Yacón (Smallanthus sonchifolius) is not the same thing as Yuca (Manihot esculenta) which is really Cassava. Yakón is a sweet crispy root, kind of like an apple , its called ground apple in some places. Yacón is being processed to make Yacón flour, and Syrup, The syrup is low calorie sweetener and has a low glycemic index.
Here is a picture of the common "Yuca" or Cassava ( Manihot esculenta ):
its very different from Yacón ( Smallanthus sonchifolius )
I am starting to believe that this plant has died out in the Dominican Republic.
no one I have shown it to, has ever seen this plant.
Here are some Yacón products now being commercialized in other countries.
Yacón looks like it could be an interesting future crop in the DR, from what I have been able to learn so far is that it tolerates a wide range of soils, ( after all the natives once cultivated it here ).
If anyone comes across this plant please post or PM me, thanks