How to convert spray concentration per acre to concentration per gallon of water?

I need to spray my apples and pears for fire blight and I bought some Streptomycin powder. In the directions on the bag they do not list the amount of material to mix per gallon of water. They list the concentration as 4 pounds of material per 600 gallons per acre. How does one break that down to amount of spray material per gallon? I have seen that type of listing before and wondered what method is used to convert to per gallon amounts.

My sprayer is a 4gal Solo back pack sprayer.

That appears straightforward to me. 4 lb equals 1812 g. 1812/600 = 3 g per gallon.

That assumes that it’s 4 lbs of the powder that you have and not 4 lbs of active ingredient. As and example If the powder is 20% active ingredient and you need 4 lb active per acre, then it would be 15 g per gallon.


Thank you fruitnut. The material I have is HARBOUR and the active ingredient is 22 % by weight on the label so I guess the 3 grams per gallon would be the right amount. The per acre thing confused me.