Fruit trees that are large (about 20 feet tall and 20 feet wide) and widely spaced (rows about 30 feet apart) within the orchard; it is the term used by horticulturalists for the type of apple trees that were grown for many years before dwarfing rootstocks became available.
dilute application: application of pesticide to fruit trees to the point of runoff, that is, until liquid begins to drip off the leaves; application is made by either an airblast sprayer or a handgun sprayer.
concentrate application (also called low-volume application): application of pesticide to fruit trees by an airblast sprayer that produces fine droplets that cover foliage very well without the large volume needed to reach the point of runoff.
dilute volume: the number of gallons of water it takes to cover an acre of fruit trees to the point of runoff.
standard dilute volume: the number of gallons of water it takes to cover an acre of standard (large) fruit trees to the point of runoff; for apple or pear trees, the standard dilute volume is 400 gallons of spray mix per acre. For peach, plum, and cherry, 300 gallons per acre is the standard dilute volume. For strawberries, brambles, blueberries, and grapes, 200 gallons per acre is the standard dilute volume.
your customized dilute volume: the number of gallons of water it should take to cover one acre of your trees to the point of runoff, usually 100 to 200 gallons per acre for semidwarf or dwarf apple trees.
your concentrate spray volume: the number of gallons of water per acre your airblast sprayer uses to adequately treat your orchard for a low-volume application, for whatever speed, pressure, and nozzle arrangement you prefer to use, usually 40 to 80 gallons per acre.
concentration (or concentrate factor): your dilute volume of water per acre divided by your concentrate volume of water per acre.
dilute rate: the amount of pesticide that should be used to make a dilute application to the point of runoff with either a handgun sprayer or an airblast sprayer; usually expressed as an amount of pesticide to be mixed per 100 gallons of water.
full rate: the maximum amount of pesticide to use per acre; calculated by multiplying the dilute rate (equals the amount of pesticide per 100 gallons) by the standard dilute volume per acre (equals 400 gallons per acre for apples).
concentrate rate: the amount of pesticide used per acre when making a concentrate (low-volume) application; this might be equal to or less than the full rate per acre.
The amount of space occupied by fruit trees; calculated by tree height, tree width, and tree spacing; used as the basis for determining the amount of water and pesticide needed to adequately cover the trees with spray.
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