation of agricultural biodiversity is perhaps more successful in marginal areas, where commercial varieties are not expedient, due to climate, soil fertility, and economy of scale restraints.

I do a lot of crazy things like planting potato seedlings from TPS out to the field around July 1st. I did not get to dig these out due to wet weather and being gone during the best two months to dig them. Only one family out of many seedlings survived this test with the freezing going down 10 inches. Two plants had one tuber each out of the F-2 population of my Primo Russet. Primo Russet is a cross of Primo and A81286-1. Primo was one of recombinant seedlings out of Argentina’s Primicia Inta, an X and Y virus resistant clone that traces a pedigree back to Feldeslohn and a numbered Argentine clone. A81286-1 is a rare breed of russet, one that has high culinary qualities in every cooking method known. It has some high vitamin C from its grandfather ….Butte.
In the normal transplanting time in May, another seedling clones that has A81286-1 as a double g. grandparent survived the freeze as well.


Big vines with deep roots and stolon initiation at deep levels that grew downwards seemed to survive best. Two hybrids, both with Awol Dude as a male parent also did well. The similarity didn’t stop there, the maternal lines---India 1038 and India 1035---both lines that do well in the Philippines for example---have some Late Blight tolerance and the health of the dead vines indicated that the L.B. resistance from Awol Dude carried thru as well.

One of the prettier clones that had nearly every tuber survive the freeze under its hill was a recombinant of my Boy Pig X Red Thumb hybrid called Pigs Knuckles. It has long, nearly fingerling red tubers with yellow eyes and fairly deep red flesh. I will certainly expand this clone and will use it in breeding a lot this coming summer. I am thinking of naming it Knuckle Down, an obvious pun on the ancestry and its ability to grow down below the frost line.

I dug hundreds and hundreds of clones and fortunately I have a sample of every type of potato I need for further breeding, whites, russets, yellows, red with yellow flesh, red with white flesh, purples with white flesh and blues with blue flesh. It appears that only 5 % of the seedling clones produced tubers that resisted the freeze.

Tom Wagner

[darwinslair]

<smile> well, our frost line goes far deeper than I ever plan on digging, unless I put in another pond.

Sorry you lost so much, but 5% of what you planted is still far more than most human gardeners will plant in a lifetime.

Tom

[Tom Wagner]

Yes, each year I seem not to get everything dug and I certainly don't plant everything. This year may be different since I will be short of varieties I really wanted. I will plant more of varieties that I would normally only plant one or so hills.

My selection pressure is usually due to other factors; color, flavor, berry production, etc., and this year I will plant a special crossing block to breed for freezing resistance. This year the frost went so much deeper than other years, therefore the value for the future is enhanced.

[salix]

I have often wondered about freezing resistance in potatoes. Every year we get "volunteers", but have never taken notes on variety or the winter's particular weather pattern. That being said, however, it usually freezes from about 2 to 4 feet deep, not taking into consideration early snow cover, mid-winter thawing and loss of snow cover etc. Should we be taking more notice and saving these hardy ones?

[Tom Wagner]

Should we be taking more notice and saving these hardy ones?

Volunteer potatoes have been a source of fascination for me simply because I have thousands of varieties each year that could be among the volunteers. But since I rotate my plantings, I may not come back to a particular field until maybe four years have passed. Blue Dinger is a clone of mine that I found a couple of years ago in a Carnation, WA field from a field I planted several years priorl It produces a lot of small tubers and I think they just get buried down deep each year and emerge late as weeds. My In-Situ plot of seedlings included a Blue Dinger family of hybrids but it had no survivors of the freezing test. Therefore, volunteerism and in-situ freezing resistance is not the same critter.

I am doing a lot of reading trying to find the operative factors of freezing damage of potatoes. I know that potato tubers freeze at 29F after a period of time at that temp and there is a name for that phenomena. I will use it later. Meanwhile the biological exogany of selecting iindividual clones without the normal freezing behavior towards some degree of tolerance to extremely cold soil will be in my breeding blocks this year.

Should I leave this breeding project to the professionals? What professionals?
Most research on freezing resistance in related to foliar resistance. Even the pentaploid ---Solanum curtilobum ----and the hybrids I have made of it have no tolerance to freezing tubers in my In-Situ plot. There could be advantage of breeding the species most noted for frost tolerance---S. acaule----foliage- wise with my (in-situ) lines, therefore there may be some synergistic usage.

Tom Wagner

[David Marek]

The first time I saw potatoes come back the next year I couldn't believe my eyes. The previous year I dug everything I could find, then tilled the raised bed, so they must have been deep ones. All the effort that we go through to store them properly when I could be planting at garlic time? I still wouldn't do it on purpose. Makes me not feel so bad about forgotten tomatoes, etc.

I have read some tropical plants from high elevations can supposedly handle below freezing temps, but have observed can't handle an Illinois frost. Maybe the 30+ degree day/ night difference is too much.