1) Change 2) Subject to vulcanization 3) To desertify or make xeric 4) To undergo such treatment 5) Undergo vulcanization 6) Vulcanise Found on https://www.crosswordclues.com/clue/vulcanize
Vul'can·ize transitive verb [ imperfect & past participle Vulcanized ; present participle & verbal noun Vulcanizing .] To change the properties of, as caoutchouc, or India rubber, by the process of vulcanization. Vulcanized fiber ... Found on http://www.encyclo.co.uk/webster/V/38