Wlould someone please share the likely cause of the issue pictured, as well as any remedy available to me? Thank you.
Here in British Columbia the government fruit tree management website recommends spraying fixed copper in September, after harvest (trees still in leaf). I've done this many times with no problems and no curl the following year, but I was growing curl-resistant varieties (Frost and Renton). Other websites recommend copper during the dormant season. I would try both.
