I have a 2011 grafted Surfire that up to recently has looked fine. We had a brief but abrupt heat wave recently. Although I protected with a cover, the 5 gallon whip started to weep from about 4 small slits in bark.

I am getting ready to try bud grafting this to another Krymsk 5 rootstock but I want to be reasonably sure that this was heat related and not disease. I don't see any borers or obvious cankers. Thanks in advance.