At 80' high agreed spraying would not be an option, however, you can still cure the tree by pouring the mixture into the roots.
To start: 30 gallons of water, 2 lbs, powdered milk (expired), 27 1/4 oz of sugar, place at least 15 Lbs of old newspaper and other biodegradables therein, let the mixture sit for several days, stir to all of the fibers in the newspaper to become saturated and separated, this usually takes about 9 days depending upon your particular weather.
then, dig a hole at the base of the tree, at least 4 feet deep and pour the contents therein, DO NOT COVER, wait for at least 2 full days for the mixture to soak more fully into the soil before re-covering the hole.
You may need to repeat this procedure every 4 years or so.
Results vary, but it usually takes a day per foot of height of the tree being treated
