With the warm, wet conditions we’ve had in southern Ontario so far this spring, Fireblight has been running rampant on apple and pear. Symptoms appear as branch tip wilting, stems crooking, leaves turning dark brown and persisting on the tree….
If you have apple and pear with a small percentage of blighted shoots which would require few pruning cuts to remove, try bagging and then pruning out symptomatic shoots during dry conditions, preferably when temperatures are in the lower 20’s C.
Pruning out apple and pear shoots in high temperatures may also increase the risk of more fireblight infections.
If you are an arborist and you need to prune apple and pear for storm damage, making several pruning cuts in the trees could open them up to infection by Fireblight bacteria. If you can, try to leave pome fruit tree pruning until later in the season when fireblight bacteria aren’t as active.
You will want to balance how much canopy you remove since taking more than 25% of the canopy could stimulate excessive vegetative growth that is…..you guessed it……very susceptible to fireblight and other diseases.