Yes, Junction Fungicide/Bactericide can be used on roses to treat for black spot.
We assume you are referring to Junction Fungicide/Bacteriacide If overspray drift is a concern when using Junction Fungicide/Bacteriacide we recommend following the Spray Drift Mangagement on page 6 of the manufacturer label. Contact your local Master Gardener for the detailed effects of this product on evergreen trees.
Wind Speed - Do not apply when wind speeds are greater than 15mph. Only apply this product if the wind direction favors on -target despotion (apporx 3 to 10mph) and there are no sensiteve areas within 250 feet downwind.
Junction Fungicide/Bactericide has a shelf life of approximately 3 to 5 years as long as it's stored in a dry, cool place.