Ducture (/ˈdʌktʃər/) is not a commonly used word in English, but it is derived from the word duct which refers to a tube or channel that carries liquid, air, or other substances. The spelling of ducture is phonetically correct as it reflects the pronunciation of the word. The first syllable "duc" is pronounced as /dʌk/ and the suffix "-ture" is pronounced as /tʃər/. The word ducture is commonly used in technical contexts to describe the structure or function of a duct.
Guidance.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.