Correct spelling for the English word "piantic" is [pˈa͡ɪəntˌɪk], [pˈaɪəntˌɪk], [p_ˈaɪ_ə_n_t_ˌɪ_k] (IPA phonetic alphabet).
Noting sensitized and readily agglutinative microorganisms, such as have been subjected to piantication.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.