01333nas a2200133   4500008004100000245007000041210006900111300001000180490000700190520086400197100002601061700002401087856008801111       2009                        eng d00aPhosphonate controls sudden oak death pathogen for up to 2 years.0 aPhosphonate controls sudden oak death pathogen for up to 2 years  a10-170 v633 a<p>Since its emergence in the late 1990s, sudden oak death has killed mature oak trees and tanoaks in 14 California counties. Treatment options are now available to safeguard these trees from infection by <em>Phytophthora ramorum</em>, the aggressive and exotic pathogen responsible for sudden oak death. We provide an update on current knowledge regarding this emergent disease in California, and present results from three controlled experiments of two chemical treatments to manage the disease in oaks and tanoaks. Phosphonate treatments, legally registered in California to control sudden oak death, were effective in slowing both infection and growth rates for at least 18 months. Conversely, an alternative method consisting of an azomite soil amendment and bark lime wash was always ineffective, and did not reduce either growth or infection rates.</p>1 aGarbelotto, Matteo, M1 aSchmidt, Douglas, J  uhttp://ucanr.org/repository/cao/landingpage.cfm?article=ca.v063n01p10&fulltext=yes#