Spruce diseases

Asked June 24, 2014, 2:30 PM EDT

Would "Arbor OTC" be effective against Rhizosphaera? Would "Arbor OTC" be effective against Stigmina lautii

Lebanon County Pennsylvania trees and shrubs master gardener program

1 Response

No, that product is labeled primarily for bacterial pathogens. Rhizosphaera and Stigmina are fungal pathogens. Early season treatments with a fungicide that contains chlorothalonil would be necessary. Stigmina will require years of treatment.