Hi, can anyone share how to prevent these leaf spots on acer called 'Phyllosticta'. Every year about mid-May half of my trees carry these spots. They didn't kill the tree but make it look a bit ugly especially when it comes to the falls color. This year I spray 'Bordeaux mix' in late Feb but didn't know that I need to apply 2-3 applications within 14 days, so I only sprayed once. So what else can I spray now to help stopping these yellow spots?. They are yet appeared but I am afraid it won't be long. I am thinking about spraying the Neem oil or Cleary 3336 Fungicide spray... Any insight is great appreciated, steven.
Myclobutanil or Fenbuconazole are able to stop Phillosticta, as Marsonia on Rose trees for instance; they are generaly used in the orchard. That is the names of the activ substances and not their commercial names. They are systémic, so you must pulverise (one of them) in the morning* with sunshine and without wind. *At 10 a.m , when the chlorophyllien function is with its maximum, for a better assimilation by the sheets.
