A Trade gallon is a term used to denote the sizes of standard plant containers in horticultural industries. A trade gallon is equal to approximately .71 U.S. liquid gallon

Gallon

The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...

s, and it should not be confused with the British Imperial gallon (equal to 1.20095 U.S. liquid gallons) or the British grain gallon

Gallon

The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...

(equal to .9375 U.S. liquid gallons)