Yep! Using parts of plants always gives you a clone - a copy of the original. Only with seeds do you get variations. Good time to plant now, SPs prefer the warmth. Give the plant at least 3 months preferably 4-5months to give you decent-sized tubers.
Tony if you like sweet potatoes and you have success we have several different varieties here - King scrub way you would be welcome to come collect some vine pieces from here , white with purple flesh , purple with purple flesh, a pinky coloured skin and flesh, orange, etc even a red but it is very slow so only small pieces are available, We feed excess vines to the cows !. they are so rampant in places... I find that the more you remove the vines from the top the more the tubers grow . Also if you are going to let them run wild mark where you plant the first one so you will know where to water and know where to dig.... we spend quite a bit of time hunting for tubers - do enjoy! if it is a a big tuber you should be able to grow a new plant from about 3cm of the tuber and then eat the rest !!! just like potatoes .
Root knot nematode may be spread by planting infested tubers its safer to take the sprouts off the sweet potato and not plant the tuber.
There's a weevil which can be spread by infected tubers. The Beauregard orange commercial variety has resistance to this pest; using the green shoots once they have roots on them will be sure not to contaminate your new bed. Strip most of the leaves off the stem and put it in some water and in a cool spot out of the direct sun. Roots will grow very quickly. The Sweet Potatoes which are not generally seen in the shops which Mary-Ann has described, are more to the expected flavour of SPs than the commercial variety. But they do produce less and are more subject to the weevils. But well worth persevering with!
Not sure what you mean by cutting off leaves and growing more tubers. Use the stems to make more SP plants and keep the tubers themselves to eat rather than using the tubers as planting material. That does work and saves any contamination with bug eggs.
Train the greenery onto a trellis to keep the nodes from rooting into the soil and reducing the size of the tubers (more tubers but smaller vs less tubers but bigger). A BLF member Glenys, came up with the idea of trellising the greenery and it's a fine idea which works well. Simpler to use a trellis if the SPs are in a pot rather than in the ground. No one trellises commercially nor do islander peoples trellis when they grow in mounds but it is still a practical solution for we small-plot food gardeners.
dont cut all the leaves of , just a light pruning and they grow larger tubers not more tubers or thats our experience and what we were told - if you prune the plant they grow better tubers others swear you should nevr prune sweet potatoes so i suppose its what individuals find out for themselves !
It's kinda counter-intuitive to reduce the food-making area (the leaves) in order to make bigger tubers! I wonder if it's to stop the runners from rooting and making more smaller tubers ... that's where the trellis comes in, you keep the leaf area but prevent the stems from rooting.
trellising may work too - All I know is that the patch we left alone - same other factors soil light water etc didnt make many or large tubers , the ones we pulled lots of runners off and feed to cattle or grew elsewhere or gave away made lots of large tubers ! And that was what we were told to do by people who had been growing them for many years and had learnt that from their ancestors >