Texas A&M Blueberry fact sheet http://aggie-horticulture.tamu.edu/fruit-nut/files/2015/04/blueberries_2015.pdf says to use 1/2 to 1oz of 21-0-0. Is the 1oz as it comes out of the bag or is it 1oz of actual nitrogen?
Dallas County Texas
You would measure the 1/2 oz. or 1 oz. directly from the bag. Since 1/2 oz. = 1 Tablespoon and 1 Oz. = 2 Tablespoons, I would use a measuring Tablespoon for measuring purposes.
I hope this helps answer your question.