If, by summer, your pear trees are weak and covered with a grey mold, chances are they’re infested with pear psylla, a tiny insect pest that can ruin a pear crop.
Damage is two-fold: Adult and nymph psylla suck plant juices, weakening foliage and causing leaves to turn yellow and curl; in addition, psylla produce sugary secretions that encourage the growth of a sticky fungus called “sooty mold” which further disfigures and weakens the tree.
After decades of searching for an all-natural defense, commercial fruit growers now rely on a product called Surround Crop Protectant as their best weapon against the dreaded psylla as well as other insect pests.