2016 has been a disappointing year due to lack of progress in finding the cause of AYLS!
There were a number of new Reports in 2016 of both ABSENT and PRESENT. The Reports show that AYLS is PRESENT in more of Western Washington all the way North to Abbotsford BC Canada, and in other US States as well as locations in Europe. Several of these Reports have not been confirmed with photographs however.
My conclusion is the 2016 Reports do not indicate that AYLS is spreading, but are merely filling in the blanks in our understanding of current distribution. Hundreds if not thousands or additional Reports from around the World are needed to fully understand the extent of AYLS.
An additional test of affected leaves resulted in NEGATIVE for the presence of Bacterial and Fungal Pathogens.
Over the past three years of active searching for the cause, I believe that we can rule out: 1. Cultural Practices due to distribution patterns. 2. Bacterial Pathogens due to test results. 3. Fungal Pathogens due to test results. 4. Nutrient causes due to two fertilized test plots, both of which showed AYLS symptoms although at a diminished level compared to unfertilized plants.
That leaves several possibilities: 1. Viral Pathogens which will only be either confirmed or denied by “Next Generation Sequencing” to search for the presence or absence of a Virus. This process is far beyond my means and is not likely to occur unless some University takes it on as an unfunded Research Project. 2. Environmental Causes, which will require thousands of Reports from around the World to get a clear idea of Distribution patterns in order to focus on possible Environmental Factors. 3. The possibility that was suggested to me this year that AYLS is “Everywhere” in Actinidia Species. I believe this is a far-fetched idea due to Reports of ABSENT from trusted Actinidia Researchers and Growers in several Countries, but without personally observing plants outside the Puget Sound Region of Western Washington, I can’t definitely rule out this possibility. A trip to Actinidia plantings in Oregon next Summer is on my list of things to do.
Since my proactive efforts to obtain Reports from growers Worldwide have generated inadequate responses (including NO Reports from the Southern Hemisphere other than a 2014 contact from New Zealand), I will limit my efforts in 2017 to periodic new posts on this page and adding any Reports that are submitted to the “Map of AYLS locations Worldwide” page. The outreach efforts are now YOUR responsibility to contact other Actinidia growers you know and Fruit Organizations you are a Member of to let them know about this Site!
Thanks, “kiwibob”, Seattle, Washington, USA
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