English Aster yellows Cited by user Citation bot on 02 Sep 2020 Aster yellows is a chronic, systemic plant disease caused by several bacterium-like organisms called phytoplasma.
English Phytoplasma Cited by user Citation bot on 28 Dec 2010 (as of March 2014) }} Phytoplasmas are specialised bacteria that are obligate parasites of plant phloem tissue and transmitting insects (vectors).