phytology vs pomology

phytology and pomology both are nouns.

Word	Noun	Adjective	Verb	Adverb
phytology	Yes	No	No	No
pomology	Yes	No	No	No

As nouns, pomology is a hyponym of phytology; that is, pomology is a word with a more specific, narrower meaning than phytology:

Other hyponyms of phytology include mycology, palaeobotany, paleobotany, algology, phycology, pteridology.

phytology (noun)	pomology (noun)
the branch of biology that studies plants	the branch of botany that studies and cultivates fruits