Dissertation Project - Do you have a Smartphone? - Help Map Sudden Oak Death in the UK

Re: Phytophthora ramorum


Nina on Thu Sep 23, 2010 7:38 amHello from beautiful Hendersonville! I had lunch with Jim Lewis, which is always a good idea, and which always means good beer.

Asfar as the outbreak in England in Larch is concerned, I don't see achange in the risk to bonsai. The disease has been in Europeannurseries for years, and it caught Europeans by surprise when thedisease suddenly showed up on really tall larch.

In the US,there has been one report on a bonsai, and ironically, it was on amallsai sitting indoors where it was no danger to anyone, and wouldhave dried up and died on its own. I would advise everybody not to moveknown hosts out of an affected region. In the US, that means not takingan oak bonsai (or camellia or manzanita or madrone or buckeye) out ofany of a number of counties in California. Nurseries in those countiesare not allowed to ship out of state without an inspection to show theyare free of the disease, but that certification does not guarantee thatyou won't get a plant with an invisible infection (That's what I study-invisible infections!). So in the US I wouldn't buy those kinds ofplants from certain nurseries. In Europe, the situation is morecomplicated, because the disease is widespread in nurseries, but notwide-spread in nature. That means your bonsai in your backyard inBelgium or Italy is not going to get the disease, but you might buy aninfected lilac or Camellia or Rhododendron from a nursery.

Alietteis NOT effective against P. ramorum. All systemics on the market are"fungistats" which means they only slow growth of the pathogen.

For US people, you can go to the website of the California Oak Mortality Task Force -- http://www.suddenoakdeath.org/-- for a huge amount of good information. For Europe, the DEFRA websiteis outstanding. (Note: I searched the DEFRA website and found no usefulinfo - Jim Lewis; I always could have missed it. www.defra.gov.uk/)