Editing Elm (section)

==== Elm phloem necrosis ====
[[Elm Yellows|Elm phloem necrosis (elm yellows)]] is a [[phytopathology|disease]] of elm trees that is spread by [[leafhoppers]] or by root grafts.<ref name="Elm Yellows">"[http://www.elmcare.com/disease/elm_yellows.htm Elm Yellows] {{webarchive|url=https://web.archive.org/web/20111004214753/http://elmcare.com/disease/elm_yellows.htm |date=4 October 2011 }}". Elmcare.Com. 19 March 2008.</ref> This very aggressive disease, with no known cure, occurs in the [[Eastern United States]], southern [[Ontario]] in Canada, and Europe. It is caused by [[phytoplasmas]] that infect the phloem (inner bark) of the tree.<ref name=Price>Price, Terry. "[http://www.forestpests.org/gfcbook/wiltdiseases.html Wilt Diseases] {{webarchive|url=https://web.archive.org/web/20110928145148/http://www.forestpests.org/gfcbook/wiltdiseases.html |date=28 September 2011 }}". Forestpests.Org. 23 March 2005. 19 March 2008.</ref> Infection and death of the [[phloem]] effectively girdles the tree and stops the flow of water and nutrients. The disease affects both wild-growing and cultivated trees.
Occasionally, cutting the infected tree before the disease completely establishes itself and cleanup and prompt disposal of infected matter has resulted in the plant's survival via stump sprouts.