In my area black knot is extremely prevalent, it’s bad enough that damsons, plums, and green gauges are basically impossible to grow (I’ve tried, they end up being more black knot than healthy tree annually, despite pruning and spraying religiously). Despite this, I have a Montmorency cherry with no signs of black knot ever, so clearly it, and perhaps other sour cherries, have a high resistance to black knot.
This gets me wondering: what is the level of resistance to black knot in peaches, almonds, apricots, sweet cherries, etc? Does anyone in an area with high levels of black knot have any experience with other prunus species? I’m especially curious about almonds, as I’m interested in getting an almond tree soon.