I have a Scots Pine that appears to have Needle Cast. I noticed it on a lower branch a couple of weeks ago, and now it is spreading across the tree. The candles are plentiful, look healthy and are extending very well. I was going to start pinching them back, but now that the Needle Cast is spreading, should I pinch at all.
If the tree loses a lot of last years needles it will lose strength. If I let the candles extend and harden off then the tree will have fresh solar panels to strengthen it again. If I don’t pinch, then I lose the development effort I have invested in the tree for the past 2 years.
I have sprayed the tree (and my other pines as well) with Daconil, and will do so again every month until winter.