Ami,
I rapidly scanned that Manitoba site and I have a problem with it, in general.
And that's b'c they're attributing all means of leaf CURL to leaf ROLL.
Leaf Roll is understood by many to be a temporary situation found when plants are young and root and foliage mass are not in balance which causes a temporary stress. It's completely reversible as the plants mature.
While the reasons for leaf CURL are many and varied ranging from most hybrids that do have curled leaves normally, to general stress as in too cold, too hot, too wet, too dry, too much of a fruit burden which can also cause leaf curl, as well as many viral diseases, and on and on.
But Daconil has never been known as something that causes leaf curl, from all I've read and also with my former long time experience with it as well as the experience of all my commercial farmer friends over a very long period of years.