Way back when people grew their own food they would save some of the potatoes to use for seed the next growing season cutting them here was at least one "eye" and then allow them to heal before planting. Many of the potatoes sold in stores are treated with growth inhibitors, although organic potatoes may not be. Best results would be gotten from seed potatoes purchased from a reliable source since these would be certified disease free.

One keeps hearing about the growth inhibitors but I have yet to see a tuber sitting around that did not sprout.

Anyway, regarding your question: unless you are making a big planting and want to completely maximize your seed stock, there is no need to cut the seed. When I do cut I dust the freshly-cut pieces in something like lime or rock powder which helps them heal up and gives a nice little boost of minerals.

The growth inhibitors generally delay, not deactivate growth.

It's a "buy more time" thing for getting them from distributor storage to the grocery store (where the will be stored totally non-ideally) and into your grocery basket before they start sprouting.

Chlorpropham is generally the inhibitor used. Maleic hydrazide is also used, but not as much because it has to be applied to the potato as it's growing rather than after-harvest in storage like chlorpropham.

If stored properly (practically impossible once it hits the grocery store and sits around out in the open and under lights for days) application can last for up to a year.

Is there any advantage to "greening" seed potatoes, IOW exposed to light long enough to change the under skin color?

I have experimented over the years and I recommend to not use eating potatoes for seed. Saving your own or buying seed potatoes is the way to go. I cut large potatoes but prefer to plant small whole potatoes. A couple weeks before planting I "chit" my stock by bringing them out of dark storage into a warmer, lighter area to let them sprout. If I cut some I do it 24-36 hours ahead. Plant sprout side up a few inches deep and then hill up only once or twice and mulch well. I have had good results under plastic mulch in my zone.

If you are thinking of storing your organic potatoes, you may decide to investigate whether these oils can be used and still keep the title "organic".

"Abstract
The replacement of synthetic chemical compounds used as potato sprout inhibitors with naturally occurring compounds has been studied in potato varieties used in the processing industry. Sprout suppressant capacity of caraway (Carum carvi, L.), peppermint (Mentha piperita, L.), coriander (Coriandrum sativum, L.) and eucalyptus (Eucalyptus globulus, Labill.) essential oils was studied and compared to the sprout suppressant capacity of chlorpropham (CIPC). For the particular conditions of this study, which used high concentrations, peppermint and coriander essential oils were the most effective sprout inhibitors with inhibition rates of more from 65 to 95% respect to their control. The use of these essential oils also prevented phytopathogenic damage. Analytical quality parameters, such as moisture content and total soluble solids, were not affected by treatment with any of the aromatic essential oils. Sensory analysis revealed no difference in appearance and taste between potatoes treated with essential oils and untreated tubers."

Here is a link that might be useful: link for above

Thanks guys I appreciate all the feedback.

Another question: would washing them thoroughly remove the anti-sprout spray and help them sprout more readily?

marshall, I would not recommend greening potatoes, but rather chitting them. This is placing the potatoes in moderate light 2 weeks before planting. This is done with potatoes that are just beginning to sprout...3/4 or less white sprout. This gives a short and sturdy sprout ready to come up right away.

I do cut the biggest ones and plant them right away with no treatment. If they are already green sprouted and planted into good conditions, they have no problems.

Unless you plan to plant acres of potatoes, cutting isn't necessary; I select the smallest ones at the feed-store and plant them whole. I always plant them with the sprouts at the bottom, reasoning that roots always emerge before shoots. Furthermore, although I have five year rotation, I experience scab, so I always work sulphur into the potato bed the previous fall -- never more than one pound per 100 sq. ft. It's something to consider if your soil is alkaline. Regards, Peter.

Great point Peter, I have very alkaline soil.

But why not plant acres and become the local potato baron of greenleafville?

Hey pn I have a better idea. I can do it in 4 square feet. Check out the link!

Here is a link that might be useful: growing 100 pounds potatoes in 4 square feet

GL, check out some of the many threads on the subject in the past at the veg forum. Conclusion: hyperbole, for the most part. Claims such as the one you linked ignore the unsurprising fact that 4 sq feet planted in seed pieces produces vines that will run over many more sq ft, of course.

Also, it was determined that the stacking method requires using a "late" variety to gain any advantage.

Good to know pn. that whole potato box thing may have to wait until next year.my main garden project for this year is to build Hugelkulter.