Maybe try the Dominican Agrarian Institute.
Cultivo de c?rcuma busca un espacio en el mercado - listindiario.com
This is their contact information
Instituto Agrario Dominicano > Contacto
They were very helpful when I contacted them re best place to get seedlings for trees (avocado, mango, lemon, grapefruit etc) and also delivered some for nothing. Please let me know if you find out re turmeric root as would love some too. I get through pounds of it making curries.
Matilda